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Fit | > er fer 4 1 ZUR oy A ot ve FR vote, À 4 PPT, Ve i f 9 g | N Ar WET, mø K "29 iR 2 BY | "WITH ONE PLATE t ee | KØBENHAVN ker CE + 1920 ACTINOCOCCUS SUBCUTANEUS — L. KOLDERUP ROSENVINGE Særtryk af I Det Kgl. Danske Videnskabernes Selskab SIDSE gere Meddelelser van, 4. RS “Blanco LUNOS BOGTRYKKERI Arbejder fra den botaniske Have i København. Nr. 115. PHYLLOPHORA BRODIEI AND ACTINOCOCCUS SUBCUTANEUS BY L. KOLDERUP ROSENVINGE WITH ONE PLATE Særtryk af Det Kgl. Danske Videnskabernes Selskab Biologiske Meddelelser VIII, 4. KØBENHAVN BIANCO LUNOS BOGTRYKKERI 1929 de” # u 0 U 7 ry Ta SY SU aa ar i i "LAS à ar É | a i ‘ue I. Historical Account. he reproduction of Phyllophora Brodiei (Turn.) J. EF has been much disputed for more than a century. Everywhere within the area of this Subarctic- North-Atlantic species globular bodies of various sizes, up to 3,5 mm. in diameter, have been found sessile on the up- per border of the frond or on particular small shoots. TURNER who first described it in 1809 (Turner 1809, plate 72) as a species different from Ph. membranifolia stated that the small spherical tubercles were composed of “jointed parallel, fibres, closely matted together, and mixed with irregularly rounded seeds”. LyNGBYE (1819, p. 11) was much in doubt as to whether these tubercles were really the fructification of the alga; he did not succeed in finding the seeds described by Turner and stated that he had earlier described and pictured these fruits in ms. under the name of Cha@tophora membranifolii, thinking that it was some parasite growing on Ph. membranifolia and so giving it the character of Ph. Brodiei. On the authority of Turner, however, he maintains the latter species. In 1834 LyNGBYE took up again more positively the hypothesis of parasitism of the tubercles, giving in Flora Danica tab. 2135,, a picture of the filaments composing the tubercles with the text here reproduced: Chatophora subcutanea Lyngb. Mnscr.: cespite roseo, filis, stellatim radiatis, simplicibus et ramosis moniliformibus. — Chæto- 1% 4 Nr. 4. L. KOLDERUP ROSENVINGE: phora membranifolii Lyngb. l.c. p.11 t.3B f.3. — The alteration of the specific name is certainly due to the fact that LYNGBYE now considered Ph. Brodiei a well charac- terized species, and the specific name alluded to the fact that the radiating filaments are covered by a distinct cuticle. GREVILLE (Alg. Brit. 1830, p. 133) pointed out that the joints (“granules”) of the filaments are “made up of three or four smaller ones”, from which it may be concluded that he saw the formation of tetrasporangia in the filaments. The hypothesis of the parasitism of these bodies was taken up by Sunr; he sent them, under the name of Rivularia rosea, to KÜTzING, who described and pictured them in 1843 (Phyc. gen. p. 177, Taf. 45. Fig. IV, 1, 2) under the name of Actinococcus roseus with the following diagnosis: A. marinus, parasiticus roseus; cellulis hinc inde quadripartitis. In der Ostsee an Coccotylus Brodiaei und anderen Algen: v. Suhr. KÜTzING seems, however, to have no idea of the identity of this supposed parasite with the “sirothelia exacte sphaerica, laevia petio- lata” described in the same work p. 412 as the fructifica- tion of Coccotylus Brodiwi. Fig. 2 shows the cells divided into four, but the orientation of the cells in the tetrads is very variable and not in accordance with reality. J. AGARDH (Sp. g. o. Alg. II, 1, p. 330, 1851) describes the nemathecia, as these bodies were named by C. AGARDH (Spec. Alg. Vol. I, 1822, p. 228), and states that the joints of the radiating filaments develop into tetrasporangia (sphæ- rospore) which are cruciately divided, but he maintains that the plant has also “kalidia” (cystocarps) which are said to resemble the nemathecia very much. The existence of such nemathecia-like cystocarps has, however, never been confirmed. Phyllophora Brodiæi and Actinococeus subcutaneus. (3) The question of the nature of the nemathecial bodies was first taken up for thorough examination by Fr. SCHMITZ in a paper on the genus Actinococcus (1893). He had worked at the question for several years and had reached the conclusion that Aclinococcus roseus must be con- sidered as a parasite growing on Phyllophora Brodiei, a view he expressed already in 1899 in the survey he publish- ed of the hitherto known genera of Floridez (Flora 1889), and this view was adopted by REINKE in his Algenflora der westl. Ostsee published in the same year. SCHMITZ found that the medullary cells of Phyllophora in the interior of the nemathecial fruit are separated more or less from each other and the interstices filled up with a complex of smaller cells forming branched rows of cells. In the outer cortex, these filaments continue as the radiating filaments in the nema- thecial wart where they later form the seriate tetrasporangia. But with these fertile filaments, groups of short cortical filaments originating from the sterile frond are frequently intermixed, in particular in young nemathecial warts. When two such warts of different ages are to be found on the opposite faces of the same segment of the frond, as will frequently happen, the filaments constituting the one wart can be followed into the interior of the fertile section of the frond and from thence to the opposite nemathecial wart. Moreover, several quite young warts may fuse together to form one nemathecial wart. In quite young warts the “fertile” cells do not become connected through pits with the cells of the sterile tissue. Such a connection seems only to be established with certain cells which then become larger and rich in protoplasm. The alleged facts could, in SCHMITZ's opinion, only be explained by the supposition that there are two different organisms, a host plant and 6 Nr. 4. L. KoLDERUP ROSENVINGE: a parasite. The origin of the latter was not, however, ex- plained. The name Actinococeus is then given to the para- site that comprises not only the nemathecial bodies but also the intramatrical filaments. At the end of Schmitz’s paper the parasite is given the name of Actinococcus sub- cutaneus (Lyngb.) Roseny.' ScHMITZ’s discoveries were tested by the French al- gologist GOMONT who convinced himself of the accuracy of Scumirz’s observations by an anatomical investigation of material in the Muséum d’histoire naturelle in Paris. On the other hand, REINKE became doubtful as to the correctness of the independence of “Actinococcus roseus”, which was no doubt connected with the fact that O. V. DARBISHIRE, then assistant at the Botanical Institute at Kiel, was working at the question. In a preliminary note (1894) and a very valuable monograph of the Phyllophora species in the western Baltic (1895) DARBISHIRE described the structure and development of the organs of reproduction and as to the nemathecia arrived at a view opposite to that of Scumirz. He gave a careful description of the an- theridia which arise in crypts sunk in the cortical layer of particular small shoots, “spermophores” at the upper end of the flat fronds. He further described the female shoots that, when young, much resemble the spermophores and like these are placed at the upper end of the frond (comp. fig. 47 I), whereas the older carpophores are said to be placed like those of Ph. membranifolia at the borders of the flat frond and have much the same appearance as those of this species. He found procarps, not before observed, in the young female shoots, and imagined that these shoots * LYNGBYE's specific name of 1834 remained unnoticed till I called attention to it (1893, p. 822). —1 Phyllophora Brodiæi and Actinococcus subcutaneus. grow out into flat leaves on the borders of which the cystocarps arise, much as in Ph. membranifolia. If this were correct, the origin of the carpophores would be very different from that in Ph. membranifolia where the carpo- phores arise on the border of the older segments of the frond and the procarps arise in their interior some time after their formation. As I have never seen specimens of Ph. Brodici with cystocarps in the Danish waters, and such specimens have not been mentioned by other authors, it was of inter- est to me to see the specimens on which DARBISHIRE has founded his statement of the presence of lateral carpo- phores and cystocarps in this species. Through the kind assistance of Dr. Curr Horrmann I have been able to examine the cystocarp-bearing specimens collected by Kuckuck at Kiel in 1891, referred to Ph. Brodiwi and men- tioned by DARBISHIRE (l.c. p. 32); they turned out to be female specimens of Ph. membranifolia erroneously referred to Ph. Brodiæi; they belong to the narrow form of the former species, common in the inner Danish waters. I have no doubt but that a similar mistake has taken place with the large “typical” plants with well developed lateral carpophores containing a cystocarp mentioned by DARBISHIRE as found at Helgoland. At any rate I cannot see why the plant pictured in fig. 46 (1. c. p. 32) should necessarily be referred to Ph. Brodiwi and not to Ph. mem- branifolia. Until better evidence is forthcoming it must be taken for granted that.cystocarps have never been as- certained in Phyllophora Brodiwi. The nemathecia, according to DARBISHIRE, arise in the first months of the year in the interior of the small fertile shoots, near their apex, single cells in the inner cortex 8 Nr. 4. L. KOLDERUP ROSENVINGE : producing from their surface cells that grow out into cell- filaments forming a particular tissue in the inner part of the leaflet, which causes a swelling of the latter; the peripherical filaments may force their way through the cortex and form a nemathecium. The author confirms the statement of Scumirz that the filaments may grow out onto the opposite face of the leaflet and form a new or several new nema- thecial cushions. Further DARBISHIRE made the important observation that the tetraspores from the nemathecia that ripen in winter are able to germinate in cultures indepen- dently of any host-plant, forming deep red cell-filaments and cell-discs or cushions that he thinks would under better conditions develop into basal discs of Phyllophora Bro- divi. DARBISHIRE concludes from his observations that the nemathecia in Ph. Brodiwi are the true and only organs that produce tetrasporangia in this species. Unfortunately Schmitz was prevented from further investigation of this problem, as he died after a short illness in January 1895. DARBISHIRE’S conception of Actinococcus as an organ belonging to Phyllophora Brodiwi was accepted in my se- cond paper on the marine Alge of Greenland (1898, p. 33), while I had followed Scumirz in 1893 (p. 822). I now relied on my own observations too, having never in the Danish or the Greenland waters met with cystocarp- bearing individuals of Phyllophora Brodiei. SCHMITZ's view would lead to the absurd conclusion that this species does not possess any kind of spores. In the following years DARBISHIRE pursued his investiga- tions on this subject at Kiel and published a new paper in 1899, On Actinococcus and Phyllophora, in which, strange to say, he accepted the view of SCHMITZ. DARBISHIRE Phyllophora Brodizi and Actinococcus subcutaneus. 9 had observed that the antheridial cavities of Phyllophora Brodiæi often accompanied the presence of Actinococcus subcutaneus, and after a close investigation of this coin- cidence he made out that it was possible to explain it by supposing that Actinococcus is a parasite that “only can enter the host when the male (or the female?) organs of the latter are present”. He thought that he had observed the entrance of Actinococcus by the small ostioles of the antheridial cavities. “The immediate product of germina- tion seems to be a small heap of perhaps 4—8 cells, one of which always comes to be near an ostiole leading to an antheridial cavity. ... A filament is then formed, which passes into the host-plant through the antheridial ostiole (Plate XV, Fig. 1)”. However, the figure quoted gives no evidence of the correctness of the given interpretation. An antheridial cavity seems to be faintly seen under a bunch of filaments, but it is situated at a lower level than the normal antheridial cavities, and it can by no means be taken for granted that the filament has entered the host at this place; it would be equally probable that the small heap of cells on the surface of the Phyllophora had been produced by a filament forcing its way outwards through the cortex, perhaps through an antheridial cavity, and that it was on the way to forming a nemathecium. DARBISHIRE maintains that the presumed parasite “is unable to pierce the outer covering of the host, when entering the latter. It can only attack the latter through the antheridial ostioles”. He _ thinks, however, that Actinococcus may also be able to enter the host by means of the opening caused by the projecting trichogyne, as he has “seen Actinococcus-bearing shoots of Phyllophora, in the cortical layers of which could be seen what were apparently remains of undeveloped carpogones” 10 Nr. 4. L. KoLDERUP ROSENVINGE: (l. c. p. 258). This latter remark is of interest, as it refers to an important fact which will be mentioned later, but it has a quite different meaning to that suggested by the author. DARBISHIRE adds that antheridia and procarps do not occur on the same plant, but this is not in accor- dance with my observations, as will be mentioned later. He supposes that the antheridia appear in the autumn and that the parasite then enters the host-plant through the ostioles. He imagines that “it is not unlikely that what we see germinating on Phyll. Brodiwi in the autumn is really a carpospore”, (l.c. p. 263) produced by an unknown sexual generation. He finally relates that “In discussing the question a short time ago with Professor REINKE, the latter suggested as a possibility, which ought not to be dismissed prima facie, that Actinococcus might really be an asexual generation of Phyll. Brodiaei, growing parasitically on the sexual generation” (1. c. p. 264). But the author does not consider it very probable that this represents the true state of affairs, and he maintains the view that the nemathecia of Phyll. Brodiwi have not yet been found. It will be seen that the problem is still very dubious after DARBISHIRE’S last paper. It has not been treated later on by researches or experiments, but R. W. PuHiILuips has given a valuable critical survey of it in 1925. In citing DARBISHIRE’S reference to cystocarps in Phyll. Brodicei he states that these organs have never yet, as far as he can ascertain, been collected in British waters. He further states, in accordance with DARBISHIRE, that he has “seen what seemed to me to be derelict procarps ... in the neighbourhood of the Actinococcus nemathecia” (1925, p. 252). REINKE’S suggestion is mentioned; PHıLLıps points out that the carposporophyte in diplobiontic Florideæ is always Phyllophora Brodizi and Actinococcus subeutaneus. 11 parasitic on the gametophyte generation and asks whether it is impossible that in this case the tetrasporophyte is so also’. Il. The Reproduction of Phyllophora membranifolia. Before describing the development and the fate of the procarps of Ph. Brodiei I shall briefly mention the repro- duction of the related Ph. membranifolia. This species is a typical diplobiontic Floridea, having sexual and asexual Fig. 1. Phyllophora membranifolia. Transverse section of androphore showing four antheridial crypts. 625 : 1. individuals. The first are of two distinct kinds, male and female. The male individuals produce the antheridia in particular yellowish or nearly colourless, up to 2 mm long, folioles borne on the upper border of the flat fronds. The antheridia, as shown by DARBISHIRE (1895, p. 30), arise in small globular crypts sunk in the outer cortical layer of the spermophores and provided with an orifice in the roof (fig. 1). — The procarps arise in the cortical layer of particular oblong or nearly globular short-stalked carpo- phores borne on the upper part of the cylindrical and the 1 H. Printz (1926, p. 60) has mentioned some specimens of Phyllo- phora Brodiæi collected in August at Trondhjem with young nemathecia not identical with the nemathecia of Aclinococcus. Upon enquiry Prof. Printz has kindly answered me that he is not now able to give any information about this observation which was made many years ago, and that he has not access now to the specimens in question. 12 Nr. 4. L. KoLperup ROSENVINGE: lower part of the flat thallus of the female plants. The carpogonial branch is three-celled, borne on a large bearing Fig. 2. Phyllophora membranifolia. A, carpogonial branch. B, procarp. a, auxiliary cell, 1, 2, c carpogonial branch. C, the auxiliary cell is pluri- nuclear. D, auxiliary cell pushing out numerous gonimoblast filaments. A 625:1. B—D 390:1. 2 cell that becomes an auxiliary cell. The carpogonium has a prolongation downwards which is laterally inserted by a Fig. 3. Phyllophora membranifolia. Portion of transverse section of ripe cystocarp. November. 390: 1. pit on the second cell of the carpogonial branch (fig. 2 A, B). A spermatium seems to have been attached to the trichogyne in fig. 2 A. The fertilization and the transfer of the sporogenous nucleus to the auxiliary cell have not been observed, but the devel- opment of the latter is shown in fig. 2, C, D. While at first it contains one nucleus, it becomes plurinuclear and pushes out prolongations, first from the under side, later from all sides, which develop into Phyllophora Brodiæi aud Actinococcus subcutaneus. 13 gonimoblast filaments, becoming septate and branched. These gonimoblast filaments penetrate into the medullary tissue of cells rich in starch and produce numerous small carpospores. In the ripe cystocarp cell filaments originating from the medullary tissue are seen traversing the mass of carpospores (fig. 3). — The nemathecia arise in summer as deep-red wedge-shaped spots on both faces of the lower part of the flat frond. They are built up of parallel fila- ments of cells which develop into tetrasporangia with the exception of the outermost cells. The division of the spor- angia takes place in winter (comp. DARBISHIRE 1895, p- 27); they are first divided by a transversal wall, later by two vertical ones. III. The Sexual Organs of Phyllophora Brodizi. The principal points to be investigated when treating of the much disputed but still unsolved problem of the re- production of this species were: 1) the first origin of the nemathecium-forming filaments, 2) the possible connection between the latter and the sexual organs of Phyllophora Brodiæi and 3) the fate of the germinating tetraspores. The sexual organs will first be mentioned. DARBISHIRE maintains that Phyll. Brodiwi is dioecious (1899, p. 258), but that does not agree with my observa- tions. Antheridia and procarps arise in particular sexual leaflets situated on the upper border of the flat fronds (fig. 5) or in the upper margin of the young segment of broad fronds (fig. 6). In both cases the two sexes usually occur in the same plant and often in the same organ, leaflet or margin. When the upper marginal zone of a frond becomes fertile, it increases considerably in a trans- verse direction and therefore becomes undulated (fig. 6), 14 Nr. 4. L. KoLDERUP ROSENVINGE: and it also increases in thickness. The small fertile shoots (fig. 5 B) are usually more or less flattened, but sometimes nearly terete or angulate; in the former case they may be canaliculate. DARBISHIRE (1895, fig. 38 and 47) has figured them and mentioned them as spermophores and female shoots respectively, and it may happen that they contain only antheridia or procarps, but usually they con- tain both sexes though often in very different quantities, Fig. 4. Phyllophora Brodiei. Fertile lobe of frond with a group of pro- carps made distinct by staining with hæmatoxyline. 47:1. and sterile leaflets also occur. On cutting a number of leaflets by microtome one may convince oneself of the irregularity of the distribution of the sexual organs, and the same is the case with the fertile border of the broad fronds. In fig. 4 is shown a lobe of an undulated margin of a frond containing numerous procarps while most of the other lobes of the same frond were without procarps. The antheridia are similar to those of Phyll. membrani- folia. As shown by DARBISHIRE (1895, p. 29, fig. 38—39, 1899, p. 257) they are developed in small flask-shaped or nearly globular cavities situated just within the surface of the sexual shoot and, when ripe, communicating with the exterior by a small ostiole (comp. fig. 7). Each cavity derives from one superficial cell. The crypts contain a number of converging filaments consisting of 3 or 4 cells i ) Phyllophora Brodiæi and Actinococcus subcutaneus. 15 Fig. 5. Phyllophora Brodiæi. A, from a dredging south of Als in June, 8,5 m. depth, nemathecia in leaflets, terminal or marginal. B, from 12 metres” depth off Ballen, Samø in August; with nemathecia and new sexual leaflets. 1,8: 1. Fig. 6. Phyllophora Brodiæi. Lille Belt, 18—19 metres’ depth, June. A, upper end of frond with undulated fertile margin. B, similar with young nematheeia, €. 5:1. "C.E AR erh 4 lg, “2 i jr 4 Be na Aie silver de wein] Ris rhea von ton DE ee Le sb ne 3 Aa pi pote ev Ar Phyllophora Brodiæi and Actinococcus subcutaneus. V1 which produce the spermatia in descending sequence. DARBISHIRE calls each filament an antheridium (1895, p. 29). These cavities may form a continuous layer or they ap- pear singly (fig. 7) and then project more or less over the surface. The antheridia were met with in the months of March and May to November. They are not restricted to the autumn, as supposed by DARBISHIRE. For the examination of the procarps the material was in several cases treated with FLEMMING’s weaker solution, Fig. 7. Phyllophora Brodiei. Two antheridial erypts. A, not fully devel- oped. B, ripe, August. 625:1. imbedded in paraffine and the microtomed sections stained a. m. HEIDENHAIN, but this method has the inconvenience that the sections are very liable to loosen from the slide owing to the great swelling power of. the intercellular substance (Scumirz’s ‘collode’) in water, so that most of the sections were lost in many cases. To avoid this, the sections were stained with hematoxyline (Mayer’s hemalum or Hansen’s hæmatoxyline), or the sexual shoots were cut with the freezing microtome and stained with the same reagents. Other fixing media used were: formaline- sublimate, Nawashin’s treatment', and further formaline alone or 70—80 per cent alcohol. And finally, Dr. HENNING ! See J. CLAUSEN, Chromosome number and the relationship of spe- cies in the genus Viola. Annals of Botany, Vol. XLI. Oct. 1927, p. 678. Vidensk. Selsk. Biol. Medd, VIII, 4. 2 18 Nr. 4. L. KOLDERUP ROSENVINGE: E. PETERSEN has kindly left at my disposal a valuable material from Ellekilde Hage in the Øresund, fixed by him with Juer’s solution, June 30th 1910. The procarps are situated in the inner cortex. When fully developed they are composed of a tricellular carpo- gonial branch and a large bearing cell which becomes an auxiliary cell, but it may happen that two carpogonial bran- å g Fig. 8. Phyllophora Brodiæi, from Lille Belt, east of Hesteskoen, June 1922, frond with crenulated border. A, procarp; a two-celled branch issues from the first cell of the carpogonial branch; a, the auxiliary cell, 1, 2, c, the cells of the carpogonial branch. B, two procarps, that to the left without trichogyne. C, carpogonial branch isolated by pressure. D, protruding trichogyne, the base of which cannot be distinguished. 560 : 1. ches are borne on the same bearing cell (fig. 10 D). Dar- BISHIRE figures a young procarp with a short trichogyne projecting a little over the surface (1895, p. 33); he con- siders the bearing cell as the lowermost cell of the carpo- gonial branch which is therefore said to be four-celled. (Comp. above p. 6). The procarps were examined in several specimens from various localities and at different seasons. They showed considerable differences so the particular specimens will Phyllophora Brodizi and Actinococcus subcutaneus. 19 be treated separately. It must first be mentioned that the great majority of the procarps observed were in- completely developed. These organs are easily recognizable by their staining power with hematoxyline (HEIDENHAIN, HANSEN’s and Mayer’s hemalum) and their abundant protoplasmic contents, and the bearing cell, too, by its great size. The latter is always present, but the carpogonial branches are often more or less defective. Even when they are normally tricellular, the out- most cell is most frequently not developed as a normal carpogonium but roundish like the other cells of the branch (fig. 8 B to the left, 10 B—D, 11C). A two- celled branch is shown in fig. 9. The best developed carpogonial branches were Fig. 9. Phyllophora ’ à 2 Brodiæi, from the projecting trichogynes were often ob- ‚ame specimen as served. That pictured in fig. 8 A shows the fig. 8 Two-celled carpogonial branch. 5601. met with in May and June, when long, pit-connections between the bearing cell and the carpogonial branch and between the cells of the latter. The carpogonium has a well devel- oped trichogyne but the ventral part is inflated, only poorly provided with protoplasm, and contains no nucleus; it is evidently avorted. The same is the case with that shown in fig. 8C where the trichogyne is short, scarcely projecting over the surface, and the contents still more faint. The carpogonium fig. B shows a nucleus, but the protoplasm is feebly developed and the trichogyne only discernible as a canal through the outer wall. In fig. D a well developed trichogyne is seen protruding far above the surface, but its lower part was not present in the section. The carpogonium 2* 20 Nr. 4. L. KOLDERUP RosENVINGE: shown in fig. 10 A had a large nucleus situated near the lower end of the cell and was attenuated above into a Fig. 10. Phyllophora Brodiæi. Collected by Dr. Henning Petersen at Elle- kilde Hage, Øresund June 1910 and treated with Juel’s solution. A, pro- carp; the carpogonium is attenuated toward the trichogyne channel but the trichogyne itself is wanting. B, the last cell has not the character of a carpogonium; the bearing cell seems to be uninuclear. C, similar, the bearing is plurinuclear. D, the bearing cell is multinuclear; it bears two carpogonial branches, but no carpogonium is developed. E, procarp showing more than the ordinary number of cells, without carpogonium. F, similar group to the left. A, B, 870:1. C—F, 480:1. short thin thread, but the trichogyne itself was wanting, though the trichogyne channel was very distinct. In all these procarps, the carpogonium had a rounded or plane base. Phyllophora Brodiæi and Actinococcus subcutaneus. 21 In a specimen from Frederikshavn gathered in October I found carpogonial filaments of a different shape, having a carpogonium with oblique base (fig. 11 A). Still more aberrant is the carpogonial branch pictured in fig. 12 A. A small ovate cell is seen under the carpogonium, con- nected with it by a pit at its upper, pointed end and con- nected by a lateral pit with a larger cell which must be Fig. 11. Phyllophora Brodiwi. Specimen collected at Deget near Frederiks- havn in October. A, two procarps with laterally inserted carpogonia. B, procarp; the carpogonium is not visible but a portion of the trichogyne is seen piercing the cuticle. C, the last cell of the carpogonium filament has not the character of a carpogonium, the bearing cell is stellate. D. The supposed carpogonium has produced a short septate, thin, downward growing filament. A, 560:1. B—D, 350 :1. supposed to be the first cell of the carpogonial branch, while the bearing cell is not to be seen. This branch shows some resemblance to the carpogonial branch of Phyllo- phora membranifolia if we compare the small cell with the prolongation downwards from the carpogonium in the latter species, but this prolongation is not separated by a transverse wall from the carpogonium. In other procarps from the same specimen I found a similar oblong smaller cell under the carpogonium. The procarp figured in fig. 22 Nr. 4. L. KoLpERrUP ROSENVINGE: 12 B, met with in the same specimen, is better in accor- dance with Phyll. membranifolia; the lowermost flat cell must be the bearing cell. The fact that two different types of procarps, both different from that first described, are met Fig. 12. Phyllophora Brodiwi. From a specimen collected in Store Belt in May, fixed with formol-sublimate. A. Three cells only are to be seen in the procarp; the bearing cell seemed to be wanting in the section. B, procarp the interpretation of which was doubtful; no transverse wall was visible at the narrowing of the carpogonium. C. At least two nuclei were present in the bearing cell that is still round. D. The bearing cell is angular, plurinuclear. E. Three bearing cells, the two showing numerous nuclei, two producing prolongations forcing their way between the surrounding cells. A, 1000:1. B—E, 560: 1. with, suggests that the procarps in this species are in a stage of degeneration. The first described type is perhaps the most reduced one, as it is most remote from that of Phyll. membranifolia. In no case were spermatia found adhering to the tri- Phyllophora Brodizi and Actinococcus subcutaneus. 23 chogynes and no other signs of a fertilization were ob- served. The case represented in fig. 11 D might suggest a transferring of a nucleus from the carpogonium to the auxiliary cell, but the narrow downward growing septate filament which has not the appearance of containing a fertile nucleus, and the long distance between the sup- posed carpogonium and the bearing cell do not favour this interpretation. Moreover, I do not feel convinced that the carpogonium-like body is really a carpogonium; it might perhaps be some endophytic Rhodophycea. IV. The Origin of the Nemathecia-producing Filaments. It happens that procarps consist of more than four cells. As shown in fig. 8 A, carpogonial branches may bear a two-celled branch on their lower-most cell, and procarps without distinct carpogonium may sometimes consist of a greater number of irregularly arranged cells (fig. 10 E, F). I was for some time inclined to believe that such groups of cells might be able to give rise to the nemathecia-produc- ing filaments; but I found no facts to support this sup- position. After searching for a long time I finally suc- ceeded in finding the origin of the filaments referred to by following the fate of the bearing cell that should normally become an auxiliary cell. This cell is originally uninucleate as shown in fig. 8B to the left, but the nucleus is not visible in most of the figures, in some cases it is hidden by the granular matter (fig. 10 B). Later a greater number of small nuclei appear, much as in the analogous cell in Phyll. membranifolia (fig. 2). In the case pictured in fig. 10D the auxiliary cell shows some 20 nuclei and these must all have arisen by division of the original single 24 Nr. 4. L. KoLpErup ROSENVINGE: nucleus, for a transfer of a fertile nucleus from the carpogonium cannot have taken place. The cell bore two carpogonial branches but neither of them had produced a normal carpogonium; the end-cells were filled with proto- plasm in both branches, and one of them showed a distinct nucleus. A similar stage is shown in fig. 10 C, where the auxiliary cell also seems to contain several nuclei and no carpogonium is developed. In fig. 12 D, the bearing cell has taken an angular shape, but fig. 12 E shows more ad- vanced stages; three bearing or auxiliary cells are here seen, one, very similar to that in fig. 10 D, having an irregular rectangular shape and bearing a two-celled car- pogonial branch toward the lower surface of the leaflet, and two others, much larger, pushing out several long protuberances in all directions, partly penetrating between the surrounding cells of the foliole. The cell to the left contains several nuclei partly entering the protuberances. The carpogonial branches of these two procarps seem to be more or less degenerated. The next stage is represented in fig. 13 B where the auxiliary cell has become still more enlarged and the protuberances have produced, at their end, cells connected with the large cell by long threads of protoplasma. These cells form branched rows forcing their way between the surrounding cells of the gametophyte. A good deal of the parallel filaments above in the figure, forming a low excrescence on the mother organ probably derive from the auxiliary cell, but in the present case it was not possible to distinguish such cells from those of the gametophyte. The cells of the carpogonial branch could no longer be recognized. A similar or a slightly more ad- vanced stage is shown in the Plate fig. I, where the large cell is seen near the centre of a young nemathecial wart. Phyllophora Brodiæi and Actinococcus subcutaneus. 25 This cell is shown more enlarged in figs. II and III, where the connection between the protuberances and the cells produced by them is very distinct. It seems that pit- connections may also be established between the large cell and cells of the gametophyte. As shown by DARBISHIRE, the nemathecia-producing filaments can be made more easily Fig. 13. Phyllophora Brodiwi. From Ellekilde Hage, Juel’s solution. (Compare fig. 10). Auxiliary cells with protuberances. A. The protube- rances penetrate between the surrounding cells. 625:1. B, more advan- ced stage. The protuberances have produced cells and cell-rows at their ends; some of these have begun to form a low tubercle, a young nema- thecium. 390: 1. visible by the addition of iodine, when the latter will turn red-brown (not dark blue) owing to their contents of finely granulated floridean starch, while the cells of the mother plant remain unstained. In fig. V reproduced after such a preparation the nemathecia-producing filaments ap- pear very distinctly owing to their dark contents, There seems in this case to be more than one fertile auxiliary 26 Nr. 4. L. KOLDERUP ROSENVINGE: cell, or, as they may be named here, central cells, from which the starch-containing filaments radiate toward the periphery, having not yet pierced the cuticle. This has taken place in the case shown in fig. VII where a number of fila- ments issuing from a strongly developed intramatrical tissue are on the point of producing small cushions on the free surface of the frond. More advanced stages are shown in figs. IV, VI and VIII, where a large cell is seen at the centre of the nemathecial body. In most cases this cell has not longer a stellate shape but is roundish and surrounded by more or less densely jointed small round cells forming a medul- lary tissue while the outer part of the nemathecial body is built up by radiating filaments. The central cell in fig. VIII contains at least one small cell encompassed by the pseudopodes of the large cell which here and there form fusions. The large cells just mentioned were observed by SCHMITZ (1893, p. 378) who, however, interpreted them as sterile cells of the host-plant attacked by fertile filaments, belonging, according to SCHMITZ, to the parasitic Actinococ- cus subcutaneus, which surround them and become connected with them by pits, where-upon the named cells increase to larger cells with abundant plasmatic contents, and he refers to fig. 2 on plate VII in his paper where a cell of stellate appearance is situated at the centre of the supposed para- sitic cushion. A similar large stellate cell is figured by SCHMITZ under the young nemathecia of Gymnogongrus Wulfeni, they are interpreted by this author as a parasite named Actinococcus aggregatus (1. c. figs. 4—7). Here too we would remind the reader that DARBISHIRE and PHIL- LIPS observed in the neighbourhood of the nemathecia Li) 1 Phyllophora Brodizi and Actinococcus subcutaneus. (Actinococcus) what they supposed to be undeveloped pro- carps. As shown by Scumitz and DARBISHIRE, the nemathecia- producing filaments force their way through the surface of the plant, in several places forming small cushions fusing together to one nemathecial body which at last becomes globu- lar. In some cases one cushion only arises, on the upper face of the fertile frond, corresponding to the face where the procarp was situated; the intercellular filaments of the tetra- sporophyte do not reach the opposite face of the frond (fig. IV). But usually a new cushion arises later, the fila- ments of the tetrasporophyte forcing their way to the opposite face of the frond where they pierce the surface at several points (fig. VII), forming a number of small cushions fusing into one. The lower cushion in fig. VIII has evidently originated from the same central cell as the upper one, but later than this, and its origin from a num- ber of distinct points is still easily to be distinguished at the lower boundary of the cushion though the outline of the cushion does not show any traces of the early fusion. The original surface of the frond is very distinct as a dark line interrupted by bright spots where the filaments have pierced it. Two such opposite cushions may finally fuse into one globular nemathecium encompassing the foliole. In fig. VI is given a transverse section of a young globular nemathecium showing a large central cell in the middle and radiating filaments directed to all sides, but exhibiting nothing of the gametophyte except the central cell and some of the surrounding cells. « r 28 Nr. 4. L. KoLDERUP ROSENVINGE: V. The Nemathecia. As mentioned above, p. 13, the procarps arise either in particular small sexual leaflets springing from the upper border of the flat fronds or in the upper marginal zone of young flat fronds, and accordingly the nemathecia are either placed on the folioles (fig. 5) or are sessile in great number in the undulated upper margin of flat frond segments (fig. 6). In the first case they are either stipitate, the short stipe representing the lower, sterile portion of the leaflet, while the nemathecium occupies its upper end (fig. 5 A above, B), or the nemathecium is inserted at the base or at the margin of a leaf which was small at the moment when the procarps arose but which may sometimes attain a considerable size (fig. 5 A), in particular when the leaf is inserted at some distance under the upper margin (fig. 5, comp. Flora Danica tab. 1476, Kützing, Tab. phyc. XIX Taf. 74). Some of the nemathecia shown in fig. 5 B were probably inserted on the base of the leaves, issuing close to them. The nemathecia arise, usually in the spring as it seems, and seem early to attain a considerable size. The maximal size is 2 to 3,5 mm. The full development is reached at the close of November when the sporangia begin to ripen, and ripe nemathecia were met with in December to February, but nemathecia with the maximal diameter are generally met with already in June and July, and in March to May they were found 1—1,5 mm. in diameter. As nemathecia of considerable size are to be found in early spring, and as the nemathecia occurring in winter are of different sizes it is probable that some nemathecia which are small in December may be kept without producing tetra- Phyllophora Brodiæi and Actinococcus subcutaneus. 29 sporangia and continue their life in the following season, whereas most nemathecia perish after the production of tetraspores, When the nemathecial bodies have attained a certain degree of development they show a differentiation in an inner medullary tissue composed of roundish cells and an outer portion built up of radiating filaments consisting of Fig. 14. Phyllophora Brodiwi. A, specimen from Middelfart, April; radial section of young nemathccium, showing the outer sterile cells and the fertile ones, the latter connected by primary pits and partly by secon- dary pits with cells of the contiguous filaments. B, fertile filaments from specimen gathered in Store Belt, November 24th, with sporangia in division. 625: 1. rather low cells connected by pits in the transversal walls (fig. 14). The 3 or 4 outermost cells in the cell-rows are longer and narrower and remain sterile, while the other cells develop into tetrasporangia (comp. DARBISHIRE 1895, p. 24). As the sterile outermost cells are early differentiated and seem not to remain meristematic, and as the number of the fertile cells increases considerably during the development 30 Nr. 4. L. KoLDERUP ROSENVINGE: of the nemathecium, an intercalary division of the inner cells seems to take place; but this question deserves fur- ther investigation. Moreover, it is remarkable that the fer- tile cells in the cell-rows are sometimes connected with cells in the contiguous cell-rows by secondary pits, formed in the usual way by the cutting off of a small cell by a longi- tudinal wall of one of the cells and fusing of it with a cell in the contiguous row (fig. 14A). It should be of interest to study the fate of the migrating nuclei in this process. The sporangia are first divided by a transverse wall and some time thereafter by two vertical or slightly in- clined walls. They begin to ripen at the end of November, and nemathecia with ripe sporangia were met with in December to February. VI. The Germination of the Tetraspores. As mentioned above, DARBISHIRE obtained germina- tion of the tetraspores of Ph. Brodiwi and stated that they produce filaments and small more or less irregular cu- shions which he thought, in 1895, would develop to basal discs of Phyllophora Brodiwi under better conditions. For studying the germination of the tetraspores fresh material was dredged in the Great Belt at the close of November 1925. The nemathecia-bearing plants were brought home to Copenhagen, cleaned and put in glass-vessels filled with filtered sea-water from the Great Belt, covered with glass-plates and placed in an unwarmed room facing north (Nov. 26th 1925). In some cases a little potassic nitrate was added to the water. The plants were placed so that the spores dropped on slides deposited on the bottom of the vessels, in some cases on shells of Mytilus modiola. After Phyllophora Brodiæi and Actinococcus subcutaneus. 31 one to two weeks numerous spores were set free, and the plants were then removed. The water in the vessels was now and then renewed and the slides cleaned with caution, diatoms, Cyanophyceæ and other Algæ being removed so far as possible. The spores newly set free are globular naked cells (fig. 16 A) 7—9 x in diameter, mostly 7—8 w, containing a large SQ Sisson Où E Fig. 15. Germlings from tetraspores of Phyllophora Brodiwi sown in the beginning of December 1925. A—B, 3'/2 months old, °”/s 1926. C—F, 6'/2 months old, *°/s 1926. G, 7 months old, */7 1926. E, optical vertical section. A, C—F, 350:1. B, 410:1. G, 560: 1. chromatophore, a hyaline, feebly refractive body, probably the nucleus, and a great number of small refractive grains. A month later (January 11th) numerous spores had sur- rounded themselves with a membrane and were divided by a vertical wall into two cells, more rarely into three. In most cases the bodies had not changed shape but were a little enlarged in circumference; only a few of them were 32 Nr. 4. L. KOLDERUP ROSENVINGE: about to produce a thinner prolongation before or after the formation of a new partition wall. In March the plants had developed into small multicellular, often irregular cu- shions, partly with long filamentous outgrowths (fig. 15 A, C); sometimes the filamentous portion was most developed (fig. 15 A). At the ciose of June the best developed germ- Fig. 16. Phyllophora Brodiwi. Germlings from tetraspores sown in the beginning of December 1925. A, spores newly liberated. B, portion of filament from germling. C, eight months old germling, '*/s 1926. D, 14 months old germling with upright shoot springing near the border 1°/2 1927. E and. F, 20 months old germlings, **/s 1927. A—C, 625:1. ; | D, 70:1. E—F, 6:1. lings were regular orbicular discs without filamentous out- growths, built up of regularly radiating, closely united fila- ments, but polystromatic and thicker in the middle- most part (fig. 15 F). The discs were rich in starch. In other cases they were smaller and thicker, often conical (fig. 15 D). At that time some of the cushions produced an upright shoot from the upper face, usually from the centre Phyllophora Brodiæi and Actinococcus subcutaneus. 30 (fig. 15 G). The cultures were kept going during the following year, but owing to the bad conditions in the old cultures the germlings now grew very slowly if at all. The best developed germlings were obtained from the bottom and the side walls of a glass-vessel in which a nemathecia- bearing plant had been laid down. Fig. 16 D shows a well developed, about 14 months old, oblong basal disc much re- sembling that found in the Bal- tic Sea by DARBISHIRE and figured by him in 1895 fig. 24. It bears a young terete upright shoot near the margin. The germlings drawn in fig. 17 are about 18 months old; they have a large roundish basal disc and E Fig. 17. Phyllophora Brodiæi. Germlings from the bottom of a a simple, terete or somewhat glass vessel in which a fructiferous complanated upright shoot plant was deposited at the close #0 of November 1925, picked up °*/s springing from the centre. Those 1997 (18 months old). 33: 1. pictured in fig. 18 are about 14 months older; they have a flat upright frond terete at the base, flattened and branched upwards, on the sides or at the top, in fig. 18 B by dichotomy. The disc shown in fig. 18D bears two erect shoots near the border. A better developed 3 mm. high, dichotomously branched 20 months old frond is shown in fig. 16 F. The two and a half year old plants shown in fig. 18 were up to 2 mm. high. The dimensions of the last-named fronds are evidently very small for plants of that age, but that is certainly only due to the bad conditions, in particular in the old cultures which were not sufficiently taken care of. At any rate, they agreed as well with young fronds of Phyllophora Vidensk. Selsk. Biol, Medd. VIII. 4. 3 34 Nr. 4. L. KoLpErup ROSENVINGE: Brodiei found in nature as could be expected under these conditions, and there can be no doubt of their identity. The germination of the spores of the nemathecia then shows conclusively that the latter do not belong to a para- site but that they represent a link in the development of Phyllophora Brodiei. CHEMIN has recently (1927) observed the germination of the tetraspores of another nema- thecium interpreted as a para- site, namely that of Gymnogon- grus norvegicus described by SCHMITZ as Actinococcus pellæ- formis (Scumitz 1893, p. 387). The spores sowed in glass-ves- sels developed basal discs which after two to three months pro- N \ A duced upright shoots of the same structure as in G. nor- Fig. 18. Phyllophora Brodiwi. 32 months old germlings from vegicus. As ascertained by CHE- the walls and the bottom of the ee tig. 17 331 MIN, this species has distinct sexual and asexual individuals; the author has found no facts supporting the hypothesis of the parasitical nature of the nemathecia, and he there- fore considers Gymn. norvegicus as a normal diplobiontic Floridea. Conclusions. From what has been shown above il must be concluded that all individuals of Phyllophora Brodiwi are (actually or virtually) sexual plants and that free-living tetraspore-bearing Phyllophora Brodiæi and Actinococcus subcutaneus. 30 plants do not exist. The antheridia and the procarps usu- ally occur on the same individual; they arise either in particular sexual folioles or in the upper margin of the flat fronds. The antheridia quite agree with those in Phyll. membranifolia. As in this species the procarps consist of a three-celled carpogonial branch and a bearing cell or auxiliary cell, but the carpogonial branch is rather variable, perhaps a consequence of degeneration, and it is probable that fertilization does not take place; at all events it has not been ascertained. The auxiliary cell much resembles that in Ph. membranifolia; in both species it has first one nucleus but later becomes plurinuclear. But while the latter is a typical diplobiontic species in which the auxiliary cell pushes out a number of outgrowths developing into the gonimoblast filaments, the auxiliary cell in Ph. Brodiei likewise pushes out a number of protuberances, but these give rise to cell-filaments forcing their way between the cells of the gametophyte in various directions but at first especially outwards where they give rise to a wartlike excrescence which develops into a nemathecium in the inner part of which the enlarged auxiliary cell or central cell is to be seen. The radiating filaments of the nemathecium give rise to seriate tetrasporangia, which ripen in winter. The system of cell-filaments issuing from the auxiliary cell in Ph. Brodiæwi and their products thus represent the tetra- sporophyte which is not here as in other Florideæ an inde- pendent free-living organism, but grows out in continuity with and “parasitically” upon the gametophyte generation. Cystocarps are never produced, the carposporophytic phase has been abandoned, and in its place a tetrasporophyte is developed. The vegetative part of the latter is only repre- sented by the intramatrical cell-filaments. 3* 36 Nr. 4. L. KoLDERUP ROSENVINGE: The above mentioned suggestion of REINKE that Actino- coccus subcutaneus might possibly be an asexual generation of Phyll. Brodiæi growing parasitically on the sexual genera- tion is thus fully confirmed. The reproduction of Phyllophora Brodiwi now elucidated is very peculiar; no other instance agreeing with it has hitherto been described. Only the remarkable reproduction in Liagora tetrasporifera Borgs. discovered by Dr. F. BØRGESEN (1927, p. 39) can be compared with it. Most of the species of this genus, belonging to the Helminthocladiacew, have normal cystocarps, arising probably after a fertilization directly from the carpogonium, and the end-cells of which give rise to a carpospore, while tetrasporangia are not known with certainty. The species referred to has apparent cystocarps arising in the same way as those of the other species, but the end-cells of the cystocarpial filaments undergo a quadripartition and yield each a cruciately divided tetra- sporangium. Thus the “‘cystocarp” does not, properly speak- ing, deserve this designation; it is not a carposporophyte but a tetrasporophyte and can be compared with the tetra- sporophyte generation of Phyllophora Brodiwi. There is, however, a significant difference in that the tetrasporophyte of Liagora tetrasporifera has the appearance and the structure of a cystocarp with the only difference that the carpospores are replaced by tetrasporangia, while the tetrasporophyte in Ph. Brodiei is differentiated in an intramatrical, vegetative part and a number of extramatrical cushions fusing together into a large globular nemathecium showing no resemblance to a cystocarp but having a structure similar to that of the nemathecia in the diplo- biontic species of the same genus. The tetrasporangia appear in Liagora letrasporifera within . - - « Phyllophora Brodiæi and Actinococcus subcutaneus. 37 a systematic group which is typically haplobiontic, where these organs as a rule do not take part in the normal life- cycle. The extraordinary appearance in question within a genus which has otherwise normal cystocarps suggests that it is due to a mutation, tetrasporangia having appeared here instead of carpospores. In the case of Phyllophora Brodiæi it seems more probable that the origin of the parasitic tetrasporophyte has been occasioned by the degeneration of the procarps and the consequent ab- sence of fertilization and of carpospores. The tetrasporo- phytes — like the gonimoblasts in Ph. membranifolia — arise as outgrowths from the bearing or auxiliary cell, but these outgrowths have not the character of gonimoblast filaments; they appear first as vegetative intramatrical fila- ments, and only later do the nemathecia arise. The whole tetrasporophyte has the character of a much reduced form of the normal tetrasporophyte as it is known in Ph. mem- branifolia; the reduction of the vegetative body is due to the parasitical life, and the globular form of the nemathe- cium is due to the small size of the latter. For a full elucidation of the question here treated of, a closer cytological research has yet to be made. It ought in particular to be ascertained whether or not a fertili- zation takes place, and whether the formation of the tetra- spores is initiated by a reduction division. The other nemathecia occurring within the Gigartinacee and regarded by Scumirz as belonging to parasites analo- gous to Aclinococcus and referred to the genera Colacolepis and Sterrocolax, will not be treated here. As mentioned above, CHEMIN has examined the nemathecia occurring « > T r 38 Nr. 4. L. KoLpErup ROSENVINGE: on Gymnogongrus norvegicus, named by SCHMITZ Aclinococ- cus pelleformis', and observed the germination of the tetraspores produced by them, and he found that these nemathecia are the true organs of the Gymnogongrus, oc- eurring only on the asexual plants. I have found the same for the nemathecia of Phyllophora epiphylla (Ph. rubens), according to SCHMITZ belonging to a parasite Colacolepis incrustans. This will be mentioned in another paper where also the nemathecium of Ahnfeltia plicata, considered by SCHMITZ as a parasite, Sterrocolax decipiens, will be trea- ted of. I am much indebted to Dr. HENNING PETERSEN for kindly giving me fixed material of Phyllophora Brodiæi, to the same and to Mr. Erik J. PETERSEN m. sc. and Mr. G. NYGAARD m. sc. for their valuable aid in executing the photographs reproduced on the plate. * PHILLIPS erroneously names it Colacolepis peltaeformis (1. ce. p. 251). Phyllophora Brodiæi and Actinococcus subcutaneus. 39 Bibliography. J. G. AGARDH (1851), Species genera et ordines Algarum. Vol. II, p- I. Lund. F. BØRGESEN (1927), Marine Algæ from the Canary Islands. III. Rhodophyceæ, Part I. K. D. Vidensk. Selsk. Biolog. Meddelel- ser, VI, 6. København. E. CHEMIN (1927), Sur le developpement des spores d’Actinococ- cus peltæformis Schm. et la signification biologique de cette Algue. Bulletin de la soc. bot. de France 1927, p. 912. O. V. DARBISHIRE (1894), Beitrag zur Anatomie und Entwicklungs- geschichte von Phyllophora. Botan. Centralblatt. Bd. 57, p. 361. — (1895), Die Phyllophora-Arten der Westlichen Ostsee Deut- schen Antheils. Wissenschaftl. Meeresuntersuchungen her- ausg. v. d. Kommission z. Unters. d. deut. Meere. Neue ‘Folge. I. Band. Heft 2. Kiel 1895. — (1899), On Actinococcus and Phyllophora. Annals of Botany. Vol. XIII, p. 253; pl. 15. M. Gomont (1894), Note sur un mémoire de M. Fr. Schmitz in- titulé Die Gattung Actinococcus Kützing. Journal de Bota- nique 1er avril 1894. Paris. GREVILLE (1830), Algæ Britanicæ. Edinburgh. L. KoLpErup ROSENVINGE (1893), Grønlands Havalger. Meddelel- ser om Gronland III. Kjobenhavn. (Les Algues marines du Groenland. Ann. d. sc. nat. 7e serie XIX 1894). — (1898), Deuxieme Mémoire sur les Algues marines du Groen- land. Meddelelser om Gronland 20. F. T. Kürzıng (1843), Phycologia generalis. Leipzig. H.C. LYNGBYE (1819), Tentamen hydrophytologiae danicae. Hafniae. R. W. Paizzips (1925), On the genera Phyllophora, Gymnogon- grus and Ahnfeldtia and their parasites. The New Phyto- logist, Vol. 24, No. 4. Henrik Printz (1926), Die Algenvegetation des Trondhjemfjordes. Skrifter utgitt av d. Norske Videnskaps-Akademi i Oslo. Math. naturv. Kl. 1926. No. 5. Oslo. Fr. Scumirz (1893), Die Gattung Actinococcus Kitz. Flora 1893. D. Turner (1809), Fuci, Vol. II. London. 40 Nr. 4. L. KoLDdEruUp ROSENVINGE: Phyllophora Brodiæi. Explanation of Plate. Microphotographs of nemathecia of Phyllophora Brodici. Figs. I—III, VI, VII from a specimen from Ellekilde Hage, Juni 30th 1910, HENN. PETERSEN. Figs. IV, V, VIII from a specimen from Ore- sund east of Taarbæk Flak, October 7th, SoREN LUND. Fig. I. Section of young nemathecial body. 110:1. Figs. II and III. The central cell of the former. 375: 1. Fig. IV. Vertical section of nemathecium only developed on one side of the frond. 57:1. Fig. V. Section of frond with nemathecia-producing filaments, stained with iodine, radiating toward the periphery. 88:1. Fig. VI. Transverse section of nemathecium. 77:1. Fig. VII. Nemathecia-producing filaments forcing their way through the cortex. The medullary tissue, interwoven with numerous nemathecia-producing filaments is indistinct owing to the fact that this tissue was situated at a higher level. 96:1. Fig. VIII. Vertical section of nemathecium showing the central cell and a smaller nemathecium on the under face of the frond, evidently arisen by fusion of several small cushions. 64:1. Forelagt paa Modet den 19. April 1929. Færdig fra Trykkeriet den 24. August 1929. KOLDERUP ROSENVING fis D. K. D. Vid. Selsk. Biol. Medd. VIII. 4 1930 SAA h f ya { hr " . 1 v + } n 4 . i \ \ { stk va Y Lea, L, + å WY bis var, ‘ un wt EY PR y i sk AN SED MEL) FANS | MOT) vis, ENHAVN, Nu.116 00° hie: VE SN OSTE wi Niet do rn AS * fale åen Ar 4 £ væ ip pes |, #4 mør, oie HECH 4 RATTE N PC PR + r PET ng ' f NEN PE NE A N At AA ONE! ERS ner Mol Left AUS u.) AA N LET re 4 fuk x ak? if ies Mon ATR VS ARBEJDER FRA DEN BOTANISKE HAVE I KØBENHAVN. Nr. 116 REPRINTED FROM THE BOTANY OF ICELAND VOL. III PART I 10. BAUDIES ON THE VEGETATION OF ICELAND BY H. MØLHOLM HANSEN WITH 12 PLATES 1930 CAEN [| THATITTIÉE a wen LE Preface Chap. I CONTENTS. Wiehe sa u 0a Wa una cle 0 a6 0.6 clin ee are nLe.e,e 05.07 sem, REE JT KE SET VE DES wea me @ 6.6 ee en 6 = a +5 mene lcelhndic Glin ates. cc. oot eter toric ee sion evo Siocon sine craters iit, LS Glimatesandt klor des ocooan oon doco odcb een: DPECIESESLTOUP SEHE TEE ELTERN OF hap HE Types of Icelandic, Viesetatiomns 0.5 5 «teri chee. etre: Chap. IV. The Icelandic Lowland Formations........ naar 0 00 COO ae Au Iynadalsbeinn. un ee ee Cae ee ee rea Tae Peet 1 Mosathemburzyegetationt ee ee Jn Melarzvegetation?.. rc. er ee Se Mo, vegetationk naar elek rere 4 Ja Gar Vegetation: SE ER ae iy Mitel Vegetation, u... 20e eee en done wae 6: Geirivegetations. 2525.22 eee cet Le Mop vegetations 2.5 «. re entente fette et erlernte 2) Jadar and. MY vegelätlan. su... ae sateen ve waters een 3: Hot vegetation an een As lage vegetation: sera et ee ee ee ee et et Cs Eisele Jam OR. ee ee die ER LP De Melarivegetationys a ar ehe een erstere ee 2. MO VESELALIOM ne Asa else ess esse Fe MY DIS VeRBLaHaI en ae Dale DE Nor rr a the ie sects SNE TS ROrestzunder snow. iin. SNE arte sie sie ol sl enaie aie HEALER ea a Za OAV ED ELARIO MSE NE A EN ENE ED NEUE ER auetr sini ceo ae AD VV Tue Icelandic AIS DIANdMEONMATIONS.25......... ess. ss BENET EVLØTIS: KON ERE SAKO SES Ban este na san dead n'a a denen eo eee BEEN TITEL SL OWUEIUVESHIEALIONSE eee es ae eee alter cree N Er PR o/s FN ee ete Kal didn we ate N 2 BELIN NANA ICR VERSA MORS a0.c' ce à Moon à dia ecove 0, se of QI ARE ISOM, RO VERBER ELO «a's 4 « sale w1 dunes ot see a e.V NT PP RP Vo ees and OOP vogelätlon.: ss ce tort COR CEE VERELALION: men em øren asian 00120 dime worse NN ERINDREDE VLSHIITNARN rare nas does ans TO I RUE aS om w Chap. VI. The Distribution of Species, Species-Groups and Life-forms in the Formations, arranged according to Increasing Prevalence of one and Te same Kisternal PACLON, se, os codes a ne LEERE EN 159Introduetionny..r..7, 0 ee ee ee ee ee ee CRU LL 122 2.48 cale OF MOISEUTE rer ee eme ebiess messe: see 123 NORA RER ae cie asis-bersenleseruel 125 DLN SPECLESESTOUDS-< en ee Eee tea oho lo te Erde ee Zu aie verse 129 CS DECIOS Te ee ee ee ee RER 138 3=Scale20f5SHOWECOVELINE en ee ee ee een een ne CCE 141 A ADDECIES ER ee este casse seat s eieisle aus io 20 Peas 0 eae RE 142 DÉS PECIESKEROUPSTE Re et dencre emsiseee cieleleie scie ee seams 146 Caml ITE IF OEMS aor nee nn Verben nee ee crée cn eececcc: LE 152 Æ Number of species and density of species... . 2... CLR 157 ConcludinséremarkS Bra Nee nen ne a ce 158 Degree of acidity in the Icelandic types of vegetation........... 160 Blantegeography. and agriculture on ee 163 Appendix: Temperature Conditions in the upper Soil Strata................. 165 DIA Ale eects Sik oie ie este wielcit ER - 175 ERECT CHIE EC ER ELU eee ie eines one N ls ee 183 PREFACE. mong the results achieved by Danish botanical research, two espe- cially aroused my liveliest interest, viz. W.Johannsen’s demon- stration of the fixity of the genotype (“the genotype of homo- zygotic organisms is normally just as “fixed in type” as e. g. chemical composition” (Arvelighed 1918, p. 102)), and C. Raunkier’s demon- stration of the distribution of the life-forms within the va- rious climatic zones (“even the most widely separated regions with entirely different floras in a floristic respect but with essentially the same climatic conditions for plant life show in the main the same bio- logical spectrum” (Livsformernes Statistik som Grundlag for biologisk Plantegeografi. 1908, pp. 68—69). From these two facts I, as an impartial observer, drew the con- clusion that in Nature the development of forms as sketched in “Livsform og Alder’ (Bot. Tidsskr. 40: 193—203, 1928) must in the last instance be regarded as a physico-chemical process, the simplest manifestation of which is to be found in the trans- formation of a chemical combination, such as e.g. that of H,0 from vapour through water to ice (the gaseous, liquid, and solid phases respectively) during progressively decrea- sing temperature. In this way the species should be chemi- cal combinations whose phases are their life forms. This, however, is merely a theory, the correctness of which is primarily determined by its fruitfulness as a scientific working hypo- thesis. Hence it was expedient to collect further material to illustrate the relation between form and environment. As assistant to Professor Raunkiær in his investigation of the preserved heath at Nørholm (in the summers of 1921—1924) I was fortunate enough to become ac- quainted with the zone formation around collections of water, to which the attention of botanists had already been drawn in "Vesterhavets Øst- og Sydkysts Vegetation” (Raunkiær 1889). At Nørholm Heath I was able to collect material to elucidate the amount of individual species and life-forms in the various zones of moisture, and thanks to financial The Botany of Iceland. Vol, III. 1 aid from the "Japetus Steenstrup Legat” I could continue and verify my observations from Nørholm Heath in the summer of 1924 by a journey through the dune region along the west coast of Jutland. When I had taken my Master's degree in the autumn of 1924, thanks to testimonials from my teachers Professors C. Raunkiær, L. Kolderup Rosenvinge and C. H. Ostenfeld, I obtained financial aid from the Carlsberg Foundation and from Dansk-Islandsk Forbunds- fond for phytogeographical researches in Iceland. In this work, too, luck befriended me. While making my preparations for the journey to Iceland, I was able to attend a course of lectures on the vegetation of Greenland given at the University in the spring term of 1925 by Professor Ostenfeld. These lectures have been of the greatest importance to me, partly during my work in Iceland, and partly during the subsequent more thorough treatment of the material. Thus ‚it is to them I owe the impulse to include in my investigations the vegetation under the various depths of snow-covering, my original in- tention being only to investigate the vegetation in the various zones of moisture. Also the division of the Icelandic flora into species-groups according to the geographical distribution of the species, the setting up of species group spectra on a parallel with the biological spectra, and the application of the species group spectra for a more thorough cha- racterisation of the environment, are fruits of these lectures. By these investigations the conception of the species as chemical combinations has been further confirmed. I have regarded the financial aid which rendered possible the re- searches described in this treatise as a great mark of confidence and, to the best of my ability, I have endeavoured not to disappoint the trust placed in me. Through this work I beg the Trustees of the Carlsberg Foundation and the Trustees of the Dansk-Islandsk Forbundsfond to accept my respectful thanks. Finally I owe thanks to Miss Annie I. Fausböll, M.A., who has undertaken the difficult task of the Eng- lish translation. Copenhagen, June 1928. DEC 1 6 1930 LISRARY NEW YORE ‘OTANICAL GARDEN I. THE ICELANDIC CLIMATE. HE.climate of Iceland is, according to Thoroddsen 1914 p. 265 f., determined not only by the geographical situation of the island and the prevalent winds of the North Atlantic, but also to a great extent dependent on the current-conditions of the surrounding seas. The south and west coasts of Iceland are washed by the warm Gulf Stream, while on the north and east coasts we have the cold polar current. The waters of the two currents meet in the sea out- side south-east of Iceland itself, on a line running from Vatnajökull to the Færoes and to the north-west off Cape Horn. It is as well to note at once that in the highland tracts of Iceland between these two points, we find a series of jökulls in decreasing volume from Vatnajökull to the jökulls of Vestfirdir. The current conditions may be more precisely described as follows: The Gulf Stream washes the shores of Iceland all along the south and south-west coasts of the island, gradually gathering to a stream which follows the coast towards the west and further towards the north. Off Cape Horn, this branch of the Gulf Stream, known as the Irminger Current, encounters the Polar Current coming from the Polar Sea. A branch of the Irminger Current again is forced outward from the- coast by this Polar Current, and another branch, rounding Cape Horn, follows the northern coasts of the island to the eastward, cooling as it goes, and finally disappearing under the water masses of the Polar Current itself. At Grimsey, it is still of great importance, but farther east, it vanishes altogether, and the shores of East Iceland are thus washed solely by the polar water. The situation, then, is as follows: the south and west coasts, i. e. the coast south of the “jökullsline’” is washed exclusively by water from the Gulf Stream. The north and east coasts are washed by polar water; the eastern by this alone, the northern by this and Gulf Stream water as well. 1* 4 H. MØLHOLM HANSEN According to Thoroddsen (1914) these features are of great im- portance in their bearing on life in the sea, both as regards its flora and fauna. We find, in fact, on the north and east coast, a flora and fauna of arctic character, whereas those of the south and west coasts are of temperate character. Up to the present, this has been confirmed by investigations on the flora of marine algæ, plankton, and the fish fauna, as well as deep sea and bottom fauna. The same conditions seem to be of no slight importance as regards life on land, as the present research inter alia will show. The temperature along the coast shows, according to Thorodd- sen, the following values: On the south and west, the mean surface temperature is 5—7° C., while to the north and east it is somewhat lower, 3—4° C. At the Vestmannaeyjar (South Iceland) the surface water during the coldest months (Decbr.—Febr.) shows a monthly average of abt. 4°C., and in the hottest months (July—Aug.) abt. 11° C., the annual mean temperature being abt. 7° C. Stykkishölmur (W. Icel.) has for Febr.—March temperatures of 0.3°—0.4° C. and July—Aug. 10.4°—10.6° C., with an annual mean temperature of 4.9° C. Grimsey (N. Icel.) a March temperature of 0.7° C., August 7.4° C., with an annual mean of 3.8° C., and Papey (E. Icel.) has a Febr.—March temperature of 0.4°—0.5° C., Aug. — Sept. 6.6°—6.2° C. with a mean temperature for the year of 3.2° C. It will be seen from this that the temperature of the surface water decreases parallel with the volume of Gulf Stream water. From South Iceland west and northward round to East Iceland we have the following values for mean annual temperature: 6.9°—4.9°— 3.8—3.2° C. East Iceland has the lowest mean temperature and the greatest volume of the Polar water; South Iceland the greatest volume of Gulf Stream water and the highest mean annual tempe- rature. | The temperature of the air is closely correlated to this (see Table 1), being, however, nearly always lower than the surface tem- perature of the sea water, the difference amounting on the average to a couple of degrees. We find, for instance for the temperature of the air, the following mean values: 5.1°—3.0°--1.5°—2.4° C. that is, following the coastline round from S-W-N-E. The greatest difference is apparent during the coldest months of the year, October to March, less in summer from April—Sep- STUDIES ON THE VEGETATION OF ICELAND 5 tember, and we find also, that only on the south and west coasts is the temperature of the air, on the average, always lower than that of the sea water, whereas on both north and east the tempe- rature of the air may remain for months higher than that of the sea water, this being especially the case on the east coast. The Polar Current carries with it great masses of ice. This current of ice can either strike Langanes or the east coast of Vest- firdir, south of Cape Horn. If it strikes Vestfirdir, then it is borne by the eastward going current along the north coast, rounding Langanes and drifting on along the east, sometimes even also along the south coast, until all the ice has melted or disappeared out into the Atlantic. When the current of ice strikes Langanes or Melrakka- sljetta, it is carried out into the Atlantic by the same current. The quantity of drift ice varies to an extraordinary degree; in some years there may be none at all, while in others, “ice years”, it may lie about until far on in summer. The result is seen in great climatic fluctuations. The winds in Iceland are determined by two centres of low barometric pressure, one lying south-west of Iceland, and another, minor one, situated towards the north-east. The former constitutes the principal factor in determining the state of the wind, and in consequence, easterly winds are most prevalent, especially on the west. In East Iceland, the eastern minimum is of no slight im- portance, westerly winds being here of more frequent occurrence than in other parts of the country. The highest frequency percentage for calm occurs in summer, and this applies to all parts of the country; the highest percentage is recorded from the Vestmannaeyjar, with an average value of 22, a percentage of calm in winter of 10—20 and in summer of 25—30. At Grimsey the percentage of calm is lowest, on an average about 10, 4—6 in winter, 16—19 in summer. East and West Iceland show somewhat similar conditions, though in winter the percentage is higher, about 10. The number of stormy days is closely correlated to this (see table 1). It applies to all parts of the country that the number is highest in winter, lowest in summer. It is, however, very variable. It storms most frequently in the south-west and south, Thus Stykkis- hölmur has, on an average, 50 stormy days per annum, the Vestmanna- eyjar 25. The number is considerably less for the north and east. Grimsey has 11, Berufjérdur only 8 stormy days annually. 6 H. MØLHOLM HANSEN These facts, however, seem merely to apply to conditions either at the level of the sea, or perhaps only by the coast. If we take a station like Mößrudalur, situated approximately on a line connecting Grimsey with Berufjérdur, but at an altitude of 480 m above sea level, this station shows an average of 39 stormy days annually, though distributed in such a way that the winter has the highest, the summer the lowest number of stormy days. Temperature conditions. Above we saw that the temperature of the air near the sea was very closely correlated to the surface tem- perature of the sea water, but with the addition that the tempera- ture of the sea water was always higher, 1—2° C., than that of the air. In table 1 are shown the average annual and monthly mean temperatures for South Iceland, West Iceland, East Iceland, and the highland Médrudalur. There is a considerable difference between the coastal stations on the one hand and the highland on the other hand, a difference which may also be shown to exist between the coastal stations mutually. The mean temperature is highest in South Iceland, being 5.1° C. at the Vestmannaeyjar. The coldest month here is December with a mean temperature of 1.2°, the warmest month is July with 10.6°. The difference between the coldest and warmest months is 9.4°. West Iceland, Stykkishölmur, has a mean annual temperature of 2.8°, the coldest month, February, registering a mean temperature of 2.7° below zero, the warmest month (July) 9.7°, with a difference of 12.4°, Berufjöröur in the east country has the same mean annual tem- perature, 2.3°; here March is the coldest month, 1.7° below zero, July the warmest, 8.5°, and the difference between the coldest and warmest months is somewhat less, 10.2°. Grimsey, in the north country, has a mean annual temperature of 1.5°, a mean temperature for March of 3.6° below zero, for July of 7.0°, difference 10.6°. The highland is considerably colder. The mean annual tem- perature for Möörudalur is 0.2° below zero, the January temperature, 7.2° below zero, the July temperature 10.0°. The difference, 17.2°, is thus considerably greater than that of the coastal stations. The number of frosty days is closely correlated to the tempe- rature conditions. The smallest number is recorded from South Iceland which shows an average of 109 per annum. Grimsey has the greatest number, 192. Berufjöröur lies between these two extremes with 158 frosty days and Stykkishölmur with 166 frosty days. Un- STUDIES ON THE VEGETATION OF ICELAND 7 fortunately there are no records from the highlands. The number is probably considerably higher here. Precipitation. The precipitation in summer is principally rain, in winter principally snow. The annual precipitation is greatest to the south and east, decreasing towards the west and being compa- ratively small in the north. In the Vestmannaeyjar the annual precipitation is 1319 mm. (see table 1), distributed over 207 days, in East Iceland it is 1117 mm., distributed over 146 days, in West Iceland, Stykkishölmur, the amount of precipitation is already considerably lower, 662 mm. distributed over 117 days. From the highland tracts we have unfortunately no investigations on the amount of precipitation for the whole year, so it is impossible to draw any comparison with the coastal stations. The number of days with precipitation for Möörudalur is 153, thus somewhat higher than for Grimsey, corresponding fairly well with East Iceland. It may, however, be taken for granted that the amount of precipitation is not nearly as great in the highland tracts as at the coast. Observations from some of the summer months at a highland station, Grimsstadir, about 385 m above the sea, in the vicinity of Médrudalur, show an average monthly value for the five months May—September of 26.8 mm, while the average monthly amount of precipitation for Grimsey for the five months is 31.4 mm. The amount of precipitation and the number of days with pre- cipitation are highest in the autumn and winter months, lowest in spring and summer. This applies especially to the regions to the south of glaciers. In winter the precipitation occurs principally in the form of snow, though with a difference in the different parts of the country. Table 1 shows the number of days with snow for the different stations where this has been investigated. In the highland tracts and the north country snow predominates, in the south there are comparatively few days with snow; while snow is rare here in the summer, it is more frequent in the north. In the highland tracts snow in summer is even the rule. At Môdrudalur the average monthly number of days with snow in summer is 2—4. Unfortunately there are no observations on the depth and du- ration of the snow-covering in the various regions of Iceland. As to the depth of the snow-covering Thoroddsen states that it varies much with the situation and the altitude above the sea, and from one year to another. As to its duration he states that the snow 8 H. MØLHOLM HANSEN TABLE 1. Climatic Conditions in Iceland. I. Berufjordur, East Iceland (64° 40’ N., 14° 15‘W., 18 m above sea level). II. The Vestmannaeyjar, South Iceland (63° 26° N., 20° 18’ W., 8 m above sea level). III. Stykkishölmur, West Iceland (65° 5‘ N., 22° 46’ W., 11 m above sea level). IV. Grimsey, North Iceland (66° 34‘ N., 18° 3‘ W., 2.5 m about sea level). V. Möörudalur, Highland Tracts (65° 19’ N., 15° 15’ W., about 480 m above sea level). The table has been compiled after Thoroddsen (the lowland stations), Thorkelsson (the preeipitation values for all stations), and Meteorolo- gisk Aarbog Part II, 1886—1916 (the highland station). The lowland stations comprise the years 1872—1906, the precipitation values cover an additional number of years. I II. 7 > = - “| S| 5 $ Eu = 3 = = |» | aD Ta ' She) oe] Ba) "1 ee | 2 |? 2 Se Mean temperature of | > = = surface water in de- | | Press ESSEN FESTER 3.21 0.7| 0.4) 0.5|1.5|3.1/|4.3| 6.0| 6.6| 6.2| 4.3) 2:6) 13 Mean temperature of | | Te ee Va 2.8 —1.2 + 1.5 +1.7 | 1.0 | 3.7 | 6.8 8.5 8.3 | 6.6 | 3.3| 1.1 +1.0 Mean precipitation in | | | TE mere 1174| 128| 991 77| 83! 73| 67! 64| 82 | 126 ! 124 | 113 | 139 Number of days with | | | precipitation’. 2. .....- 146) 15| 14) 12| 11] 10) 9| 10| 10| 13] 13) 14| 15 Number of days with | | | | | SHON SEE ee ee 50 Silt wens ONE BI 23:04 » | 0.1| 0.5 3 6 7 Number of days with | Rec | FODS een lets 1711 11) Ag) 11|.14| 17 | 19) 21) 18] 16) oe Number of days with | | | FOSS SEE, | 158] 24| 22] 25| 18| 10] 2| »| 03] 2| 13} 18] 24 Number of days with | SACS rr eters) ests 8 1 1 1" 11'0.4.10.1|:0.2] 020.4) 4 1 1 | | Mean temperature of | | | | surface water in de- | | | | Pres SEER 6.9| 4.1) 4.1! 4.5|6.1|7.7|9.5 110.9 10.8 | 9.1| 6.8 | 5.1| 41 Mean temperature of | | | A er ata corey 5.1) 1.3) 1.3) 1.4 4.0 | 6.3 | 9.0 110.6 10.2 | 8.2| 5.1) 3.0! 12 Mean preeipitation in | | | | RI ee 1354 | 150 | 123 | 118 | 94 | 80| 80| 77| 76 | 139 | 144 | 135 | 138 Number of days with | | | precipitation ........ 207| 21| 18 pe | 17/ 15| 15| 15] 14] 18 | 19] 19] 19 Number of days with | | | SNOW 27 EL TER 44); 9) 8 8| 4| 1102 » >| 0.3| 21 4 8 Number of days with | | Kt: 1062: bi, Tos ee eee | 49 2 2 2 | 3| 5| 8 8 6 2 <4 2 2 Number of days with | | | | MORE Re 1091 20) 18! 17) 10) 3/0.1 >| 0.4) 1| "8 a3) 238 Number of days with | | | | TA: SARA AT 251 Bile oa 3 2) 1105103103|. 2| Bae i | | STUDIES ON THE VEGETATION OF ICELAND TABLE 1 CONTINUED. | | | x =, Ines ale | » | 3 n | © 2 ls) 4) 2) 2) Blzle|e| Ble) 4) le: © = = | & aAisis5/ 2 Sn 5 © © Ca ih hoe "© = < KE le am 3 = = Ic ee) | A Z |A Bean temperature of == — — ES = surface water in de- | | | | oe | 4.9] 0.9] 0.3| 0.4| 1.7/4.7 8.2 10.4 |10.6 Mean temperature of | | | | TET» N ee 2.8 |+2.2 |+2.7 +2.3| 0.8 4.3 17.8 | 9.7| 9.2 Mean precipitation in | at RENT nee ces ceicie 654| 74| 691 50) 37!37|37! 34| 41 Number of days with | precipitation. . ...:.. 1207| 21) 19) 18) 1615| 1514 Number of days with | | STER BASS ERE gen 7:82.17 1677212 Sas 8| 3/0.4| 0.1 Number of days with | | SEE oa 9| 0.31 05) 0.4| 0.7 12.011.3| 1.6| 1.3 Number of days with | | ER 1661 26) 25) 26| 19) 9) 1) >| 0.2] Number of days with | | HGS Se ocedscebonege 50 6 6 6 4} 41 2 1 2 5 IV. Mean temperature of | surface water in de- Be Bienen 3.8| 1.8] 14] 0.7| 1.3 12.6 4.2 | 6.6| 7.4 Mean temperature of N SEE JR 1.5 |+2.0 |+3.0 |+3.6 |+1.2 11.7 5.5 | 7.0) 6.8 Mean precipitation in ae rain 274) 161 17) 17| 13/15118) 281! 34 Number of days with | precipitation........ 117) 10) 20)" 10 9178176 8 Number of days with bo LL ASS le ce vo 46 1| 1 2 A Gi 70 10 Number of days with ERE cer 1921 25) 24| 27) 2417| 5 2 Number of days with Se EURE 11 Tan Ad 1| 0.3 0.2 0.4| 0.2| 0.2 V. Mean temperature of | | PR ri se +0.2 27.2 +6.7 +6.4 |+2.1 3.2 8.5 10.0), 7.4 Mean precipitation in | | | mm (Grimstadir).... >} »| »| »| »[/19|27| 29| 34 Number of days with | Paw precipitation........ | 1531 13| 13] 14] 18/12] 8| 12] Number of days with | | | RE PETITE 109 |! 12) 12 19 || 124) Sis 2 Number of days with | | | | AAAS se 7 1) ie eta ge fC Dh Number of days with | | | 121 ensure 39| 6 i I 2| 2) 3 1 10 H. MØLHOLM HANSEN often remains on the ground for a long time in the north country, while this is more rarely the case in the south-west. In the south country it may often happen that the lowland tracts are destitute of snow for months on end. Here the precipitation is in the form of rain, whereas, in the adjacent highland tracts it falls as snow. Fog. In the calm and rainy regions to the east and south, fogs often occur, whereas the more storm-blown west coast is rarely visited by fog. Thus Berufjérdur has no less than 171 annual days of fog, while Stykkishölmur has only 9 days of fog. Fog occurs most frequently in summer, still even the winter months show a number of foggy days on the east coast, about 10. If on the basis of the above statements, we attempt to make a comprehensive survey of the climate of the separate parts, we must distinguish between a lowland climate and a highland climate. The lowland climate is of a pronounced oceanic character with but slight difference between the summer and winter temperatures. The climate of the east country is cold, foggy, and rainy, with slight circulation of the air. That of the south country is warmer, espe- cially in winter. In the west country, again, the temperature falls somewhat, and the precipitation is considerably less. Fog is rare, but on the other hand, the weather grows very stormy. The north country is the coldest, but on the other hand the driest. Fog and storm are not very common (the station here is Grimsey, which does not, probably, give a perfectly valid picture of the climatic conditions of the north country). The main difference between the north and south countries is that the north country is more continental in character than the south country. The summer temperature is very much the same for both parts, the average for all stations being about 9—10” C., but the winter is considerably colder in the north than in the south, 4° C. below zero in the north, 1° C. below zero in the south. The difference between the warmest and the coldest month is 13.2” in the north, but only 11” in the south. The highland climate. The climate of the highland tracts is considerably more continental than that of the lowlands. The sum- mer temperature is very much the same in both places, but the winter temperature is considerably lower in the highland tracts and STUDIES ON THE VEGETATION OF ICELAND 11 the difference between the coldest and the warmest months is thus great, 17.2° C. The precipitation is slight and storms are frequent. To this must further be added a probably very thick and at any rate constant covering of snow in winter. Of interest in connection with plant geography is further the situation of the jökulls and the snow-line. We have previously seen that most of the jökulls gather along a line connecting the two places where the waters of the Gulf Stream and the polar water meet, respectively to the south-east and the north-west of Iceland. The line begins with the large Vatnajékull on the south-east and extends north-westwards over Tungnafellsjökull, Hofsjökull, Langjökull, and Eiriksjökull until it terminates in Gläma and Drangajökull in Vest- firdir. To the north of the range of jökulls there are only a few small jökulls on the peninsula between the Eyja- and Skagafjördur while to the south we have the large Myrdalsjökull and some smaller ones, more especially Snefellsj6kull. The area of the jökulls is largest towards the cold, humid, and foggy eastern regions and decreases strongly towards the north-west. The area of Vatnajökull is about 8000 km”; of Hofsjökull about 1350 km?, of Langjökull 1300 km”, of Glama about 60 km”, and of Drangajökull 350 km”. Vatnajékull’s greatest altitude above sea level is 2119 m., that of Hofsjökull 1700 m., of Langjökull 1400 m., of Glama and Drangajökull about 900 m. The snow-line lies at very different altitudes, coming down lowest on the south side, while on the north side it lies somewhat higher, the east and west sides occupying an intermediate position. On Vatnajökull the snow-line on the north side lies at a height of 1300 m., on the north side of Hofsjökull at 1200 m., and on the north side of Langjökull at a height of 1100 m. On the south side the snow-line lies at a level of 900 m. In Vestfirdir the height of the snow-line above the sea is 400—650 m. On Myrdalsjékull the snow-line lies at a height of 1100 m. on the north side, and 800— 900 m. on the south side. Below the snow-line proper comes a zone with snow-drifts which either never melt, the permanent snow-drifts, or only melt in very hot summers, the variable snow-drifts. It is difficult to set any lower limit to these two zones. On Arnarvatns- heidi north-east of Langjökull, where the snow-line lies at a height 12 H. MØLHOLM HANSEN of 1000—1100 m., the lower limit of permanent snow-drifts lies at a height of 600—700 m. above sea level, and that of the variable snow-drifts at a height of 500—600 m. The setting up of climate zones, i. e. of a zone of lowland climate, a zone of highland climate, and various snow zones, results in a similar formation of floristic and vegetation zones to which we shall contribute in the following. Il. CLIMATE AND FLORA. u above-described rather rigorous climate in connection with the homogeneous soil, consisting of basaltic rocks and their weathering products, is no doubt in great part, and perhaps even more than the isolated position of the island, responsible for the paucity of species apparent in the phanerogams. Thus the most recent treatment of the Icelandic flora, St. Stefansson’s “Flora Is- lands”, 2. ed. 1924, gives a total of only 375 phanerogams and vas- cular cryptogams (the number of species of Taraxacum and Hiera- cium is, however, taken from the 1st edition of the Flora, 1901). The floristic peculiarities are here disregarded. They have pre- viously been treated by Grønlund and Warming. Some bio- logical facts are of greater interest in this connection. In »Flöra Islands« the country is divided into 5 areas, viz. the East Country or the land between the Langanes Mountains and Hornafjöröur; the North Country between the Langanes Mountains and Hrütafjöröur; the North West Country or Vestfirdir; the South West Country between Gilsfjöröur and the Reykjanes Mountains, and finally the South Country between the Reykjanes Mountains and Hornafjöröur. The distribution of each species in each of the aforementioned 5 areas is given in the Flora. By determining the life form of each species and calculating the percentage of the va- rious life forms in the total number of phanerogams we arrive at the biological spectra given in table 3, p. 17, partly for the whole country partly for each of the 5 areas. Of greatest interest are the chamaephytes, the chamaephyte percentage for the whole country being 15.2; hence, as shown by Raunkizr in 1908, Iceland belongs to the subarctic hemicryptophyte-chamaephyte area. For the rest there is a striking, even though slight, difference in the content of chamaephytes in each of the 5 areas. The South Country has a chamaephyte percentage of 15.1, the South West Country has 15.2, 14 H. MØLHOLM HANSEN Vestfirdir 16.0, the North Country 16.6, and the East Country 18.0. There is thus an unbroken rise in the chamaephyte percentage from the South Country, whose chamaephyte percentage corresponds to that of the whole country, towards the west and north, until it at- tains its highest value, 18.0, in the east. It is difficult to ascertain what climatic factor causes this rise, and more probably we may assume that not one but many factors are determining. The physical factor which varies parallelly with the variations in life forms is the annual mean temperature of the oceanic surface water. This as we showed above, was closely correlated to the amount of Gulf Stream water and Polar water at the coasts. The variation in other climatic conditions, whether it be in the air temperature, number of days with frost, the coldest or warmest month, amount of pre- cipitation, number of days with precipitation, days with snow, frost or gales, does not agree nearly so well with the variation in life form as the temperature conditions of the surface water. The correlation of the biological peculiarities of the flora, more especially of the chamaephyte percentage, and the current conditions of the adjacent seas is likewise confirmed in the surrounding countries. Table 2 gives the biological spectra for West and East Greenland, calculated on the basis of the flora lists given by Ostenfeld (1926). The west and east coasts of Greenland are each divided into 8 minor corresponding areas. The east coast is washed by a Polar current coming from the north, the Greenland Current, while the west coast is washed by a current coming from the south. In ac- cordance herewith we find that the chamaephyte percentage in the individual, corresponding, minor areas as well as for the two coastal tracts as a whole is highest in the east, lowest in the west. The table shows the composition of the biological spectra. Starting from the number of species, the chamaephyte percentage for the whole of East Greenland is 25.2, for West Greenland 21.6. Starting from the points sum, the ratio will be 28.6 to 25.2. Only South Green- land has a chamaephyte percentage lower than 20, viz. 18.6. If we pass over to the west coast of Baffin Bay and Davis Strait, we find that a current from the north, the Labrador Current, flows along the eastern coast of Baffin Land, and according to Raunkiær (1908), the chamaephyte percentage for Baffin Land is 30, while for the whole of West Greenland it was only 21.6. Passing from Iceland towards the east, we find the west coast of Norway washed by the warm Gulf Stream, and here, as a matter STUDIES ON THE VEGETATION OF ICELAND 15 TABLE 2. The Biological Spectra of West and East Greenland. 31.9 53.6) | 101) 43 W. Grl. 80°—83° N. Lat. VIII 2,9 | 69| > 769—809 — VII 5.5 | 109 | > | 31.2 | 52.3 | 11.0 | 4.6 | 0.9 ae = Wr. Ba >30 | 527 | 128 | 40) 13 69°71" — Va... | 5.1 | 197] >» | 274 | 523 | 118 | 6.1 | 25 Disko Vb.. 7.5 | 214) » | 25.7 | 53.3 | 12.1 | 6.1 | 2.8 660—699 — IV 6.0 | 233 > | 25.8 | 51.1 | 9.9 | 9.0 | 4.3 GEO 66 — if 7.8 | 217 | 0.5 | 24.4 | 548 | 9.7 | 7.4 | 3.2 6964 —' I 9.3 | 216 | 1.4 | 21.3 | 56.5 88 | 74 46 S. Grl. 61°—60°—61° I ... | 11.4 | 236 | 1.3 | 18.6 | 542 | 106 | 7.6 | 7.6 E. Grl. 61°—65° N. Lat. I ... 9.2 || 153 > 1229 | 60.1 | 9.2 | 46 | 3.3 Angmagsalik IH ...| 90 | 167 | » | 246 | 58.1 | 8.4 | 6.0 | 3.0 67°—70° N.Lat. IV ... | 7.5 190 |" >| 308 | 542 | 9.2 | 42 | 17 Scoresby Sound V … | 6.3 | 160 | > | 29.4 | 52.5 | 125 | 3.8 | 19 720-760 N.Lat. VI ... || 4.8 | 126 | » | 29.4 | 540 | 119 | 2.4 | 24 760—819 — VI .:.| 5.5 | 91] » | 330 | 49.5 | 143 | 33 | » 810—830 — VIII ...| 43 | 47] » | 426 | 447 | 106 | 21 | > BE Greenland ...:........:-:, | 8.2 | 352 | 0.9 | 21.6 | 54.0 | 10.5 | 7.7 | 54 East Greenland ................. | 7.1 | 238 | 25.2 | 57.6 | 10.0 | 4.2 | 2.9 West Greenland................. | 7:3 11640 | 0.4 | 252 | 53.4 | 10.7 | 6.7 | 3.6 Ben Grcenland..... 1... u 7,1 | 864 | > | 28.6 | 54.6 | 10.6 | 4.1 | 2.1 of fact, the chamaephyte percentage is considerably lower. According to Raunkiær (1908), Tromsø in 69—70° N. has a chamaephyte per- centage of 10, and Vardø, in a still more northerly situation but protected from the sea, has a chamaephyte percentage of c. 15. It is thus beyond doubt that there is a connection between the biological spectra and the current conditions ofthe surrounding seas. For the rest it is probably the temperature conditions which have most influence on the composition on the flora, that is to say, the annual mean temperature or more probably perhaps the tem- perature conditions of the winter. Passing from the lowlands to the highland, the annual mean temperature, as shown above, grows 1) In the tables the abbreviations are as follows: n: number of species, Pt: Pteridophytes, Ph: Phanerophytes, Ch: Chamaephytes, H: Hemicryptophytes, G: Geophytes, HH: Helo- and Hydrophytes and Th: Therophytes. 16 H. MØLHOLM HANSEN lower and lower, while the winter grows colder and colder. At the same time the flora shows a greater and greater paucity of species. Unfortunately Stefånsson's “Flöra Islands” gives no upper limit for the individual species, and as far as Iceland is concerned, only very few authors have stated at what altitudes they have found the plants collected by them. Thoroddsen (1914) has given most in this respect. By comparing what is found in the literature concerning the occurrence of the plants in the highland tracts with my own notes, but especially thanks to a long series of flora lists courteously left at my disposal by Mr. Pålmi Hannesson, I have been able to work out the biological spectra of the highland tracts of Iceland given below, divided into zones of 100 m each, from 300 m to 1200 m, - the highest locality in which plants have been found. While 375 species of vascular plants have been found in the whole country, only 224 species have, up to the present, been found above the 300 m curve, and only c. 100 species above the 600 m curve. Going higher still, we find only 40 species above the 800 m curve, and the number is further reduced when we reach the snow- line above which all higher plant life is excluded. It applies to Iceland as to other arctic regions, the Faeroes, northern Norway and Greenland, that only a limited number of species has any lower limit, while most of the species decrease as we go upward and sooner or later reach their upper limit. The following species are of common occurrence right up to the snow-line: — Luzula arcuata, Elymus arenarius, Poa glauca, P. alpina, Festuca ovina, Salix glauca, S. herbacea, Oxyria digyna, Cerastium alpinum, Silene acaulis, S. ma- ritima, Ranunculus glacialis, Arabis petræa, A. alpina, Empetrum ni- grum, Saxifraga groenlandica, S. oppositifolia, S. nivalis, and Armeria vulgaris. With few exceptions all the above-mentioned species are of common occurrence in Greenland right up into the northern parts. From considerations of space the species lists are not included. The biological spectra calculated from them are given in table 3. There is a difference in the occurrence of the individual life forms. Some show a decrease as we go upwards, others increase, and others again are constant. The H percentage is fairly constant through all zones, c. 50. Pt, G, HH and Th decrease strongly as we go upward; above the 800 m curve these types have only been noted a few times. With respect to their content of these life forms, various differences may be shown to exist between the various zones, and possibly the highland tracts between 300 and 800 m may by means STUDIES ON THE VEGETATION OF ICELAND 17 TABLE 3. The Biological Spectra of Iceland. A j Ghi te Ho) GPE Tb MI v À | > 1200 m..............0.. 387 1,2 (444 74| » | 3.7 et Eee 20 » | 20] » | 50.0 | 40.0 110.0! »| » ST AR | 28 | 3.7| 27 | » | 40.7 | 519 | 7.4) >| >» nie | 26 >| 26 RE 42.3 | 50.0 | 7.7 oh RE LL. 65|32| 63) »|365 | 460 |127| 16 | 32 2 TT MERE | 9ı|22| 89) > | 29.2 | 53.9 |112| 34 | 22 ee SS ESSEN Fe ae | 1172 | 4.5) 112 | 0» ES 56.30) 89|54| 45 Ra LKR | 161 | 5.2 | 153 | 0.7 | 21.6 | 54.9 |12.4| 5.2 | 52 us | 204 | 7.9 | 189 | 1.1 | 20.1 | 51.9 | 12.2] 5.8 | 9.0 EMEA 126 | 5.0 | 120 | 0.8 | 25.0 | 50.0 | 12.5| 7.5 | 42 LS 166 :| 7.8 | 154 | 0.6 | 24.0 | 46.1 | 13.6| 6.5 | 9.2 nd... 272 | 6.3 | 256 | 0.8 | 18.0 | 512 | 12.5| 7.4 | 10.2 Den Iceland. .....:1..... >. 331 | 7.5 | 308 |-1.0 | 16.6 | 52.3 | 11.0 | 9.1 | 10.1 rene | 277 | 8.2 | 256 | 0.8 | 16.0 | 53.9 | 12.5 | 6.6 | 10.2 re | 314 | 8.3 | 290 | 0.7 | 15.2 | 51.4 | 11.4] 9.3 | 12.1 SE 337 SR SEN | 309 | 6.2 | 291 | 1.0 | 15.1 | 52.2 | 11.3| 8.9 | 11.3 The Highland tracts 8—1200.. | 40 |52 | 38 |.» | 34.2 | 52.6|105| »| 2.6 = = — 3— 800.. | 224 | 7.7 | 208 | 1.0 | 21.2 | 52.9 11553 | 8.2 The whole of Iceland ........ 375 | 7.4 | 349 | 1.1 | 15.2 | 52.4 | 10.6 | 9.2 | 11.5 The Highland tracts 8—-1200 . | 102 | 2.0 | 100 | » | 44.0 | 47.0 | 8.0| >» | 1.0 — — — 3— 800.. | 638 | 5.3 | 606 | 0.5 | 244 | 53.1 |11.6| 4.8 | 5.6 The whole of Iceland ........ 11503 | 5.8 |1401 | 0.9 | 16.1 | 52.2 11.7 | 8.2 | 10.8 of these differences be divided into a lower zone rich in G and HH, and an upper zone in which these types grow rarer. Ph are only sparingly represented in the lowest zones. Ch are of the greatest interest. In the lowest zone, between 300 and 400 m, the Ch per- centage is 20.1; in the next, 21.6, and henceforth there is a marked increase 25.0--29.2—36.5, until, in the zones above the 800 m curve, we get a Ch percentage varying between 40 and 50 for the individual zones. For the whole highland tract the Ch percentage is 21.2. By means of the life forms it is thus possible to divide the highland tracts of Iceland into zones delimited and characterised by the percentage content of the individual life forms. It must, however, be reserved for future and more thorough-going investi- gations to do this as also to draw a comparison between the Ice- landic zones on the one hand, and the Scandinavian and Alpine The Botany of Iceland, Vol. HI, 2 18 H. MØLHOLM HANSEN zones on the other hand. The above-mentioned facts may, however, be utilised to fix one biological line of demarkation in Iceland, viz. the 20 p.c. Ch biochore. The lowest zone, the 300—400 m zone, has a Ch percentage of 20.1. The Ch percentage in the lowlands is below 20, and as it is a rule that species decrease in number as we go upward, while only a few or no species are added from above, the 20 p.c. Ch biochore may with fair accuracy be put at the lower limit of the zone, i. e. at c. 300 m above sea level. If we compare the position of the 20 p. c. Ch biochore in Iceland with the position of this line in other regions, we shall find very good agreement. In Scotland, according to Raunkiær (1908), the 20 p.c. Ch biochore lies at a height of c. 800 m above sea level, and in the Faeroes at c.500 m. In Greenland only the southernmost part, 61—60° N., lies south of the 20 p. c. Ch biochore. In other words, here the line has come down to sea level. Hence the position in Iceland of the 20 p.c. Ch biochore at an altitude of c. 300 m is in very good agreement with facts in the surrounding countries. That Ch is the life form best adapted to the Icelandic climate will also appear from the lists in another way. It is clear from the way in which the spectra are calculated that the rarer species will easily come to dominate too much. This error may, however, be rectified by comparing the spectrum formed for a series of zones in the usual way with the spectrum which may be formed from the total of the notes for all zones. Below in table 3 this has been done for Iceland as a whole, for the highland tracts between 300 and 800 m, and for the tracts between 800 and 1200 m. It will appear from the table with all desirable plainness that Ch show the best adaptation, H are indifferent, and Pt, F, HH and Th show the poorest adaptation to the Icelandic climate. The geophytes present interesting facts. In the lowlands they are best adapted to the climate, in the highland tracts between 300 and 800 m they are indifferent, while above the 800 m curve, similarly to H, they thrive badly. Though we must thus suppose from the above that Raunkizr’s life forms would afford a convenient basis even for a more thorough- going investigation of the flora and vegetation of Iceland, a classi- fication of the flora according to other viewpoints will always be of interest. Hence I have also divided the flora into groups according to the distribution of the species in Europe and the adjacent arctic STUDIES ON THE VEGETATION OF ICELAND 19 regions. For we cannot take it for granted that a species, because it has come to a certain region, will at once assume the most pro- nounced life form of the region in question. The dominating life form in arctic regions is Ch, yet we find species with another life form, and these species must be supposed to be just as well adapted to arctic regions as several of the chamaephytes growing there. Conversely, in regions having a hemicryptophyte climate, we may find Ch. A species like Calluna vulgaris must be assumed to be just as well adapted to the Danish climate as many hemicrypto- phytes. Even though Raunkiær’s life forms give an ex- cellent biological picture of the climate, they do not give the most accurate picture of it. The distribution of the species must rank first in this respect. However, there must be no disagreement between results obtained by means of Raunkizr’s life forms and those obtained by investigations based on the geographical distribution of the species, though at the outset we must expect the latter to give the more pronounced result. Raunkiær’s life forms picture the morphological adaptation of the spe- cies, the species groups give expression to their physio- logical adaptation, both, however, express their adap- tation to the same life conditions. Various enquirers in various countries have at different times worked out a classification of the floras of their respective countries. Thus Watson divided the British flora into groups according to the geographical distribution of the species. A. Blytt divided the Nor- wegian flora on a somewhat similar principle, and various Swedish enquirers, i.a. Gunnar Andersson and H. Hesselman, have clas- sified the Swedish flora. Ostenfeld has classified the flora of the Faeroes, Porsild and Ostenfeld the Greenlandish flora. The principle acted upon by all these enquirers was to separate all spe- cies haying a pronounced northern or southern distribution from all such as showed an equal distribution over the entire area. This resulted in the first instance in the setting up of three groups, while Watson and Blytt in addition classified the species according as they had a pronounced Atlantic or continental distribution. An attempt to bring together the species groups of the various authors and thus arrive at a classification of the Icelandic flora proved impossible, since their species groups overlap to such a de- 9% 20 H. MØLHOLM HANSEN gree that no satisfactory result was obtainable. I had then no other alternative but to attempt a classification myself. In working out this, an acquaintance with the groups of other authors has of course been of great use to me. The best way would no doubt be to determine the course of the Ch biochores in the arctic regions and in Europe and next to determine between which biochores the individual Icelandic species most frequently occur, and then classify the flora on the basis of these data. This work I began but had to give it up again as it took so much time that I dared not at the present juncture embark upon it. The principles which I then adopted, and on which the clas- sification of the flora given below is based, are the following. First I divided the flora into two larger groups A and E, according as the species were of common occurrence in arctic and subarctic regions but were absent or rare in temperate zones (group A), or the species were common in or typical of the more southerly regions (group E). The A group corresponds approximately to the “arctic species’, “alpine species”, “mountain plants” etc. of the various authors, while the E group corresponds to the “British species”, “European species”, “Northern species”, “Southern species”, ““Low- land species” etc. The distinction between these two groups does not cause any difficulties, these do not appear until we attempt to subdivide them. In the following the A group is subdivided into three minor groups according to the northern limits of the species, or their ability to withstand cold, in such a way that group 3 ex- tends farthest north or highest up the mountains while group 1 stops first, and group 2 occupies an intermediate position. On the same principle group E is subdivided into 4 minor groups, group 4 including the species occurring farthest north and group 1 those occurring farthest south. The Icelandic flora is thus divided into 7 groups according to the distribution of the species and more pre- cisely according to their “temperature demands”. The distribution of the species has been investigated in the following countries: — Ellesmereland, North Greenland, Spitsbergen, West and East Greenland, Iceland, the Faeroes, Norway, Sweden, Finland, Novaia Zemlia, Ireland, Scotland, England, Denmark, the Baltic States, and north-eastern Germany. The works on the re- spective floras will be found in the bibliography. — In fig. 1 tempe- rature curves for a series of stations along the western coasts of Greenland and Scandinavia are shown. erry PIN: A M JT Ae Fig. I. Temperature Curves for a Series of Stations along the Coasts of W. Green- land, Iceland, and Scandinavia. From tables in Hann, 1911. 1. North Greenland: 82° N., 63.70 W, 2, Upernivik 720 47' N., 550 53° W, 12 m. above sea-level, 8. Jakobshavn 690 13’ N.. 500 55° W., 13 m. above sea-level. 4. Godthaab 64° 11° N., 510 46° W., 11 m. above sea-level. 5. Ivigtut 610 12: N., 489 11° W,, 5 m. above sea-level. 6. Grimsey, N. Iceland 669 34’ N., 180 3° W., 2.5 m. above sea-level. 7. Vestmannaeyjar, S. Iceland 63° 26° N., 209 18’ W., 8 m. above sea-level. 8. Fruholmen 71° 6° N,, 230 59° E., 15 m. above sea-level. 9. Skomvaer 670 24' N., 119 54’ E., 20 m. above sea-level, 10. Christianssund. 630 7’ N, 70 45° E., 15 m, above sea-level. 11. Bergen 600 23° N., 5° 21’ E,, 20 m. above sea-level, 12, Fanø 55° 27’ N., 80 24’ E., 5 m. above sea-level, H. MØLHOLM HANSEN The 7 species groups contain the following species: — H Agropyrum violaceum Ch Antennaria alpina Ch Arenaria ciliata Ch Armeria sibirica Campanula uniflora Cardamine bellidiflora Carex capillaris — glareosa — incurva nardina — pedata — rigida —— ‘T©upestris — salina — saxatilis Catabrosa algida Ch Cerastium alpinum Ch Draba alpina Ch — nivalis Ch Dryas octopetala H Elyna Bellardi H Epilobium latifolium Equisetum variegatum Erigeron uniflorus H Eriophorum Scheuchzeri Juncus biglumis = castaneus H Th H Ch SEZTPETETEED US Sr ler HO Ch Ch H A 3. Arctic species common in North Greenland north of 76°. Juncus triglumis Koenigia islandica Luzula arcuata Mertensia maritima Minuartia biflora — verna Oxyria digyna Papaver radicatum Pedicularis flammea Poa glauca Polygonum viviparum Ranunculus glacialis — hyperboreus — pygmæus Sagina intermedia Salix glauca — herbacea Saxifraga cernua — sroenlandica — Hirculus = nivalis — oppositifolia -= rivularis = stellaris Silene acaulis Stellaria humifusa Trisetum spicatum Woodsia ilvensis. between 66° and 76° N. Alchemilla alpina — glomerulans Arabis alpina Archangelica officinalis Bartschia alpina Betula nana Bryanthus coeruleus Carex alpina — bicolor — brunnescens — capitata — festiva — lagopina — microglochin —- rariflora DRORPELTEOCHERERO Ch Ch G H Ch H H Th Th Th Th Ch H G H A2. Arctic Species whose Northern Limit in West Greenland lies Cassiope hypnoides Cerastium trigynum Corallorhiza innata Deschampsia alpina Diapensia lapponica Draba incana Epilobium anagallidifolium Euphrasia latifolia Gentiana nivalis = serrata — tenella Gnaphalium supinum Hieracium alpinum Juncus arcticus — trifidus STUDIES ON THE VEGETATION OF ICELAND 23 Ch Loiseleuria procumbens H Luzula spicata Lycopodium alpinum : Ch Minuartia stricta H Phleum alpinum Th Pleurogyne rotata H Poa alpina H Potentilla verna K Rhodiola rosea Ch Saxifraga aizoides Ch Saxifraga Aizoon H Sedum villosum Ch Sibbaldia procumbens HH Sparganium submuticum H Stellaria borealis H Taraxacum croceum H Thalictrum alpinum H Tofieldia borealis H Veronica alpina Ch — fruticans H Viscaria alpina. Al. Arctic-Subarctic Species whose Northern Limit in West Green- land lies between 60 and 66° N. H Alchemilla acutidens H Hieracium arctocerinthe H == faeröensis H — dovrense Ch Arabis petræa H — islandicum Athyrium alpestre H = nigrescens Botrychium lanceolatum H _ prenanthoides H Carex atrata H — strictum G — chordorrhiza Isoëtes echinospora HH — norvegica G Juncus balticus G — sparsiflora G Listera cordata Ch Cerastium nigrescens H Luzula sudetica H Cornus suecica H Poa laxa Ch Draba rupestris H Primula stricta Dryopteris lonchitis Th Rhinanthus groenlandica H - Epilobium alsinifolium Ch Sagina Linnæi H — Hornemanni Ch Salix lanata H — lactiflorum Ch — phylicifolia H Erigeron borealis Ch Saxifraga Cotyledon H Galium trifidum Ch — hypnoides Th Gentiana aurea Th Sedum annuum H Gnaphalium norvegicum Selaginella selaginoides G Habenaria viridis H Sesleria coerulea H Haloscias scoticum Ch Silene maritima H Stellaria crassifolia. E4. European Species whose Northern Limit in West Greenland lies north of 66° N. H Alchemilla minor H Alopecurus aristulatus HH Batrachium trichophyllus Botrychium Lunaria H Calamagrostis neglecta HH Callitriche autumnalis HH — verna H Campanula rotundifolia H Cardamine pratensis H Carex canescens G — dioica I Cochlearia officinalis HH Comarum palustre Cystopteris fragilis Dryopteris dilatata G Elymus arenarius Ch E3. European Species whose Northern Limit in West Greenland lies between 60° and 66° N. ar ee H. MØLHOLM HANSEN Empetrum nigrum Epilobium angustifolium Equisetum arvense Eriophorum polystachyum Festuca ovina = rubra Habenaria albida Hippuris vulgaris Honckenya peploides Juncus supinus Juniperus communis Limosella aquatica Lycopodium annotinum = selago Menyanthes trifoliata Montia rivularis Myriophyllum spicatum Pinguicula vulgaris Pirola minor — secunda Plantago maritima Achillea millefolium Agrostis alba — canina Anthoxanthum odoratum Atriplex hastata Betula pubescens Callitriche hamulata Capsella bursa pastoris Carex Goodenoughii — Lyngbyei — oederi — panicea — rostrata Catabrosa aquatica Cerastium cæspitosum Deschampsia flexuosa Drosera rotundifolia Dryopteris filix mas = phegopteris = pulchella Equisetum hiemale Epilobium palustre Geranium silvaticum Gnaphalium uliginosum Hezsmkmmmmsmsn ROSER m >= HH Th Poa pratensis Polygonum aviculare Potamogeton aipinus -- filiformis -- gramineus = pusillus Potentilla anserina Puceinellia retroflexa Radicula islandica Ranunculus acer = reptans Rumex acetosella Scirpus acicularis = ceespitosus Stellaria media Thymus serpyllum Triglochin palustre Utricularia minor Vaccinium uliginosum — vitis idæa Habenaria hyperborea Hieracium murorum Juncus alpinus — bufonius — filiformis Lathyrus maritimus Leontodon autumnalis Luzula multiflora Lycopodium clavatum Matricaria inodora Myriophyllum alternifl. Nardus stricta Poa annua — nemoralis Puccinellia maritima Rubus saxatilis Rumex acelosa — domesticus Sagina nodosa — procumbens Scirpus palustris — pauciflorus Sparganium affine Subularia aquatica STUDIES ON THE VEGETATION OF ICELAND 25 Ch Vaccinium oxycoccus H Viola palustris H Vicia cracca HH Zostera marina H Viola canina E2. European Species absent from Greenland but without any Nor- thern Limit in Scandinavia. H Agrostis tenuis H Milium effusum H Alopecurus geniculatus Th Myosotis arvensis H Angelica silvestris G Orchis maculatus H Aracium paludosum H Oxalis acetosella Ch Arctostaphylos uva ursi G Paris quadrifolia Athyrium filix femina H Parnassia palustris Th Cakile maritima H Pirola rotundifolia Ch Calluna vulgaris H Plantago major H Caltha palustris H Poa trivialis G Carex limosa Ph Populus tremula H Carum carvi HH Potamogeton perfoliatus H Deschampsia cæspitosa H Ranunculus repens Equisetum limosum Th Rhinanthus crista galli — palustre Ph Sorbus aucuparia — pratense Th Spergula arvensis Th Erysimum hieracifolium H Spiræa ulmaria Th Galeopsis Tetrahit. H Taraxacum vulgare H Galium boreale G Trientalis europæa H — uliginosum H Trifolium repens H Gentiana amarella H Triglochin maritimum H Geum rivale H Urtica dioica H Glaux maritima Th — urens H Hieracium silvaticum Ch Vaccinium Myrtillus G Hierochloë odorata Ch Veronica officinalis H Lathyrus palustris H = scutellata Th Melampyrum silvaticum H — serpyllifolia E1. European Species with a distinct Northern Limit in Scandinavia. H Agropyrum caninum Th Crassula aquatica G — repens H Epilobium collinum H Anthyllis vulneraria Th Erophila verna H Avena elatior H Festuca pratensis Blechnum spicant H Fragaria vesca H Brunella vulgaris H Galium silvestre HH Callitriche stagnalis H — verum Th Cardamine hirsuta H Gentiana campestris H — silvatica HH Glyceria fluitans G Carex glauca H Gnaphalium silvaticum H — paniculata H Hieracium Schmidtii H — pilulifera H Hydrocotyle vulgaris G Cirsium arvense H Juncus lamprocarpus 26 H. MOLHOLM HANSEN H Knautia arvensis Th Polygonum persicaria Th Lamium intermedium HH Potamogeton natans H Lathyrus pratensis Ph Rosa canina Th Linum catharticum Ch — spinossissima G Listera ovata HH: Ruppia maritima H Litorella uniflora H Sagina subulata H Lychnis flos cuculi H Sangvisorba officinalis Th Myosotis hispida Ch Sedum acre Th — micrantha Th Senecio vulgaris Th == versicolor Th Sisymbrium sophia HH Myriophyllum verticillatum HH Sparganium minimum Ophioglossum vulgatum H Succisa pratensis G Orchis latifolius H Valeriana officinalis H Phleum pratense HH Veronica anagallis H Plantago lanceolata H Vicia sepium Polypodium vulgare H Viola silvestris HH Polygonum amphibium Th — tricolor HH Zannichellia palustris. On the basis of particulars as to the proportion of each species in the floras of the above-mentioned countries, the Icelandic species were referred to one of the 7 species groups. While it is comparatively easy to place the species in the A or E groups, as this is only a question of ascertaining whether the main distribution of the species is above or below, north or south of three limits, the 20 °/o Ch bio- chore, a subdivision at the outset necessitates the selection of a pa- rallel of latitude, to the north of which the species do not occur. At each species group is stated the parallel of latitude selected as the upper limit of the species. In order to gain a comprehensive view of the extent to which it has been possible to gather the species into groups expressing adaptation to the arctic climate, the following conditions have been reviewed: — 1) The presence of the ‚species groups in the floras of the different countries, 2) the distri- bution of the groups in Iceland, and 3) the content of Raunkizr’s life forms in each group. I. In table 4 are given the individual countries examined, be- ginning with those that are most arctic in character, as Ellesmere- land, North Greenland, and Spitsbergen, and ending with the most temperate. In the first column is stated the number of species which the country in question has in common with Iceland. The next two columns state how many of these species, common to both, belong to the A- and E-groups, and the last columns give particulars of the sub-groups. ” STUDIES ON THE VEGETATION OF ICELAND À HI TABLE 4. Distribution of the Species Groups in Northern Europe and the Arctic Regions. |} n | A| E jas an ge E2 | EI | Bremereland.. . 3-1. Ss. er 55 45 | 10 || 43 2 » | 10 » Se: North Greenland 76°—83°—76° | 66 ee > » | 15 » | | > RS REF RENE SE ce nen 53 | 43 | 10 | 43 > » | 10 » > | West Greenland 66°—76°..... | 170 | 111 | 59|55 | 50 | 6] 57) 2| » | » East Greenland 60°—76° ..... | 177 | 117 60 | 53 | 46 | 18 | 44 | 150 055 meena oi. a | #231 51 1 2338 1923.17. HS BR) ma South-West Greenland 60°—66° | 228 | 121 | 107 | 50 | 49 22 | 53 | 53 | 1 a | 375 | 151 | 224 155 | 51 ! 45 | 57 | 53 | 53 | 61 nes... lee. 1919 | 73 | 146 | 27 | 21 | 25 | 45 | 38 | 29 | 34 Ss SEE Ir | 367 | 144 | 223 | 54 | 50 | 40 | 57 |52 | 53 | 61 eee Re SR se 363 | 141 | 222 | 52 | 49 | 40 | 57 | 51 | 53 | 61 rio | 344 | 132 | 212 | 52 | 45 | 35 | 57 | 50 | 53 | 52 SS eee de. | 304 || 86 | 218 | 28 | 32 | 26 | 56 | 50 | 52 | 60 0 ere PR 243 | 36 | 207/14] 8 | 14 | 52 | 49 | 48 | 58 1 SONORE | 231) 20211] 8| 5| 7|53 | 49 | 51 | 58 an else 1,238 |, 32 teeth SA 12, AO WAST S| is 60 The Baltic States ............ | 231 | 20 | 211) 6| 5| 9153) 50 | 53 | 55 North-East Germany ......... | 231) 15 | 216 | 3| 3) 955 | 50 | 53 | 58 In the countries north of Iceland it is especially the A species which constitute the greater part of the common species, and the farther north we go, the more numerous are the A 3 species. In the countries south of Iceland the reverse is the case; here comparatively the greatest number of the common species belongs to the E groups. In Scandinavia and Finland the proportion of the A groups to the E groups is approximately as in Iceland. The table shows the distribution of the species groups illustrated exclusively by the quantitative relation of the species to each other. The facts relating to the distribution would, however, appear much more distinctly if the frequency of the species in the separate coun- tries were taken into account, and a classification were worked out for Scandinavia. II. The Distribution of the Species Groups in Iceland. Below in table 5 the quantitative relation between the species groups has been calculated in per cent partly of the number of 28 H. MØLHOLM HANSEN TABEL 5. Distribution of the Species Groups in Iceland. n A E | A3 | A2 | A1 | E4 | E3 | E2 | El SOUDE APRES RARE | 28 | 78.6 | 21.4 | 57.1 | 10.7 |10.7117.9| 3.6| » sl IR | 20 | 85.0 | 15.0 | 65 0 10.0 | 10.0 | 15.0 » > ADDON ee | 281182.1 | 17.957.1| 14.3 |10.7114.3| 36| »| > ST EN RAT Le | 26188.5|11.51654|11.5|11.5|115| >| »| » LE TER | 65 80.0 | 20.0 | 44.6 24.6 | 10.8] 18.5| 1.5 il iat (EAT RE | 91] 73.6 | 26.4 || 35.2 | 25.3 | 13.2120.9| 4.4] 11] > BE Bree Saye sch: | 117 | 69.2 | 30.8 || 29.1 | 28.2 | 12.0 | 19.7} 6.8] 3.4] 0.9 Be OU) er es. 161 59.6 |40.4 23.6 24.8 11.2 18,6 13.0) 7.5) 1.2 ADD en eee eee NE) | 204 49.5 | 50.5) 19.6 20.1 9.8| 18.6 | 15.2| 13.7] 2.9 RE teen eet | 126 57.9 | 42.1] 21.4 | 25.4 11.1] 21.4) 14.3] 5.6) 0.8 MAR tee ie oe eos oe | 166 | 50.6 | 49.4 | 18.7 | 20.4 | 11.4) 19.3 16.3) 11.4) 2.4 East lceland. .......2...... 272 \45.2 54.8 16.5 | 17.3 | 11.4 | 16.9 | 17.3 | 13.2| 7.4 Northuleeland...2..2.0..0.%- | 331|44.4 | 55.6 16.3 | 15.1| 13.0 | 17.2 | 15.1 | 13.0-/ 10.3 VÆS BAT ODDER ee: 277 | 43.7 | 56.3] 15.5 | 15.9 | 12.3 | 18.1 | 16.6 | 14.4| 7.2 South-West Iceland ........ 314 | 40.4 59.6 | 13.7 | 14.3 | 12.4 | 16.9 | 16.2 | 14.0 | 12.4 South Iceland... ........... 309 | 39.2 | 60.8 | 13.9 | 13.9 | 11.3) 17.2 | 15.5 | 13.9 | 14.2 ee fe = 7 The highland tracts8—1200m | 40 80.0 20.0 57.5 12.5/10.0/ 15.0, 5.0) »| » — — — 3— 800 - 48.2 20.1 | 20.5 11.2|17.4|15.2|12.9| 2.7 The whole of Iceland ...... 375 | 40.3 | 59.7 | 14.6 13.6 | 12.0 | 15.2 | 14.1 | 14.1 | 16.3 bo Ra ps o — © 183.3 | 16.7 60.8 11.8 10.8) 14.7 20)» ane 162.2 | 37.8) 27.1 | 24.0/ 11.1) 19.1| 10.2| 7.1| 14 (152 152 12.1 | 17.2 | 16.1 | 13.7 | 10.4 | The highland tracts 8—1200 m | 102 — — — 3— 800 - | 638 The whole of Iceland ...... 1503 | 42.5 | 57.5 species, partly of the number of points 1) for the whole of Iceland, which means, practically, for the lowlands of Iceland, 2) for the highland tracts between the 300 and 800 m curves, and, finally, 3) for the highland tracts between the 800 and 1200 m curves. It appears from the table with all desirable plainness that the A group is best adapted to Icelandic conditions, considerably better than the E group. This is evident both from the values computed from the species figures and those computed from the points, but it is espe- cially evident on comparison between the percentages within the same altitude group. If, next, we consider the subgroups, the table shows a gradual adaptation to arctic conditions. E 2 and especially E 1 show the poorest adaptation, not even the lowlands seem to offer favourable conditions for the species of these two groups. E 3 thrives well here, STUDIES ON THE VEGETATION OF ICELAND TABLE 6. Quantitative Distribution of the Species Groups in Iceland. i ———— 29 | | The | | | | | | lentire| A | E | A3 | A2 | A1 JEA E3 | E2|E1 | flora | | number of species .. | ............ 375| 151| 224| 55 51) 45| 57| 53| 53| 61 East Iceland. ....... absent — |27.5|18.6|33.5/18.2| 7.8|31.1|19.3 | 11.3 | 32.1 | 67.2 | scattered-rare | 27.5 | 25.8 | 28.5 | 27.3 | 23.5 | 26.7 | 15.8 | 35.9 | 37.8 | 26.3 | common 45.1 | 55.6 | 38.0 | 54.5 | 68.6 | 42.2 | 64.9 | 52.8 | 30.2| 6.6 || rn t , es || BT | Te North Iceland ...... | absent ZU 17.9 | 15:8: 1.220) Lot » | 5.7 | 18.9 | 44.3 || scattered-rare | 40.8 || 37.1 43.3 | 40.0 | 25.4 | 46.6 || 36.8 | 37.7 | 49.1 | 49 7 common 47.5 | 60.3 | 38.8 || 58.2 | 72.6 | 48.9 | 63.1 | 56.6 | 32.1| 6.6 North-West Iceland . | . absent 26.1 | 19.9 30.4 | 21.8 13:72 244 1122327132245: 6722 | scattered-rare | 32.0 | 28.5 34.4 | 23.7 | 25.5 | 37.7 | 26.3 | 35.8 | 49.1 | 27.9 | common 41.9 |51.7 | 35.3 | 54.5 | 60.8 | 37.8 |61.4 | 51.0 | 26.4 5.0 South-West Iceland . | absent 16.3 | 15.9 | 16.5 | 21.8 | 11.8 | 13.3] 7.0! 3.8 | 17.0 | 36.1 | scattered-rare | 37.3 | 30.5 | 42 0 | 23.7 | 23.6 | 46.7 | 28.1 | 37.7 | 45.3 | 55.7 common 46.4 | 53.6 | 41.5 | 54.5 | 64.7 | 40.0 | 64.9 | 58.5 | 37.7 | 8.2 South Iceland ...... | absent 17.6 | 19.9 | 16.1) 21.8 | 15.7 22.2 | 7.0| 9.4 | 18.9 | 27.9 'scattered-rare | 37.3 | 27.8 | 43.8 | 23.7 | 23.6 | 37.8 | 33.3 | 39.6 | 45.3 | 55.7 common 45.1 | 52.3 | 40.2 | 54.5 | 60.8 | 40.0 | 59.6 | 51.0 | 35.9 | 16.4 | TTT 5-0. 0 absent 19.8 || 15.4 | 22.9 | 17.1 | 10.2 | 19.1| 9.1! 8.7 | 22.3 48.5 scattered-rare | 35.0 | 30.0 | 38.4 | 27.7 | 24.3 | 39.1 | 28.1 | 37.3 | 45.3 | 42.9 | common 45.2 | 54.7 | 38.8 | 55.2 | 65.5 | 41.8 | 62.8 | 54.0 | 32.5 | 8.6 but conditions even in the lower areas of the highland tracts are unfavourable to this group. For E 4 this is not the case until we reach the upper areas of the highlands. In the lower highland tracts this group even seems to thrive better than in the lowlands. The same is the case with the subgroups of A. A 1 is mainly indifferent though it occurs most frequently in the lowlands, A 2 exhibits the highest percentage in the lower highland tracts, but in any case finds the upper highland tracts unfavourable, while A 3 shows the absolutely highest percentage in that area. Between A3 as one extreme and E 1 as the other the remaining groups show a fairly smooth gradation. In Stefän Stefänsson’s »Flöra Islands« it is stated for each spe- cies with what degree of commonness it occurs in each of the 5 parts 30 H. MØLHOLM HANSEN of the country E., N., N. W., S. W., and S. Iceland. The designation algeng, hjer & hvar, or sjaldgæf after each species denotes whether the species is common, scattered or rare. For each of the 5 parts of the country have been added up the species of the respective groups 1) which are absent, 2) which are scattered to rare or 3) which are common within the area. The investigation has been carried out for the flora as a whole, for thé main groups, Å and E, and for the sub- groups under these two groups, and the result expressed in percent of the species number of the group in question has been given in table 6. The means for all parts of the country are given below in the table. The A group has more common species, less rare or absent species than the E group; while on an average 15,4 p. c. of the species of the A group are absent in each part of the country, the same figure for the E group is 22,9 p. c. For the commonly occurring species the proportion of A to E is as 54.7 to 38.8. If next we turn to the subgroups, the table shows that A 2 has the greatest number of common species, while A 3 and especially A 1 show a smaller number. Of the E subgroups, E 4 has the greatest number of common species, 62,8 p.c., E 1 the smallest number, 8,6 p.c. E3 and E2 occupy an intermediate position with 54,0 p. c. and 32.5 p. c. respectively of common species. The numerical values for the rarer and absent species entirely confirm the sequence. In addition the table shows the quantitative conditions of the flora and species groups in the 5 Icelandic areas. The A group occurs most frequently to the east and north, the E group to the south and south-west. In the A group this is due especially to A 2, in the E.group, to E2 and E 1. Aided by the above-mentioned tables we can now give the following description of the distribution of the Icelandic species groups in northern Europe and the arctic regions. The E group comprises species of common occurrence in Cen- tral Europe. The species have their main distribution to the south of or below the forest limit, the 20 p.c. Ch biochore. The various species, however, transcend this limit in varying degree in conse- quence of which the following 4 subgroups may be distinguished. E 1 requires the greatest amount of heat. In England, Denmark, northern Germany, and southern Scandinavia the E 1 species are of common occurrence. In Finland they only occur in the most southerly part, in northern Scandinavia only or principally on shel- STUDIES ON THE VEGETATION OF ICELAND 31 tered sunny slopes. In Iceland most of the E 1 species are rare, they only occur in the lowlands especially towards the south, and thrive best near the hot springs. E 2. Like the E 1 species, the species of this group are restricted to the lowlands in Iceland, and occur more commonly south of than north of the »jökull lines. However, these species occur more commonly than the species of the previous group. In Scandinavia and Finland they extend right up to the northern coasts, but none of them have reached Greenland. E 3. Like E 2 the species of this group have no northern limit in Scandinavia and Finland. In Iceland they are common lowland species which still thrive well in the lower zone of the highlands but disappear higher up; they occur commonly and with equal frequency in the various parts of the country. The species are found in South Greenland as pronounced southern types. 66° N. has been chosen as the northern limit of the group in West Greenland. E 4 is the subgroup which has most common species in Ice- land, and the species are of common occurrence right up into the upper zone of the highland tracts. In Greenland, too, the species are of common occurrence, some species even extend right up into North Greenland. The A group comprises arctic and subarctic species having their main distribution near, north of, or above the forest limit, the 20°/o Ch biochore. The species are common in Greenland, Spits- bergen, Iceland, and on the Scandinavian and Scotch mountains. In more southerly countries the species are either absent (and this applies to the majority), or they occur sporadically and in small quantity. A 3 comprises the species which extend farthest north in the arctic region and are therefore capable of withstanding the severest cold. In Scandinavia these species are confined to the most markedly arctie localities; in Iceland they are a characteristic feature of the upper highland zone. A 2 comprises most of the common species of the A groups in Iceland. The species of this group are more in evidence north of than south of the “jökull line” and seem to thrive better in the lower highland tracts than above and below. In Greenland these species are of common occurrence though they do not, like the A 3 species, extend into North Greenland. DØ H. MØLHOLM HANSEN A 1 comprises such species as must be termed arctic though they do not extend very far north in Greenland. Their northern limit in West Greenland lies south of 66° N. In Iceland the species are equally distributed through all altitude zones, though with a slight maximum in the lowlands. The A 1 species occur most com- monly north of the “jökull line”, especially in North Iceland. III. Investigation of the distribution of the species, partly in the North European and the adjacent arctic countries, and partly in Iceland, gave the result that the 7 subgroups show a fairly smooth gradation from A 3, which is adapted to the coldest conditions, to E 1, which requires the greatest amount of heat. The increasing adaption to arctic conditions may, however, be demonstrated in another way, too, viz. by a comparison of the individual groups with respect to their content of Raunkizr’s life forms. If the groups and subgroups express an increasing degree of adaption to the arctic climate, this must appear by the fact that that group or those groups which are best adapted to the arctic climate shows or show the greatest content of arctic life forms and fewest temperate life forms, whereas the reverse must be the case with the remaining groups. Against each species in the above list is given the life form of the species in question, and in table 7 are stated the biological spectra of the groups. According to Raunkiær (1908, 1912), Ch is the life form which is best adapted to the arctic climate, while H and G are indifferent, and Ph, HH, and Th are adapted to non-arctic conditions. By com- parison of the biological spectra of the A and E groups with the spectrum of the entire flora, it will be seen that the A group is more arctic in character, the E group more temperate in character than the flora as a whole. The subgroups under A and E bear the same relation to their respective main groups as these to the whole flora. The high HH percentage in E 4 and partly also in E 1 is however, worth noting. On reviewing the biological spectra of the various parts and zones of Iceland we saw that the Ch °/o was lowest (15 °/o) in the south country where the amount of warm water at the coasts was greatest, that it then rose gradually as the amount of Polar water STUDIES ON THE VEGETATION OF ICELAND 33 TABLE 7. The Biological Spectra of the Species Groups. Pt n Ph Ch H G HH Th be whole flora......... 1.4 349 el 152 52.4 10.6 9.2 alas EN (See 5.6 || 143 24 CHD 1053215 1122 22782 76:3 nice en: 8.7 | 206 1.9 7.3 | 51.9) 10.2 | 13.6 | 15.0 Ca | Ne; 3.8 53 » 30:27 52:37 7.1173 3.8 1.9 neun 4.0 50 > 26.0 52.0 10.0 2.0 | 10.0 ee 1225 40 | > 22:5 55.0 1275 2, ANSER | — -|| — || —— ——— - - L LORS SE SYET ss 11.8 51 sl 43.1 9,8 | 25.5 9.8 A RSS 10.4 48 2.1 6:37 56.3 | 12.5) 10.4 | 12:5 ER RER 8.2 49 4.1 200598 TOs 72220 16.3 7 | Der 589 5770 1 23.4. 30:0 8.6 | 15.5 20.7 at the coasts increased, and the amount of Gulf Stream water de- creased, towards the west and north, until it reached its highest value, 18 p.c. in East Iceland, at the same time as the Polar water became prevalent at the coast. This was the result round the entire coast, and on passing from the level of the sea towards the snow- line the Ch. percentage rose very greatly, from c. 20 p. c. at the 300 m curve to c.50p.c. at the snow-line, the 1200 m curve. If we examine the relations of the species groups under the same conditions, as done in table 5, we find a very close corre- spondence between the A percentage and the Ch percentage. If we proceed in the same way round the coast from South Iceland via W. and N. to East Iceland, the A percentage shows an unbroken rise from 39.2 p.c. in South Iceland, to 45.2 p.c. in East Iceland, and if we pass from the sea to the snow-line, the same fact appears. The A percentage for the whole country is 40.3, at the 300 m curve it is 49.5, rising to 80 at the snow-line. The table likewise shows the relations of the subgroups. The 20 p.c. Ch biochore seems to coin- cide with the 50 p.c. A biochore. Raunkiærs life forms and the phytogeographical spe- cies groups thus react similarly to the same external conditions. The species groups are, however, more sen- Sitive than the life forms. The Botany of Iceland, Vol, II. 3 IRZ/TYBES. OF ICELANDIC VEGETATIOZ dE types of the Icelandic vegetation, their floristic composition, and their distribution in the various parts of Iceland have been treated in a series of works by Chr. Gronlund (1887 and 1884), St. Stefansson (1895), Helgi Jönsson (1895, 1900, 1905 and 1913), C. H. Ostenfeld (1899 and 1905), Th. Thoroddsen (1914), and Ingimar Oskarsson (1927). In “The Botany of Iceland” 1914, pp. 317—343, Thoroddsen gives a general view of the types of Icelandic vegetation, attaching to each type a brief discussion of its floristic peculiarities. According to this the types of vegetation occurring in Iceland are the following: 1. The Vegetation of the Coast Line. a. Rock vegetation, b. fowling cliff vegetation, c. sand strand vegetation, d. salt- marsh vegetation. The Vegetation of Fresh Water. a. Vegetation of running water, b. of lakes and pools. 3. The Vegetation around Springs (the Dy Vegetation). 4. The Vegetation around Hot Springs. a. Around hot alkaline springs, b. around the solfataras. 5. The Vegetation on Wet Soil. a. Myri vegetation, b. flöi vegetation. 6. The Vegetation on Rocky Flats. a. On gravelly flats (melar), b. stone-covered ridges (holt), c. river gravel (urd), d. rocky boulders (hamrar), e. (eyrar), f. clayey flats (flag). 7. The Vegetation of the Mountain Slopes. Under this head come the herb slope and the herb flats. 8 Psammophilous Vegetations. a. Sand-covered tracts (san- dar), b. blown sand (dunes). 9. The Vegetation of the Lava Streams; in various stages of development. Do STUDIES ON THE VEGETATION OF ICELAND 35 10. The Grimmia Heath Vegetation. 11. Grassland. a. Grass slopes, b. knolly grassland (græsmo), c. dry uncultivated grassland without knolls (valllendi), d. the homefield ü(tn). 12. Heather Moors. 13. Willow Copses. 14. Birch Copses and Birch Forests. The principles on which the above classification has been based take account partly of environment and partly of purely phy- siognomic features. If, however, a biological point of view is adop- ted, it will be natural to continue according to the principles em- ployed above in the division of the Icelandic zones of altitude. In Ingimar Oskarsson’s paper on the vegetation and flora in Vestfirdir all the species noted are given under each type of vege- tation, and for each species its upper and lower limit. Table 8 below has been worked up from these data and gives both the spectra of the species groups and the biological spectra of the indi- vidual altitudinal zones for the whole area and, finally, for the individual types of vegetation. With regard to the altitudinal zones the table shows a steady decrease in the number of species from below upwards. The bio- logical spectra show a H percentage which is practically constant throughout all zones, but a steadily increasing Ch percentage and steadily decreasing Th, HH, and G percentages from the lower towards the upper zones. The corresponding change in the spectra of the species groups is an increasing excess of A, especially A 3, species, and a steady decrease of E species, the E1 species dis- appearing first, the E4 species last. All these facts are thus in close agreement with those stated for the whole country. — Only the po- sition of the 20 p.c. Ch biochore forms an exception since it lies considerably lower here. The vegetation spectra have apparently a very variegated ap- pearance. It is, however, possible to combine them to form several characteristic groups. Thus one group comprises the series melar — mo — herb flat, in which the melar vegetation has the highest A percentage and the lowest E percentage. The reverse is the case with the herb flats, while the mo occupies an intermediate position. Another group consists of the melar — mo — myri and fresh- water vegetations. Here the difference is that the melar has the 9 36 H. MØLHOLM HANSEN TABLE 8. Species Group Spectra and Biological Spectra of the Altitudinal Zones and Types of Vegetation in Vestfirdir (based on Ingimar Oskarsson’s lists of species (1927). n |A| E|A3/A2 Al|E4 E3 E2 E1lPh Ch H | G|HH/Th | = I Mi} ae | | Sale | | N) re 14\93| 7\50|43| »| 7 > | » | 43) 50 | 7 > » Se eee 3589| 11] 52| 34| 3] 9| 3) > |» | >|43/46| 9| 3] > DE LT ARTEN 741 68| 32| 27| 27| 14| 16| 14) 3 | > | >|31151114| 4] » BEDUOREN AL. 112151 | 49| 21| 19| 12] 22| 17 | 8 | 2| 1124 46158 5 VETO rn | 191 41 59|| 15| 14| 12| 21) 19/14 | 5 | 1117152115} 6) 9 ERA Ber Be een) bei Bei Ue Ves Bee | _ The entire area.. 212/44) 56) 16| 16| 11) 19) 18,13 5 | 1) 18/52/14) 7 | 8 Highland melar.. | 45 182 | 18] 42| 31| 9| 13| 4) > »/40 49 |11|.» | > Dwarf willow veg. | 27 70 30| 22| 41) 7] 19| 4) 7 |» || >|30/52|19| » | » Lowland melar.. | 82160 40| 22 23| 15) 17| 12) 5 | 6) 134/54, 9) > | 2 Heath vegetation. | 80/49| 51 | 11| 23 15) 20| 18) 11 | 313125 5418| >| 1 Mo vegetation ... | 73151 49| 15| 25 11) 18| 19 8 |4||»|22|56|14| » | 8 Myri vegetation.. | 6949| 51|| 19 | 19| 12| 25| 15 | 10 | 2 | >| 10|52)25| 9 | 4 Littoral meadow. | 20/50 | 50| 35| 5 10) 25) 25, > |» | »|10/60)15| > | 15 Grass-field veg... | 57/30/70) 7| 11| 12] 18| 25/19 | 9 | »| 12/60/12] » |16 Herb-field....... | 3132| 68) 10| 23| »| 23| 26/16 |3 | >119|61|16| » | 3 Bireli copse’. .....: 47\23| 77| A| 11| 9126| 28/21 2 |4/21/40/|30| > | 4 Freshwater veg... | 13| 8| 92| »| 8 »| 64/ 31| 8 | » | >| »115115]70 | » Hot springs ..... | 12] > 1100|) » | >| »,25|42| 8 125 | »| »167| 8| » |25 highest Ch percentage, the mo the highest H percentage, the myri the highest G percentage, and the freshwater vegetation the highest HH percentage. A third group is formed by the littoral vegetation, the grassfield vegetation, and the vegetation of the hot springs. These three types of vegetation are all characterised by a high H percentage and, in proportion to the other types of vegetation and to the area as a whole, an unusually high Th percentage. In the species group spectra, however, they differ essentially. Between the freshwater vegetation and the vegetation of the hot springs which both show an unusually high E percentage, there is a striking difference in the spectra of the E subgroups, the fresh- water vegetation having its maximum in E4 and the vegetation of the hot springs in E3. The deviation is, however, greatest in El STUDIES ON THE VEGETATION OF ICELAND 31 where the freshwater vegetation is not represented at all, while the hot springs have another maximum here. In a subsequent chapter I shall return to the vegetation spectra given in table 8. In this connection it will suffice to point out that it is probably the same forces, viz. differences of tempe- rature, which have been active in the formation of the Icelandic types of vegetation which have determined the floristic differences of the altitudinal zones. The factors especially causing differences of temperature in a given area of Iceland are partly differences with respect to the amount of snow and partly differences with respect to the amount of water. Hence the first task of an analyst of plant formations, after an examination of the vegetation at various heights above sea level, will be to investigate the influence on distribution of these two factors, and by this means attempt a grouping of the Icelandic types of vegetation. In the two succeeding chapters I shall therefore give a more detailed account of the results I arrived at on analysing the forma- tions on a journey in Iceland in the summer of 1925. In yet another chapter the influence on the vegetation of differences in snow-covering and the moisture of the soil will be more thoroughly discussed, and finally the results thus gained will be utilised in setting up the types of Icelandic vegetation which have, up to the present, been more thoroughly investigated. An analytical study of the formations has hitherto been carried out in 4 different places in Iceland, viz. on Lyngdalsheidi in Arness- sysla in the south country, partly at c. 100 m above sea level, and further at c. 250—300 m and c. 400 m above sea level; on Arnar- vatnsheidi near Ulfsvatn in the highlands northwest of Langjökull at c. 500 m above sea level; in the valley bottom at Lækjamôt in Vididalur in the north country, and in the valley bottom at Nordtunga in Borgarfjöröur in the south-west country. The investigation was carried out by means of Raunkizr’s circling method. With a few exceptions, 25 random samples from each locality, each of 1/10 sq. m., were analysed. I have not thought it appropriate to take into account other methods of analysis, partly because those which could here be considered are of a later date than Raunkizr’s circling method and to a certain extent resemble it, partly because, from a scientific point of view, they must be re- garded as retrograde. Up to the present, Raunkiær’s circling 38 H. MØLHOLM HANSEN method is the only method for investigation of the vege- tation which, in determining the quantitative distribu- tion of the individual species, makes use of the flora list principle, a principle which has always formed the basis of scien- tific plant geography, and which must also be adopted in the doc- trine of formations if this branch of botany is to lay claim to scientific equality with the other phytogeographical branches of the science. In naming the individual types of vegetation, I have used the Icelandic names and thus adhered to a custom often adopted in plant geography, that of retaining old names where such were found. At the same time reference of my own more thoroughly investigated types to the previous, more diffusely treated types of vegetation has been avoided, and this is in so far fortunate as it would seem that the latter have been determined with more regard to their physi- ognomy than to their environment. On the whole, however, the boundary lines coincide. Some of the names have already been used by Helgi Jönsson (1895); for those which do not occur in his paper I am indebted to the courtesy of Icelandic farmers or to Magister Pälmi Hannesson. IV. THE ICELANDIC LOWLAND FORMATIONS. A. LYNGDALSHEIDI. F from some elevated point, say Hrölfshölar or Thrasaborgir, (cfr. figs. 2 & 3) we try to get a general idea of the vegetation on Lyngdalsheidi, it will, at that distance, appear to us as an immense monotonous greyish green carpet sprinkled with smaller or larger patches of a yellowish or vivid green colour. These three shades of colour answer to the three most widespread types of vegetation on Lyngdalsheidi, viz. the mo, which forms the bulk of the vege- tation, the Grimmia heath, mosathembur, which covers the more prominent parts of the landscape as a yellowish carpet, and the snow patches, geiri, which form fresh green oases in the shelter of slopes and hills or in the old beds of rivulets. This is how the landscape appears in the vegetation period. Earlier in the year, e. g. at the close of the period when the snow melts, the mo and mosathembur vegetations have their natural co- lour, while the snow still covers the geiri vegetation. In winter the mo as well as the geiri vegetation are covered with snow, while the mosathembur vegetation is bare. Of less importance than these three types are a few other vege- tation types. Where there is a strong wind on the steeper parts, the vegetation and the layer of mould blow away and leave a soil covered with stones and gravel which forms the starting point for the melar vegetation. On the numerous small cones deposited by the little streams of melting snow, especially in Lyngdalen, but also on the flat parts ot the volcanic shield we find the valllendi vegetation, and on areas not sufficiently drained there occurs the myri vegetation. In the following we shall subject these 6 types of vegetation to a closer analysis. 40 H. MØLHOLM HANSEN The Mosathembur Vegetation. Cf. fig. 4, and table 9 A-B. On the more prominent parts of Lyngdalsheidi, from which the snow is at once swept away by the wind in the winter, we find the mosathembur vegetation developed. Even a long distance off this type of vegetation is easily recognisable by its yellowish hue. This colour is due to Grimmia hypnoides which covers the surface in a dense and deep elastic carpet. When the Grimmia heath is sufficiently large, the moss carpet is, as it were, split up into large tablets separated by systems of lines; the lines of one system as a rule converge towards a point in the lower edge of the moss carpet, another system forming larger or smaller angles with the first one. These lines do not extend into the surrounding mo, there we find the usual knoll formation. Table 9 A gives the circling results of the phanerogamous flora of the mosathembur vegetation. The five first columns represent TABLE 9A. The Mosathembur Vegetation on Lyngdalsheidi. 1—5 Localities in Lyngdalur, c. 200 m above sea level, 2/7 1925.06 10: Hrölfshölar 280-320 m above sea level, !/r 1925. 11 Thrasaborgir, c. 400 m above sea level, ”?/7 1925. (25. !/ıo m?) LOVES | 4. 5 6) 70,82 729275109 603 as] a | CAREX Tigre A3 G 96 88 84 96 96 48 36 56 44) 24 32 Salix herbacea......... | A’3 Ch || »/24| 4 4140 100 92 100 100 100 80 Besturarmubrai....uu 3. E4 H 56 28/44 56 | 56 >| 28| >| >| > Thalictrum alpinum ... | A2 H |72120136128148| »| »| 24| 4| 28] » Polygonum viviparum.. A3 G 8/20|12| »|28 | 32128! 32| 36| 48 || 8 Equisetum pratense... | E2 G 4116| »|20| 8) »| >| 28| 8] 4] » Armeria vulgaris ...... A3 Ch >| 4| 4| 8| 4) 4| 3| 20| 16| 12) > Silene acaulis ......... A3 | Ch |. >| 4| »| »|12| 4) 4] 8| 16) 20) > Empetrum nigrum..... E4 Ch >} »| »| »| 8| 8| 8| 8|12| 8| > Juncus trifidus ........ | A2 H >} >| »| >| 41 4| 8| »| 8| Al > Galium Normanni ..... | aı | H | 8| 4] >| >»[22| >| 2] >| 2] oo Cerastium alpinum .. A3 Ch SNA >| >| 12]. | 9 | ee Fesfuca >| >) >| >) A2 Luzula spicata......... | A2 H > | >| »| »|12| » | >| >| #10 Vaccinium uliginosum . | E4 Ch >) al >! 2] >| >| | A Equisetum variegatum . A3 H 116 | BES BETEN Be | >| >| "ol Rumex acetosa ........ E3 H > | ler > I sl:» |. 1402108 | > Agrostis canina........ E 3 H »| >| »| >| 4) »|.> pl ee ||| STUDIES ON THE VEGETATION OF ICELAND 11 TABLE 9B. Biological Spectra of the Mosathembur Vegetation. 1—11 correspond to 1—11 in table 9 A. 1 2 3 4 5 6 7 8 9 10 11 Pormts sum"... - 268 | 212 | 192 | 212 | 344 || 208 | 184 | 304 | 268 | 256 | 120 Number of species 8 10 8 6 14 9 7 9 14} il 3 Density of species | 2.7| 2.1| 1.9| 21| 3.4| 21|j 18) 30| 27} 2.6] 1.2 2 See eee 77.6 79.2 72.9 64.2 77.9 94.2 95.7 78.9 89.6 93.8 100.0 So Se ac 22.4 | 20.8 | 27.1) 35.8| 22.1] 5.8| 4.3) 21.1) 10.4| 6.3] 0.0 Beet... le. 47.8 67.9 54.2 50.9 55.8 92.3 91.3 71.1 80.6 79.7 100.0 EEE 26.9| 9.41 18.8| 13.21 18.61 19| 43! 7.9|. 9.0. 14.1 2 EST 30 9 > » 3.5 > > > Een 20.9| 13.2) 25.0| 26.4| 18.6) 5.8) 43) 11.8] 7.5| 4.7 > 2 SRE eee » > > > 1.2 > > > > er 1.5) 7.51 2:1) 9:4) 724 mt 19:2) 3101" 1-6 E 1 ss... 2 > > » > » > > > > D 3.0| 17.0 4.2) 5.7| 22.1) 57.7| 60.9| 44.7| 58.2 | 54.7 66.7 Se 56.7 | 24.5 45.8 39.6) 39.5 38 43 17.1 9.0| 15.6 > 0. 40.3 58.5 50.0 54.7 38.4 38.5 34.8 38.2 32.8 29.7 33.3 CE REPARER RP > > » > | > » » > > » y Be. er > » > | » » > > > | > > mosathembur in Lyngdalur c. 200 m above sea level, 6—10 that of Hrölfshölar c. 300 m above sea level, and No. 11 that of Thrasa- borgir at a level of 400 m. The phanerogamous vegetation is poor in species and open. In 2.5 sq. m on an average c. 10 species will occur with a density of 2—3. Biologically the mosathembur vegetation is remarkable by its high percentage of arctic, particularly high arctic, species, and more especially by its high G percentage. In Lyngdalur, cf. Nos. 1—5, it is H and G that predominate, while Ch is of minor importance. Here the dominant species are Carex rigida, Polygonum viviparum, Thalictum alpinum and Festuca rubra. Higher up, at Hrölfshölar, H gives place to Ch. Here Salix herbacea is the most frequently occurring species. Everywhere throughout the moss carpet this plant sends up the tip of a branch bearing two or three leaves, while the rest of the plant is buried 42 H. MØLHOLM HANSEN in the moss. Other species met with are especially Carex rigida, Polygonum viviparum, Silene acaulis, Armeria and Empetrum. Pro- ceeding still higher, Salix herbacea is the only more conspicuous phanerogam in the moss carpet. At its lower limit the mosathembur vegetation passes over into the Elyna mo. Above we have described the appearance and composition of the mosathembur vegetation on Lyngdalsheidi. If we enquire into its occurrence in other parts of Iceland, we find it described by Helgi Jönsson for East Iceland (1895, p. 70), for South Iceland (1905, pp. 40—42), and for Snæfellsnes (1900, p. 68 and p. 85). It is most abundantly developed in East Iceland where it covers large stretches of the mountain slopes in several of the fiords, and it is particularly well developed at high levels. In South and South-West Iceland it does not occur so plentifully, and apart from the lava fields, covers only small areas. Its appearance and composition, how- ever, are in close agreement in the various localities and correspond to what was given above for Lyngdalsheidi. In North Iceland and the highland tracts the mosathembur does not seem to occur as a stable typical vegetation. Ostenfeld does not refer to it in "Skildringer af Vegetationen i Island” III—IV (1905) either from Vestfirdir or from Melrakkasljetta. Personally I have looked for it in vain in Hüna Fléi, in the highlands at Arnar- vatnsheidi, and on Holtavöröuheidi. Typical mosathembur was not seen in any of these localities; it had been replaced by the melar vegetation. The moss mo observed by St. Stefansson on Grimstungnaheidi which “should most probably be understood as a transitional form between heather mo and pond vegetation’, the surface being uneven, more or less tufted, and the soil moist, at any rate in the first part of the summer, must not be confused with the mosathembur vege- tation which only occurs on the relatively dry stretches. Thus, the mosathembur vegetation in Iceland seems to be pe- culiar to the higher levels of the rainy and foggy east, south, and south-west country, that is to say, the coun- try south of the jökull line. North of this line, where the cli- mate is more continental, it does not occur as the typical vegetation, being replaced by the melar vegetation here. If we enquire into its distribution in the surrounding countries, we find it developed both to the north and to the south. Kolderup STUDIES ON THE VEGETATION OF ICELAND 43 Rosenvinge records a moss heath from South Greenland (1896, pp- 211—214) which, on p. 214, he refers to the Icelandic Grimmia heath. On the distribution of the moss heath the author writes on p. 213, “All the aforementioned localities are situated in the coastal area or not very far from the coast, whereas I have never observed such moss heaths in the interior.” The most northerly moss heath is recorded from Marrak (63° 25’ N.). In East Greenland and far- ther north in West Greenland moss heath does not seem to occur. Ostenfeld records Grimmia heath from the Faeroes (1906, pp- 116). Here it is peculiar to high mountain plateaus and is most abundantly developed in the northern islands. “It is a forma- tion which seems peculiar to an insular and chilly climate” (p. 117). From the higher regions of the Scottish mountains a Grimmia heath of identical appearance and composition is recorded in Tans- ley’s Types of British Vegetation, 1911 p. 211. In Scandinavia the Grimmia heath seems to have been replaced by the Lichen heath. It holds good of the geographical distribution ofthe Grimmia heath as of its distribution in Iceland that it coincides with the position of the 20°/o Ch biochore, and is peculiar to areas with abundant rainfall. The Melar Vegetation. Cf. fig 5 and table 10 A-B. In the most exposed parts of the Grimmia patches the erosion of the wind in the rents of the moss carpet may often be observed. The single stems of the moss are loosened and carried away to- gether with the layer of mould below. The erosion spreads both downwards and round about in the adjacent parts. Its downward action does not stop until the whole surface is paved with the scattered stones dispersed in the layer of mould. In the adjacent parts there is probably no limit to the activity of the erosion. When the mosathembur vegetation has been blown away, the wind works in the same way on the surrounding mo. Consequently large areas of the most exposed parts of Lyngdalsheidi are swept bare of vege- tation, especially around Hrölfshölar and Thrasaborgir. These de- nuded areas, often termed “fell field” in phytogeographical literature, are called “melar” in Icelandic. It is peculiar to melar in contrast to other types of vegetation that it is the colour and appearance of the soil rather than the vegetation that determine the physiognomy of the landscape. Ac- 44 H. MØLHOLM HANSEN cording to differences with regard to exposure, snow-covering, moisture of the soil, and age of the area, there seem to be differ- TABLE 10. The Melar Vegetation on Lyngdalsheidi. Localities 1—7 are situated round Hrölfshölar at about a height of 250 m above sea level. 1—2 examined on !?/7 1925, 3—6 on ??/r, and 7 on °/7 1925. (255 4/40 m7). foe are | 5) |; Polygonum viviparum... | A3 G 76 84 | 68 | 60 80 68 Aprastis.eanina ...2..... E3 H 6022687 112201 <8.) 24 60 88 Salıx lrerbaccasean. ra: A3 | Ch | 24 | 60 | 64 | 16 » 8 64 Bestneagrubrar. "7"... EAN EEE 527015209 400102001936 84 44 OVID ANS LEE E4 | -H 24 | \64-)'.52 | 56 | 20 32 | 44 Empetrum nigrum...... ea Gh. ||) 29) 682-28 » | > | 100 | 92 Jumeustrifidus........,.. I EN Hr | 44 | 56 ! 56 | 16 4 40 : 36 Thymus serpyllum ...... iE ct 20 M66 |) 46 4 | 20 12 | 76 Luzula spicata .......... A 2 H | 36 | 36 | 40 | 24 | 24 » | 24 Loiseleuria procumbens.. | A2 Ch, ||.» 1.980) >>| , »*. >) ODDE Dryas octopetala........ | Ad | Ch | 8 40 AX) fey 20 56 Cerastium alpinum...... | A3 | Ch | 36 8 36.| 24°) 16 100 4 Armeria vulgaris........ RAS Sch a War Fan eat Ze Silenevacanlis zen, A3 Ch | 16 24 16 | 12 20 » | 16 Atrial Simp etice aun eerie ite | Al Ch Sul 24200 20 24 » » Cassiope hypnoides...... A2 Ch er) | > I 32 | 20 Alchemilla alpina ....... A2 Ch || » su ae lo er 12 Bartschiasalpina......... A2 ENS » | 4 | » | > AS (CÉRÉMONIE Ce ee: A3 (Ge Es 4 | » 2 > » TES Deschampsia alpina ..... A 2 H | | 4 SAME > | Bees — flexuosa.... Eo H | » » » » » 8 32 Elyna Bellardi.......... GAGS HER > DENT » | 20 Equisetum variegatum... | A3 H > es) » » 3 aes 4 Galium boreale ......... | E2 H I er ea: » >) > » | 20 — NOrmaAnnI. ...... | Al jai I Oe » | > » 64 — VER ENE ef | E1 H > ee yea) > sea Luzula arcuata.........% | A3 HA 70e | 24 241 0 > ASS Pingvicula vulgaris ...... INGE A 2 SEI ee > 12 yall es » ES Poasglauca@ er A3 H | 4 » 16 » 4 » » Bumexsacetosatrrag erne E 3 H | » 4 > 8 » » Salıxsslan came mega A3 Ch ees | © | 8 » > » 4 Saxifraga hypnoides..... Al | Gh » » » > 8 a) Selaginella selaginoides .. A Come » » > » ke Silene maritima......... | A in Ws sx ies » 4 » Le; Tofieldia palustris....... N ge LE 52] I | Po ko > ye Trisetum spicatum...... | A3 He supe ls «4 » » » » | 203 Vaccinium uliginosum... | E4 | Ch | » 4 » » » 28 24 TABLE 108. STUDIES ON THE VEGETATION OF ICELAND 1 2 3 4 5 6 7 SPORES SUM ois cross ss ae 412 692 580 320 220 688 940 Eirsmber of species... ....- 14 20 22 15 13 14 29 Density Of SDECIES.......... 4.1 6.9 5.8 3'2 PER, 6.9 9.4 REE OP AE 62.1 56.6 75.2 72.5 | 50.9 52.9 54.5 EN PN 37.9 43.4 24.8 27.5 49.1 47.1 45.5 ET TON See Gear 40.8 32.9 52.4 50.0 23.6 PT (oS 28.5 2 LS pelo ois s'dis-clsers, © anaraeie.e 19.4 19.7 19.3 15.0 107 25.6 17.4 a D3 OSes 1.9 | 4.0 3.4 179 14.5 » 8.5 ers 'e aj sae ale a she sites une 23.3 33.5 Dell 25.0 34.5 aia 29.8 LE: Le SR EN 6 vero: Re 14.6 9.8 2 € 25 14.5 9.9 12.8 RS dan so see >. » > » > » PE] u ees Sistas > | > » > > 0.9 nee conso e 28.2 | 45.1 42.8 31.5 45.5 55.2 47.3 ee eens 53.4 | 42.2 45.5 43.8 54.5 33.1 44.6 ee EEE 18.5 | 1257 313157) 18.8 > 11.6 8.1 HH else unless @ 610 6 set. « © 0.8 6, 0e, > > » > > > » nus > > > > > > > Biological Spectra of the Melar Vegetation. 45 ences in the vegetation, but owing to the small part played by the vegetation in the appearance of the landscape it is difficult to form an idea as to how much this is the case. It is easiest to ascertain the connection between the vegetation and the age of the area as melar soil. On recently denuded patches hardly any plants are seen, whereas a good deal are seen to have immigrated at a somewhat later stage. Fig. 5 shows such a melar vegetation near Hrölfshölar, and table 10 A 1 and 4—5 give the circling results for this and similar localities on Lyngdalsheidi. The density of species is still rather low, 2—4, in spite of the comparatively high number of spe- cies, c. 15. Of life forms H and Ch are almost the sole prevailing ones. The most conspicuous species are Thymus serpyllum, Salix herbacea, Armeria, Silene acaulis, Cerastium alpinum, and Arabis petræa; of herbaceous plants Juncus trifidus, Luzula spicata, Poly- gonum viviparum, Agrostis canina, Festuca ovina, and F. rubra are met with. On still older stretches of melar not only the vegetation but also the character of the soil have undergone change. The soil 46 H. MØLHOLM HANSEN owing to the fact that polygon-formation and solifluction are be- ginning to be prominent. The vegetation appears changed not only because species already present occur with greater frequency but also because new species have been added. The number of species has almost been doubled, the density has increased from c. 2—4 to c. 6—9. In table 10, 2—3 and 6—7 show the composition of the species on older, more stable tracts of melar. The increase falls especially to Ch. Of new species we may particularly mention Dryas octopetala, Empetrum nigrum, Cassiope hypnoides, Loiseleuria procum- bens, Luzula arcuata, and a number of mo plants. Dryas octopetala only occurs in melar on Lyngdalsheidi, not, as is the case in the highlands and the north country, in mo. The presence of Loiseleuria and Cassiope would seem to show that the localities referred to not only differ from the abovementioned in age but also by being more snow-covered in winter. On Lyngdalsheidi the melar vegetation is not very widespread, at any rate compared with the mo. In other parts of Iceland, how- ever, it plays a prominent part in the physiognomy of the land- scape, not only in the lowlands where it occurs in greatest quantity near the sea, but also and especially in the highlands where the country for miles is covered exclusively with the melar vegetation. At the higher levels it is almost the sole prevailing vegetation. The melar vegetation or fell field is an arctic type of vegetation and has its greatest distribution north of Iceland, though it occurs at high levels in the Faeroes, Scotland and Scandinavia. In spite of the great physiognomic differences be- tween the melar and the mosathembur vegetation, the two types must be included in the same class, charac- terised with regard to environment by not being covered with snow in the winterandbiologicallybythecompara- tively great quantity of Ch and A species, especially A3 species. Both types have their main distribution in arc- tic regions about, above, or north of the 20 p.c. Ch bio- chore. The two types show a striking difference in re- gard to their biological spectra, the melar vegetation having a comparatively high H percentage and a low G percentage, the mosathembur vegetation a high G per- centage. STUDIES ON THE VEGETATION OF ICELAND 47 The Mo Vegetation. Figs. 6—7, table 11 A—B. The mo is the type of vegetation which occupies the largest area of Lyngdalsheidi as well as in the rest of the Icelandic low- lands. The term mo as used here includes all such for- mations as are normally covered with snow in the win- ter, whose degree of moisture is exclusively determined by the precipitation, not by the ground water, the soil of which is not in motion, uncultivated, and not covered with forest or copsewood. Thus defined, mo comprises the following of H. Jonsson’s formations: heath, heather mo, grass mo, dwarf willow (in part), and grass-field (in part). The soil of the mo is always more or less covered with knolls as shown in fig. 6. According to the inclination of the surface some differences appear which do not, however, seem to be of great im- portance in their bearing on the vegetation. Where the surface is level or slightly inclined, the knolls are almost polygonal, half a metre high and broad, and separated from each other by narrow furrows. Where the soil is more inclined, the knolls grow smaller and arrange themselves in longitudinal rows parallel to the edge of the slope. The form of the knoll undergoes a change, not only in that it becomes more elongated, but also because it begins to move downwards. This occurs by a displacement of the material of the knoll itself, apparent by its bulging in the middle of the more or less vertical side facing the valley, and becoming flattened on the upper side. Sometimes the upper side is bare, devoid of vegetation. If all the knolls become flat and bare on the upper side, and out- wardly delimited by a vegetation curve, we get typical solifluction, which is especially well developed on melar in the highland tracts. If the slope becomes still steeper, the solifluction will assume the character of a landslip. Then it is no longer the single knolls but the substratum that slips, and in consequence the vegetable covering may be preserved intact. Such landslips were observed in the highest stage of development in the highlands and the north country. Since the mo forms the bulk of the vegetation as a feature of the landscape, it is obvious that forms transitional between the mo and the other types of vegetation must occur. In table 11, Nos. 1—5 represent the typical mo, No.6 is a transitional form between mo and mosathembur, No. 7a transitional form between mo and jadar, 48 H. MØLHOLM HANSEN TABLE 11. The Mo Vegetation on Lyngdalsheidi. Localities 1—7 situated in Lyngdalur c. 200 m above sea level. 8 between Hrölfshölar and Thrasaborgir c. 300 m above sea level (cf. table 13, 9). 9 on Thrasaborgir c. 400 m above sea level (cf. 13, 10). 1—5 and 8—9 represent the typical mo vegetation, 6 a form transitional between mo and mosathembur, 7 a moist mo. 1-6 examined on ”%/7 1925, 7 on 23/7 1925, and 8—9 on 77/7 1925. (25. ?/ıo m°). 1 | 221-841 2.1.5) Oh TE 72 | 76 | 72 | 92 | 56 | 68 | 64 | 96 |96 Salx her DACeA EE EE | A3 Ch Empetrum nigrum..... E 4 Ch | 80 80 84 | 96 100 | 64 | 92 | 36 | 84 Polygonum viviparum . A3 G 92 | 64 | 96 | 84 | 92 | 56 | 96 | 80 | 96 HÉSincasrubra 222... E 4 H 92 80 96 100 96 84 92 88 84 Agrostis canina......:. E3 H 80 84 88 92 100 60 100 100 84 Deschampsia flexuosa.. | E3 H | 56 | 60 | 72 | 60 | 72 16 | 60 | 76 | 52 Carex rigida........... A3 G 92 84 88 100 64 84 96 84 80 Juneusktriidus........ A2 H | 68 | 60 48 | 56 | 48 | 20 | 56 | 64 | 20 Luzula spicata......... A 2 H | 32 | 56 | 56 | 60 | 48 | 60 | 48 | 40 | 8 Galium boreale …. E2 | H |72|60 80 |76 | 76| 4 | 80 | 92 |56 ==) Normann Al H 72 | 68 80 | 88 | 76 | 56 | 76 | 84 32 Selaginella selaginoides. | A1 Ch | 52 | 56 | 84 | 88 | 48 | 4 | 80 | 40 |20 Equisetum pratense ... | E2 G 40 | 56 96 | 36 | 24 | 40 | 28 | » | » — variegatum. | A3 | H 36 | 16 |1ı2| 8| 4] 16/12] 8 |48 Thalictrum alpinum ... | A2 H |36 | 16 | 20 | 44 | 12 | 40 | 64 | 52 |68 Silene acaulis ......... A3 | Ch | 28 | 32 | 32 | 20 | 16 | 12 | 24 | 20 | 24 Thymus serpyllum..... E4 Ch | 24 | 40 | 64 | 60 100 | 8116) >| » Cerastium alpinum .... | A3 Ch 12 |16 | > |36| 8.|32 |») ums Trisetum spicatum .... | A3 H 20 | 24 | 36 | 60 | 36 | 4 | 28 | » > Festuca ovina......... | E4 H | 16 | 28 | 28 | 52 | 56 | 32 | 60 | 4/ 8 Agrostis tenuis ........ | E2 H sal nd) Ted a 4 | > >» | » | 4 Cardamine pratensis... | E4 H | 48 | 24 | 12 | 32 | 12 8|48| »| » Vaccinium uliginosum . | E4 H | 4 » 8 | 16 | 44 | 122100 nIRS Elyna Bellardi ........ | A3 | H | 12 | 52 | 28 | 20 » | >| » 1.548 Anthoxanthumodoratum | E3:| H | 2224 > 4| 32 | » 8 | eat) Poa glaces de 1.4250 | A3 | H |28|20| 8|28| 20120 | 4) » | >» Pingvicula vulgaris .... | EH | 4 | > 8 | 24) 4 | » » » | » Galitimverum.-.-".. 1 eal H | 16 | 16 8 8 | > > ae: Arctostaphylos uva ursi | E2 Ch | ) » > 4 | » > | : | Armeria vulgaris ...... | A3 Ch | » De eal » | 12 » | 4] » Botrychium Lunaria... | E4 G | 8 | 4 > » | » Calluna vulgaris....... | E2 Ch | 4 | 4 > A orale | ANER Carex sparsiflora ...... | Al G | 4 | 4 > > > 112 | »| > Cerastium cæspitosum . | E3 Ch | > » » > | » > | 42 Deschampsia caespitosa, | E 2 | H | > | 4 | » | 4 | 28 | » | » Equisetum arvense .... E 4 Ge 9) BSS 071720 | » | 40 | 12 | » |12 — hiemale .... ES WIDE DE LE 2 8| > | 2 | RE Euphrasia latifolia..... ADS et A | Sh An » | | | | | STUDIES ON THE VEGETATION OF ICELAND TABLE 11A CONTINUED. 49 1 2 3 4 5 6 ii 8 9 E ren ——— = Geranium silvaticum... E3 H ’ 4 4 » > JA NÆR Gnaphalium supinum .. A2 Ch » > 2 > > > Pas Habenaria hyperborea . E3 G 4 » > > > sr Loiseleuria procumbens A 2 Ch » » | » » > » | >» | 40 Luzula multiflora ...... E 3 H > a sy Paley CNE Bekalpına 2... 2.5... yr TI » ARS > he ey > Potentilla verna ....... INDE NW val > | | 4 > >|. 8 | > > Ranunculus acer....... | E4 | H 4 > ae) | 4 » > | 4] > Rues acetosa .......- | E3 H 8 > AMG = 012 >| » | 4 Belsrolauea- 2... ce A3 Ch > 4 > 4 À > » | > ee Ady | Ch ER ae 8 | > — phylicifolia ...... Al Ch » DESERT >| 24 | > Taraxacum officinale... E2 H Al 3 | ES » | 12 | > Tofieldia palustris ..... A 2 H » > » | del» > > | SY a Magia canina. ::........ E3 H |) 16) 1212 > » > 2.194 3° | — palustris ........ E3 H 8 » > »| 8 » | 20] >|» Viscaria alpina ........ | A2 H > en Pe: ate | » > > | » | > TABLE 118. Biological Spectra of the Mo-Vegetation. I | i | | | | 1 2 | 3 | 4 | 5 | GNT | 8 | 9 BES ee | | Points sum ......... 1240 | 1232 | 1344 | 1524 | 1304 | 860 | 1384 | 980 | 944 Number of species .. | 35 31 3371,38 35.210 27.11.82 | 200 24 Density of species... | 12.4 | 12.3 | 13.4 | 15.2 | 13.0 | 8.6 | 13.8 | 9.8 | 9.4 a | 52.9 | 52.5 | 50.3 | 53.8 | 41.1 | 56.7 | 50.6 58.7 57.6 fo RE | 47.1 | 47.4 | 49.7 | 46.2 | 58.9 | 43.3 | 49.4 | 41.2 | 42.4 ER PORTE 31.6. 315° 27.7 | 30.4 | 20:5. || 85.3) 17234. || 30.2) || 36.4 a | 110 | 10.7| 10.1 | 115 | 8.9 | 14.4 | 12.7 | 15.9 | 15.7 D 25550 > e. | 103 | 104 | 125 | 118 10.7 | 7.0 | 14.5 | 12.9 | 5.5 a) ae BD ar hss aa 4) 21,9 “ 21,3 22.6 | 26.8 | 31.9 | 27.4 ! 24.0 | 13.5 ! 20.8 IT 13.5 14.9 13.1 11.5 18.1 | 10.2 14.7 | 18.4 | 14.8 CANNES 103 | 101 | 134! 79 | ss| 56 | 107| 94 | 64 ATEN > o> <0 1.3 1.3 0.6 > 0,6 > » | > | 0.4 ere NEN 22,3 | 25.0 | 25.9 | 28.1 | 30.4 || 23.3 | 23.1 | 20.8 | 29.7 Lo rer skønne 59.0 | 57.5 | 52.7 | 55.6 | 55.2 | 50.7 | 59.2 | 62.4 50.0 schau 18.7 Mp 1721413 15,7 13.8 | 25.6 17,6 | 16,7 | 19,9 | | | A > 3 ; > 2 > | > | » » area 3 » | 03| 05| 061 05 » | > |. 04 The Botany of Iceland. Vol, III, 4 50 H. MOLHOLM HANSEN and finally, $—9 are the mo vegetation at a somewhat higher level above the sea. The mo vegetation is very rich in species, in 2.5 sq. m. there occur on an average 35 species of phanerogams or c. 10 p.c. of all Icelandic phanerogams. For the typical mo on Lyngdalsheidi the density of species is 12—15. The biological spectrum shows that H forms the bulk of the vegetation, constituting 50 —60 p.c. of all the species noted. The Ch percentage is 25—30, the G percentage 15—2. Th occurs very sparingly. The proportion of the two spe- cies groups A and E is as 1 to 1. As far as the floristic composition is concerned it is difficult to point out one or more species that are physiognomically dominant, and in that respect the knoll formation is most conspicuous. Of chamaephytes Salix herbacea and Empetrum nigrum are most important, species such as Thymus serpyllum, Silene acaulis, and Cerastium alpinum being less conspicuous. The other Salix species, such as S. glauca, S. lanala, and S. phylicifolia are practically of no consequence, and the same is the case with Vaccinium uliginosum — this species occurs principally in mo which adjoins geiri, as shown in table 11, 5. Calluna vulgaris and Arctostaphylos uva ursi only occur in some few specimens in the mo round Lyngdalur; further down, at the foot of Lyngdalsheidi, both species were phy- siognomically predominant in the mo, whereas they were only found in the geiri in Lyngdalur. Loiseleuria procumbens only occurred sporadically; higher up, at Thrasaborgir, it was considerably more frequent. Of herbaceous plants Polygonum viviparum, Galium bo- reale, G. Normanni and Thalictrum alpinum are most important, a few other species occur more sporadically, particularly Cardamine pratensis. It is, however, grasses or cyperaceous plants that dominate, such as Festuca rubra, F. ovina, Agrostis canina, Carex rigida, Juncus trifidus, Elyna Bellardi, Luzula spicata, further Deschampsia flexuosa, Trisetum spicatum, Anthoxanthum odoratum, and Poa glauca. Of vascular cryptogams Selaginella selaginoides, Equiselum pratense, and E. variegatum are most frequently met with, while Botrychium Lu- naria and a few other Equisetum species occur now and again. The typical mo on Lyngdalsheidi is thus characterised by a long series of species, each species occurring with a mean frequency characteristic of the species in question (mean F.-percentage) from which value the individual occurrences deviate but little. In table 11, STUDIES ON THE VEGETATION OF ICELAND ul 1—5 show what species are characteristic of the mo, and the F.- percentage of the individual species. Passing from the mo to one of the vegetation types previously mentioned, a transition zone will often be met with in which the frequencies of the species have undergone great changes. In table 11, 5, 6, and 7 show such transition zones passing into geiri, mosathembur, and jadar respec- tively. A comparison of these zones, on the one hand with the mo vegetation, on the other with the respective types of vegetation, will show that statistically, biologically and floristically, the zones occupy this intermediate position. No. 5 shows the transition from mo to geiri. The geiri plants Vaccinium uliginosum, Luzula multiflora, and Anthoxanthum odoratum show a comparatively high F.- percentage, while a mo plant Elyna Bellardi is inconspicuous. The proportion of A and E species points in the same direction. No.6 is a transitional form between mo- sathembur and mo. A number of species which occur commonly in the mo, only appear sporadically here: this is the case with Deschampsia flexuosa, Galium boreale, Selaginella selaginoides, Thymus serpyllum, and Trisetum spicatum. The density of the species is ap- preciably diminished, being 8.6, and the character of the environment more arctic. The G percentage is comparatively high. No. 7 is the moist mo which forms the transition to the jadar vegetation. Most of the plants of the mo recur with the same F.- percentage, a number of jadar plants such as Deschampsia ceespitosa, Luzula multiflora, Salix phylicifolia, Viola palustris, Cardamine pra- tensis, and Taraxacum officinale begin to thrive better. Nos. 8—9 are typical mo at a somewhat higher level, viz. 300— 400 m above sea level. The vegetation has assumed a more arctic character. Salix herbacea is beginning to predominate in the phy- siognomy of the vegetation. As previously indicated, the mo is the most widely distributed type of vegetation in the Icelandic lowland where it probably com- prises a fairly large number of formations. It must be left to future plant geographers to classify and characterise these formations with regard to environment, biology, and flora, and to correlate them. The Jadar Vegetation. Between the mo, whose degree of moisture is exclusively de- termined by the precipitation, and the myri, whose degree of moisture is determined, in addition, by the ground water, there occurs a belt 4* 52 H. MØLHOLM HANSEN TABLE 124. The Valllendi Vegetation on Lyngdalsheidi. All the localities examined were situated in the upper part of Lyngdalur at the foot of Hrölfshölar c. 200 m above sea level. 1—2 Salix-valllendi, 3—6 Deschampsia caespitosa-valllendi. 1—2 examined on ””/7 1925, 3—6 on “6/7 1925, (25. 1/10 m?). 1 2 3 4 > 6 Dalixwlanatar aici: 2202 Al Ch 72 36 > > > — phylicifolia........ Al Ch 60 64 > Vaccinium uliginosum ... E 4 Ch 44 12 > > » Agrostis tenuis.......... 12 H 4 56 100 96 100 96 Besturarrubra.. Le - E 4 H 96 88 92 96 96 100 Deschampsia caespitosa.. E2 H 56 28 92 68 88 92 — flexuosa.... E3 H » » 32 48 4 24 Carex rgida:-:......-.. A 3 G 20 24 96 68 68 40 Viola palustris...... A E 3 H 8 32 92 68 96 76 Galium boreale ......... E 2 H 44 52 88 88 80 88 Equisetum pratense ..... E 2 G 52 48 20 2 48 56 ASTOSHS CADINGA .....1-...- E3 H 84 76 28 48 56 4 Polygonum viviparum ... A 3 G 64 68 8 8 56 12 GHMMAVETEMS 7. E1 H > 12 8 52 4 16 Alchemilla alpina....... A 2 Ch > 4 > > Cardamine pratensis .... E 4 H , 12 > 20 Empetrum nigrum ...... E 4 Ch 8 + 4 | » > Equisetum arvense...... E4 G » 20 4 — variegatum .. A3 H > > 4 8 > > Bestucasovinar, 2... E 4 H 4 40 > 4 8 Galium Normanni....... Al H » 12 » 4 > 4 Hierochloé odorata...... E 2 G > 4 » 8 4 Koenigia islandica....... A3 Th 28 > » > » > Enzulasspieatar,.....,.- A2 FH’ CA » > > > Pingvicula vulgaris...... E4 H Aal > > > 8 » Salix lana te cls eh os A3 Ch » 12 » > 4 > CTD ACEI ier clon ne A3 Ch 12 8 > 4 > > Selaginella selaginoides .. Al GRYN > > » 4 » + Taraxacum officinale .... E2 H 3: ul 4 > » 4 Thymus serpyllum ...... Ewen: » | 4 » > » » which is moist in winter, spring, and autumn, but comparatively dry in the vegetation period. On this soil of a medium degree of moisture we meet with a vegetation which is in great part an in- termediate form between the mo and the myri vegetation but which, at the same time, comprises a number of specific species. It must be left to future investigators to decide whether there is sufficient STUDIES ON THE VEGETATION OF ICELAND 5a TABLE 128. Biological Spectra of the Valllendi Vegetation. 1 2 3 4 > 6 SE SUTIN esse wer ae 0 | 684 | 680 668 736 652 mumber Of species: .- .\....... 19 21 15 16 15 17 Bensıty OF SPECIES; 25%. 5. re 6.7 6.8 Ge 0067 7.4 6.5 ie so PR RE ER 38.7 33.3 15.9 | 14.4 17.4 92 ON UE at 61.3 66.7 84.1 85.6 | 82.6 90.8 Be nassen SE 18.5 16.4 15.9 | 132 17.4 | 8.0 EEE hare 0.6 0.6 > | u > 48 | > i eee 19.6 | 164 Wily walkout oa) 3 | 1.2 re Cr nan 232.1. 91.6 15.3 | 15.6 16S 6 208 SEE NE RE 13.7 15.8 224 | 24.6 22 16.0 he 24.4 27.5 AI E3LEt, 44.0 52.1 Ra ere count > 923128 | kr 0.5 DK eee eee 292 | 211 | ; 18 | 05 | 06 ee seen 46.4 58.5 81.2 86.8 723 | 81.6 ee EEE 20.2 20.5 | 18.8 11.4 271.2, We SUES > . OE eee > » | > | » » | » Does CR APE a A Pore 4.2 » > | > > > difference between this type, the jadar vegetation, on the one hand, and the mo and myri vegetations on the other hand, to set it up as a type of the same standing as these. Much would seem to in- dicate that this is the case. Thus it is a factor of some importance that it appears as a very characteristic feature of the landscape in the highland tracts. Deschampsia cespitosa, Poa pratensis, and Agrostis tenuis are characteristic species on jadar soil. Types of Icelandic vegetation included herein are valllendi, tin, and myri jadar. The very remarkable flag vegetation is always associated with it, but owing to very divergent physiognomical, biological, and floristic pe- culiarities it must be set up as a special type of vegetation. On Lyngdalsheidi the jadar vegetation was represented by vall- lendi and myri jadar. The Valllendi Vegetation. Cf. fig.8 and table 12 A—B. On the numerous small flat cones deposited by the streams of melting snow, occurring partly in Lyngdalur and partly scattered about throughout the heath, a characteristic vegetation, the valllendi 54 H. M@LHOLM HANSEN vegetation, was met with. It is possible to distinguish between two formations, a Salix lanata formation on the freshly formed soil, and a Deschampsia cespilosa formation on somewhat older soil. In table 12, 1—6 show the composition of the vegetation in the two formations. Nos. 1—2 represent the Salix lanata valllendi. The soil is only covered with vegetation in patches, the bed of the stream spreading like a net over the surface from the top of the cone, the meshes being filled in with the patches of vegetation. The vegetation is remarkable by the fact that chamaephytes are comparatively do- minant physiognomically, especially the two Salix species, Salix lanata and S. phylicifolia; other Ch occur more sparingly, thus Vac- cinium uliginosum, Salix herbacea, S. glauca and Empetrum nigrum. Of other plants grasses predominate, especially Deschampsia cespitosa, Agrostis canina, and Festuca rubra, in less degree Festuca ovina and Agrostis tenuis. Of other species of more or less importance we may mention Polygonum viviparum, Equisetum pratense, Galium boreale, Viola palustris, and Carex rigida. Nos. 3—6 represent the Deschampsia cæspitosa valllendi. This formation is always found where the two formations occur together, behind the Salix valllendi. The deposition of material has practically ceased here, no bare patches of sand are ever found, and the soil is covered by a dense vegetation of mosses. The vegetation consists of a luxuriant carpet of hemicryptophytes, principally grasses. Physiognomically Deschampsia cespitosa is the dominant species; in addition Agrostis tenuis, Festuca rubra, Des- champsia flexuosa, Carex rigida, and Agrostis canina are abundantly represented. Some herbaceous plants occur in the grassy carpet, thus Galium boreale, and Viola palustris, and less abundantly Equi- setum pratense, Polygonum viviparum, and Galium verum. The two formations occur with the same density of species, c. 7, and from a biological point of view they are remarkable by their large number of southern plants. An essential difference between them is the Ch content. Possibly this difference is due to cultural influences such as grazing or haying. The Myri Vegetation, the myri jadar and the flöi vegetation. From considerations of space and owing to the close agreement between these types in Lyngdalur and at Björk, they will be treated later when the vegetation at Björk is dealt with. Q1 STUDIES ON THE VEGETATION OF ICELAND The Geiri Vegetation. Figs. 9—10 and table 13 A—B. Where for orographic reasons the snow forms a covering early in the autumn, remains on the ground in a more or less deep layer throughout the winter, and does not melt until late spring, a special type of vegetation is developed which may be called by the Icelandic name Geiri (the vegetation of the snow-patches). It is a characteristic of the snow patch that the underlying soil is never knolly as is the case with the surrounding mo, and further that the vegetation is fairly luxuriant. These two circumstances in conjunction make the snow patch very conspicous even from a long way off (see figs. 9—10). In table 13 A the circling results for the geiri vegetation of Lyng- dalsheidi have been tabulated; this vegetation is only present in the middle and upper tracts of the heath, from c. 200 m above sea level and upwards. It was most characteristic at the upper levels. The geiri vegetation comprises several formations which can be distinguished with regard to their environment by differences in the duration and depth of the snow-covering, the height above the sea, and illumination. As regards the general composition of the vegetation the following holds good. Vaccinium uliginosum is abso- lutely the dominant plant, in conjunction with Empetrum nigrum and Deschampsia flexuosa it forms the bulk of the dense luxuriant carpet of vegetation. Species like Salix herbacea, Calluna vulgaris, Agrostis canina, Festuca rubra, Anthoxanthum odoratum, Luzula mulliflora, Carex rigida, Galium boreale, G. Normanni, Cardamine pratensis, and Taraxacum officinale also abound. Rubus saxalilis, Geranium silvalicum, and Vaccinium myrtillus are characteristic of the geiri on Lyngdalsheidi. None of these species has been met with in any other type of vegetation. Some typical mo plants occur dis- persed throughout the vegetation, in greatest quantity in the least typical snow patches, or in the margin of the larger ones. In small depressions in the mo, where the snow-covering gives rise to another vegetation than in the mo itself, this vegetation is fairly uniform throughout the depression. In deeper depressions a difference between the vegetation at the bottom and up the sides may be perceived. In table 13 A, 4—5 show respectively the typical geiri vegetation and the vegetation on the sunny northern side of the snow patch. Here the density of species is somewhat greater, 15.5 as against 13.6, owing to a contingent of mo plants. In still deeper snow patches one may distinguish between a 56 H. MØLHOLM HANSEN TABLE 13 A. The Geiri Vegetation on Lyngdalsheidi. Localities 1—8 situated in Lyngdalur c. 200 m above sea level. 9 between Hrölfshölar and Thrasaborgir c. 300 m above sea level (cf. table 11, 8). 10 on Thrasaborgir c. 400 m above sea level (cf. table 11,9). 1 examined on ?/7 1925, 2 on °/7, 3 on 8/7, 4—8 on 19/7, 9—10 on 77/7 1925. 1-4, 9-10: 25.74/19 m“, 5-8: 10 */10 m°). Vaccinium uliginosum... E4 Ch 100 100 100 96 100 100 » > 88 28 Empetrum nigrum...... E4 Ch 100 100 100 80 100 100 90 » 80 64 Deschampsia flexuosa.... E3 H 100 100 96 96 100 100 70 100 100 96 Galium boreale ...-...... E2 H 100 92 84 72 90 70 40 70 68 84 Salix Herbacea 22... 2... A3 Ch | 68| 16| 16|76| 30| 20! 80| >| 96] 96 Elan valsaris !..:..... E2 Ch | 40| 52| 64 28 100 70 100 >| >| » Agrostis canina ......... E3 H 68 100 76 44 60 80 90 70 100 76 HA IENUISE is E.2 H 8| »| 72,80) 30, 80; > 100| 8152 Polygonum viviparum ... A3 G | 48| 8| 2152! 60! »| 8D0| >; 40/68 Resear ses se E4 H 56 52 80 80 70 70 70 70 68 80 Anthoxanthum odoratum E3 H 4| 52| 28/72 100 | 40| 10| >|) 12|24 Luzula multiflora ....... E3 H 20; »|20) 40) 10) 20) x} 4) > Gare witida. scene ged 0 A3 G 40 68 64 60 60 30 » 70 84 64 Galium Normanni....... Al H 32| 32) 8|36| 70| >| 40) >| > | 8 NETTER El H 4| 16| >112| 50| 10| 20| >| a] 4 Selaginella selaginoides .. Al Ch || 12| 8| 8/24] 20| >| 30| || 1236 Equisetum pratense..... E2 G 16| 16| 4|12| 40| 10) 20) 10) 24| 8 Taraxacum officinale .... E2 H 4| 32| 12168| »| 20| >| >1.12| 8 Geranium silvaticum .... E3 H >|..4| 41/24) 70| >| >») San Vaccinium Myrtillus..... E2 Ch > > >'88 60 30! » > | 12 | 88 Deschampsia cæspitosa .. E 2 H >| > 5142151! >] oO Magia palustris 333 DSL E3 H >| »| 28/176) »| 20| » 1001 44/52 Cardamine pratensis...., E4 H 36| 12| 4/32) 60! >| >| >|» Kubusssaxatilis.. ......... E3 H 12| A| 4/12) > >| >| >)» 1753 Gnaphalium supinum ... A2 Ch > > » | » > > > » | 12188 Sibbaldia procumbens ... A 2 Ch >) >| >| >| >| >| >| >| Alchemilla alpina ...... A2 Ch »|'»>|: sl, 2) >| 2) 2a — LT) PE E4 H >| 9}. 91241 >| 2]. 9) Sage Hierochloé odorata...... E 2 G > 8| >| >| »| >| »| Sean Armeria vulgaris........ Å 3 Ch >) 2] -2| 4). >|. >| OS Bartschia alpina ........ | A2 H »| »|-»| »| >. 1-10) 10 Betula nana ee LA? Ch > Z A ARE 11 Pele > » » > »| » Carex sparsiflora ........ Al G 8. 8 » >|») >» | >| > Cassiope hypnoides ..... A2 Ch >| ne >| >» »| »| arf a} 4 Elyna Bellardi.,....... 2 A3 H » > > 10 >| 10 » 21017 Equisetum arvense...... E4 G » > » » » | »| 4 — hiemale...... [Page SAS ls = ON A NE PACE UT »| »| of 4l:4 Eriophorumpolystachyum | E4 G > rx a > > STUDIES ON THE VEGETATION OF ICELAND >» / TABLE 13A CONTINUED. Euphrasia latifolia ...... | A2 Th 4 Bestuca OvINA.......:.. E4 H 4 » 20 ) > 4 Gnaphalium norvegicum . Al H > > » Hieracium silvaticum.... i 2 H > » | 10 | > Banens trifidüus.-.......- | A°2 H 8 » 40 | » 120 ) ) Leontodon autumnale ... | E3 H > » » | 24) » » » | 4 | 4 Bazala spicata...: »..... | A2 H 8 2 ) » 10 > Lycopodium alpinum.... | A2 H » > > > » | 8 Mardus strieta.......... | E3 H » > > 8 > Grecs maculata:........ | E2 G » | 8 | 40 » |10 | » IA MIDOr, se E 4 H > > » 4 > » > » Ranunculus acer ........ E4 H 3.10 > »| >» > 4 AE EV ee une ee A3 Ch > > » 10 » | » 4 == TEE RA ee eo Al Ch ER En LSE AP SEE | >| » — phylicifolia........ AT eG Wo eel Beas 5 » | » | 4 Thalictrum alpinum..... AH 112.181.» 18) este | 1870 Thymus serpyllum ...... E4 Ch A NAS EE «3 [80 | » 120 | » | » Tofieldia palustris....... | A2 H ee 10 | » | ss Trisetum spicatum ...... 187453 H N ED en ee er lee » | » RIGE CATIINIA "5 3,6... | E3 H | » | » » | » | 40 | ala LME OI sunny northern margin, No.7, the typical geiri vegetation chiefly occurring along the sides of the snow patch, No.6, and the vegetation at the bottom of the snow patch, No. 8. The northern margin is more arctic in character than the typical vegetation. The A per- centage is 39.6, while it is only 5.8 for the typical vegetation. The bottom vegetation is almost identical with the previously described Deschampsia cespitosa valllendi both biologically and floristically. The vegetation of the snow patches at higher levels of Lyngdals- heidi, thus at a height of c. 300—400 m, is shown in table 13 A, 9—10. In its broad features it corresponds to the geiri vegetation at lower levels, though a number of species of common occurrence in the snow patches of Lyngdalur have disappeared, thus Calluna vulgaris, Luzula multiflora, and several Galium species. Others again have become less conspicuous, but on the other hand some new spe- cies have been added such as Gnaphalium supinum, G. norvegicum, Sibbaldia procumbens, Alchemilla alpina, A. minor, Hierochloé odorata, and Veronica alpina. These species seem to be characteristic of the snow patches in the upper parts of Lyngdalsheidi. 58 H. MØLHOLM HANSEN TABLE 138. Biological Spectra of the Geiri-Vegetation. 1 2 3 4 5 6 7 8 9 10 Points sum....... 892 | 928 868 1360 |1550 860 | 960 | 670 | 960 | 1104 Number of species 24 27 22 35 27 17 23 9 28 33 Density of species. 8.9 9.3 SI UGH |) ISSN] GEO TE 6.7 9.6 | 11.0 (Aa NE ete Meds; nis à 26.9 | 16:8 1,1247 197 | 20:0 5.8 | 39.6 | 10.4 | 30:0 | 40:9 PACE OR Na TL 73.1 83.2 | 87.6 80.3 80.0 | 94.2 | 60.4 89.6 | 70.0 | 59.1 EC ete ena is | 99.109 ur | 116.) 58 | 177 | 1021] 999 | 21.0 Ae) eae ee ee AV] 34.1 41.3 >| 09| 26 > | 14.6 >| 58 | 152 Al SER and ee Siete 63 5.6 3.2 4.7 5.8 7.3 1.3 | COO RP err 33.2 | 29.7 | 32.7 | 23.8 | 26.5 | 31.4 | 20.8 | 10.4 | 25.0 | 178 E3............... 20.6 | 30.2 | 27.6 | 28.5 | 265 | 29.1 | 19.8 | 40.3 | 30.0 | 236 PET PEACE 18:8 | 21:6 1 27.212741 | 23.9) | 326.) 17.7 | 38:8 | 15.072074 El............... 04 | 17 le > 04 S| el ony ea 36.8 | 31.5 | 34.6 | 29.4 | 323 | 372 | 42.7 > | 33.8 | 34.8 | eg Mie ER Re 50.7 56.9 57.6 60.3 548 58.1 45.8 88.1 49.2 | 48.2 (Se easy en BE 12:6 | 11.6 | 7.8 | 10.3 | 12.9 | 4.7°| 11:5-| 119 | 174 1362 HH so a es Dans pee > > > » » Th PraKe ie.» le len rate ep ae » 2 > 2 > 7 0.4 In arctic, Scandinavian, Scottish, and alpine regions these plants are likewise, according to the records, peculiar to places with a deep and persistent snow-covering. The two Alchemilla spp. seem to prefer the upper parts of the snow patch, whereas they are absent from the lower parts. — The two snow patch localities correspond to two mo localities, viz. 8—9 in table 11. Biologically the geiri vegetation is characterised by its low A percentage and high E percentage. The increase in the E percentage is especially due to E 3 and E 2. B. THE VEGETATION AT BJORK. Above we have described the vegetation in the middle and upper tracts of Lyngdalsheidi, in the following we will subject the vegetation at its foot to further discussion. All investigations of the vegetation were carried out in the vicinity of the Bjérk farm and with this as their base. It is situated at the foot of Lyngdalsheidi’s eastern side at an altitude of c. 100 m. STUDIES ON THE VEGETATION OF ICELAND 59 Some of the types of vegetation recorded from Lyngdalur recur here, viz. mo, jadar, myri, and flöi, while melar, mosathembur, and geiri were not developed. In addition there occurred the flag vegetation. The Mo Vegetation. Cf. table 14 A—B. In its broad features the appearance and floristic composition of the mo around Björk corresponds to the above-described mo at the higher levels of Lyngdalsheidi. The soil has ihe same knolly surface as that previously decribed, but the knolls are less conspicuous on the slopes than on the flatter parts. The composition of the vegetation is likewise very similar. Almost all the species found in the mo in Lyngdalur recur here and in approximately the same proportions. There are, however, also typical differences partly between this mo and that at the higher levels, and partly between the various parts of the mo around Björk. Three mo formations could be distinguished, an Elyna mo, an Arctostaphylos mo, and a Calluna-Empetrum mo. These three for- mations differ in the following way. The Elyna mo is found on the top of the many little mounds and hills which are covered at the higher levels of Lyngdalsheidi by the mosathembur vege- tation, and have a comparatively thin snow-covering. The Arc- tostaphylos mo is found on the sunny slopes of these hills below the Elyna mo, and in the drier depressions among them. The snow-covering is somewhat deeper here and more persistent than in the Elyna mo; it is the normal snow-covering in these parts. Transitional between the Arctostaphylos mo and the jadar is the third mo formation, the Calluna-Empetrum mo. Like the Arctostaphylos mo, this formation has the normal snow-covering in winter, but differs from the Arctostaphylos mo by being more damp. Here the ground water has an appreciable influence on the vegetation. In table 14 A the circling results for these three mo formations have been tabulated. Plants common to the three mo formations and the mo at higher levels and characteristic of the mo are, e. g. Empetrum nigrum, Thymus serpyllum, Salix herbacea, Festuca rubra, F. ovina, Agrostis canina, Carex rigida, Juncus trifidus, Luzula spicata, Poly- gonum viviparum, Thalictrum alpinum, Selaginella selaginoides, and Equisetum variegatum. Table 14 A shows the proportion in which the various species occur and the good agreement between the 60 H. MØLHOLM HANSEN TABLE 14 a. The Mo Vegetation at Bjork. Localities 1—10 are all situated round Björk c. 100 m above sea level. 1—4 the Elyna mo, 5—7 the Arctostaphylos mo, 8—10 the Calluna- Empetrum mo (the moist mo). 1, 3 and 5 examined on 15/7 1925, 2, 6, 7 and 8 on 27/7, 9 on 71/7, and 4 and 10 on 74/7 1925. (25. 1/10 m?). Arctostaphylos uva ursi.. E 2 Ch 4) »/88| 96| 96) 4) 4 Calluna vulgaris ........ E 2 Ch 12 4 » 76 80 100 96 80 80 Empetrum nigrum ...... E4 Ch 100 92 88 80 100 100 100 100 100 100 Thymus serpyllum ...... E 4 Ch 96 92 76 56 88 92 72 64 80 64 Vaceinium uliginosum ... E4 Ch 8|12| 12| >| 88! 80| 72| 68| 36| 44 Salix herbacea .......--. A3 Ch | 72160] 68| 4/80! 68| 32) 28| 20) 20 Pesined zuhra 5.223 E 4 H 96 96 100 96 92 100 92 100 100. 96 ar AT ann E4 H 76 40 8 28 84 80 68 76 60 84 Deschampsia flexuosa.... E3 H 8 8 40) 16 68 52 40 56 > 36) 20 Agrostis canina ......... E3 H 88 96 96 100 96 100 92 84 100 88 Kara rapide. tee A3 G 76 92 92 80 64 88 60 68 88 76 Polygonum viviparum ... A3 G 84 72 56 48 68 80 80 100 92 84 Thalictrum alpinum..... A2 H 32 24 64 36 16 48 64 68 68 60 Galium Normanni....... Al H 88 88 96 80 72 56 32 48, 44 68 ROCHE s. JE E2 H 4,48 12 40 84 52) 44 28) 68) 48 JUNCUS fnidus..-:...:12e A2 H 48|48 36) 48" 44 | 36| 40) 32| 76| 36 EiynaBellardi.......s-.,% A3 H 36,68 48| 60) 16, 4 16) 44| 64| 28 ani spicata. oc es A2 H 64/20) 32| 321 24) 36| 52) 16) 12) 28 Selaginella selaginoides .. Al Ch || 52/36) 32| 40) 20| 28) 4| 52) 48) 28 Equisetum pratense ..... E2 G 36 16 16 4 20 44 40 60) 88 32 — variegatum .. | A3 H »|24| 24| 32| 4| 32| 16) 8| 12] 36 Sıleneracanlisız.., 40... A 3 Ch | 32112, 16) 20) 4) 121 4| 4| 8/16 Trisetum spicatum ...... A 3 H 8120| 8| 52) »| 20| »| 8] 24| > Anthoxanthum odoratum. E3 H >| 40} 41 20| 12] 4] 12] »| > Luzula multiflora ....... E3 | H >| 16| >| 16) 4| 24] 8] 8] 22 Cardamine pratensis .... E4 H 4) »| 12| 36) > 24 84 52 56 Salıı ETES NOR MERE AA A 1 Ch 4| »| AN 12| >| A| 28] 16| 28 — phylicifolia........ A1 | Ch > >| > 28| 4| 8 Carex sparsiflora ........ A G > »| >| 8| 2| >| 40] SID Deschampsia caespitosa.. | E2 H »| >| »| >| >| >| >| 12) 24120 Taraxacum officinale .... E2 H es ÆT lue 41 20; 4) 20 Asrostisitenuis.. 4.2: -0- E 2 H >| > » »| 4| > 20| 81-28 Equisetum arvense ...... E 4 G >| >| >| 40! >| >| >| 4 Sie Rumex ’acelosar se mr | E3 H ee | 229 Meee » »| »| 8 | 4| 8 Viola palustris.......... | E 3 H »| > > > »|.2| >| Szene Alchemilla alpina ....... |) A2 Ch »| »| 4 » > > » » » » Armeria vulgaris........ A3 Ch >| 4! >|.» » >|» 104 Bartschia alpina ..,..... A 2 H »| > > > » » 4 » » STUDIES ON THE VEGETATION OF ICELAND 61 TABLE 14A CONTINUED. Botrychium Lunaria .... E 4 G BER ES Au NT AIS PA LE: TES 3 barer Tariflora …......... A2 G > » ) > » » » > 4 2 Cerastium alpinum...... A3 Ch || 24 | > » |28 | » | : 2,420 78) |S Equisetum hiemale...... E3 H x | »| 4| >» » | » » » | » Erigeron neglectus ...... Al H Se PNA NE A IE 0 eee ted, | > Euphrasia latifolia ...... A2 Th Sh [esa ee ig ee Gala verum .:.".....0... E.1 H » 112 | 32 | 36 || > ) | 12 |20 | 4 | > Habenaria viridis ....... Al G 4 » » | | >» > Hieracium silvaticum.... E2 H 21302: AVE EN > »| 4] 4| > Leontodon autumnale ... E 3 H > 2 > | »f » | 4 Pingvicula vulgaris...... E4 H |» 4 | 41 8| 8| > epee IAMICA see. sce o's nn A3 H > PÅ DENE SEN RE: » » || » 4 Potentilla verna......... A2 H Be se) be ae ee ee er li Ranunculus acer........ E4 H » |» Re I» | > I>| 41 > Rhinanthus minor ...... E2 Th > » Sa] | SN RES RE 2 ES SE DETTE Be MRS A3 Ch »|» 4 | » > » >| » |» BEER CANINA en E3 H > | » | 8 | Ihr 12 | > TABLE 148. Biological Spectra of the Mo-Vegetation. | | | | | 1 | 2 | 3 4 5 6 7 | 8 | 9 | 10 | | | Points sum ....... | 1148 1096 1168 | 1124 | 1368 | 1424 | 1304 | 1532 | 1508 | 1396 Number of species. | 25 25 32 31 ar | Bie dae 41 4211536 Density of species. | 11.5 | 11.0 | 11.7 | 11.2 | 13.7 | 14.2 | 13.0 || 15.3 15.1 | 14.0 2. | 54.0 | 52.2 | 51.4 | 51.6 31.6 | 36.5 | 31.6 || 37.9 | 39.8 | 40.1 SERPENT | 46.0 47.8 | 48.6 | 48.4 | 68.4 | 63.5 | 68.4 | 62.1 60.2 | 59.9 ee TANT | | ee | 28.9 | 32.1 | 28.4 | 29.9 | 17.3 | 21.3 | 16.0 | 17.2 | 21.0 | 19.8 ae | 12.9 | 84 | 116 | 107] 61 | 84| 123] 78 | 10.9 | 10.0 32 | 122 | 117 | 113 | ı10 | 82| 67| 341128 | 80 | 103 ars | 33.8 | 30.3 | 26.0 | 30.2 | 33.0 | 32.0 | 33.1 | 33.4 | 30.2 | 34.1 TOP PRE | 8.7 | 9.5 | 164 | 11.0 | 15.2 | 118 | 123 | 11.5 | 114 | 95 NÉ | 35 | 69 | 3.4| 3.9 | 20.2 | 19.7 | 22.1 | 15.9 | 18.3 | 16.3 AR | » 11 2.7 3.2 » » 0.9 1.3 0.3 » >... | 33.4 | 29.6 | 26.0 | 21.0 | 40.6 | 39.0 | 37.1 | 31.1 | 268 | 28.7 PPS neuer 48.8 54.0 58.9 63.3 47.7 | 44.7 | 49.1 | 50.7 53.3 | 54.4 ÉCART | 17.8 | 16.4 | 15.1 | 15.7 | 11.7 | 15.7 | 13.8 | 18.0 | 19.9 | 16.9 ee kei rate. » » » 2 > | » | » | > » > er RE à » > > »| 06] »| 0383| » » 62 H. MØLHOLM HANSEN species in the three formations; if compared with table 11, it will further show the agreement between the mo at Björk and that of Lyngdalur. The Elyna Mo. Table 14 A, 1—4. The dominant here is Elyna Bellardi. It occurs especially at the top of the knolls and with its brown, tufted stems it contributes markedly to the peculiar physiognomy of the vegetation. Other characteristic plants are Silene acaulis, Cerastium alpinum, Trisetum spicatum, and Poa glauca. These species attain their finest development here even though they are also found in the other formations. Further it is characteristic of the Elyna mo that a number of species otherwise always present in the mo are rare or absent here, viz. Vaccinim uliginosum, Calluna vulgaris, Arctostaphylos uva ursi, Deschampsia flexuosa, Galium boreale, and Luzula multiflora. All these plants are southern species. The Arctostaphylos mo. Table 14 A, 5—7. Physiognomically characteristic of this formaiion are above all Arctostaphylos uva ursi, Calluna vulgaris, and Vaccinium uliginosum; further there occur Des- champsia flexuosa, Galium boreale, Luzu lamultiflora, and Anthoxanthum odoratum. On the other hand, Elyna Bellardi, Selaginella selaginoides, Silene acaulis, Cerastium alpinum, Trisetum spicatum, and Poa glauca are not dominant, a feature by which this formation differs from the Elyna mo. The difference between the two mo formations thus consists in the fact that the Elyna mo has many arctic but com- paratively few southern species in contrast to the Arctostaphylos mo in which the southern species are dominant. This difference is decidedly due to the difference in the snow-covering. From both for- mations the species requiring moisture, which occur in the Empetrum mo, are absent. The Calluna-Empetrum Mo. As mentioned above, this for- mation occurs as a narrow border between the Arctostaphylos mo and the jadar, and it is particularly well developed where the ground is slightly inclined. The most striking difference between this and the above-mentioned formation is the absence of Arctostaphylos uva ursi. Owing to the immediate vicinity of the jadar some of the plants characteristic of that formation are met with, though sporadically, thus Carex sparsiflora, Cardamine pratensis, Deschampsia cespilosa, Taraxacum officinale, Agrostis tenuis, Equisetum arvense, Viola palustris, Salix lanata, and S. phylicifolia. STUDIES ON THE VEGETATION OF ICELAND 63 The situation of these two formations in relation to each other affords an excellent illustration of the relation to moisture of Arcto- staphylos uva ursi and Calluna vulgaris. On the heath of Jutland we may similarly distinguish between a higher tract with Arcstosta- phylos and Calluna and a lower tract where Arctostaphylos is absent. Though the environment differs widely in the Icelandic mo and the heath of Jutland, it is worth noting that species which they have in common react similarly to the same change of environment. It is not the sum of environmental factors but the indi- vidual factors of the environment which determine the distribution of the species. The Jadar and Myri Vegetations: Fig. 11 and table 15 A—B. In areas where the degree of moisture is determined both by the precipitation and the ground water we meet with those stretches which are called “myrar’ in Icelandic. Owing to the abundant precipitation the myri is very extensively distributed throughout the Icelandic lowlands. Several types of myri are found. Of most com- mon occurrence is the »förmyri« or swampy myri, formed in cup-shaped depressions on level or slightly inclined ground. Its for- mation and peculiarities are due to the sour stagnant ground water. Where the soil grows very damp, that is to say, where the ground water covers the bottom all the year round, swampy stretches, “floar” are formed. The second type of myri is the »hallamyri” or well myri. This is formed where the ground water is pressed up out of the soil, hence it is often seen at the foot of mountains. Where the water is pressed up with such force that springs are formed and where the bottom is therefore swampy and damp all the year round the “dy” vegetation is formed. The third type of myri is the “fetmyri’” or irrorated myri formed on tracts inundated by water for shorter or longer periods of the year. Natural fetinyrar are thus formed on the banks of rivers but most extensively in deltas near the sea. The characteristic plant in this type of myri is Carex Lyngbyei, and since this plant is an important forage plant, successful damming experiments have lately been made with a view to creating conditions for an inundation myri in places where it was not formerly found. Three different types of vegetation are associated with these three types of myri. I was afforded most opportunity for a thorough- going study of the swampy myri which I investigated both in Lyng- 64 H. MØLHOLM HANSEN dalur, at Björk, and at Lekjamot in the north country. The ridge myri I have only investigated at Lækjamåt, while I had no oppor- tunity of a close study of the fétmyri. The composition of the swampy myri in Lyngdalur and at Björk is shown in table 15A, 1—11. Fig. 11 shows the appearance of the myri at Björk. The soil is markedly knolly, but the knolls are smaller and more scattered than on the mo. According to the degree of moisture of the soil it is possible to distinguish between the following formations. The myri jadar (the margin of the myri) or the grass myri is first met with on passing from the mo on to the myri. Upwards it passes into the moist mo, the Calluna-Empetrum mo. The ground water hardly ever comes up to the surface, but the bottom is damp in spring, winter, and autumn, whereas, in the vegetation period, it is com- paratively dry. Outwards the jadar passes into the dry cypera- ceous myri, the Salix myri. The soil is here considerably more moist, in wet summers the water will perhaps cover the surface throughout the vegetation period; normally, however, this vegetation will not be covered with surface water the greater part of the vege- tation period, in dry summers perhaps not at all. On the dampest soil we find the moist cyperaceous myri or the Betula nana mvri. The bottom must here be assumed to be covered with water even in normal summers; in very dry summers dry bottom may no doubt be found in this formation, too. The flöi, or swamp, is met with in spots in this formation. Here the bottom is always covered with water, even in dry summers. The knolls, so typical of the myri, are not present in the flöi, and while the soil of the myri is firm to the tread, rendered solid by a dense web of Cyperaceae rhizomes, the ground in the flöi is soft and muddy, and one moves on it in constant fear of sinking into the slush. On a gentle slope these 4 belts will succeed each other in the sequence described above, adjoining the moist mo upwards, while outwards they will perhaps be succeeded by a collection of water, a “tjörn” (tarn). Where the surface is more irregular, a compara- tively moist formation will not rarely adjoin a comparatively dry one, while the intermediate formations are not developed. The Jadar Vegetation. Table 15 A, 1—3 shows the floristic composition of this vegetation in Lyngdalur and at Björk. The STUDIES ON THE VEGETATION OF ICELAND 65 number of species and density are comparatively high, on an average c. 40 species in 25 sq. m. with a density of ec. 14. The southern species play a much greater part than the arctic species; of the life forms H predominate with an average percentage amount of more than 50. Ch attain their minimum here; both above and below they constitute a larger percentage amount of the vegetation than here. The G percentage is somewhat higher than in the mo. With regard to the floristic composition, we find not only a number of species from the mo, such as Empetrum nigrum, Vac- cinium uliginosum, Salix herbacea, Polygonum viviparum, Thalictrum alpinum, Agrostis canina, Festuca rubra, F. ovina, and Carex rigida, but also a number of species which must be said to be peculiar to the jadar. Of these Deschampsia cespitosa, the typical dominant for the jadar, must especially be noted, even though its F.- percentage is not always very high. Further Agrostis tenuis, Carex sparsiflora, C. capitata, Taraxacum officinale, Cardamine pratensis, and Viola palustris, as also the Salix species, S. phylicifolia and S. lanata. Most of these species attain their maximum development here. Of plants peculiar to the myri Carex Goodenoughü is the only one which plays any great part in the jadar vegetation. The Salix Myri. Table 15 A—B, 4—6. Similarly to the jadar this formation has a large average number of species and high average density, though not as high as in the jadar. While grasses were dominant in the jadar here it is the Cyperaceae, and the result is a great decrease in the H percentage and a corresponding increase of the G percentage in the biological spectrum. HH are gradually gaining ground and are represented by c. 6—8 p.c. in the spectrum. The Ch percentage is somewhat higher than in the jadar. The proportion of A and E species is practically the same for this and the above-mentioned formation, but there is a displacement within the subgroups. The E 2 percentage is comparatively high in the former, considerably lower in the latter formation. Floristically the Salix myri differs from the jadar in that the grasses play a very slight part, while the Salix species are the same. From the Betula nana myri it is distinct by the absence of the characteristic species of that formation, Belula nana, but it has the same cyperaceous flora. The dominant species are Garex Goode- noughit, Eriophorum polystachyum and the Salix spp. especially The Botany of Iceland, Vol, III, 5 66 DABLE 15 AA H. MØLHOLM HANSEN The Jadar and Myri Vegetation on Lyngdalsheidi and at Bjork. Localities 1—3 represent the Jadar vegetation. c. 200 m above sea level. 2—3 at Bjork c. 100 m above sea level. 4—6 the Salix myri, 4—5 at Björk, 6 in Lyngdalur. 7—11 the Betula nana myri, 7—9 in Lyngdalur, 10—11 at Björk. 9 examined on {/7 1925, 2 and 11 on 18/7, 5 on 29/7, 4 on 71/7, 1, 6, 7 and 8 on ??/7, and 10 on 75/7 1925. (25. 0 nr). Deschampsia caespitosa. | Calamagrostis neglecta . | Agrostis tenuis Carex rigida Cardamine pratensis... Agrostis canina Viola palustris Festuca rubra ovina lanata e nr» nee es 0, Equisetum arvense .... Polygonum viviparum.. Thalietrum alpinum ... Comarum palustre Carex Goodenoughii .. Tarıllorakern..n.. ss... ss... Vaccinium uliginosum . Betula nana Carex sparsiflora capitata Taraxacum officinale ... Luzula multiflora ...... Equisetum pratense.... variegatum . Galium Normanni boreale Potentilla verna ....... Selaginella selaginoides. Salix glauca ss... ss... ee se 28 Je No. 1 in Lyngdalur 1 ARS ARE | 7) 8 92102 EI E2 H 64 | 44 | 72| 12 | 4| » » » » » E 4 H 56| 8| 44 > »| 8 » » E 2 H || 96/44) 4! 4! 4] »| »|]°»| » A3 G 1100 28! 56) 4 8/| 60] > | 52| 48 » » E 4 H 48 60 80| 60 20| 24| 4 | >| 8 MGR E3 | H | 72|32| 48| 32| 32] 28] »| 4| »|- »| » E3 | H | 36/68/ 28| 88) 64) 44] »| »| »| »| 12 E4 H || 96 96 100| 88 80 92] 12; 32| 32! 4| 24 E4 H 72 | 80 68) 96 48 | 44 | »| 12 > » | 20 A1 Ch | 88,32, 8] 20) 32 | 72 |40| 12| 16| 24| 24 Al Ch »|52| 52) 76 60 8| » > > IN oe! A3 Ch | 20|60| 12|| 28; 56 | 4816| 24) 4 » | 16 E 4 G 48 | 60 | 20 | 20; 56; 16| » » » » > A3 G | 96 92! 92) 96 92 92 92 92 96| 88 72 A2 H | 96 80 80/40) 84 80112 64 68| »| 36 E4 | HH | 12/28 | 4] 76| 72| 56/16) »| 28| 40) 44 E3 G | 88 76 32 100 100 100 96 | 96 100 100 100 A2 G | 28| 4| »||88| 52 88188 92| 92| 44! 64 Al G » | 12 12, 72 4188 96 100 100 92 E3 | HH »| 8 8| 32) 4] 8] 36| 76| 44 | 28 E4 G |48128 8] 96| 76| 68 88 52 72 100 80 E4 | Ch || 28|88| 56| 76 96 24148 | 84 | 52| 92) 80 E4 | Ch 4/92 40|| 56 100 2476 100 100 100 | 88 A2 Ch »| » »| 12 16| 8124| 84 100 100 | 80 Al G 12 |16 | 20 » »| »| »| » > » » A2 H 4| 4| 16 > » » » E 2 H 1124118690 » 8 » » » » » » E 3 H GH RSI 4 8 »| » » » » E2 G 8| 8| 28 » » »| >» > » » » A3 H 40 | 12| 24} 36| 20 8 » » > > Al H 24:36. 48 | 1274.12 » » » » E2 H 40 | 20} 28| 4! 20) 16| » » » » | 12 A 2 H 12| 8| 16| 4] 12 » || 4 » » » » A 1 Ch | 20128 | 40| 16) 8| 4| »| 4) 4 lee) A3 Ch 8120| 4] 8| 36| 12/16) »| 20; 4) 4 STUDIES ON THE VEGETATION OF ICELAND 67 TABLE 15A CONTINUED. Pingvicula vulgaris .... | E4 H | >| >| > 4] 4] 9] Scirpus caespitosus .... | E4 H | »| »| >! >» | » | » 120 [40 140 | » | 8 Menyanthes trifoliata... | E4 | HH | > | » | » |20 | » | » | » | 12 | » |20 | 36 = | | | | EN erases alba. ......... | E3 H | > » | 4 |20 | » | > » | » | 3 | » Calluna vulgaris ....... } E2 | Ch] >/12] >] >| >]2] >| >] >] >| » ar Alpina. :..,:... | A2 H |12|] >| >] >| >»/2] 9] »] » ) — canescens ....... | E4 H | » | » |16 | » | | ZEA) SE: » | 9 == (10) (ae ee E4 GA UNE » » » 4 | 4 | » > | >| » A MOSA G 2c ace | E2 G » » » ESA" | » 3:13 » !20 = EE eee | E3 G » | > 124 » | » [| > Ir au n Nat Deschampsia alpina.... | A2 | H | 4 salle eae ee Es — flexuosa .. | E3 Boil, sel bao 0 » | » | » | » | » | » | > | » Elyna Bellardi......... Ae) BW x [iat EN otha Wo leo ES Lis Equisetum limosum ... | E2 | HH | » | » | » | » | 4 [sl »|>»|» | 12 16 Eriophorum Scheuchzeri | A3 | HH | » | » | » | 8 | » HE TEN NE ae | 8 Euphrasia latifolia ..... | A2 Th » » > | » » | 4 | » » su Galinm verum:........ | E1 H » | » 8 » » |» > » » A RE Am rivale: ::........ | E2 H “Seer eng >| 8 | >| 1.» | » | 4 Hierochloë odorata..... E 2 G 40 | 8! » | » 116181 » | » | » | » | » Juncus balticus........ Al G » TE | oe! Ms ml | » | » — filiformis ...... E3 G | 2.1 Aldiana ot Vive ECS LE — ET | A2 H AN ca Teel 32 LE Sole 23 > Leontodon autumnalis.. E3 H au Alpes | EN AE A IEA Needs eas Leet » Luzula spicata ........ | A2 H » | » RAMNAS ie ee a Er 5 DE SE, MR AIDUA 6,6 «5 0.00 0/0 « A2 H + DH Pica Sa) ES ae DRE table u ke Ai ve SÅRE SAADE Ol ao pratensis:.:....... | E4 G > 8 leeren ee] Ranunculus acer....... | E4 | H » | a] xl» >| a} of] >| | » Rhinanthus minor..... Re ae le is ne 9 PER CC Rumex acetosa........ | E3 H sol ee SO) | et 33 | 3 las (ese Say LT OS Spiræa ulmaria........ LE2 H ze DO PO PS EP RTE Ce le ee Thymus serpyllum..... | E4 | Ch » | 4116 | » |» | » | »! | » |» | Tofieldia palustris ..... Wee elle] waere Triglochin palustre .... | E4 | H | >| >| >» |» | A|»| >] >| »| >| Trisetum spicatum .... | A3 | H |2|4 | »| »| 4/4) > |» | 4| » | 4 MOI CANINA :......... | E3 H » | ANS 13 | » | » | v | » | » | 3 i ll | S. lanata. The species common to this formation and those above, and which are not present or only occur sporadically in the moist Betula nana myri are the following. Salix herbacea, S. lanata, Viola palustris, Cardamine pratensis, Agrostis canina, Festuca rubra and F. ovina, and Equisetum arvense. The following species are 5* 68 H. MOLHOLM HANSEN TABLE 158. Biological Spectra of the Jadar- and Myri Vegetation. Bontsssumeneree 11376 1404 | 1352 | 1360 1408 1076" 752 1004 | 1076 | 888 | 1032 Number of species | 38 42 42 39 38 34 19 | 21 23 16 | 35 Density of species | 13.8 14.0 13.5 | 13.6 | 141 10.8| 7.5| 10.0| 10.8 | .8.9| 10.3 | | | | | 7 34.8| 364 33.8 39.8! 47.2 50.0| 52.6 | 51.7 40.5 40.7 APR ere 42 Bier 57.3 65.2 63.6 66.2 60.2 52.8 50.0| 47.4 48.3 | 59.5| 59.3 A3 20.1] 15.4! 14.5| 13.2| 15.3| 212) 16.5) 17.5| 16.0 DA 10.1 NE | | | | | Mole, | 122! 68| 95) 10.6 11.6| 16.7| 16.5| 23.9| 24.5| 16.2) 182 Ad | 10.5! 12.5! 124| 10.0! 12.8! 9.3! 17.0) 11.2| 11.2|14.0| 12.4 BR | | | - DE CERN ET | 30.2 | 39.3 | 32.2| 45.5 | 39.8 | 32.7 | 36.2 | 33.9 32.0 41.9) 39.9 DIS Battin i 8 | 15.4| 14.2| 12.7| 18.8 | 16.8| 16.4 13.8] 13.5| 16.4 |16.2| 14.0 Da 21. 11.6| 11.7) 18.0] 2.1] 3.6) 37) >| »| >| 14754 ES ER | > >| 0.6|| > » > || > > > » » | | | | eee [aes ier Qe veda cts ep 1122) 27.6) 16.9 215 28.7| 18.6 | 29.3 30.7 27.5 36.0 29.5 Bhar Persea eho | 52.9 45.3 61.8 38.8 29.8) 34.2) 7.4 15.9) 15.2) 2.3| 15.9 GESANDT | 33.7, 24.2 21.0 31.5 33.8 40.9, 60.1 47.8 47.6 48.6 | 41.9 HAS eae ; 0.9) 26) 0.3) 8.2] 7.7) 5.9 | 32 5.6) 9.7 13.1) 12.8 Dae een. 0.3! 0.3 » | 0.4 | » » | » » | > common to the dry and the + moist Cyperaceae myri. Carex Goode- noughü, C. chordorrhiza, and C. rariflora, besides Eriophorum poly- stachyum. Common to all three formations are Empetrum nigrum, Vaccinium uliginosum, Salix phylicifolia, Polygonum viviparum, and Thalictrum alpinum. The Betula nana Myri. Table 15 A—B, 7—11. In this formation the change from jadar to Salix myri has pro- gressed still further. The number and density of the species is appreciably diminished. H have decreased considerably and G have attained a maximum, The Ch and HH percentages have also risen. The species group spectrum has likewise undergone a change. The quantity of A species has increased somewhat, and in the A subgroups there is displacement from A 3 to A2 and Al. The E subgroups show a displacement in the direction of E 4. Physiognomically chamaephytes and Cyperaceae are dominant, thus of chamaephytes especially Betula nana, Vaccinium uliginosum, STUDIES ON THE VEGETATION OF ICELAND 69 and Empetrum nigrum, and in less degree Salix phylicifolia. Of Cyperaceae Carex Goodenoughü, C. chordorrhiza, C. rariflora, and Eriophorum polystachyum are particularly conspicuous. To these must be added Polygonum viviparum and Thalictrum alpinum. Of the marsh plants Carex rostrata is the most important. Comarum palustre, Menyanthes trifoliata and Equisetum limosum occur more sporadically. The Flôi Vegetation. Table 16 A—B, 1—5. The vegetation is not evenly distributed over the surface of the myri; a number of the species, especially the chamaephytes, are peculiar to the knolls, others, the Cyperaceae, only occur in the spaces between the knolls. Passing from the myri towards the fli, the spaces between the knolls grow larger and larger until the knolls have quite disappeared and with them their vegetation. In table 16 A—B are tabulated the circling results for all the low- land localities investigated in Iceland, from Lyngdalsheidi, Björk and Lækjamôt. The reason why so few localities were investigated was that the rainy summer of 1925 afforded very poor working con- ditions. In spite of the few localities, the table gives interesting and mutually agreeing particulars of the flöi vegetation. Compared with the myri vegetation it is very poor in species, the number of species being 2—4, the density 1—2. Geophytes and helophytic Cyperaceae form the bulk of the vegetation, thus especially Erio- phorum polystachyum, Carex Goodenoughü, C. chordorrhiza and C. rostrata. A few other species occur sporadically. The greatest interest attaches to the biological conditions when compared with those of the myri vegetation. The species group spectrum shows a strong concentration in the central part of the spectrum from E 3 to A 1; the lower groups, and in part the upper ones, are not represented in the spectrum. This spectrum seems to be typical of vegetations on a water- covered surface. The Subularia flag, whose vegetation is covered by a water layer as deep as that of the flöi, has practically the same species group spectrum as the flöi with a large predominance in the central part of the spectrum. The same is the case with the highland fléi. The statistical and biological conditions of the flöi are, as a comparison of the respective tables will show, a further development 70 TABLE 16A-B. H. MØLHOLM HANSEN The Fléi Vegetation in Lyngdalur, at Björk, and at Lekjamot. 1—2 situated in Lyngdalur, 3—4 at Björk, and 5 at the bottom of the valley at Lækjamôt. 1—2 examined on *?/7 1925, 3—4 on 77/7 1925, and 5 on 71/g 1925. Carex Goodenoughii........ —s2chordorcrhizar. 2... Eriophorum polystachyum.. Gavezrostratat wei che. ie Ranunculus reptans........ Carexirarifliora. as el SAR AUS een cn Gom arum palustre ......... Menyanthes trifoliata....... Numbersofispeciesr........ Densityaoisspeciesir oe, te 2 3 4 5 I 7 er ; i E3 G 36 | 100 32 100 » Al G eee! » | 100 | 100 E 4 G | 4 20 100 E3 HH » 100 » > E4 H 88 | » il Peg A2 G he) > 12 > A3 G » » 4 E 4 HH | 4 » E4 HH > 4 » Flag- 2 | 2 5 4 3 vegetation! 1.2 1.0 1.4 2.3 2.0 al ee sie > 3.8 » | 48.3 | 51.0 100 | 71.8 | 100.0 | 96.2 | 100.0 | 51.7 | 49.0 » 28.2 » » » » 2.0 » » » » » 5.2 » » » » 3.8 » 43.1 49.0 23.314184 "71.0 | “> | 813) | Ver 76.7 53.5 | 29.0 | 96.2 91.7 | 43.1 » » | » » » > » » » » » » » » 10:0 1 112° 71:0 » » > > 23:3 127 29.0 | 100.0 25 | 100.0 | 100.0 » » > » 75 » » 66.7 76.1 » » » » » of the changes occurring in the myri formations from the compara- tively dry to the comparatively wet formations. The Flag Vegetation. Cf. figs. 12—13 and table 17 A—B. On the border line between mo and myri are often found long In a floristic and physiognomic respect the flag deviates much from the surrounding mo or myri, and by its mixture of pronounced arctic (A 3) and narrow strips of land called “flag” in Icelandic. Cf table 17h10. STUDIES ON THE VEGETATION OF ICELAND 71 pronounced southern (Th) types of plants it is one of the most re- markable and interesting vegetations of Iceland. The flag occurs as from 2—3 to 15—20 m. wide and often very long clayey flats delimited upwards towards the mo by a more or less connected slope and outwards towards the myri by a con- nected ridge (cf. figs. 11—12). The soil of the flag is level and hori- zontal. If covered with water the whole of the summer it is a naked clayey flat without any trace of knolls. If such a flat is laid dry, the familiar polygonal cracks appear. If the soil is not covered with water in the summer, it will always be cracked, and a greater or smaller number of small knolls covered with vegetation will be spread over the surface. Such is the typical appearance of the flag. If the soil grows drier still, the knolls increase in number as well as in size and we get the flag mo, though the bare clay surface still predominates. The flag vegetation seems to comprise a number of for- mations. Table 17 A shows the circling results for three such for- mations, the Subularia flag, the Koenigia flag, and the flag mo. The Subularia flag was examined in a single locality, the myri at Björk. Here a long strip of Koenigia flag occurred in con- nection with a small brook. The Subularia flag was found at the transition from the Koenigia flag to the brook. At the time when the investigation was made, (the close of July), the soil was covered with water. In the deepest water only scattered specimens of Subu- laria aquatica were found (table 17 A, 1), while further in (table 17 A, 2) it was found in company with some other species such as Koenigia islandica, Juncus bufonius, Equisetum arvense. From East Iceland a formation has been recorded by Helgi Jönsson which must probably be referred to the flag. “Where the soil has an admixture of clay little pools are formed in the depressions which evaporate in the course of the summer. In these places the vegetation varies not a little, consisting now almost ex- clusively of Subularia aquatica, now on the other hand only of Ranunculus reptans which colours such spots quite yellow. I have seen both species occur in such quantities that they coloured the whole bottom of the pool white or yellow. In other places I saw that the vegetation consisted of Ranunculus reptans, Subularia aqua- lica, Alopecurus fulvus and Juncus supinus fairly equally distributed, so that neither one nor the other could be designated as the cha- racteristic plant.” 72 H. MØLHOLM HANSEN TABLE TER: The Flag Vegetation at Björk and Lækjamot. Localities 1—5 situated in South Iceland at Björk c. 100 m above sea level. 1—2 Subularia flag; 3—5 Koenigia flag; 6—7 flag mo from North Iceland, Lækjamôt, c. 50 m above sea level. 1, 2, and 5 examined on 25/7 1925, 3 on 18/7, and 4 on 7!/7 1925; 6—7 on ?°/s 1925. (25. 4/10 m°). | | I ee fr RP ET |: Es | 2 | | Subularia aquatica ...... | E3 | Th | 80 | 76 a ie Ary a li Koenigia islandica....... A3 | Th | » | 80 | 100 | 100 | 100 | 100 | 100 JUNCUS bufonius are... | E3 | Th » | 60 76 96 | 64 » Sedum villosum......... | CR ERE » ) 96 | 100 | 100 88 84 Agrostis alba’. rese. E3 H 1221416 92 100 96 96 88 Juncus triglumis ........ NPA INR | 76 | 68 | 36 64 | 68 I pighumis.....<..- | AS | H 48 | 36 | 36 | 48-| 88 Triglochin palustre...... EA | H SE 16 88 68 68 68 | 32 Polygonum viviparum ... A 3 G > > 72 76 76 88 68 Equisetum arvense ...... E 4 G 28 | 36 44 48 36 52 | 25 Sapma MOWOSH. ... sn... E3 H » 48 60 24 52 | 56 PestucasOvinae. oc... - E4 H 28 36 20 36 | 32 Deschampsia alpina ..... | A2 H i 8 40 4 28 1 28 Muza spieatar.. es... A2 H » > 24 12 48 72 | 80 Mimuartia verna......... | A3 Ch 2 ) 20 36 12 » | » Cerastium caepitosum ... E3 Ch » » 24 60 > 88 60 — alpinum...... | A3 Ch > » 48 48 56 Süleneracaulisem.r....... A3 Ch > ) » » » 20 40 Armeria vulgaris ........ A 3 Ch » » » » » 24 | 24 Kumexzacelosarn........ E3 H ) > > 40 | 16 Poatalpina”- 5 :4""..:.. | A2 H » » ? 28 |: 8 — ENTE ea SIS tir de A3 H 4 12 Thalictrum alpinum..... A 2 H 3 » 4 > » 28 12 Parnassia palustris ...... 1152 H » » er > 28 4 Carex capillaris rn... A3 H ) 2 > 20 8 Pingvicula vulgaris...... E4 H 3 8 4 Agrostis tenuis.......... ERNE ) » ) 2 8 » >» Arenaria ciliata ....n.... 3 Ch 1149 » RAN ae Yaak (ee | » 20 Cardamine pratensis .... E4 | H 2 » | 8 » > | » > Drabatincana ers A2 HT » » | » » | » 8 » Empetrum nigrum ...... E4 Ch » Ye er ae a a ee ee 4 » Epilobium alsinifolium .. | A1 | H > > | » 1:4 |: = | a Equisetum pratense ..... | E2 | G » UMA F3 4 À » > Euphrasia latifolia ...... | A2 Th > lee > | » 4 estuca aN b Lace here | E4 H | » SMU NSB RS 24 | 4 STUDIES ON THE VEGETATION OF ICELAND 73 TABLE 17A CONTINUED. Te | Sell ard + 5 6 7 ae ea de unit RER ES: trihduS... -. . :. A2 H | > > » > » | | 8 Leontodon autumnalis... | E3 | H > » » ) >» | 8 > Linum catharticum ..... E1 Th » » | » 8 » | Potentilla verna......... BS JH air; » » | COAST" Rhinanthus minor....... E 2 Th > ll es ) 4 | 2 Bas herbacea .......... A 3 Ch » » || 16 > | | Saxifraga oppositifolia ... | A3 Ch » N HEN | | 4 Spergula arvensis ....... | E2 chi) » | yeh 38 » | » Taraxacum officinale .... | E2 Fas pila > > || ho : | 4 Thymus serpyllum...... | E4 Ch » » | ge 4 | 4 Mopalnsiris 2... | E3 H » » | i » » | » » TABLE 17B. Biological Spectra of the Flag Vegetation. | | lees 2 3 | 4 RG 7 ne... | 120 | 284 | 884 | 960 | 812 | 1156 | 1040 Bamber of species ......... 3 16 21 19 20 MØRE ee PENSE Of Species.......... 1.2 2.8 8.8 9.6 sale rn UG 10.4 RER » 28.2.|:52.5,|: 492 |. 56.7 58.1 | 68.5 EG ios oie ana out 100.0 | 71.8 | 47.5 | 50.8 | 43.3 | 41.9 3155 à » | 28.2 | 37.6 | 32.9 | 37.9 | 36.0 | 46.9 MN ooo cine 5S hav Cw el leg 158, 10487 | 22.0) ah I ke » | » » 0.4 » | » » Lu hrs Lis AT 28.84 |/ 184: | :19.5:: | 16:2, | 18:7: | 44.9 9.6 CSN 76.7 | 53.5 | 27.6 | 32.9 | 22.6 | 24.6 | 21.2 EPP > » | 05 0.9 20 | 25 0.8 M CAP ER REE on ESS » 0.9 ‘ as | » | » | 72 | 104 | 79 | 159 | 200 Le PPT | 10.0 11.2 | 59.3 | 54.6 | 57.1 63.3 | 60.8 AL | 23.3 | 12.7 | 13.6 | 12.9 | 14.8 | 12.1 | 92 ihn | » » » » | à. | » 2 TR PP PT Pr | 66.7 | 76.1 | 19.9 | 22.1 | 20.7 | 87 | 100 I have seen both these formations, the Subularia and the Ran. reptans formation, in the south country, and I can confirm Helgi Jönsson’s statement that they occur on a water-covered soil. The 74 H. MØLHOLM HANSEN Subularia formation has been described above, the Ran. reptans for- mation under the flöi (p. 70). There seems, however, to be no little difference between the environment of these two formations. The Subularia formation is found where the motion of the water (tem- porarily or continually?) is so strong that it causes a shifting of the bottom material, in the Ran. reptans formation it is less strong and no shifting takes place. As the third link in the chain we have the foi; here the water is stagnant and the bottom covered with mosses. All three formations have but a small density of species and practically the same species group spectrum, a high E percentage and concentration in the central part of the spectrum. The biolo- gical spectrum is of special interest. In the Subularia formation Th are dominant, in the R. reptans formation H, and in the flöi G. The Koenigia flag and the flag mo represent the flag ve- getation proper. The circling results are tabulated in table 17A, 3—7. Nos. 3—5 show the composition of the vegetation on flag at Björk in the south country. The dominant species are in the first place Koenigia islandica and Sedum villosum. Further Agrostis alba and Juncus spp. abound, J. bufonius, J. triglumis, J. biglumis, Tri- glochin palustre, Polygonum viviparum, Equisetum arvense, Sagina nodosa, Minuartia verna, Cerastium alpinum, C. cespitosum, Des- champsia alpina, Festuca ovina, and Luzula spicata. The table gives more precise information as to the part played by the in- dividual species and the variation from locality to locality. Spora- dically a number of plants occur which mostly originate from the surrounding formations, jadar and mo. Nos. 6—7 represent the flag mo at Lækjamôt in the north country. The dominant species are practically the same here (though Juncus bufonius was absent in the north country), and the individual species occur with almost the same F.-percentage. An essential dif- ference between the flag mo and the Koenigia flag is due to the presence of a quantity of mo plants in the flag mo, thus especially Thalictrum alpinum, Rumex acelosa, Poa alpina and P. glauca, Par- nassia palustris, Armeria vulgaris, Carex capillaris, Silene acaulis and several others. Another marked difference between the flag mo and the Koenigia flag is the great number of little knolls found in the former. | The individual species are differently distributed over the sur- face, some species being associated with the clayey soil others with the knolls. On the clayey soil the vegetation is open, and here we STUDIES ON THE VEGETATION OF ICELAND 713 prineipally or exclusively find such species as Koenigia islandica, Sedum villosum, Juncus bufonius, biglumis and triglumis, Triglochin palustre, Equisetum arvense, Cerastium cœæspitosum, Sagina nodosa, Minuartia verna. On the small knolls the vegetation is connected and here we find the species Agrostis alba, Deschampsia alpina, the Festuca spp., Armeria vulgaris, Rumex acetosa and several others, principally such as are common to mo and jathar. Helgi Jönsson was the first to describe the flag vegetation, though without thus naming it. His description of the vegetation on the “clayey flats” which is referred to the “open vegetation of the low- lands” corresponds to the description given above of the flag vege- tation. In “Studier over Ost Islands Vegetation” 1895, p. 86, he says, “they (i. e. the clayey flats) have most frequently a monotonous ve- getation consisting of Sedum villosum, Koenigia islandica, Juncus triglumis and other more casually growing plants. This vegetation on clay varies not a little in composition; of the forms I have seen, I note especially the following: a. The vegetation consists only of Sedum villosum which occurs in a rather dense growth and gives a fresh appearance to the clayey flats by its pretty flowers. b. The vegetation consists only of Koenigia islandica which also occurs in a rather dense growth but in this locality it is most frequently of a red colour. c. The vegetation consists of Sedum villosum and Koenigia islandica either in equal quantities or with now one, now the other as the dominant. d. The vegetation consists of Juncus triglumis as the dominant plant, besides scattered individuals of Sedum villosum and Koenigia islandica, and Agrostis alba in scat- tered tufts.” “It should be noted that in many places a transition to the mo vegetation is seen where most of the species of the mo occur (Gramineae, Juncaceae) growing in scattered tufts with bare clay between, it is merely a younger stage of the grass mo.” In “Vegetationen paa Snæfellsnæs” 1900, pp. 43—44, we read: “Plants characteristic of the clayey flats are Sedum villosum, Koenigia islandica, Juncus alpinus and J. triglumis. The two first-mentioned are most prominent and often occur in an astonishing quantity. The most frequently occurring species are Agrostis alba, Aira alpina, Sagina nodosa, Triglochin palustre, Epilobium palustre, Luzula spi- cata, L. multiflora. In East Iceland this vegetation had quite the same appearance. When these flats dry up in the summer, they are often divided by cracks into many small polygonal areas, 76 H. MØLHOLM HANSEN lozenges, the surface contracting so much owing to the disappear- ance of the water that it cracks. On the flats here. described these are of very different duration, most frequently they last a very short time, disappearing when the surface becomes damp again. For the vegetation these cracks, as far as I can see, are of no importance, since it nearly always occurs on the lozenges themselves.” In "Vegetationen paa Syd Island”, 1905, pp. 13—14, he writes, “Open clayey flats are met with in many places.” “The vegetation on the clayey flats is always very poor in species, and only where the vegetation of the clayey flats is passing into the surrounding associations do we meet with a greater abundance of species. The typical clayey flats as a rule contain the same species everywhere. The few species which are exclusively or principally found on the clayey flats and must thus be designated as characteristic of them are the following: Sedum villosum, Koenigia islandica, Spergula ar- vensis, Juncus alpinus, J. triglumis. The most commonly occurring are Agrostis alba, Juncus bufonius, Equiselum arvense, Epilobium pa- lustre, Poa annua, Stellaria crassifolia, St. media, Ceraslium vulgare, Polygonum aviculare, Sagina procumbens. More rarely we meet with Triglochin palustre, Alopecurus fulvus, Scirpus pauciflorus, Eriophorum Scheuchzeri, Sedum annuum, Poa glauca, Rumex acetosa, Silene ma- ritima, Phleum alpinum, Myosotis arvensis, Veronica serpyllifolia, Rumex acetosella, Thymus serpyllum, Leontodon.” By the above quotations from H. Jönsson’s descriptions of the vegetation and by the circling results given here the flag vegetation has been characterised floristically. If we are to characterise the vegetation biologically, the best way will be to compare the bio- logical spectra of the flag and the neighbouring vegetations, i.e. the mo and the jadar. Table 18 gives the biological spectra of these types of vegetation at Björk and Lakjamöt, viz. respectively moist mo, flag (or flag mo), jadar (or myri). It will appear from the table that the flag vegetation is poorer in species and shows less density of species than the surrounding types of vegetation, the mo and the jadar. This applies especially to the Koenigia flag. As regards the content of Raunkier’s life forms, the flag is especially remarkable by its high Th percentage. As shown above, the Subularia flag had a Th percentage of 71, the Koenigia flag a Th percentage of 20.9, and the flag mo a Th per- centage of 9.4. The table likewise shows a comparatively high H percentage and comparatively low Ch and G percentages. The pro- STUDIES ON THE VEGETATION OF ICELAND .. —1 TABLE 18. Biological Conditions in Mo, Flag, and Jadar at Björk (I) and Lækjamot (Il). Cf. the text. Number | Density | a 5 < ‘Clo KT G Th of species | of species | | | mo... | 39.7 148 | 289 | 523 | 188 | 0.1 LT LASER SE BOV ODER rssh ARE SE ES ON ECTS | 20.9 SETS EIER 42.0 13.8 | 22.3 | 536 | 241 | 0.2 ost m nenne 42.5 159 | 247 | 580 | 141 | 3.3 SEA MNO! a. ce vs 629.09 A dO 18.0 62) 10:7 9.4 Myri vegetation......... | 30 | 112 | 12.5 39.9 | 45.9 21 I | EN Eg NE b | A | ELA TEA 2 ARE BES | ER JE | | | | || | | Bi Meist mo.........: 39.3 | 60.7 | 19.3 | 9.6 | 10.4 | 32.6 | 10.8 | 16.8 | 0.5 LT OT ANRT | 52.8 | 47.2 | 36.1 | 16.5 | 0.1 | 18.1 | 27.7 | 11 | .0.3 LICE ENT | 35.6 | 64.4 | | 15.0 | 8.2 | 12.5 | 35.8 | 13.5 | 14.9 | 0.3 | == all zu II. Moist mo.......... | 56.5 | 43.5 | 32.6 | 15.9 | 8.0 | 22.6 | 10.2 | 88| 2.0 ea.) | 63.3 | 36.7 1415 BAR: aN 4 re 1.2: nes Myri vegetation.... | 50.0 | 50.0 | 22.6 | 25.1 | 23 | 246 | 165 | 87 portion of Th, G, and H is no doubt directly dependent on the comparatively strong desiccation of the flag in the summer. On passing from the mo to the myri on gently sloping ground, in places where no flag vegetation has been developed, there will, as will be shown in more detail later on, occur a decrease of the Ch percentage and an increase of the H, Th, and G percentages at the level answering to the flag zone. Apart from the geophytes this is the same change as characterised the flag vegetation. Hence the flag vegetation must not be regarded as such an isolated phenomenon as its physiognomy and peculiar biology would seem to suggest at a first glance, it must be regarded as an extreme stage of development of those conditions of environment which are found and act in the stage of moisture with which the flag vegetation is associated. If we consider the species group spectrum, here, too, we shall find a peculiar difference between the flag vegetation and the sur- rounding types. The proportion of arctic plants is comparatively high in the flag, and this is due to a rise in the A3 and A 2 per- 78 H. MØLHOLM HANSEN centages, while the A1 species are practically absent. In the E sub- groups the peculiarity appears in the fact that the decrease comes especially under E 2 and likewise in no small degree under the E 4 species, while the E 3 percentage is considerably higher than in the surrounding types of vegetation, mo and jadar or myri. Both the localities examined, the south country as well as the north country, show the same deviation from the adjacent types of vegetation with regard to the species group spectra. The flag vegetation is thus characterised by comparatively high A3, A2, and E3 percentages, and by comparatively low Al, E4, and E2 percentages. As regards the distribution of the flag vegelation it may be said that in Iceland it seems to be peculiar to the lowlands alone. Per- sonally I have sought the flag vegetation in vain in the highland tracts of South Iceland (Lyngdalsheidi), of Arnarvatnsheidi and Holta- vorduheidi (Tvidägra). Magister Palmi Hannesson, who has ex- plored the highlands for a number of years, has informed me orally that a flag vegetation has never been observed here. Helgi Jöns- son refers the clayey flats (i.e. the flag vegetation) to the “open vegetation of the lowlands” (it is not mentioned that they only occur in the lowlands). If we may infer from this that the clayey flats have not been seen by Helgi Jonsson in the highlands, all observations would seem to indicate that the flag vegetation is limited to the lowlands. In Iceland the flag vegetation has been observed in all parts of the country. As mentioned above, H. Jönsson has described it from East Iceland, South Iceland, and South-West Iceland. On my journey in the summer of 1925 I observed flag vegetation in the south country (at the foot of Lyngdalsheidi) in the south-west country (Norötunga in Borgarfjöröur), and in the north country (Lækjamôt in Vididalur). According to the oral communication of Mr. Jacob Lindal, the farmer at Lækjamét, who has travelled through the north country as consulting agriculturalist for a number of years, the flag vegetation is of common occurrence throughout this part. Judging from the literature, the flag vegetation seems to be peculiar to Iceland. I have not been able to find in the phyto- geographical literature on the surrounding countries any record of types of vegetation which may be compared with or referred to the flag vegetation in its typical form. Hence the flag vegetation seems to be a type of ve- getation peculiar to the Icelandic lowlands. STUDIES ON THE VEGETATION OF ICELAND 79 The special association of the flag vegetation with the Icelandic lowlands is, however, probably more apparent than real, for the flag vegetation seems to be a northerly, highly specific offshoot of a series of peculiar Th formations which are met with in Denmark, too, on moderately moist soil. These Th formations have not, however, been more closely investigated though they had early at- tracted the attention of botanists by their peculiar flora. The fol- lowing are some of the most characteristic species: Radiola milli- grana, Linum catharticum, Scirpus setaceus, Centunculus minimus, Myosurus minimus, Gnaphalium uliginosum, a number of small Juncus spp. J. bufonius, J. tenuis, J. capitatus, and J. pygmeeus, besides Bul- liarda aquatica. On slightly damper soil we meet with species such as Subularia aquatica, Pilularia globulifera, Elatine hexandra, Montia spp., Ranunculus reptans, Juncus supinus, Peplis portula, Limosella aquatica. This flora is especially met with on dunes, on damp moors, or in badly cultivated rye fields, and occurs frequently at any rate in western Jutland. In meadows, especially littoral meadows, in addition to a number of species already mentioned, we meet with a number of Gentiana spp., Rhinanthus, Euphrasia, Odontites, and Sagina species. Even in damp birch woods Th formations may be met with consisting of Geranium Robertianum and Impatiens noli tangere. However, it is not only the characteristic life form that is com- mon to the Danish Th formations on soil of moderate moisture and the Icelandic flag, they have also a number of species in common; thus the following species recorded from the flag are found in Den- mark in company with the above-mentioned species. Ranunculus reptans, Subularia aquatica, Juncus bufonius, J. supinus, Triglochin palustre, Agrostis alba, Equisetum arvense, Sagina nodosa, Parnassia palustris, Linum catharticum, Rhinanthus minor, Spergula arvensis, Stellaria media, Scirpus pauciflorus. A comparison of these lists may perhaps be of aid in tracing the forces which give rise to the flag in Iceland. The causes for the occurrence of the Th formations on moderately moist soil in Denmark must be sought partly in fluctuations in the level of the water, partly in the frost phenomena present here and resulting in crumbling and aeration of the soil. When the moderately moist Th formations attain their finest development in the Icelandic low- lands which are sub-arctic and Atlantic in character, this must no doubt be due to a corresponding increase in these factors, especially the frost phenomena. 80 H. MØLMOLM HANSEN C. LÆKJAMOT (THE NORTH COUNTRY). With the farm Lækjamét as my starting point I had an op- portunity of studying the vegetation in a valley in North Iceland for some days in the middle of August 1925. The principal types of vegetation are the same here as in the south country, viz. melar, mo, and myri. The following applies to their distribution. Up the sides of the valley, at the top only the melar vegetation is met with, lower down there occurs a belt in which the mo prevails with spots of melar, but devoid of myri, and at the foot there is a belt where the myri vegetation is dominant and where mo and melar are only found over small areas. In the bottom of the valley the depressions are occupied by the myri vegetation, the more elevated areas by melar and mo. Along the banks of the rivers the vegetation consists mainly of jadar. Between the vegetation of the valley sides and that of the valley bottom there is the essential difference that the myri vegetation of the valley sides consists exclusively of halla myri (well myri), while in the valley bottom it consist exclusively of förmyri (swampy myri). On the boundary line between mo and myri, flag mo was met with, both on the valley floor and on the sides of the valley. Such is the appearance of a transverse section of a vally in North Iceland. Unfortunately time did not permit me to investigate a longitudinal section. What I have seen fragmentarily would seem to show that at any rate the floor of the valley exhibits typical and interesting differences, especially as regards the myri vegetation. At the head of the valley, where there was no level bottom, the halla myri (including the dy vegetation) extended right down to the river. This was the case at Adalbol in the Austerädalur. Further out, as at Lekjamot in the Vididalur, halla myri is only found on the mountain slopes, while the level bottom of the valley is covered with the förmyri (including the flöi vegetation). Still further out the förmyri seems to have been replaced by the fetmyri, the Carex cryptocarpa myri (including the fen vegetation, the Equisetum limosum swamp). This at any rate was the case at the mouth of the Vatnsdalur. Tables 19 A and 20A show the circling results for melar, mo, and myri in the neighbourhood of L&kjamöt. The circling results for the flag mo are given in table 17 A together with the flag ve- getation from the south country. STUDIES ON THE VEGETATION OF ICELAND 81 TABLE 19 À. The Melar and Mo Vegetation at Lekjamot. 1—3 the melar vegetation, 4—7 the mo vegetation, 4—5 the comparatively dry mo, 6—7 the comparatively moist mo. Localities 1, 5, and 7 are situated at the bottom of the valley N.W. of Lækjamôt c. 50 m above sea level; 2, 3, 4, and 6 on the valley slope on the western side of Vididalsfjall, directly east of Lækjamôt c. 75 m above sea level. 4 and 6 were examined on 19/8 1925, 1, 2, 3, 5, and 7 on ?°/s 1925. (1. 20.1/10 m?, 2—7. 25. 1/10 m?). 1 2 3 4 | > 6 1 | 4 —— — Far a EMME SDE EA. oo. ....... Al \¢ Chu 12 8 | Srenaria ciliata....:...-.. A3 Ch 10 16 8 Minuartia verna......... AS. | (Che 25: 1682. | 12 Saxifraga oppositifolia ... A3 Chi) 7102173621260 > Dryas octopetala ........ A3 Ch | 5 | 44 | 40 96 | 72 | 60 Thymus serpyllum ...... E4 Ch | 50 | 56 56 84 | 92 | 68 | 52 Armeria vulgaris........ A3 | Ch 10 16 16 | 44 24 || 28 8 Silene acaulis’..........- A3 | Ch 50 | 52 | 60 72 1:52, 407.28 Cerastium alpinum...... A3 Ch | 50 | 56 | 44 40 16 || 56 16 Buzala spicata -....:.... A2 H 45 | 48 | 48 64 | 60 | 44 | 48 D ect... A 3 H | 25 | 60 | 44 | 24 | 24 | 24 | 16 Festuca ovina........... | E4 H 50 | 44 | 44 28 | 32 | 48 | 68 ee | E4 | H | 5 | 40 | 52 | 96 | 88 | 84 | 96 Agrostis canina ......... | E3 H 5. MAINS | 68 | 92 | 80 | 92 Galium Normanni....... | aı | # | 10 | 20 | 48 | 32 | 60 | 72 | 64 Euphrasia latifolia ...... | A2 Th 10 | 20 | 20 | 44 | 16 | 28 | 24 Balız herbacea .......... | A3 Ch 4 | 20 52 | 80 | 56 | 60 Selaginella selaginoides .. Al Ch 12.| 16 | 60 | 52 | 48 | 36 Juncus trifidus.......... A2 H 871.202 104421760211 602740 Elyna Bellardi.......... A3 H 24 | 12 | 80 | 92 | 68 | 88 Carex capillaris ......... | A3 H 44 | 28 | 68 | 92 | 76 | 40 Polygonum viviparum ... | A3 G 52 | 48 100 | 96 |100 80 Thalictrum alpinum..... A 2 H 32 | 40 | 96 | 92 |100 | 64 Trisetum spicatum ...... A 3 H ay | 19% | 24 | » | 40 4 | 24 Tofieldia palustris....... A2 H » 4 24 | 52 | 36 | 8 8 Empetrum nigrum ...... E4 Ch 4 | 88 | 96 | 72 | 52 Vaccinium uliginosum... E4 Ch » | 56 | 80 | 68 | 28 Equisetum arvense ...... | E4 G | 4 4 |:20 | 40 | 28 | 20 — pratense ..... E2 | G 8 RURAL Carex rigida ............ | A3 G ; 4 | 60 | 48 | 80 | 44 Luzula multiflora ....... E3 H | 28 | 12 | 32 | 24 VE ER A 2 H > 16 4 | 40 | 12 Pingvicula vulgaris...... | E4 H 4 12 | 40 8 | 12 Rumex acetosa.......... | E38 H | 8 8 | 40 | 4 Deschampsia caespitosa.. | E 2 H 5 | 4 » | 52 | 36 Carex sparsiflora. ....... Al G > » 10 DER 12 I | 16 Agrostis alba ........... E3 | H » | 5 re ee E 2 H | » kunst oe PE PICS The Botany of Iceland, Vol, III, 6 82 H. MØLHOLM HANSEN TABLE 19A CONTINUED. | | 1 elisa 4.| 5 (Co | | F FOER || | Anthoxanthum odoratum. EAS | we ) > > | 8 m, Bartschia alpina ........ | A2 H | > 16 » | 4 | Beinlaunanamer ee | A2 Ch Dal 5 4 8 | 8 Botrychium Lunaria..... E 4 G 3 RE >|; 8 Carex alpina: 8:5, À 20): HL, Ne | > 4 Cerastium caespitosum .. | E3 | Ch | LE > 8 >» | 4 Deschampsia flexuosa.... E3 H | | I Sulz Drabahincana naar: SPAS 5 > > || COS Equisetum variegatum... A3 | H | | 4 4 60 | 40 | > Galium verum .......... E 1 Ha [dens » » | |. SEE — + boreale .-2...... | 139 H » » | 56 Gentianagauteaw. re. NT TB) » UW 4 3.13 » — campestris..... E1 H yo A » eal het! 2 20 — tenella oun 6s se | A2 Th | hg | » 3 ) 4 Habenaria viridis ....... Al G | > » | 24 » | 12 > Koenigia islandica....... | A3 Th » 8 |.» | > Parnassia palustris...... | E2 HER NES 55% 4 | 52 16 Plantago maritima ...... | E4 Be ica | ms 4 os » Rhinanthus minor ...... | E2 Th | » » » | 16 > 62 | > Rumex acetosella........ Ed AH ag et a ee Sel >" > i ae Sagina nodosa .......... | 16) rd al” » » | 4 12 | » | 4 Salix glauca ............ Ps loch | >| > | >» |) 207) 6 IS Sedum villosum......... ER: u RES » | » | » 4 | » » Silene maritima......... AI Ch | 10 » 2 | » » | Rune. Violageanmarr... ©... E3 1s 9 SS » 12 un palustris rr RER Eee | E3 H | » » » | » » | » 8 I Il | The Melar Vegetation. Cf. Table 19 A, 1—3. Locality No. 1 represents the vegetation in an area of the bottom of the valley at Lækjamåt, swept bare by the wind; Nos. 2 and 3, on the other hand, are from the foot of Viöidalsfjall. In all three localities the vegetation was open, not covering the substratum en- tirely; in No.1 the surface was covered with gravel and stones without any appreciable trace of solifluction, in Nos. 2 and 3, on the other hand, there was polygonal formation and solifluction. Compared with the mo vegetation, the Ch, A, and especially the A 3 species play a comparatively prominent part, whereas G and the lower E sub-groups are very sparsely represented. The most conspicuous species are Cerastium alpinum, Silene acaulis, Armeria vulgaris, Thymus serpyllum, Dryas octopetala, Luzula spicata, Festuca ovina and rubra, Poa glauca, Agroslis canina, Euphrasia latifolia, STUDIES ON THE VEGETATION OF ICELAND 83 TABLE 198. Biological Spectra of the Melar- and Mo Vegetation at Lekjamot. AE Re 1 ANS EE a | BR “ en... 450 | 780 | 828 | 1776 | 1704. | 1748 | 1420 Number of species ......... 20 30 31 | 42 | 36 41 44 Density of species ......... 4.5 7.8 8.3 | 17.8 | 17.0 17.5 14.2 ee | 60.0 | 77.9 | 79.2 | 66.0 | 62.0 60.0 52.1 ese 40.0 | 22.1 | 20.8 | 34.0 | 38.0 | 39.1 | 47.9 20 . | 41.1 | 57.9 | 522 | 403 | 38.3 | 36.2 | 29.0 ee 13.3 | 144 | 184 | 189 | 164 | 169 | 149 Lo rer oa Sg aloes bee ge 2 5.6 5.6 8.7 || 6.8 7.3 7.8 8.2 ee 38.9 | 19.0 | 19.3 | 218 | 27.5 | 21.5 | 23.7 a Sees pe NE CA ole ae A Fr i 0 eee » 1.0 0.5 5.4 3.1 | 42 9.3 Es dede nie e 2 0.5 > | » 0.2 | » 3.9 NE es 50.0 | 43.6 | 41.1 | 35.1 | 345 | 29.1 | 20.3 nm a nie 47.8 45.6 488 48.4 50.0 52.2 63.7 sa a 8.2 Ga) de et AR » » » » > » » ns: an ies oe ARS 2.2 2.6 Ze. 09 ST Galium Normanni, Saxifraga opposilifolia, Arenaria ciliata, Minuartia verna, and Arabis petrea. The last four species are only found in melar, the others also in the mo where, however, their physiognomic effect is obscured by more dominant plants. Of species peculiar to the melar vegetation at Lækjamét we may especially mention Rumex acelosella and Silene maritima, while the following species are characteristic of the melar at Vididalsfjall: Salix herbacea, Selaginella selaginoides, Juncus trifidus, Elyna Bellardi, Carex capillaris, Trisetum spicalum, Polygonum viviparum, Tofieldia palustris, and Thalictrum alpinum. None of these species are specific to melar, they may all be found in the surrounding mo formations. The Mo Vegetation. Table 19 A, 4—7. On the mo vegetation I was able to analyse 4 localities, 2 at high and 2 at low levels, one set at the bottom of the valley and one on the slope. The surface of the mo is knolly here as elsewhere, but the top 6* 84 H. MØLHOLM HANSEN of the knolls, especially on the side facing the sea (north), had sometimes been deprived of its carpet of vegetation, exposing the loose interior of the knoll to the desiccating and eroding action of the wind. Hence large areas of the valley bottom have been trans- formed into barren stretches of gravel covered with the melar ve- gatation described above. The number and density of species — especially the latter — are comparatively high in the mo both in comparison with the sur- rounding vegetations and with the mo vegetation in other parts of Iceland. The greatest density hitherto demonstrated, viz. 17.8, was found on the mountain slopes of Vididalsfjall. H play a very pro- minent part in the composition of the vegetation, while Ch have de- creased. The G percentage has increased while the Th percentage is unaltered, c. 3. The species group spectrum shows a change in the same direction. The A and especially the A 3 species have de- creased in quantity, whereas the E species, especially the lower sub- groups, have increased. Even if the chamaephytes are of subordinate importance in respect of species and points, species such as Dryas octopetala, Empetrum nigrum, Vaccinium uliginosum, and Thymus serpyllum are physiognomic. Of other dominant chamaephytes we may mention Cerastium alpinum, Silene acaulis, Armeria vulgaris, and Salix herbacea. Grasses and cyperaceous plants play a very prominent part, especially Elyna Bellardi; further Luzula spicata, L. multiflora, Juncus trifidus, Carex capillaris, C. rigida, and C. sparsiflora, Festuca ovina and F. rubra, Poa glauca and P. alpina, Agrostis canina, and Trisetum spicatum. Of herbaceous plants we find especially Polygonum viviparum, and Thalictrum alpinum, further Rumex acetosa, Tofieldia palustris, Ping- vicula vulgaris, and Galium Normanni; of pteridophytes Selaginella selaginoides and Equisetum spp., thus Equisetum arvense, E. pratense, and E. variegatum. The Th are Euphrasia latifolia, Rhinanthus minor, and Gentiana spp. Some floristic differences may be shown to exist between the different types of mo. In the low mo Deschampsia cespitosa will always be met with; even though the F.- percentage is not very high, the species is physiognomically fairly predominant. Carex sparsiflora is also more frequently met with in the low mo than at higher levels. In the mo of the valley slopes the following species not found at the bottom are met with. Equisetum variegatum, Rhinanthus minor, Habenaria viridis, Parnassia palustris, and Bartschia alpina. STUDIES ON THE VEGETATION OF ICELAND 85 It is chiefly these species which cause the greater density of species on the valley slopes. Biological differences also occur. Thus the Ch percentage is higher in the high than in the low mo, whereas the reverse is the case with the H percentage. The high E percentage of locality No. 7 is due to a deeper and more constant snow-covering in the winter. The Myri Vegetation. Cf. table 20 A, 1—7. Owing to the short time at disposal only a very few of the myri formations were investigated; these were a series of moist formations in the halla myri (1—5), and a couple of formations in the för- myri (6—7). The halla myri is only found along the foot of mountains, and it is essential to its occurrence that the ground-water comes to the surface. This causes a peculiar difference between the halla myri (well myri) and the förmyri (swampy myri). In the förmyri the amount of moisture is determined by the precipitation on and around the depressions in the myri; the quantity of nutrition sup- plied by the precipitation is comparatively small or nil, just as also the temperature conditions are relatively closely dependent on the temperature of the air. In the halla myri the nutrient salts are constantly renewed by the ground water, the temperature of which will more or less influence the temperature of the soil according to its amount. The temperature of the ground water is constant throughout the year, that is to say, it is equal to the mean annual temperature in the locality in question. Thus the halla myri will be warmer in the winter but cooler in the summer than the swampy myri. As a result the species group spectra differ widely. The lower E sub-groups (E 3 and E 2) dominate in the halla myri owing to the favourable temperature conditions in the winter (I) and A 2 and A3 species owing to the cool summer soil (!), while the A 1 species are peculiar to the flöi of the formyri. Owing to the larger amount of nutrition the number and density of the species is greater in the halla myri than in the förmyri, especially in the dampest areas. The biological spectra agree in regard to the preponderance of the geophytes, while there is an essential difference in the chamaephytes, the Ch percentage being highest in the förmyri. In the halla myri the physiognomical dominant is Equisetum dalustre, as in the förmyri it is Carex Goodenoughii besides Erio- 86 H. MOLHOLM HANSEN TABLE 20 A. The Myri Vegetation at Lekjamot. Localities 1—5 situated at the foot of Vididalsfjall on its western side c.75 m above sea level and represent Halla myri of various degrees of moisture. 6—7 situated at the bottom of the valley c. 50 m above sea level, For myri. 1, 3, 6, and 7 examined on ?1/s 1925; 2, 4, and 5 on 2218. 192522025 10.17): | | | | 1 | 2 | 3 | 4 | Sel or | EEE Nes | FE Carex spanicea kreere E3 ING 84 | 8 871,2 16 | Scirpus caespitosus...... E 4 H | 76 4 4 12 8 Carex microglochin...... A2 G 80 | 20 | 32 | 36 » » | == A Capillaris):). 4c =<: | A3 H 84 | 96 | 20 ) » | 12 > Tofieldia palustris....... | A2 H 56 | 24 > > > 8 Pingvicula vulgaris ...... E4 Le RE NE > > 8:20 Equisetum variegatum.,. | A3 H » 48 12 > 4 » » — palustre ..... | 2 |G 60 96 64 88 84 > Luzula multiflora ....... Mae "H 16 60 8 » > 16 Bartschia alpina ........ NAS is Et 24 48 » » > » Calamagrostis neglecta... E4 H > 16 | 12 » | 52 4 Trigochin palustre ...... | E4 | H > » | 20 | 40 | 64 41 Menyanthes trifoliata .... | E4 | HH > » 48 |. 48 | 4 » | Joucusaipinns 2172405... | E3 | H 4 > 4 | 52 | 36 » | » Eriophorum Scheuchzeri. | A3 HH » » » » | 56 bassline es Carex Lyngbyel ... ....0.. =; E3 | G » ÿ » » 1100 > Eriophorumpolystachyum E4 G 96 | 16 | 24 | 32 | 40 | 96 100 Polygonum viviparum ... A3 | G 1100 |100 | 88 | 52 » || 76 ” Thalictrum alpinum..... | A2 H 40 | 84 | 44 » | » | 60 » Carex Goodenoughii ..... | E3 G 72 | 92 | 96 |100 | 56 | 76 | — u rarılloTa ES | A2 G | 40 | 96 100 |100 | 60 | 68 | >» — chordorrhiza...... | Al G 12 » | 68 | 20 » 8 | 100 eA ic: herein (88540 EGEN hoe > > » | » | 84 > FSA RA US SR SD A3 G 16 » 4 » » | 68 4 Vaccinium uliginosum... | E4 Ch || 92 | 80 | 68 4 | » | 96 | Betulasnanalec sess ck. GAR, Ch > a 8 4 i 3 68 » Agrostis alba. 22... 0 | “ES H > 4 Ann > | » 3 — Cana ace E3 H | » » Al) > » Un) Anthoxanthum odoratum. E 3 Hs » » » RE: » Cardamine pratensis..... | E.4 H 4 el We et aes > | a2 » Carex rigida ...... ..... FERRER CR DER TENTE ERNEST > — -rostrain.. ice Baar > > | 12 » » | >» » Cerastium caespitosum .. E3 ET eerie re 2 » » | » Deschampsia caespitosa.. E 2 H | » 4 | » a Le » Dryas octopetala ........ | A 3 Ch » A ae | » » » | » > Elyna Bellardi.:......... | A3 Hl > DE te » » | «4 » Empetrum nigrum...... ‘ | E4 Ch s34 3]: 24 | » » » || 32 » STUDIES ON THE VEGETATION OF ICELAND TABLE 20A GONTINUED. 87 Euphrasia latifolia FETTE N LE ahs. 0.0 cue st Juncus arcticus trifidus triglumis Luzula spicata Parnassia palustris SE DER Rhinanthus minor Salix glauca herbacea Silene acaulis Thymus serpyllum ner Tre. A2 Th B4 | H eave DS © AH OR à Ban AS AG ay 0 EL A3 | H Ken E2 | H Aa ME E2 | Th A3 | Ch A3 | Ch A St cH E4 | Ch | 2 4 | 36 4 12 48 shew 8 2 ER LE » 4 4 4 ) » 20 » 4 4 4 4 12 1553 4 4 4 | 5 | 4 > » » >» > 12 12 » » | » » | » TABLE 20B. Giri RR = 24 | 32 | > Is men | : | | | | | a Biological Spectra of the Myri Vegetation at Lekjamot. Points sum Number of species ......... MAD Of species... ER ne EEE Tree WET nn EEE ET eee set te, RC e0…e DEE EEE Eee EEE TE TE | 1 | a NES 4 5 | 6 | 7 ERTL) | | 1048 | 1180 | 780 | 600 | 572 | 908 | 204 | 29 37 29 14 13 27 3 10 11.80 1,778 |, GO Bt Ker 20 | = ws a Aly = | | | | 45.4 | 546 | 51.3 | 37.3 | 23.1 | 43.6 |. 510 54.2 45.4 | 48.7 62.7 | 76.9 | 56.4 | 49.0 19.8: | -25.4 | 17.4 | 107 | 12.6. | 19.4 |. -3,0 23.7 | 26.4 | 23.6 | 23.3 | 10.5 | 22.9 Fe 199271 °10,8° || 3.3 » 13 | 490 | 30.5 | 18.3 | 23.1 | 22.6 | 28.7 | 43.6 | 49.0 16.8 | 16.6. | 17.4 | 25.4 | 33.6 | 12.8 69 | 10.5 | 82 | 147 | 147 | 10.3 | 146 | 108 |: 0,7 > | 229 | 36.1 | 44.6 | 19.0 | 19.3 | 30.1 | 22.0 > 53.8 38.0 62.1 71.3 | 594 | 55.1 | 100.0 | > | 7172| 80 | 105. |, °» » 1.08 1.84 | wi ie ah 38 H. MØLHOLM HANSEN phorum polystachyum, and in the fétmyri Carex Lyngbyei. Of other plants it is mostly Cyperaceæ which are found intermixed with Equisetum palustre, thus species like Eriophorum polystachyum, Carex Goodenoughii, C. rariflora, C. microglochin, C. capillaris, C. panicea, and C. chordorrhiza, besides Scirpus cespitosus. Other more conspi- cuous plants are Polygonum viviparum, Thalictrum alpinum, Luzula multiflora, Bartschia alpina, Tofieldia palustris, Pinguicula vulgaris, Selaginella selaginoides, and Equisetum variegatum; of Ch only Vac- cinium uliginosum occurs with any noticeably high F.- percentage. Locality No. 2 represents the typical, i. e. the most widespread halla myri formation; No. 1 is from a somewhat high level, Nos. 4—5 from rather damp soil. If the water in the depression is stagnant, Carex rariflora will be the physiognomical dominant (cf. No. 4), if it contains running water, Carex Lyngbyei will dominate, perhaps in company with Eriophorum Scheuchzeri (cf. Nr. 5). The two for- mations can be recognised, even at a distance, by their colours, the Carex rariflora formation by a darkgreen hue, the Carex Lyngbyei formation by its yellowish green tinge. The surface differs from the typical formation by being devoid of knolls. Where springs are formed in the halla myri, a moss vegetation will develop. On this vegetation, the dy, Helgi Jonsson writes as follows (1900, p. 25): — “the moss pools occur most frequently at the foot of the mountains where the numerous springs appear; here they pass imperceptibly into the myri.” “The mosses which seem to predominate are Philonotis fontana and Mniobryum albicans v. glacialis.’ “Scattered here and there in the moss carpet there occur Epilobium alsinefolium, E. Hornemanni, Cerastium trigynum, Montia rivularis, Saxifraga rivularis, Ranunculus hyperboreus, and Catabrosa aquatica. In addition there occur Epilobium palustre, FE. lactiflorum, Eriophorum Scheuchzeri, Carex cryptocarpa, C. canescens, Eriophorum angustifolium, Equisetum palustre, Carex rariflora, Me- nyanthes and Saxifraga stellaris. The mosses are exclusively dominant; the intermixed species are both few and far between.” The förmyri is only found at the bottom of the valley. An es- sentiel difference between halla myri and förmyri is this that Equi- setum palustre is lacking in the förmyri, Betula nana in the halla myri. The most conspicuous plants are Eriophorum polystachyum, Vaccinium uliginosum, and Betula nana, further Carex Goodenoughii, rariflora, saxatilis, and dioica, besides Polygonum viviparum and STUDIES ON THE VEGETATION OF ICELAND 89 Thalictrum alpinum. Of minor importance are Festuca ovina, F. rubra, Cardamine pratensis, and Empetrum nigrum. Where the ground-water covers the soil throughout the year the knolls disappear, the surface is level, and the flöi vegetation is formed (cf. table 20,7). The dominant species are Eriophorum poly- stachyum and Carex chordorrhiza. D. NORDTUNGA. In the preceding part we have dealt with all the lowland types of vegetation except the forest. In the following I shall give a description of it in so far as I was able to examine it during a couple of days’ stay on the farm Norötunga in Borgarfjordur. Here the forest occurs both at the bottom of the valley and on the sunny northern slope, but not on the shady southern slope. The succeeding investigations, however, apply especially to the forest at the bottom of the valley. Viewed from one of the valley slopes the forest does not appear as a continuous growth in the sense that the trees are equally di- stributed over the entire area of growth, but open patches where the birch is low, very scattered, or entirely absent, alternate with stretches where the growth is denser. It was, however, especially on the outskirts that this was the case, in the interior of the forest the growth was continuous. Fig. 14 shows a glade in the forest. The soil is full of large knolls. The statistical results are given in table 21 A. Nos. 1—2 are from the forest itself, 3—6 from the glades in the forest, No. 7, finally, is the mo some distance outside the forest between the latter and the farm. On the forest-ground proper grasses are dominant, the following being the most numerous: Deschampsia flexuosa, Anthoxanthum odoratum, Agrostis canina and A. tenuis, further Festuca rubra; of herbaceous plants there occur Thalictrum alpinum, Carex rigida, Galium boreale and Normanni, and Polygonum viviparum. The chamaephytes are of minor importance, Vaccinium uliginosum and Empetrum nigrum are found here and there. The vegetation of the glades occupies an intermediate po- sition between the forest-ground and the mo. The species known from the forest-ground recur here, moreover a number of typical 90 TABLE 21A. H. MØLHOLM HANSEN The Forest Undergrowth at Nordtunga. Localities 1—2 represent forest undergrowth below dense birch copses, 3—6 the vegetation in open birch copses or glades; 7 is the mo vegeta- tion outside the forest. 1, 4 and 6 examined on ”5/s 1725, 3 on 78/s, DA 5) yavel 7 Betula pubescens Deschampsia flexuosa.... Anthoxanthum IASTOSUISECAMINAl = = von 2er | Festuca rubra Thalictrum alpinum Carex rigida Galium boreale = Normanni Polygonum viviparum ... Vaccinium uliginosum... Empetrum nigrum Juneusgrritduser..n....e DES on N Nenn Galhumiverame 7": "2 | Luzula multiflora ElynauBelagdierereen ee Thymus serpyllum Salıxaberbaceagn 2.0. Equisetum pratense Luzula spicata ...:........ Selaginella selaginoides .. Silene acaulis ASTOSUSTENUIS.. 2.8. Armeria vulgaris........ Botrychium Lunaria..... | Cardamine pratensis..... Cerastium alpinum...... caespitosum .. Equisetum arvense variegatum... | Erigeron neglectus Euphrasia latifolia ...... Geranium silvaticum .... Hieracium silvaticum.... | Hierochloé odorata...... | Leontodon autumnalis... Pingvicula vulgaris odoratum | on 27/5 1925. (25. 1/10 m?). 1 2 3 4 5 6 E3 F | 100 | 100 | 88 | 24 4 4 E3 H | 96 | 100 80 76 80 84 E3 H | 68 48 || 48 68 64 | 92 E3 H | 60 | 60 | 44 | 96 | 60 | 88 | E4 H | 52 | 44 | 76 | 76 | 92 | 88 A2 H | 60 | 60 | 60 | 80 | 76 | 96 A3 G | 44 76 60 80 64 76 E2 H 32 48 80 72 68 92 Al H | 36 4 | 32 | 64 | 60 | 56 A3 GR 0236 12 44 64 | 60 76 E4 | ch | 36 | 24 | 88 | 92 | 84 | 76 EA | CH 24 56 | 76 | 72.| 84 A2 H | 8 4 | 20 | 40 | 28 | 20 E4 | H | 4 | 16 | 20 | 52 | 48 | 32 E 1 H | 8 8 | 44 | 56 | 56 | 36 E 3 H | 8 8 |. 48 |:36 |. 244120 Riot | 4.) 32: 16 1008 E 4 Ch | 12 4 200 | ll | N eg B26 36 | 4 » | 32 A2 | H la ka) 6 Al Ch 4 Be > 4 A3 Ch | » » » E2 H s6. |) 64.) =. 9 > A3 | Ch | | | » | > E 4 GÆR ) » 0) ) +, Aa E4),| ma 28 | 8 | 12004 A3 Ch 4 An » E3 Che In 4 4 |) ae E4 G » » 8 > | 4 A3 H | 4 » » | » Al H > Sle 8 | Os A2 Th teh » (| oe EA SK | 20 | » FOR ead | 4 > E 2 G , | > | » | 4 E3 H | AN Sa. 1) 4 4°| 204 E4 | H I» Sat ME AJ STUDIES ON THE VEGETATION OF ICELAND 91 TABLE 214 CONTINUED. 1 2 3 4 5 6 i NZ... A 2 H 4 > Era... A 3 H 12 8 > =) i ot :._....... E4 G 12 3 12 Potentilla verna ......... A 2 H 8 4 > 12 Ranunculus acer ........ E 4 H 8 > Rubus saxatilis ........ E3 H N 4 i LIL MERE eer E 3 H 8 8 4 > + Taraxacum officinale .... E2 H 4 12 8 12 Trisetum spicatum ...... A3 H 2 16 + 4 16 Viola palustris.......... E3 H 4 8 8 16 TABLE 218. Biological Spectra of 21 A. 1 2 3 4 5 6 7 0 LT EE 704 772 1072 | 1172 | 1068 1124 1392 (604) | (672) | (984) | (1148) | (1064) | (1120) Number of species ......... 20 26 30 27 26 27 31 Density of species.......... 6.0 6.7 9.8 11.5 10.6 11.2 13.9 2 een 29.0 | 212 | 216 | 35.3 | 30.0 31.0 48.0 Ee eee 71.0 788 784 642 70.0 69.0 52.0 een ann 13.6 124 | 104 17.4 14.2 15.3 25.3 2 rr ae eee 10.2 8.3 7.8 113 | 10.1 10.3 147 mm mm à = 5.1 0.5 34 12 3.6 3.3 8.0 | ua --- 5165 | 18.1 | 239 | 273 | 307 | 274 | 330 2 48:9 | 435 | 35.1 | 259 | 228 28.8 9.2 i 2e 4.5 16.1 15.3 6.1 11.2 9.6 9.8 = PSN 1.1 1.0 4.1 4.8 3.2 3.2 i a EE ] SN PRES 11.3 5.4 16.3 17.1 17.3 15.4 29.0 ee 75.5 744 728 69.7 68.0 689 55.2 Se 13.2 | 202 | 110 | 132 | 147 | 157 | 155 Dd da PP > ; > ; i Ce EPA PEN PIRE 3 - i > 0.3 mo plants begin to appear. though only here and there. Grasses still dominate, thus Deschampsia flexuosa, Anthoxanthum odoratum, Agrostis canina, Festuca rubra and ovina, Luzula multiflora, Juncus 92 H. MØLMOLM HANSEN trifidus, and Carex rigida; some herbaceous plants likewise occur, thus Polygonum viviparum, Thalictrum alpinum, Galium boreale, Nor- manni, and verum. The chamaephytes Vaccinium uliginosum and Empetrum nigrum occur with as high an F.-percentage in the mo. The mo is the typical Icelandic mo, with the same species that occur elsewhere; selected at random the most conspicuous plants are: Agrostis canina, Festuca rubra and ovina, Carex rigida, Poly- gonum viviparum, Thalictrum alpinum, Galium boreale and Normanni, Vaccinium uliginosum, Empetrum nigrum, Juncus trifidus, Luzula spicata, Selaginella selaginoides, Elyna Bellardi, Thymus serpyllum, Salix herbacea, Trisetum spicatum, and Silene acaulis. The following essential difference between the mo and the forest-ground vegetation may be noted. The mo vegetation is characterised by Ch and A species, the forest-ground vegetation by H, especially grasses, and E species. These differences will no doubt prove greater upon closer investigation. The forest-ground at Nordtunga was non-ty- pical in so far as a series of typical forest-ground plants such as Fragaria vesca, Rubus saxatilis, Geum rivale, Brunella vulgaris, Trifo- lium repens, Geranium silvaticum, Vaccinium myrtillus, Arctostaphylos uva ursi, Calluna vulgaris and several others did not occur here. V. THE ICELANDIC HIGHLAND FORMATIONS. N° thorough investigations of the highland vegetation which might serve as a basis for comparison with the lowland vegetation and the vegetation in other localities in the highlands having so far been carried out, I have endeavoured to furnish such a basis by my investigations. By its geographical position, its height above sea level, and the grandeur of its scenery, Tvidägra, the highland plateau west of Langjökull, seemed to me best fitted for such a pur- pose. Hence the investigations described below have been carried out there, that is, more precisely indicated, in the region round Ulfs- vatn on Arnarvatnsheidi. Before I proceed to a more detailed description of my own in- vestigations I shall give an account of what is known about the highland vegetation. The first more comprehensive description is that of St. Stefansson (1894). On p. 199 Stefansson writes: “At the Vatnsdalshals and on the high plateau we especially meet with three formations, viz. the myri, melar and heather mo vegeta- tions.” The latter I found best developed in the so-called “Helga- vatnsnupar”, gravelly heights on the eastern margin of the Vatns- dalshals. The depressions between these are more or less, and some- times entirely, covered with a greenish-brown carpet formed of Empetrum nigrum, Vaccinium uliginosum, and Betula nana completely mixed up with each other. Salix herbacea and glauca also occur almost everywhere throughout this carpet, whereas Salix lanata appears only here and there. Loiseleuria procumbens is found in no small quantity in several places, and Cassiope hypnoides is met with here and there. In several places the dwarf birch predominates over the crowberry (Empetrum nigrum), but as a rule the latter is dominant. Of other plants I shall mention first Dryas octopetala, which is hardly ever absent from any Icelandic heather mo, next Thymus serpyllum, Polygonum viviparum, Galium silvestre, Silene 94 H. MØLHOLM HANSEN acaulis, Armeria (here and there), Cerastium alpinum, Tofieldia bore- alis, Juncus trifidus, Luzula spicata and L. multiflora, Alchemilla al- pina, Pingvicula vulgaris, Carex rigida, Festuca rubra, and further, where the soil is a littte damp, Saxifraga Hirculus, and Sedum villosum”. On the high plateau to the south of Vatnsdalur the heather mo is “stunted and patchy” and “the gravelly subsoil comes to the surface everywhere.” The composition of the species is as follows: Empetrum, Betula nana, Salix glauca, (here and there), Salix her- bacea, a very scattered growth of Vaccinium uliginosum, Dryas octo- petala, (rather sparingly), Elyna Bellardi, Silene acaulis, Armeria mari- tima, Cerastium alpinum, Polygonum viviparum, Trisetum spicalum, Poa caesia, Festuca ovina v. vivipara, Thalictrum alpinum, and Arabis petrea. The melar vegetation on Vatnsdalshals is described as follows; ‘Silene acaulis and in some places Dryas are the most conspicuous plants, notably in the flowering season but, in addition to these and several other plants growing among the heather, there also occur Silene maritima, Saxifraga oppositifolia, S. decipiens, S. nivalis, and on high, almost quite bare, gravelly flats Arenaria ciliata, Alsine verna, f. propinqua, Arabis petrea f. glabra and hispida, Draba verna, Trisetum subspicatum, Rumex acetosella, Armeria mari- fima and others.” In the highlands south of the valley the melar vegetation “re- sembles that of Vatnsdalshals, but is much poorer in species.” On Vatnsdalsfjall, “on the gravelly crest of the mountain, c. 2000‘ above the sea, the typical mountain field or melar vegetation, where the plants occur in isolated specimens with large bare patches between, attains its full development, almost without the invasion of any foreign elements. I observed the following species: Ranun- culus glacialis, Luzula arcuata, (both characteristic of high moun- tains), Luzula spicata, Poa pratensis, P. alpina (vivipar), P. caesia, Aira alpina, Saxifraga nivalis, S. oppositifolia, S. hypnoides, Cerastium alpinum, Erigeron alpinus, Polygonum viviparum, Silene acaulis, Dryas octopetala (in small quantity), Potentilla maculata, Ranunculus acer, Armeria sibirica, Salix herbacea, Triselum subspicatum.” On Vididalsfjall, at a height of c. 3000‘ the melar vegetation had the following composition: Silene acaulis, Saxifraga oppositifolia, Sedum acre, Ranunculus glacialis, further Cerastium alpinum f. lanata, Poa alpina, Aira alpina, Poa caesia, Saxifraga hypnoides, S. decipiens, STUDIES ON THE VEGETATION OF ICELAND 95 Polygonum viviparum, Silene acaulis, Armeria maritima, Salix her- bacea, Arabis petræa, A. alpina, Saxifraga cernua and S. nivalis. The third type of vegetation mentioned by Stefänsson is the myri vegetation. This is described as follows in pp. 201—203. “On Grimstungnaheidi to the south-west of Vatnsdalur I met with a rather widespread form of vegetation which somewhat resembled the usual heather mo by its uneven, more or less knolly surface and its greyish hue, but the soil is rather damp, at least in the early summer, and here Grimmia hypnoides is entirely dominant, covering large areas completely.” These moss moes “which must in the main be regarded as transitional between the heather mo and the extensive vegetation of the pools” are poor in flowering plants, though Cassiope hypnoides and Pedicularis flammea are of common occurrence. On the vegetation proper of the pools Stefänsson writes: “even at a distance two variations of this vegetation may easily be distinguished, the brownish Eriophorum pools characterised by Erio- phorum angustifolium and the bluish-green Carex pools, where the bluish or greyish-green C. ampullacea is the dominant plant. This difference is so striking that the peasants have a special term for each of these; the former, the Eriophorum pools, are called “Brok- fla”, while the latter pools are called “Ljosastarar flå”. They also differ somewhat with regard to composition of species. In the Eriophorum pools Carex pulla, C. alpina, C. vulgaris, and C. hyper- borea are the most conspicuous, whereas, in the Carex pools, Carex rariflora, C. vaginata, and C. vulgaris are very common, likewise Juncus biglumis. But as a whole this vegetation of the highland pools is extremely poor in species, and of dicotyledons I only ob- served very few” e.g. Cardamine pratensis and Slellaria crassifolia. “Below, on Vatnsdalshals the vegetation of the pools is somewhat richer and more like that of the pools at the bottom of the valley, though not nearly so luxuriant. It consists in the main of the common sedges, e. g. Carex vulgaris, C. chordorrhiza, C. rariflora and C. rigida, Eriophorum polystachyum, and Scirpus cespitosus.” These are the three types of vegetation, mo, melar, and myri, occurring in the highland tracts around Vatnsdalur. However, from the descriptions we must assume that, in addition to these three, there occurs a fourth type viz. the geiri or snow patch vegeta- tion. Thus Stefansson, when dealing with the vegetation on Vidi- dalsfjall, on p. 196, writes as follows: “Some of the little grooves 96 H. MØLHOLM HANSEN extending like green or brownish-green bands down the greyish slopes were, where the soil was damp, overgrown with grass and cyperaceous plants, others, on the other hand, had a dwarfish heath vegetation where as usual Empetrum was dominant in company with Vaccinium uliginosum and Salix herbacea. In the greater de- pressions this heath vegetation was very abundant. In such a de- pression I observed: Empetrum, Vaccinium uliginosum and Myrtillus, Salix herbacea and glauca, Anthoxanthum odoratum, Leontodon au- tumnalis, Phleum alpinum, Rumex acetosa, Coeloglossum viride, Aira flexuosa and several others.” “On small flat, sometimes almost horizontal, ledges far up the mountain, c. 1500—2000‘ above the sea, but notably in the cup-shaped depressions and smaller round valleys where the snow remains until far into the early summer, and a layer of humus has gradually formed on the rocky bottom, the dwarf willow becomes entirely dominant. This small very hardy dwarfish growth in such localities forms a dense “half-inch wood” which covers large areas of the barren rocky ground like oases.” Of flowering plants I noted the following in a large area of dwarf willows: Salix glauca (few and small specimens), Poa alpina, Aira alpina, Thalictrum al- pinum, Cerastium alpinum, Thymus serpyllum, Erigeron alpinus, Luzula spicata, L. arcuata, Galium silvestre, Oxyria digyna, Armeria maritima, Phleum alpinum, Polygonum viviparum, Festuca rubra, Ra- nunculus acer, Gnaphalium supinum, Rumex acetosa, Carex lagopina, C. rigida. Further Alchemilla vulgaris and Sibbaldia were intermixed with the dwarf willow covering, but these plants also formed dense growths on damp spots rich in humus. The common heath plants Dryas, Empetrum, and Juncus trifidus occurred in very small quan- tity. But this composition of the species varies somewhat according to the varying degree of moisture of the soil. Thus, on a cold and damp slope with a north-eastern exposure, where the turf was chiefly formed of Salix herbacea, in addition to many of the above- mentioned plants I noted the following: Cerastium trigynum, Ra- nunculus pygmeeus (in several places these two latter species are found as associates), Saxifraga stellaris, Veronica alpina, Epilobium alpinum, all in quantity; further Taraxacum officinale, Equisetum variegatum, and Alchemilla alpina.” On pp. 194--195: “the three latter (Gnaphalium norvegicum, G. supinum, and Sibbaldia procumbens) occurred here and there in small depressions and grooves in such quantity that they formed STUDIES ON THE VEGETATION OF ICELAND 97 a continuous carpet.” The three species referred to are some of the most typical plants of the snow patches in Iceland. The above-cited descriptions of localities in connection with the flora lists given correspond closely to the geiri vegetation elsewhere, e.g. on Lyngdalsheidi and Arnarvatnsheidi, and even though Ste- fansson does not distinguish the geiri or snow patch vegetation as a separate type, its presence in the highland tracts around Vatns- dalur may be taken for granted. Hence the vegetation here con- sists of the following four types: melar, mo, myri, and geiri. The highland vegetation of East Iceland and Snæfellsnes has been described in more detail by Helgi Jonsson. In “Vegetationen paa Snæfellsnes”, where the highland vegetation is dealt with, Helgi Jönsson distinguishes between 3 types, viz. grimmia heath, moun- tain pools, and fell-field (“Fjeldmark’’). Of the fell-field we find the following statement on p. 27 ff: “the fell-field, as taken here, extends over the upper region of the mountain from the upper limit of the heather moor at c. 300—400 m. above the sea, to the snow line, with the exception of the mountain pools and the grimmia heath.” “Its surface is very heterogeneous, consisting now of extensive gravelly or gravelly and clayey flats, now of more or less downward sloping stretches, bare rocks and screes. In smaller hollows the subsoil is covered with layers of clay, and in depressions lakes of greatly varying sizes are met with.” “The plants of the fell field are scattered here and there, either in solitary specimens at a considerable distance from each other, or they are collected in small scattered tufts. Often they occur in patches, forming a carpet, notably the mosses, Salix herbacea and Sibbaldia. The scattered plants and the scattered patches of growth do not, however, affect the physiognomy of the landscape. What characterises the fell field is principally the stony, gravelly, or clayey soil.” “The vegetation of the fell field is very heterogeneous since, as was pointed out, the soil is very varied. As regards the appearance of the vegetation, the factors of decisive importance, besides the height above the sea, are the greater or less exposure of the locality and its water supply.” “The part played by the phanerogams in the composition of the vegetation grows less and less with increasing height; at the lower limit of the fell field on the other hand, they are very abundant. Here small Empetreta are met with in patches, Loiseleuriela, Cassi- The Botany of Iceland, Vol. II. 7 98 H. MØLHOLM HANSEN opeta, Saliceta (herbacea) and Sibbaldieta in irregular and confusing intermixture. Interspersed among them there are many herbs which do not belong to the fell field, especially the herbs of the heather moor. There is no well-marked limit here, but the fell field may be plainly distinguished by the fact that the plants of the heather moor are not able to form any heath but grow in paiches or as scattered specimens, and that the small characteristic Saliceta (her- bacea) and Sibbaldieta of the fell field have begun to appear.” H. Jonsson distinguishes between the following 5 types of vege- tation in the fell field: gravelly flats, screes, the Anthelia-crust, the Salix herbacea and Sibbaldia vegetation, and the Philonotis fontana dy. I. The gravelly flats. “With the exception of the naked rocks, the gravelly flats are those parts of the fell-field which are poorest in vegetation. In the upper part of the fell-field they are exceedingly poor in plants, especially if they are exposed; in the lower part of the exposed flats often only a solitary Ranunculus glacialis or a solitary Cerastium alpinum is met with. On less ex- posed flats in the lower part of the fell-field a considerably richer vegetation is met with.” In such a locality Salix herbacea and Al- chemilla alpina occurred in patches, further Armeria, Aira alpina, Luzula spicata, Oxyria digyna, Cerastium alpinum, Silene acaulis, Arabis petræa, Galium silvestre, and Saxifraga cespitosa. “On the gravelly flats which are studded with small shelter- givers, small stones dispersed more or less closely over the flat, we meet with the richest vegetation which can occur on a gravelly flat in the fell-field. Round the little stones there occur narrow fringes of Grimmia hypnoides. In the Grimmia fringes grow the most frequently occurring plants of the fell-field. Il. The screes. “From the last-mentioned gravelly flats there occur the smoothest transitions to the screes. When the shelter- givers, the scattered stones, become larger and occur closer together, the surface loses the character of a gravelly flat and must be re- garded as a scree with small stones. Here Grimmia hypnoides is the most important plant, though it does not form heath.” “As regards the plants intermixed with it, we must distinguish between the upper and the lower fell-field, or levels above and below 600 m.” In the upper fell field there is as a rule only an intermixture of lichens, the phanerogams are poorly represented. “Thus, in the upper part of the fell-field on Snæfellsnes Jökull at an altitude of 600 m. only the following species were met with: Armeria maritima, STUDIES ON THE VEGETATION OF ICELAND 99 Silene acaulis, Luzula arcuata, Arabis petræa, Aira alpina, Oxyria digyna, Salix herbacea, and Saxifraga rivularis. “At higher levels only some few individuals of Salix herbacea, Sibbaldia procumbens, and Aira alpina were met with.” “In the lower fell-field the phanerogams play a much more pro- minent part”. The most frequent plants here are: Salix herbacea, Saxifraga rivularis, Sibbaldia procumbens, Oxyria digyna, Ranunculus glacialis, Pedicularis flammea, Luzula arcuata, and Epilobium ana- gallidifolium. “The following occur frequently: Silene acaulis, Carex rigida, Polygonum viviparum, Empetrum nigrum, Loiseleuria procumbens, Cassiope hypnoides, Armeria maritima, Arabis petra, Veronica alpina, Thalictrum alpinum, Luzula spicata, Juncus trifidus, Saxifraga cespi- tosa, Alchemilla alpina, Cerastium alpinum, Aira alpina, Thymus Ser- pyllum, Saxifraga oppositifolia, Gnaphalium supinum, Cerastium tri- gynum, Poa glauca.” “The less frequent are: Betula nana, Dryas octopetala, Papaver radicatum, Salix glauca, Trisetum subspicatum, Poa alpina, Pyrola minor, Saxifraga nivalis, S. hypnoides, Galium silvestre, Ranunculus acer, Cystopteris fragilis. Of rarer occurrence are: Taraxacum levi- gatum, Rumex acetosa, Rhodiola rosea, Carex lagopina, Potentilla verna, Luzula multiflora, Festuca ovina.” III. The Anthelia crust. “On gravelly, clayey, or stony soil, in the mountains, at an altitude of 300—700 m., increasing with the height, a grey crust, dispersed in patches, is very often met with. It is formed exclusively of Anthelia nivalis. Interspersed with it I sometimes found Grimmia hypnoides, G. ericoides and Salix herbacea. This Anthelietum often borders on the Salix herbacea depressions. Transitional forms between the Anthelia and the Salix herbacea vegetation are occasionally found.” IV. The Salix herbacea and Sibbaldia vegetation. “... occupies the aforementioned depressions where the clayey strata cover the subsoil. The main dispersal of this vegetation lies be- tween 300 and 600 m. above sea level. In the lower part there is often a strong admixture of the elements of the heather moor, and at an altitude of over 600 m. it passes into the moss vegetation. An undergrowth formed of mosses is nearly always present.” “Very often it is formed of Grimmia hypnoides and occasionally of An- thelia nivalis.’ “Not a few of the phanerogams of the fell-field are interspersed in the Salix and Sibbaldia patches. As far as I could 72 100 H. MØLHOLM HANSEN see, the following species were exclusively associated with this ve- getation: Taraxacum laevigatum, Epilobium anagallidifolium, Carex lagopina, Gnaphalium supinum, Pirola minor.” "Of the two dominant species, Salix herbacea and Sibbaldia procumbens, Salix herbacea is found in the greatest proportion. They either occur as separate dominants, or they dominate together intermixed with one another, and then either in equal number or with preponderance of the one or the other.” V. The Philonotis fontana Dy. “On damp gravel and at small springs small cushions of Philonotis fontana occur. In these light-green cushions of moss some flowering plant is generally met with, Cerastium trigynum and Saxifraga rivularis especially show a predilection for these spots. These moss cushions correspond to the dy occurring at lower levels.” The second type of vegetation which H. Jönsson distinguishes is that of rock pools. 1900, p.20 he writes: “Up the mountains, though not at very high levels, there occurs a characteristic vege- tation met with near pools, the vegetation of the rock pools; these pools are especially Eriophorum pools where E. angustifolium is solely predominant. They are extremely poor in species, yet we may mention the occurrence of scattered Carex rostrata, C. pulla, and C. alpina.” The third type of vegetation is the Grimmia heath. We have previously dealt with this vegetation (p. 40) with the main result that it belonged to the higher regions of the country to the south and east of the jokull line. It was most abundantly developed in the foggy and rainy regions of East Iceland, decreasing to the westward, and being absent in the north. “In the lowlands and at the lower levels of the mountains it changes in time and gives place to other plant societies; as a rule many phanerogams and vascular cryptogams are intermixed with it. These decrease con- siderably with increasing height above the sea, and have almost entirely disappeared from the Grimmia heath of the highest levels (at c. 600—700 m.); there only solitary, very widely scattered, com- mon fell-field plants are met with.” A comparison shows a great, but probably more apparent than real, difference between the vegetation schemata of the two authors. Stefansson describes the following types: melar, mo, myri, and snow-patch, Helgi Jönsson: fell-field (with sub-divisions gravelly flats, screes, the Anthelia crust, the Salix herbacea and Sibbaldia STUDIES ON THE VEGETATION OF ICELAND 101 vegetation, and the Philonotis dy), rock pools and Grimmia heath. Since the Grimmia heath does not occur in North Iceland, this type may be left out of consideration, and of the remainder only the myri and the rocky pools are identical. Judging from the description, H. Jonsson’s fell-field comprises Stefansson’s melar, mo, and snow-patch, gravelly flats and screes corresponding to melar and mo, while the Anthelia crust and the Salix herbacea and Sibbaldia ve- getation must be regarded as snow patch vegetations. Thus for the highlands we get the following vegetation scheme which, in its main lines, is the same as on Lyngdalsheidi, viz. 1) melar (and, in addition, for South and East Iceland, Grimmia heath), 2) mo, 3) myri (in- cluding dy), and snow-patch (including the Salix herbacea and Sib- baldia vegetation and the Anthelia crust). In the following each of these types will be dealt with in more detail. As previously mentioned, the investigations to be described in the following were carried out on Arnarvatnsheidi. The latter forms part of the large plateau north-west of Langjökull which divides the Hüna Flöi area of valleys in the north from the Borgarfjöröur area of valleys to the south. The surface of the plateau consists of de- posits of the glacial period and appears as a landscape with count- less downs, depressions, and lakes. Of more conspicuous types of vegetation we find: melar, Betula nana mo, the knolly mo, jadar, myri and flöi, and geiri. The melar vegetation attains development at the top and on the ridges of the downs, occasionally some distance down the slopes. The Betula nana mo (or the level mo) occurs on large flats at high levels among tracts of melar. The mo (the knolly mo) occurs in small hollows in the Betula nana mo, along the slopes of the downs, in large flat depressions at high levels, and in the margins of the snow patches. Jadar occurs especially in the depressions between the downs and on the borders of the myrar, while the myri vegetation occurs in the larger and deeper depressions and around the lakes. The moister parts of the myri are occupied by the flöi. The geiri vegetation attains its finest development in large shovel-formed depressions in the hills, most frequently, though not so typically, developed along the slopes of the hills. As elsewhere in Iceland, the melar and geiri vegetations are dependent respectively on a slight and a deep snow-covering. The 102 H. MØLHOLM HANSEN series: mo, jadar, myri, and fléi depends on the increasing content of moisture in the soil. In the following I shall describe the phy- siognomic, biological, and floristic relations of the individual types of vegetations. The Melar Vegetation. Cf. figs. 15—17 and table 22 A, 1—6. As mentioned above, the melar vegetation occurs at the top and on the ridges of the moraine walls. In the winter, when the land- scape is covered with snow, these are either bare or have a very slight snow-covering. Consequently the frost penetrates deeper into the earth which again causes a slower process of thawing in the spring. This in connection with the position causes solifluction from the ridge of the hill towards the depression. On a steep slope the material will pour down in large tongues, as seen in fig. 23; if the slope is less steep, it will arrange itself in small ledges with a naked, gravelly horizontal surface, outwardly bounded by an edge covered with plants which connects the two corners of the ledge like a sweeping garland. Looking towards the depression, such an area of solifluction looks very poor in plants (cf. fig. 16), looking towards the ridge of the hill, the same surface seems somewhat more clothed with plants (cf. fig. 17). The characteristics of melar are thus a slight or no snow- covering, solifluction, and a bare gravelly or stony soil. The composition of the melar vegetation has been given in table 22 A, 1—6. Despite the open vegetation a relative abundance and density of species occur. The average number of species is 27, the density c. 8, varying from 5.6 to 9.4. In the biological spectrum the chamaephytes dominate with an average percentage of 52.4, H and especially G are relatively less important. The Th percentage is c. 2. Even if this figure is low, it is comparatively high compared with the Th percentage of the south country, a fact which it seems natural to connect with the relatively continental climate of the highlands. On melar in the north country the Th percentage is still higher; here the climate not only tends to be more continental than in the south country, but is also milder than in the highlands. The A and E species are as 4 to 1; within the A sub-groups A 3 is especially conspicuous, the average percentage being 55.4. Of the E sub-groups only E 4 occurs and with a somewhat lower per- centage than in the other types of vegetation. STUDIES ON THE VEGETATION OF ICELAND 103 Of plants which are characteristic, that is to say, which either occur here exclusively or occur here with the greatest F.- percentage, or which are comparatively frequent on melar, we may mention the following chamaephytes: Thymus serpyllum, Cerastium alpinum, Arabis petrea, Minuartia verna, Arenaria ciliata, Saxifraga cespitosa, and S. oppositifolia, Dryas octopetala, Empetrum nigrum, Salix her- bacea, and Silene acaulis. Of hypogeophytes we mostly meet with grasses and cyperaceous plants. The following species occur: Poa glauca, Festuca ovina, Juncus trifidus, Luzula arcuata, and L. spicata, further Polygonum viviparum. Of species found exclusively on melar and thus characteristic of this type, we may mention Arabis petrea, Luzula arcuata, Saxifraga cespitosa and S. oppositifolia. Of thero- phytes only Euphrasia latifolia occurs. The Betula nana mo. Cf. fig. 18 and table 22 A, 7—11. This type of vegetation, provisionally named after its dominant chamaephyte, Betula nana, and referred to the mo on account of its comparatively close carpet of vegetation, occurs especially in large flat stretches among tracts of melar. The surface is not knolly as in the typical mo, nor does solifluction occur in any appreciable degree, as in melar. In small hollows in the Betula nana mo (the level mo), we meet with the knolly mo, which would seem to in- dicate a comparatively low degree of moisture in the soil of the Betula nana mo. Its distribution points to a snow-covering intermediate between the two types melar and knolly mo. The vegetation is continuous, a feature which renders the Betula nana mo physiognomically very different from melar. The number and density of species are, however, not very much higher than in melar, the number of species being 32, the density 11.3, varying from 10.4 to 13.0. In the biological spectrum Ch are still dominant, even though the Ch percentage is reduced from 52 to 47. The re- duction of the Ch percentage has resulted in an increase in the G percentage from 9.9 to 15.2. The species group spectrum shows a similar change; the A percentage has been reduced from 81 to 70, the A3 percentage from 55 to 43, while, on the other hand, the A 2 percentage has risen. The increase of the E percentage falls prac- tically only to E 4, which shows a percentage of 29 against 19 in the melar vegetation. The E 3 group only occurs with a percentage of 0.8. The difference between melar and the Betula nana mo is most striking in a floristic respect, as even a hasty glance at table 22 A 104 H. MØLHOLM HANSEN TABLE 224. The Melar and Betula nana Mo Vegation on Arnarvatnsheidi. Localities 1—6 represent the melar vegetation, 7—11 the Betula nana mo. All localities situated near Ulfsvatn c. 500 m. above sea level. No.1 exa- mined on 4/s 1925, 2 and 7 on °/s, and 8 on ®/s; 4 and 9 on ?/s, 5—6 and 10—11 on °/s 1925. (25. 1/10 m?). 1.121 3) 4015146 | 7 | 8° | (9s Grea eaizilasancuatacs een A3 H 12112 12/16 12 | 8 | > Saxifraga caespitosa ..... A3 | Ch 8/20) 4| 16) 16 | 16 — oppositifolia ... | A3 | Ch 8| »112| 4116| » Arabis PetræÆA.---------- A 1 Ch | 28 | 32 60 12 | 36 | 48 3 > Euphrasia latifolia ...... A2 | Th | 12116, A| 8) 16) A| 4) 16) 4 8 Cassiope hypnoides...... A2 | Ch | 32| 8| »| 36] 4] »||40| 12] 32] >| 8 Minuartia verna....... . | a3 | Ch | 40/36/28] 12|44| 48] 4| 28] 8|12] 4 Thymus serpyllum ...... E4 | Ch | 44|52|48| 24|52|76 | 32| >| »| 4| 4 Poacklauean. satel k's nies A3 | H | 48/60/44| 28/48/44] 16] A| 4] 4] > = alpine Ae cc's ois A2| H | 8] 8| >| »|16/16] 8| 4) 4|12| 12 Cerastium alpinum...... A3 Ch | 36152120 | 3652/64 | 16] 20; »| 4| 8 Dryas octopetala........ A3 | Ch | 52|32|28| 52/48 |32| 56 | 8| 12132! 20 Luzula spicata.......... A2 | H | 80/72 36) 68 64 92 48) 64| 40/40) 28 Polygonum viviparum ... | A3 G 100 72 48 100 68 80 96 100 100 92 100 Empetrum nigrum ...... | E4 | Ch | 64/24/12] 64| 4| »|100| 80| 96,96 | 92 Salix herbacea .......... A3 | Ch 64 40 68 76 72 32 84 84 84 96 80 Silene acaulis........... | A3 | Ch 72/44 44| 80 84 68 60 68| 64 60 44 Juncus trifidus.......... | A2 | H | 60! 8|28| 56,56 52] 56| 20| 52|44| 28 Festuca ovina........... E 4 H | 52 36 44| 60 68 80 20 48) 48 (56) 40 na... EA | H | 20 24 »| 8|12| | 88| 68 84 52 92 Thalictrum alpinum..... A2 H | 4 | 12 BR | 8 60 88 72 88 72 Slim Blanca eu. AS) Ch. 8.116,58 | ai 3 40 | 72.80 44 Betula nana esis clecis-s «2 | A2 | Ch A FI AUS RAIN 48 | 16| 48 48 | 64 Vaccinium uliginosum... | E4 | Ch | 4, 8 »| 12) »| >| 72 60! 76 88 92 Gr SUT een A3 G le. > > | 28 60| 56 40 52 Elyna Bellardi.......... | A3 | H | 4112 8112| »| 32| 4] 2468| 20 Armeria vulgaris ........ A3 | Ch | 8|12| >| 20 32 | 40| 12| 4) 24 Galium Normanni....... A1 | H | 4| »| 8| 4| »| 8|32|12| 4/32] 42 Viscaria alpina.......... A2 | H |12| 8| 4] 4| 8| 8 20| 4120| 12 Equisetum arvense ...... | E4 G | > 4 || 28 | 20 24 | 16 | 40 — variegatum .. | A3 H 4| A| »| 4| »| »| 28] 20| 4/20) 20 Selaginella selaginoides .. | A1 | Ch | »| »| »| »| »| »| 8| 8| 12/28) 32 Loiseleuria procumbens . | A2 | Ch »| >| »| A| >] »| 12| 8| 8) Alu Agrostis canina ......... | E3 | H | aloo [> | >| » 12! > | 8120! Arenaria ciliata......... AS | Gia Wet alae lad dm) eile | »| pel Bartschia alpina ........ A2 H »| 4| »| »| » | >| 20; 4| »| » | 8 Gentiana tenella ........ A2 | Th | | >» 8 | » Re: Koenigia islandica....... A3 | Th | 4/28 | >| »| 4 STUDIES ON THE VEGETATION OF ICELAND 105 TABLE 224 CONTINUED. Pedicularis flammea..... A3 H 4 > » | 16 4 Pingvicula vulgaris ...... E 4 H | 12 8 20 | > Rumex acetosa........ 2 E 3 H 4 LTL IT LETÉTE ee Al Ch 4 Saxifraga Hirculus ...... A3 H > 4 Sedum villosum......... A2 H 8 |12| >} 4) 4 Tofieldia palustris....... A 2 HR sh > > | 48 8 | > Trisetum spicatum ...... A 3 H |12 | 16 12 | 4 36 12 8 TABLE 228. Biological Spectra of the Melar and Betula nana Mo. emits. stim........- 936 792! 560 848 | 812 | 800 | 1304 | 1044 1064 1172 1080 Number of species... ||. 34 | 31 | 20 | 32 | 24 | 21 | 36 32 29 29 32 Density of species .. | 9.4 7.9} 5.6 8.5 8.1! 8.0) 13.0! 10.4! 10.6 11.7 10.8 eee 79.1 81.8 81.4 79.2 83.3 80.0 71.5 | 736 68.4 71.7 66.3 | 20.9 | 18.2 | 18.6 20.8 | 16.7| 20.0) 28.5) 26.4) 31.6| 28.3| 33.7 ee 51.3 59.1 56.4 55.7 59.1 50.5 40.5 47.5 41.4 44.7 40.0 et ee 24.4 | 18.7 12.9 | 21.7 | 19.7 22.5 | 27.6 24.1 25.6) 21.8 22.2 mm 34| 40112.1 19, 44 7.0 3.4 1.9 15) 5.1| 41 | | | ' | er | EN EET = va 7 i anne 20.9 | 18.2 | 18.6 20.8 | 16.7 | 20.0 27.6| 26.4 308 26.6| 33.3 ee ss PR SEER Ye an aT ee E 2 sms | 3 2 » » | » > > | 2 > 3 | > ee » | » » > » » | | 3 \ > Er I 7 a mare Il = Fa 5 Ten reed 50.0 49.0 | 59.3 53.3 53.2 49.5 46.6 45.2 49.2 47.4 47.8 PR 37.6 36.4 | 31.4 | 34.0 36.5 39.5 40.8 36.0 33.5 39.9 33.3 he 10.7! 9.1! 8.6| 11.8 | 8.4 | 10.5 || 11.7 | 17.2| 16.9! 12.6) 17.8 4 | > »| >» | » > > » > ANNEE 1.7| 5.6| 0.7| 0.9| 20} 05) 09] 15) 04 >| 11 will show. Some species occur exclusively or prineipally on melar, others exclusively or principally in the Betula nana mo, while a third group is common to both types of vegetation. The table shows more precisely which species belong to the respective groups. Phy- siognomically the chamaephytes dominate. A random selection of 106 H. MØLHOLM HANSEN the more conspicuous species includes: Empetrum nigrum, Salix herbacea, S. glauca, Betula nana, Vaccinium uliginosum, Dryas octo- petala, Silene acaulis, and Armeria vulgaris. The species Cassiope hypnoides and Loiseleuria procumbens occur more frequently than in melar even though they are not as dominant as in the knolly mo. Of hemicryptophytes and geophytes the following occur: Poly- gonum viviparum, Juncus trifidus, Luzula spicata, Festuca ovina, Viscaria alpina, Galium Normanni, Thalictrum alpinum, Elyna Bel- lardi, Carex rigida, Festuca rubra, and Poa alpina. Of pteridophytes Selaginella selaginoides, Equisetum arvense, and E. variegatum are met with. Along the upper margin of the large snow patches there occurs a narrow belt in which Betula nana is the physiognomic dominant. This formation will be dealt with later, under the geiri vegetation. The Knolly Mo. Cf. fig. 19 and table This type of vegetation commonly occurs on ‘flat ice slopes, on the lower slopes of elevations and ridges with melar above, in small hollows in the Betula nana mo, and on the borders of the snow patches. The surface is always knolly, but the knolls are neither very large nor very high. Judging by the position the snow- covering is deeper than in the two preceding types, the melar and the level mo, though less deep than in the snow patches. As re- gards moisture, the knolly mo occupies an intermediate position between the level mo and the jadar vegetation. The change in number of species and in density is continued from melar through the level mo to the knolly mo and here we have the values 35 and 15 respectively for the number of species and the density. Biologically the change is likevise continued: the Ch percentage has decreased, while the G and H percentages have increased. The E and A percentages have remained constant, while there is still a decrease in the A 3 percentage. There is a rise in the E 3 percentage. While in the Betula nana mo Ch were dominant and H were the subordinate element, the reverse is the case in the knolly mo. Here H are the dominant. The respective averages for Ch and H in the two types of vegatation are 47:38 and 37 : 47. The predominant chamaephytes are Empetrum nigrum, Vacci- nium, and Salix herbacea. In more scattered growth there occur Salix glauca, Silene acaulis, Armeria vulgaris, Dryas octopetala, Thy- STUDIES ON THE VEGETATION OF ICELAND TABLE 23 A. The Mo and Jadar Vegetation on Arnarvatnsheidi. 107 Localities 1—5 represent the mo vegetation, 6—10 the Jadar vegetation. All localities situated near Ulfsvatn c. 500 m. above sea level. 1, 2. 5 exa- mined on °/s 1925; 8 on °/s, 3 and 6 on !?/s, 4 and 9 on !?/s, 7 and 10 on 11/5 1925. (7, 10. 1/10 m?;. 1-6, 8—10, 25. 4/10 m?). Dryas octopetala ........ Thymus serpyllum ...... Cassiope hypnoides...... Loiseleuria procumbens.. Bisma Bellardi .........:. | Bancas trifidus:......... Selaginella selaginoides .. merostis Canina’.......-: Trisetum spicatum ...... | Tofieldia palustris ....... Mascara alpina.......... Bartschia alpina ........ Empetrum nigrum ...... | Vaccinium uliginosum ... Luzula spicata .......... FREE acanlis..-...:.... Equisetum variegatum... Pabscherbacea ........-. Armeria vulgaris........ Polygonum viviparum ... Thalictrum alpinum..... HEER TIPS 6's 155 soya vie sien BESES Tnbra..........: mar 5 5 oso «0.0 ... PACA. 4:2 | Rumex acetosa.......... Galium Normanni....... Cerastium alpinum...... | Equisetum arvense...... | Deschampsia alpina ..... | Salix phylicifolia........ Cardamine pratensis..... | Taraxacum officinale .. Potentilla verna......... RON Draiensis.,.:,,....., É Agrostis tenuis.......... | Alchemilla minor ....... E3 E4 A2 A3 Ch H H | 16 | 80 100 70 92 100 100 90 96 100 Ve = ¥ > = CO v 108 H. MØLHOLM HANSEN TABLE 23A CONTINUED. | tee et 40-50) 6 | 718) 9110 Anthoxanthum odoratum. E3 H y ) » >» | 4 : » | 4 4 Betulasnanaee eee ere A 2 Ch ) 4 »| 4) 4 Botrychium Lunaria... . E4 G 4184, 4 2 » y Calamagrostis neglecta... E 4 H » » >» | 16 || » |10)| 322132 Carex) Alpina"... A 2 H » | > »| 4) 4) 8 — ee E4 G > 4 » | 24082 | 12 — Goodenoughii ..... E 3 G >. | ES EA) » | > ma — zraritlora nennen. ADs 7G » »| 4| 8) 4 Cerastium trigynum..... A 2 Ch ) » | 40 M1 Deschampsia flexuosa.... E3 H 12 | 8 | 4 | 4 12 |40| »| » | » Drabañrupestris rn... A 1 Ch 32 I 4 |40| »| » | 4 Equisetum pratense ..... E 2 G » » > 8 | 20 | > Eriophorumpolystachyum | E4 G » | » |» | » | » | »|48116 [ 8 Euphrasia latifolia ...... A 2 Th Ja] DANS POUR > ) »|12| 4 |24 Gentiana mivalis 2...r... A2 Th » | Soll ed » 3.1: IRAN = tenella... ...... Av! 5 | "Th | 2} 4) > | > | 20) >) oa Hieracium alpinum ..... A 2 H »| 4] > » | »| »| » | » Koenigia islandica....... A3 Th el 49 504) © » | » | 10) 8| > Luzula arcuata.......... A3 H aha} > | > |) >, sous — multiflora ....... E3 H 4 | 125155 Minuartia biflora........ A3 | Ch | »| >|42|»| 4 | »| » DE — VOIE ere A 3 Ch AN | 16 | » » »| »| » » Pedicularis flammea..... A3 H »|4|»|»|12]| » | »[16 | Phleum alpınum........ A2 H | tem | as » | 4 |40| »|16 | 4 Pingvicula vulgaris...... E4 H 4 |20 | > | 12.) 8) 2 | 21220008 Ranunculus acer ........ | E4 H | » |» | » | » | » |30 >| »| >» Salixal anata ste ee. Al Ch | » » | » | » » » »|112| 4 | » Saxifraga Hirculus....... IAB Be > | > lol » 16 | 4] > ee | Sedum villosum......... A2 H | » BE RES REX: | » » | AS | » Sibbaldia procumbens ... | A2 Ch | ye hal >| | > | 10} » | ete Veronica alpine?" PASS AL SE | {> ol > | >,| > 110) Sue Viola palustris ss... | Lam Er | » » | 2 | 2 il 2 | » | 40 » | 4 | | | | | | mus serpyllum, Cassiope hypnoides, and Loiseleuria procumbens. For the rest grasses and cyperaceous plants dominate, thus Elyna Bellardi, Juncus trifidus, Luzula spicata, and Carex rigida, further Festuca rubra, F. ovina, Agrostis canina, Trisetum spicatum, Deschampsia flexuosa, Poa alpina and P. glauca. ‘Of herbaceous plants we find especially Polygonum viviparum and Thalictrum alpinum; less do- minant plants are Tofieldia palustris, Rumex acetosa, Viscaria alpina, Bartschia alpina, Galium Normanni, and Pinguicula vulgaris. Pte- ridophytes are represented by Selaginella selaginoides, Equisetum STUDIES ON THE VEGETATION OF ICELAND 109 TABLE 238. Biological Spectra of the Mo and Jadar Vegetation. 1 2 1 4 5 6 7 8 9 | 10 | —— | = = A = — = Points sum....... 1364 | 1572 | 1528| 1520| 1200| 1304| 1180| 1084| 1232 | 1208 Number of species. | 35 36 3622235 35 | 40 30 38 | 42 39 Density of species. || 13.6 | 15.7 | 15.3 | 15.2 | 12.0 | 13.0 | 11.8 | 108 | 12.3 | 12.1 —— — — =] —= — =— — —= — ———m ——— — me ee | 69.2 | 75.2 | 74.1 | 73.2 | 65.0 | 71.2 | 52.5 | 64.2 | 61.0 | 66.2 ER 30.8 24.7 | 25.9 | 26.8 | 35.0 | 28.8 47.5 | 35.8 | 39.0 33.8 i eee | 37.5 | 36.6 | 41.1 | 40.3 | 41.7 | 40.8 | 19.5 | 35.4 | 36.7 | 38.4 ee | 226 | 303 | 24.3 | 26.7 | 20.0 | 21.8 | 24.6 | 23.2 | 18.2 | 242 MR 1... | 91| 84] 86| 63| 33] 86| 85| 55] 62| 36 ee | 23.8 | 19.8 | 20.9 | 24.5 | 33.2 | 20.2 | 31.4 | 31.7 | 29.2 |27.8 i. Se | 70! 48} 50| 24) 20) 67| 93| 15 .58| 46 teers sk |» > >, >| 1) 18| 68| 26| 200 18 El nue din a pe 0 6 0 0 6 ee | 2 » » » | » » » | » » | ) Bei... | 37.8 | 36.6 | 37.4 | 40.5 | 37.0 | 25.1 | 144 | 21.4 | 23.7 | 17.9 |) eee 50.4 48.6 52.1 44.5 39.0 | 53.4 | 57.6 | 46.9 | 47.4 fee TT ue. | 11.7 | 13.7 | 10.2 | 15.0 | 24.0 | 21.5 | 26.3 | 29.5 | 28.6 | 28.5 CESSE | » > | »- » | » | » | » » | » » x. | »| 10) 08 RENE EU ee EURE variegalum, and E. arvense. Botrychium Lunaria occurs singly but constantly. Thus to the above-mentioned physiognomic and biological dif- ferences between the level and the knolly mo must be added the following floristic differences: Salix glauca and Betula nana occur exclusively in the level mo. With a lower F.- percentage in the knolly mo we meet with Festuca ovina, Minuartia verna, Silene acaulis, and several others. Predominantly occurring in the knolly mo, we find: Loiseleuria procumbens, Agrostis canina, Trisetum spicatum, Poa alpina, Deschampsia flexuosa, Carex rigida, Rumex acetosa, Selaginella, Equi- selum variegatum, Bartschia alpina and several others. The two types of mo must thus be said to be well distinguished. The Jadar Vegetation. Cf. fig. 20 and table 23 A, 6—10. In depressions between the moraine walls, on the borders of the myrar, in small damp hollows in the mo, and as a fringe along the rivers the jadar vegetation is met with. When typically deve- 110 H. MØLHOLM HANSEN loped it is easily distinguished from the other types of vegetation by the very large knolls of which the surface consists. These often attain a height of 1 m. or more and 1 or several m in diameter. The distance between the individual knolls is up to 1/> m. The jadar vegetation belongs to moderately damp soil having a normal snow-covering in the winter. The composition of the vegetation can be shown to differ somewhat in the different localities, and possibly several types of highland jadar may with good reason be established in the future, according to the degree and kind of moi- sture of the soil, and the amount of shelter provided by the snow- covering. On an average, the density of species was c. 12, the number of species 35, in the jadar localities examined by me. Ch have become much less dominant, the Ch percentage is only 20.5 and attains a relative minimum with this value, whereas the H percentage attains its maximum here, the average H percentage being 51.3. The G percentage which has risen steadily has reached a value of 27; it is noteworthy that the Th percentage attains a relative maximum of 1.5 in the jadar vegetation. The peculiarities to be noted in the species group spectrum are a diminution of the A percentage due in the main to a diminution of the A 3 percentage, a slight rise in the E 3 percentage, and the appearance of E 2 species in a quantity of 3.3 per cent. The more conspicuous chamaephytes are Empetrum nigrum and the Salix species Salix herbacea, glauca, and phylicifolia; Salix phylicifolia is the characteristic dominant for jadar. In more scat- tered growth there occur Vaccinium uliginosum, Silene acaulis, Armeria vulgaris, and Cerastium alpinum. For the rest it is H and G which characterise the vegetation, notably Carex rigida, and in addition, on the wettest soil, Deschampsia alpina. The more prominent species are Polygonum viviparum, Thalictrum alpinum, Luzula spicata, Carex rigida, Equisetum arvense, E. variegatum, Festuca rubra, F. ovina, Deschampsia alpina, Poa alpina, Rumex acetosa, Galium Normanni, Cardamine pratensis, Taraxacum officinale, Potentilla verna, Poa pra- tensis, Calamagrostis neglecta, Viola palustris, and Saxifraga Hirculus. A number of these species are characteristic of the jadar. A couple of types which I had not time to examine more closely shall be briefly mentioned here. One is the moss mo which St. Stefansson has described from Grimstungnaheidi (1894, p. 201 (cf. p. 10)). This type of vegetation was also found on Arnarvatns- STUDIES ON THE VEGETATION OF ICELAND 111 heidi, and there it seemed to be peculiar to hollows, the bottom of which consisted of large boulders over which Grimmia had spread a deep dense carpet with scattered specimens of Carex rigida, Pedi- cularis flammea, Saxifraga Hirculus and several others. The other type is the jadar along the banks of rivers. Physiognomically it resembles the jadar further inland, but floristic- ally it differs from it by the fact that a number of species such as Carex Goodenoughü, Caltha palustris, Geum rivale, Comarum pa- lustre, and Menyanthes trifoliata either exclusively or practically ex- clusively occur here, and that merely as a narrow fringe only few metres wide along both sides of the stream. Since in the lowlands the species occur both in the myri far from running water and along streams, their predilection for streams in the highlands can- not be due to any general property of these, such as an abundance of nourishment and oxygen, but must be referred to other causes. Since all the aforementioned plants are southern species, and since the presence of water in the highlands also otherwise favours the southern species, it seems natural to suppose that the more abun- dant occurrence of more southern plants in immediate association with running water is due to the fact that running water warms the soil more than stagnant water even though water in all cases acts as a reservoir of heat. The Myri and Flöi Vegetation. Cf. figs. 21—22 and table 24 A, 1—13. i The myri vegetation occurs in the dampest hollows and espe- cially around the numerous lakes. A depression with myri has the following appearance. On somewhat damper ground than the above- described jadar with the large knolls, there occurs a Carex myri with small knolls. The damper central parts have a level surface without knolls and consist of a mosaic of formations which are fairly distinct and visible at a distance by the different tinges they communicate to the landscape. The knolly Carex myri may send out darker stripes into the myri, while the level myri itself consists of yellowish-green patches with Carex rostrata as the dominant, white patches in which Eriophorum polystachyum in fruit dominates, brown patches with Carex rariflora, and smaller or larger collections of water. According to the degree of moisture of the soil, three zones of moisture may be distinguished; the knolly Carex myri on the least 112 H. MØLHOLM HANSEN TABLE 24 A. The Myri and Fléi Vegetation on Arnarvatnsheidi. Localities 1—4 represent the driest myri nearest the jadar, 5—9 the moister myri passing into flöi outwards, 10—13. Localities 1, 2, 5, 6,7, 13 examined on °/s 1925; 8, 11, 12 on 1/8, 10 on !?/s, 3, 4, 9 on 14/8 1925. (25. %/ı0 m?). 112 )-3 4 5) 6 | 7 | & | 9 ORE EA SES Euphrasia latifolia... | A2 | Th 8| 4) >| 4 Saxifraga Hirculus ... | A3 | H | 32; 8 8 > Festuca rubra. .. ... E4| H Sl 2058 > » — OVINate 2-00 E4| H CAS re > > Garexzalpinar.2..r...; A2 H 8| 4 12 Luzula spicata....... | AZ| H | 24) 12) 4) : » > Thalictrum alpinum.. | A2 | H || 52| 32| 8 > > Garexwigida 7.253. Er A3| G | 24| 80 100 | 20 >| > Ole Er TE E4| G | 9| 24| 4164 28 | Equisetum arvense... | E4| G | 84 | 12| 92| »| >| »| » 20| > »| » Empetrum nigrum... | E4 | Ch | 60 28 16 76 | >| »| 41) Senn | » Vaccinium uliginosum. | E4 | Ch | 44} 12 20 80 | 4| »| 32] »| »| » ae Salix herbacea ....... | A3 | Ch | 80| 72| 92/60) 4; 8) »| 16] 16] »| 8 8| > in OLANCA 7... | A3| Ch | 48) 72 64 56 20 | 64 80 32.) Sil oe ete 4| 12 — phylicifolia..... AT | Ch, 20), 8|-4) 4] 20| 4| 4) >| 12) 18h | > Equisetum variegatum | A3 | H | 40| 32/ 60/40) 4| 4| 8|36| 4] >| »| 52| Cardamine pratensis.. | E4 | H 64 56 72 8 16 20 12) 16 | > a ae | Calamagrostis neglecta | E4 | H »| 48| 84/56) 16! 12) 36! »| 64) 36| >| 12) 36 Polygonum viviparum. | A3| G 100 100 96 96 84 88 92 100 68 » 16 12| 16 Eriophorum polysta- | | | gaya ect... st, |E4| G 88 84 52 92 100 100 4 100 100 100 100 100 100 Carex rariflora....... A2! G |36 36 32 96 100 100 100 100 100, > 20 4 68 — ‘chordorrhiza... | A1| G » | » |20| 64| »| 64) 121100| »| 28| 4| » —erostratarer ne. ES. | HH >| »| »112| 8 | 96] »| »| 20] »| »| 16 — saxatilis....... | A3| G | 4| >| »120| >| »| >1 16] 8] 20). 4] 12] » — Goodenoughii .. E3 G > | > NES > > > | ae » » » 100 Armeria vulgaris..... A3 | Ch HE TI IE » | >| » » | Bartschia alpina ..... A2 SE © >a 1) DS |e »| » »| » Er” Betala. nana 7,2... | A2 | Ch 12| “> > >| >] > Comarum palustre... E4 HH >| 4 > | » » »| > Elyna Bellardi....... 1 28339 DH Al >» > | -»| >| SU Galium Normanni.... | Aı H | »| 4 > > >| »| »| » Juncus biglumis ..... [A3| H | » » > al »| »| 9) Sm — Midas | SAS TH 4 | >| » » »| > >| | Ar — triglumis ..... A3| H | >| | » 12! »| » > 11 Pedicularis flammea.. | A3| H | »| 4| »| » | » | >| >| So Poa: alpina er. hee A2 | H LEA | 2 2 BØR. » || > | — ‘pratensis: ee EE | GH Sais Da | | »| , » Rumex acetosa....... E3 | H "AL FARS SU PRET DRE à Bree SÅ RES | >} a ato) > Trisetum spicatum ... | A3 | H CO | » | >| »| » | ores —T — pres zz fgskämk — — — — STUDIES ON THE VEGETATION OF ICELAND 113 TABLE 24B. Biological Spectra of the Myri and Floi Vegetation. Points sum 944 | 768 | 840 | 840 || 436 | 404 | 496 | 504) 504 || 276 | 196 | 212 | 248 Number of species .. 23 | 27 | 22 | 20 11 10), 71071213 12 5 8 10 6 Density of | | species .. | 9.4] 7.7| 84| 84 | 4.4] 4.0] 5.0] 5.0] 5.0 | 28| 20) 21| 25 ‘115 ee 51.3 64.1 55.2 53.8 | 67.9 66.3 70.2 | 65.1 | 62.7 | 7.2 | 49.0 | 45.3 | 38.7 Bee =>: 48.7 53.9 44.8 46.2 | 32.1 | 33.7 | 29.8 | 34.9 | 37.3 92.8 | 51.0 | 54.7 | 61.3 Be... 35.2 49.0 19.0 | 37.6 25.7 40.6 | 36.3 | 42.9 | 20.6 | 7.2 20.4 | 41.5 | 11.3 Be wi» 14.0| 13.5) 5.7| 13.3 | 22.9 24.8 20.2 19.8 | 19.8 > 10.2) 1.9|27.4 Se 211 16 0.5 | 2.9 ||19.3| 1.0/13.7| 2.4|22.2 184 | 1.9 > à ID m rn = I if | 48.7 | 35.9 | 43.8 44.7 | 30.3 | 33.7 | 10.5 | 34.9| 37.3 | 49.3 | 51.0 | 54.7 | 54.8 BY... »| 10) 14 19 »|1194| »| 43.5 | 6.5 > PNR : sn... | >» Bar... 26.7 27.1 23.3 | 32.9 | 10.1 19.8 | 16.9 15.9 7.9 »|143| 5.7! 4.8 ae 26.7 | 28.6 | 31.0 | 16.7 | 8.3| 8.9| 11.3 | 13.5 | 13.5 | 13.0 > | 32.1 | 14.5 a ere 45.7 43.8 45.2 48.6 79.8 71.2 52.4 70.6 78.6 79.7 85.7 62.3 74.2 Be... | » >| 05| 14] 1.8 » | 19.4 » » | 7.2 > » 65 7. | 0.8! 0.5 >| 0.5 > » » » » damp soil, the Carex rariflora myri on damper soil, and the Erio- phorum polystachyum fléi on the dampest ground. In table 24 A, Nos. 1—4 represent the knolly myri, 5—9 the Carex rariflora myri, and 10—13 the flöi. The knolly Carex myri is most abundant in species and shows the greatest density of species of the myri formations. The number of species is 23, and the density 8.5. Ch play a more prominent part here than in the jadar and attain a relative maximum of 27.5 per cent. H show a strong decrease, while the rise in G is still continuing; the last Th meet with the first HH. The species group spectrum shows a large content of A3 and E 4 species. The physiognomie dominants are the chamaephytes and the Cyperaceæ, of the chamaephytes especially Salix herbacea, S. glauca, and S. phylicifolia, further Empetrum nigrum and Vaccinium uligi- nosum, of the Cyperaceæ Eriophorum polystachyum, Carex rigida, C. dioica, C. rariflora, and here and there Carex alpina and C. sax- The Botany of Iceland. Vol. II. 8 114 H. MØLHOLM HANSEN atilis. Of more or less importance are Polygonum viviparum, Cala- magrostis neglecta, Equisetum arvense and E. variegatum, Cardamine pratensis, Thalictrum alpinum, Luzula spicata, Festuca ovina, F. rubra, and Saxifraga Hirculus. The Carex rariflora Myri. Cf. fig. 22 and table 24A, 5-9. On still damper ground the knolls disappear and with them a number of species, so that the species now only number 11.2, while the density of species is 4.7. The geophytes, comprising especially Cyperaceæ, form the bulk of the vegetation. The G percentage is 70.5, the HH percentage 4.2, the Ch and H percentages 14.1 and 11.1 respectively. The species group spectrum shows the peculiarity of a rise in the A percentage from 56 to 66 caused by a great rise in the A2 and A 1 percentages; the A 3 percentage, on the other hand, is still reduced. The dominant species are Carex rariflora and Erio- phorum polystachyum, also, in spots, Carex chordorrhiza and C. ro- strata. Other frequently occurring plants are Polygonum viviparum, Salix glauca, and Cardamine pratensis. The Eriophorum polystachyum Flöi. Cf. Table 24 A, 10—13. On the flöi, the dampest soil clothed with plants, knolls are likewise absent, the ground is swampy as in the lowland flöi, and not firm enough to walk on. The succession of changes in number of species, density of species, biological spectrum and species group spectrum in the myri formations here reaches its climax, as was also the case in the lowland flöi. The sole dominant here is Eriophorum polystachyum, here and there a few myri plants occur such as Carex rariflora, C. chordor- rhiza, C. rostrata, C. saxatilis, Polygonum viviparum, Salix glauca, and Calamagrostis neglecta. The Geiri Vegetation. Cf. table 25 A, 1—6 and figs. 23—25. On slopes with a southern, western, and northern exposure a special vegetation, the snow patch or geiri vegetation, may be met with. Its peculiarities are conditioned by a deep and constant snow- covering in the winter. The snow falls early on these areas, covers them without intermission throughout the winter, and only melts well on in the spring. The snow patches occur in two different forms. Most frequently the snow lies in long narrow bands on the southern, western, and STUDIES ON THE VEGETATION OF ICELAND 115 northern slopes of the hills (cf. fig. 23), abutting above on the melar, whence the soil rolls down on to it, and passing below into the knolly mo. More rarely the snow patches occur in the shape of large depres- sions having the form of a parabola in the western and southern slopes of the hills. The shape of these large patches of snow is very characteristic; above they are separated from the melar by a narrow steep edge. The sides of the snow patch slope strongly above, are less steep further down, and finally pass into the bottom of the patch which as a slightly hollow surface slopes gently towards the mouth of the snow patch. The shape most of all resembles a large shovel dug into the slope. The bed ofa rivulet extends some way into the patch. Outwardly this form, too, passes into the knolly mo. The surface is level and without knollsin both forms of snow patch, as may be seen with sufficient plainness in the figures. While the vegetation is uniform throughout the whole snow patch in the first type, differing only according to the exposure, a distinction can be drawn in large snow patches between a marginal zone, the vegetation on the sides, and a bottom vegetation. The vegetation is most characteristic in the large snow patches, a number of snow patch plants being exclusively found here, just as the mar- ginal zone is a formation peculiar to the large snow patches. As regards the vegetation of the bottom, it seems to correspond to that af smaller snow patches with a northern exposure, while the vege- tation of the sides corresponds to that of smaller snow patches with a southern exposure. Hence the floristic relations of the snow patches may be dealt with under one head, the following three formations requiring to be treated: 1) a marginal zone with Betula nana, and possibly Juniperus communis, 2) a Geranium belt compris- ing small patches having a southern or western exposure and the vegetation of the sides of the large snow patches, and 3) the bot- tom vegetation, which comprises, in addition, the vegetation of snow patches having a northern exposure. Table 25 A, 1—6 shows the circling results for the vegetation of the snow patches. No. 1 is the vegetation of the marginal zone, Nos. 2—4 the Geranium belt, and Nos. 5—6 the bottom vegetation. Nos. 1, 2—3, and 6 originate from the same large snow patch, 5 and 4 represent the smaller patches, respectively with a northern and a southern exposure. 8* 116 H. MØLHOLM HANSEN TABLE 25 A. The Geiri Vegetation on Arnarvatnsheidi. Locality 1 represents the marginal vegetation of the snow patch, 2—4 the vegetation on the sides of the snow patch, 5—6 the vegetation on the bottom of the snow patch. No.2 examined on ”/s 1925; 1, 3, 6 on °/s, 4 on 8/s, 5 on ?/s 1925. (25. 1/10 m?). | | 1 2 3 4 5 6 = — nn BE ... Betula@managerer et 0 A 2 Ch 72 » Thymus serpyllum ...... E4 | Ch 48 > 12 1 Dryas octopetala ........ | A3 | Ch 16 he saa | Sileneracaulise a rer A3 Ch 12 A| » » Armeria vulgaris........ A3 Ch 16 » > JUNCHSAILIRAUS 2 ee. AZ USE OA 8 8 » ElynasBellardier..2..... A3 lal yp 12 MN PR UE CT » Geranium silvaticum .... E 3 H 12 | 96 | 84 |100 4 ) Vaccinium uliginosum... | E4 Ch | 88 | 64 | 96 96 100 » Salızöherbaeea.. .. 0... As Ch | 68 96 88 | 80 100 | 100 AL N rc cries 6's | A3 Ch | 52 | 64 56 44 84 92 — phylicifolia........ | A1 | Ch | 8 | 56 | 28 16 | 12 Empetrum nigrum ...... | E4 Ch | 92 68 68 88 100 » Polygonum viviparum ... | A3 G 76 845 (52 68 64 44 Thalictrum alpinum..... | A2 | m | 88 | 80 |100 | 100 | 72 gets Carex mig 4.026.302 HLA’S |G 80], 727 792° 884) BO Deschampsia flexuosa.... | E 3 H 72 96 96 | 100 | 92 56 Festuca rubra........... VB ae) UE 6 | BO 12044 | 48 | 76 Agrostis canina ......... | E3 H | 24 | 68 16 80 80 96 Hierochloë odorata...... | G2 G | 4 | 56 8 | 200 20 2 Anthoxanthum odoratum. | E3 H | 8 VSB Ali) 28 60 > 4 Selaginella selaginoides .. | Al Ch 208 ae Neat 56 > > Galium Normanni....... la oH 06, 8 (salt PNEU. 2-0 Ede |. Hi) 20:2] +12: | 2800052 AUS > Equisetum arvense...... | E4 G | 16 | 60 | 16 8 | 48 | 84 — variegatum... | A3 H 36 10 16 8 20 12 Rumex acetosa.......... | ES | °H | 12 | 32 |. 44 4 | 4. | 64 Phleum alpinum........ | A2 H » || 36 12 12: MER 24 Ranuneulus acer cc. | E 4 H » 44 28 4 1, 20 Violaspalusteiser een | ES He) ESS 24 48 » || 40 20 Taraxacum officinale .... | E2 H | rail, 12 48 > 40 20 Agrostis tennis eee ne. 1 2 H 221 2 64 » » » Alchemilla minor ....... | E4 Hal | 20 16 4 | » Sibbaldia procumbens ... | A2 Ch | > | 36 » » > 44 Gnaphalium supinum ... A2 Char 24 » > » 72 Alchemilla alpina ....... | AB OH | ya) 16.0 4 » > Betula alpestris ar... Ada “Chelsea is? > » 4 > » Botrychium Lunaria .... E4 Galet les N: » Calamagrostis neglecta... E4 H | » | » > | 2 » 8 STUDIES ON THE VEGETATION OF ICELAND TABLE 25A CONTINUED. 117 1 2 3 + 5 6 Cardamine pratensis .... E 4 H 4 Deschampsia caespitosa.. E2 H 4 3 Bestuca ovina........... E4 H 12 4 Gentiana nivalis......... A 2 Th 8 > Habenaria viridis ....... ALI G 12 Hieracium alpinum ..... A 2 H 4 Leontodon autumnalis... E3 Éd) ) | > » 12 Peanlayspicata .........- A 2 H 20 | 8 » ETAT ATOUT CRE eae A 2 H 20 | 44 ) 8 » 12 = PAUCA. .-...-..... À 3 H » 4 » Potentilla verna......... A2 H > i > 12 > Weronica alpina ......... À 2 H 4 > » TABLE 258. Biological Spectra of the Geiri Vegetation. — — | - — 1 2 3 4 | 5 6 NTI HÆRE; sae I lip ae OE LO Sener 1180. | 1428 | 1192 | 1272 || 1004 | 996 Number of species ............ | 34 29 34 33 ra HE RED? Density of species............. | 11.8 | 14.3 11.9 12.2 is, 10.000 e106 2.7. 57.6 | 440 | 419 | 465 | 462 | 494 2 22 ECS ter rl | 42.4 56.0 | 58.1 53.5 | 53.8 50.6 | | eine SE 31.2 22.4 25.8 23.0 || 35.9 32.5 2 ere eu 19.3 16.0 11.7 11.3 | 9.2 16.9 PR 7.1 5.6 44 | 123 | 12 » Ce RP dne ked tte 28.5 22.1 20.5 20.8 29.9 18.9 a ann aha 11.5 28.3 24.8 27.0 17.9 28.5 SE Ae er ere er 0.7 4.8 10.4 1.6 6.0 3.2 TE REED 1% 0.8 2.3 4.1 » » ERP PE 42.0 29.7 31.2 31.4 39.4 30.9 NARI eh jene 42.7 51.3 54.7 | 51.9 38.2 47.4 DE PPT EE 15.3 19.0 14.1 | 16.1 22.3 21.7 A oc. win hae BÆRES » > Pe > 0.6 » > The Marginal Zone. Along the entire upper edge of the large snow patches there occurs a narrow belt, rarely more than 1—2 metres wide, where a 118 H. MØLHOLM HANSEN number of chamaephytes attain a luxuriant development. The do- minant species are Betula nana, Empetrum nigrum, Salix glauca and herbacea, and Vaccinium uliginosum; in some snow patches one may likewise find Juniperus communis and Betula alpestris. All species attain a vigorous growth and form a dense mat of shrub- like vegetation. Beneath the chamaephytes there is a bottom layer formed of species like Deschampsia flexuosa, Festuca rubra, Carex rigida, Polygonum viviparum, Thalictrum alpinum, Galium Normanni, ‚and a number of mo plants such as Thymus Serpyllum, Dryas oc- topetala, Silene acaulis, Armeria vulgaris, Juncus trifidus, Elyna Bel- lardi, Luzula spicata and several others. The Geranium silvaticum Belt. This formation initiates the snow patch vegetation proper. As stated above, it occurs on the steep sides of the large snow patches and in the smaller ones on slopes having a southern and western exposure. É H are considerably more dominant here than in the marginal zone whereas Ch are of minor importance. The most conspicuous plant is Geranium silvaticum (cf. fig. 25). Under this plant and mixed with it there occurs a dense vegetation of Ch and herbs: Vaccinium uliginosum, Salix herbacea, S. glauca, and S. phylicifolia, Empetrum nigrum, Polygonum viviparum, Thalictrum alpinum, Equisetum ar- vense, Carex rigida, Deschampsia flexuosa, Agrostis canina and A. te- nuis, Festuca rubra, Hierochloé odorata, Anthoxanthum odoralum, Phleum alpinum, Poa alpina, Rumex acetosa, Ranunculus acer, Viola palustris, Taraxacum officinale, Galium verum, Alchemilla alpina, and A. minor, and Sibbaldia procumbens. The table shows more precisely the quantitative distribution of the individual species. In the main the three localities examined by me are in accordance even though some few species deviate. The deviations probably express differences of environment, but the material is so small that there is no reason for a more detailed discussion, The Bottom Vegetation. Covering the bottom of the snow patch, below the Geranium belt and well marked off from it, there occurs a Salix glauca- Gnaphalium supinum formation. This formation is somewhat poorer in species than the Geranium belt above. The density of STUDIES ON THE VEGETATION OF ICELAND 119 species is likewise less, 10.0 as against 14.3. The dominant or typi- cal species are Salix glauca, S. herbacea, Sibbaldia procumbens, and Gnaphalium supinum. Vaccinium uliginosum, Empetrum nigrum, and Salix phylicifolia have entirely disappeared. Of more or less do- minant species we may mention Equiselum arvense, Carex rigida, Deschampsia flexuosa, Agrostis canina, Festuca rubra, Rumex acelosa, Viola palustris, Taraxacum and Leontodon. Table 25 A, 5 shows the circling results for a smaller snow patch having a northern exposure. In its broad features this locality corresponds to the bottom vegetation of the large snow patches. Floristically there is the difference that Vaccinium uliginosum and Empetrum nigrum are present in the small snow patches, while Sibbaldia procumbens and Gnaphalium supinum are only present in the larger ones. Just as, within the myri formations, the flöi forms the extreme point in a sequence of changes conditioned by the length of the period when the ground is covered with water and the depth of the water-layer, so also, in the formations lying above the ground- water, the geiri shows a succession of changes conditioned by the length of time that the ground is covered with snow and the depth of the layer of snow. Passing from melar by way of the mo to geiri, the depth and duration of the snow-covering increases more and more. Melar is without snow or almost without snow through- out the winter, the mo has the snow-covering normal to the area, while the geiri is already covered at the first snowfall in the autumn, retains a deep and constant snow-covering throughout the winter, and only becomes bare again when the snow melts far on in the spring. Now these conditions have the following effect on the vegetation. Where the snow-covering is slight, it consists principally of arctic species and life-forms, whereas, where it is deep, it consists of southern species and life-forms. Thus melar has a Ch percentage of 52, an H percentage of 36, an A percentage of 81 and an A 3 percentage of 55. The E percentage is 0. The mo (the knolly mo) has a Ch percentage of 38, an H percentage of 47, the A percentage is 71, the A3 percentage 39, and the E3 percentage 4. The geiri (the Geranium silvaticum belt) has a Ch percentage 120 H. MØLHOLM HANSEN of 31, the H percentage is 53, the A percentage 44, the A 3 percen- tage 24, and the E (3—2—1) percentage 35. The Geranium belt represents the area where the characteristics peculiar to geiri are most striking. If we pass from the marginal zone through the Geranium belt to the bottom vegetation, or from a snow patch with a southern exposure to one with a northern exposure, the southern contingent is largest in the Geranium belt or the snow patch with the southern exposure, while it again de- creases in the bottom vegetation or on the northern slope. This is especially due to a decrease in the southernmost E subgroups. Looking for the cause of this change we find it in the unusu- ally long period during which the formations in question are covered with snow. In the case of the southern types of plants, which obtain the most favourable life-conditions in the Geranium belt (that is to say, the greatest possible protection from the winter cold and the most favourable temperature in the period of vegetation), the long-lasting snow-covering causes the vegetation period to become too short for these plants. The number and density of species which attain their highest values, 36 and 15 respectively, in the mo, have the values 32 and 13 in the Geranium belt. This diminution is continued in the bottom vegetation, so that here the number of species is only 21 and the density 10. If these changes are continued, with the successive diminution of the number of species and the quantity of southern species, as a final result we may anticipate to find, at still greater altitudes above the sea, the Salix herbacea and Sibbaldia formations described by Helgi Jonsson and at still higher levels the Anthelia-vegetation. At the level at which Arnarvatnsheidi is situated, in the lower zone of the mountain region, we have thus the following types of vegetation. I. Melar, conditioned by a slight snow-covering and a compara- tively strong desiccation of the soil. II. The Betula nana mo, where the snow-covering is deeper and the moisture of the soil greater: while the melar vegetation is peculiar to the denudation area of solifluction, the Betula nana mo is peculiar to the accumulation area. STUDIES ON THE VEGETATION OF ICELAND 121 III. The knolly mo. The snow-covering and moisture of the soil are still greater. No solifluction, but incipient formation of knolls. IV. Jadar, peculiar to moderately moist soil with normal snow- covering and maximum formation of knolls. V. Myri. The soil is constantly moist, the ground-water coming up above the surface. Two formations may be distinguished, an upper, more dry, formation in which knolls occur, and a lower, more moist, formation in which the surface is level and without knolls. VI. Flöi. Constantly covered with water, the bottom level, no knoll formation. VII. Geiri. Snow-covering deep, bottom comparatively moist, especially in the lower formations, surface level, no knolls. The types of vegetation in other parts of the highlands seem to correspond to these. VI THE DISTRIBUTION OF. SPECIES; ‚SPE@E=Z GROUPS, AND LIFE-FORMS IN THE FORMATIONS, ARRANGED ACCORDING TO INCREASING PREVAL- ENCE OF ONE AND THE SAME EXTERNAL FACTOR 1: the two preceding chapters we have treated in more detail a series of Icelandic formations with respect to their environment and their floristic and biological characteristics. A very important part still remains to be treated, viz. a determination of the areas covered by the individual species within the tracts examined. The most obvious method of determination would be to map the formations within the tracts examined, and determine their areas on the basis hereof. But this work would involve too much time and trouble if it were to be accomplished in a fairly reliable way. A more practical method has been worked out by Thore Fries in 1919. The mode of procedure in this method, “the synecological line taxation method”, is as follows. A system of definite lines, drawn according to more precise rules, is laid down, and the lengths of line covering the respective formations, are then measured. If the system of lines is correctly laid, that is to say, if the lines are laid sufficiently close together, the sum of the lengths of line cover- ing a given formation will afford a measure for the area covered by the formation within the tract examined, and the proportion of the length of line covering a given formation to the total length of the line system will correspond to the proportion of the area covered by the formation to the total area of the tract examined. (Th. Fries, 1919, p. 3). In my investigations of the Icelandic vegetation I did not em- ploy Fries’s line taxation method, a fact which I have often regretted during my elaboration of the material, but during inves- tigations in Denmark I have often experienced how practical this method is compared with the usual mapping of the formations of an area. Thus I have the same experience of the line taxalion method as has Thore Fries of Raunkiær’s circling method.... STUDIES ON THE VEGETATION OF ICELAND 123 "the method, in my opinion, constitutes an ingenious and satisfactory solution of the problem.” (Th. Fries, 1919, p. 4). I can likewise fully support the author when he goes on to say, “Raunkier’s circling method and the synecological line taxation method complete each other. By the former we obtain exact knowledge of the nature of the units, by the latter of their area and distribution. Synecological plant geography should be able to make great progress in exactitude by these two methods. Synecology now need no more rank last in this respect among the various branches of botany, on the contrary, it should soon be able to take up its position as one of the first.” However, the results which these two methods will be able to produce, viz. an exact description of the plant series of the face of the earth, only constitute one aspect of plant geography, the geogra- phical aspect. For such a description is primarily of importance in its bearing on geography. The botanical aspect proper will only appear when, in addition, we investigate the external factors which determine the distribution of the individual biological or syste- matic units. If we follow the ordinary scientific method of investigating the facts in connection with a given unit by varying only one external factor at a time and as far as possible keeping all the other factors constant, this means, in the case of the doctrine of formations, that we must primarily examine the distribution of the indi- vidual species within the formations, arranged according to increasing prevalence of one and the same external factor. The resulting facts may then be made the basis of more detailed ecological considerations. In the present chapter we have examined the distribution of a series of Icelandic species partly in relation to the Icelandic scale of moisture, partly in relation to the scale of snow-covering. The material employed is the same which was utilised for the formation statistics of the two preceding chapters. On the basis of this ma- terial we have further examined the distribution of Raunkiær's life-forms and the species groups in relation to the above-mentioned two scales. The Scale of Moisture. Under the treatment of the formations in the localities examined the degree of moisture has been more precisely described. 124 H. MØLHOLM HANSEN We may distinguish between an area in which the moisture of the soil is entirely dependent on the precipitation throughout the year, an area whose moisture throughout the year depends also on the ground-water, and an intermediate area in which the moisture of the soil depends on the precipitation in the summer, while in the winter it is also dependent on the ground-water. This area is re- presented by the jadar vegetation. If, on a gently sloping surface, we pass upwards from the jadar vegetation, we may distinguish here between three different zones of moisture: a lower zone in the mo, where the influence of the ground-water is still demonstrable, the mo itself, where this influence no longer exists, and an upper zone (the melar vegetation), which, on account of its open vegetation, is exposed to a stronger desicca- tion than the more densely covered mo. If, from the jadar vegetation, we pass downwards, we can like- wise distinguish between three different zones of moisture: an upper myri formation, not very damp in the summer, a lower myri for- mation saturated with water, and finally the flöi, which is covered with water throughout the year. Thus we may distinguish between 7 different zones of moisture in Iceland. Zone I comprises the Elyna mo at Bjørk and the melar vege- tation on Lyngdalsheidi, at Leekjamot, and on Arnar- vatnsheidi. Zone II comprises the Arctostaphylos mo at Bjørk, the ordinary mo at Lyngdalsheidi, the high mo at Lækjamåt, the mo at Nordtunga, and the Betula nana mo on Arnarvatns- heidi. Zone III comprises the Calluna-Empetrum mo at Bjork, the moist mo on Lyndalsheidi, and at Lækjamôt, and the knolly mo on Arnarvatnsheidi. . Zone IV comprises the jadar vegetation at Bjork, on Lyngdals- heidi, and on Arnarvatnsheidi. Zone V comprises the Salix myri at Bjork and on Lyngdalsheidi, and the knolly myri on Arnarvatnsheidi. Zone VI comprises the Betula nana myri at Lækjamôt and Bjork and on Lyngdalsheidi, and the level myri on Arnar- vatnsheidi. Zone VII, finally, comprises the flöi vegetation at Bjork, on Lyng- dalsheidi at Lækjamôt, and on Arnarvatnsheidi. STUDIES ON THE VEGETATION OF ICELAND 125 These 7 zones may be pointed out without difficulty wherever the ground does not slope too steeply. As soon as the ground be- comes more rugged and uneven, irregularities in the distribution of the zones may be observed. One or more zones will not be developed; thus moist myri may be observed to adjoin high mo without the intermediate zones having attained development. The interrelationship of the zones can, however, be confirmed wherever the mo, or the myri, is the dominant feature of the landscape. In hollows in the mo the jadar will always be the first type of vegeta- tion to be met with, and with the progressive size and depth of the depression the other types will follow in the above-described se- quence. Wherever an elevation occurs in the myri, the types of vegetation will succeed each other from the edge of the myri to the summit of the elevation in the same regular way in conformity to law. These conditions are repeated again and again in every part of the island. Table 26 shows the distribution of the life-forms and the spe- cies-groups in relation to the scale of moisture in the various series of investigations. The Roman numerals I—VII correspond to the 7 zones of moisture mentioned above. Life Forms. Their Distribution in Relation to the Scale of Moisture. In a previous chapter (pp. 13—33) the influence of the climate on the prevalence of species-groups and life-forms in the flora was subjected to a more detailed investigation. As far as the life-forms were concerned Ch proved of special interest by the close correlation between the rise in the Ch percentage and the severity of the cli- mate. Passing round the coast from South Iceland by way of western and northern Iceland to East Iceland, the Ch percentage showed a continuous rise, and passing from the level of the sea towards the snow-line, the same was the case, only in even greater degree. The same was the case with the A percentage. The statistical investigations of the formations confirm this. Thus, if we compare the Ch percentage of the Elyna mo at Bjork, the formation in the southern lowlands which is most arctic in character, with the melar at Laekjamöt, the most pronounced arctic formation in the north country (both localities at a height of c. 100 m.), we shall see that in the former case the Ch percentage is 28, in 126 H. MØLHOLM HANSEN the latter 45. On Arnavatnsheidi, at a level of c. 500 m., the same formation shows a Ch percentage of 52. Taking the mosathembur vegetation of Lyngdalsheidi from altitudes of c. 250 m., 332 m., and 400 m, we get the following scale for the Ch percentage: 10—55—68, with a corresponding rise of the A percentage: 75 —90 — 100. Thus the influence of the cold on the Ch and A spe- cies is beyond all doubt. Table 26 shows the distribution of the life-forms in relation to the scale of moisture, A remarkable circumstance appears in con- nection with the chamaephytes. From a comparative minimum in zone IV (the jadar vegetation) the Ch percentage increases in value, upwards as well as downwards. This applies equally to the Bjork series, the Lyngdalsheidi series, and the highland series. In the Lækjamôt series the increase does not appear in the lower part of the scale for the halla myri series, whereas the rule seems to apply to the för myri series here. It is difficult to find any plausible reason why Ch should thrive best in the mo and the myri, and badly in the intermediate jadar. Anyhow, it is a fact that the environment in the jadar is unfavour- able to Ch. Species such as Empetrum nigrum, Vaccinium uligi- nosum, and Betula nana occur with a higher F.- percentage above as well as below the jadar. Possibly the cause may be found in the annual variations in the level of the water. It is of minor importance to Ch whether the moisture is great or small, if only it is the same ali the time. If great variations take place, as is the case in jadar where the plants grow now on damp, now on dry soil, Ch decline. On the heaths of Jutland it may often be observed how great variations in the water level tend to kill the chamaephytes, and at the level of moisture corresponding to the jadar, viz. the edge of the bog, the following facts may be observed. In the middle of the heath where the variations are only small, the chamaephytes play a prominent part in the composition of the vegetation, near the valley of the river where the variations are greater, the chamae- phytes disappear. In a series of investigations on this zone of moisture at Norholm Heath the former formation showed an average Ch percentage of 55, while the latter formation had only a Ch per- centage of 4. STUDIES ON THE VEGETATION OF ICELAND 127 Possibly the depression of the Ch percentage in Zone IV may be referred to similar circumstances. If we compare the A percentage and the Ch percentage in the scale of moisture, both series are seen to take a corresponding course with a relative minimum in Zone IV. Thus the depression may perhaps also be due to the temperature conditions which are more favourable to the vegetation in this zone than in those above and below. The hemicryptophytes are peculiar to the upper, drier part of the scale of moisture with perhaps a slight indication of a rise from Zone I to Zone IV. From this zone onward there is, at any rate, a strong decrease. The maximum of the hemicryptophytes in the moderately moist area which coincides with the relative mini- mum of the chamaephytes is most pronounced in the highland tracts. The hemicryptophytes dominate more in the lowland than in the highland formations, and of the lowland formations those of the south country are more abundantly provided with H than those of the north country. Thus, in contrast to the chamaephytes, the hemicryptophytes seem to thrive best in a moderately moist envi- ronment of favourable temperature. This appears with even greater distinctness in the distribution of the species, as is sufficiently evident from the biological spectra in table 8 for the heath and mo vegetation, in contrast to the vegetation of the littoral meadows and the grassland. The therophytes play no very great part in the composition of the vegetation in Iceland. They occur most abundantly in the relatively continental parts of Iceland, the highlands and the north country; in the rainy south country they hardly occur at all in the typical formations. In the north country they occur more abun- dantly in the lowlands than in the highlands. In the scale of moisture Th attain two maxima, one in Zone I (melar), and one in Zone IV (jadar). In the part showing the greatest moisture they do not occur at all. The rise in Zone IV is of spe- cial interest: for the individuals it is most marked in the highland series, for the species it is even more marked than for the indivi- duals, as shown by the biological spectra of the vegetation of the littoral meadows and the grassland in Vestfirdir. The Th per- centage for these two types of vegetation which correspond to the jadar vegetation, is 15—16, for the heath and mo vegetation it is only 1—8. 128 H. MØLHOLM HANSEN Ås previously mentioned, the flag vegetation is peculiar to this level, and this type of vegetation has just those characteristics which were pointed out for Zone IV, or the jadar vegetation, viz. a low chamaephyte percentage and high H and Th percentages; these conditions are, however, more pronounced in the flag than in the jadar vegetation. Thus the forces which produce and sustain the flag vegetation act, though in slighter degree, wherever this level of moisture occurs, even where no flag is developed. The cryptophytes, i.e. the helophytes and geophytes, are peculiar to the lower sections of the scale of moisture, just as Ch, Th, and H are peculiar to its upper sections. HH are most abun- dant in the lowlands and the south country, decreasing in quantity as we pass to higher levels. This agrees with the HH percentage in the Greenlandish local floras where, as previously shown, the HH percentage decreases from south to north along the west coast as well as the east coast. As regards the distribution of HH in the scale of moisture, they naturally occur in the greatest quantity in the flöi on soil that is constantly covered with water; thence they decrease strongly through the.myri, until they disappear entirely in jadar. The geophytes have a similar distribution. In Zone VII, the dampest section of the scale, they attain their maximum; thence the G percentage decreases strongly and steadily throughout the scale until, in Zone I, they attain their minimum which is lowest in the north country and highland tracts, highest in the south country. Thus the geophytes, on this point too, present a contrast to the therophytes and chamaephytes. In regard to species the cryptophytes show the same conformity to law; thus the freshwater vegetation of Vestfirdir has an HH percentage of 70, the myri vegetation an HH percentage of only 9. In the same locality the G percentage of the myri is 25, of the mo, 14, and of melar only 9. We have now seen the distribution of Raunkizr’s life-forms in the Icelandic scale of moisture. From the circling results it appears that the individual life-forms attain their maximum deve- lopment at different grades of the scale. Passing from the bottom to the top of the scale, the following sequence appears Heloph. — Geoph. — Hemicryptoph. — Theroph. & Chamaeph. STUDIES ON THE VEGETATION OF ICELAND 129 In the 4 moisture series examined so far, the life-forms show, in the main, the same sequence. If the biological spectra are based on species lists alone, we get the same sequence. This distribution must be regarded as more specific to the life- forms than to conditions in Iceland. In Denmark the vegetation of Nørholm Heath has been ex- amined with the same minute graduation of the external factors as in Iceland. The sequence of the maxima of the life-forms in the scale of moisture was the same on Norholm Heath (which, however. had more than 7 grades) as in Iceland, viz. HH. G, H, and Ch from below upwards. The rise in the Ch percentage in the lower section of the scale is not found here, however; on the other hand, there is a rise of the H percentage. Raunkiær (1909, 1912), C. Olsen (1914, 1921), and Grontved (1927) examined the vegetation on solid soil exposed to the sun. From their researches it will likewise appear that, if biological spectra for the various (more diffusely limited) zones of moisture are worked out on the basis of the circling results, the sequence will se HH,G,H, Ch, and Th. If biological spectra for the various zones of moisture from sunny open solid soil were worked out on the basis of the species lists alone, the sequence of life-forms was still seen to be the same. The correlation between moisture of soil and life-form pointed out above must be said, therefore, to be generally valid. In con- sidering the physical causes active in the formation of life-forms, a knowledge of this correlation is indispensable. The Species-Groups. Their Distribution in the Scale of Moisture. On the basis of particulars of the presence and quantitative distribution of the individual species in northern Europe and the adjacent arctic regions we have, in a previous chapter, divided the Icelandic flora into groups according to the temperature requirements of the species. The flora was first divided into two large groups: the A group which has its main distribution in arctic regions to the north of or, in mountain regions, above, the tree limit, the 20 per cent Ch bio- chore; and the E group which has its main distribution in the The Botany of Iceland. Vol. III, 9 130 H. MØLHOLM HANSEN TABLE 26. The Distribution of Species Groups and Life Forms in the Scale of Moisture. 1: The Björk Series. 2. The Lyngdalsheidi Series. 3. The Lekjamot Series. 4. The Arnarvatnsheidi Series. (Cfr. the text). 8 |22| 28] A|E A3| A2/A1/E4/E3\E2)E1|Ph/Ch| H | G [HH Th gs |@% | °% EN 4536 | 29 |11.452|48| 30 | 11 [11 | 30 11) 4| 2| » 2856| 16 ; Ir: 4096 | 30 113.633 |67| 18! 9 | 6 | 33/13 /21)0.3| »|39 47| 14 0.2 I sch. 4436 | 40 |14.8|39|61| 19 10 |10 | 33 11,17!0.5, » 2952| 18! » [01 IV ie 2756 | 42 | 13.836 |64| 15: 8 113 | 36! 14|15/0.3| » 22/541 23] 2102 VAR MIE 2768 | 39 | 13.9187 |63| 14 11 |11 | 43/18| 3| »| »|25|34| 33] 8] » NEST 1920 | 26 | 9:6141|59| 10 17 |13 | 41/15 | 3| >» 33| 9| 45/13 | > Vie ve 376 | 5 | 1.9124 [76 3 |22| 9167 » 63 37 D: ACL 3852 | 18 | 5.5 60/40 36119 | 5 | 30 10.0502 » 43 39/18! » | » Host 3644 | 34 [13.350 | 50| 29 |10 | 11 | 25/14/10] 1) »|26156| 17| » |03 1 r ie; 1384 | 32 | 13.8 | 51 | 49| 23 | 13 | 15 | 24115111 23169|18| > | » IN 2... 1376 | 38 1138143157 | 20 | 12 | 11 | 30115 112| »| »|12153| 34| 1/03 VASTE. 1076 | 34 10.847 |52| 21/17 | 9 | 33116| 4 19|34| 41| 6 |0.4 VRR AM | 2832 | 21 | 94151149) 17| 22 | 13 | 34 | 15 >|29)13| 52) 6| » va 928 | 2 | 1.1] 2198 2 | 36 63 >|36| 65) > | » he, 2058 | 27 | 6917525 | 52/16 | 7 | 24| 1| ılo2|» 5/47! 5| >| 3 PRE 3480 | 39 |17.4|64|36 | 39/18 | 7 | 25| 7| 410.1| » 35:49! 14 2 en 3168 | 43 115.957 |43 33 16 | 8 | 2310| 8) 21» 2558| 14| »| 3 IR 22281 33 |11.2|50|50) 23/25 | 2! 24/17) 9| »|>»/13140/46| »| 2 Does 780 | 29 | 7.8|51|49| 17 24 | 10 | 24 17| 8| >| »|11/19| 62] 8| 14 BE NESA: 1172 | 14 | 5.930 |70| 22/17 | 2 | 26 30/15| >| >/0.3125| 65] 9| » VE 908 || 27 | 9.144156 19123 | 1144/13" »| »1»123122/65| » |» 6123122. | 204 | 3 | 20151149! 21 » a9 | 49! »| »| >|» > 100| » | » | | | | PED en | 4748 | 27 | 7.9|81|19| 55|20| 6 | 19| »; »| »|»152,36| 10; »| 2 Hee 5664 | 32 | 11.3] 70 | 30! 43124 | 3 | 29! 1| »| »|| »|48|37| 15 1 Miele | 7184 || 35 |14.4||71|29 39/25 | 7 | 24) 4] »| >| »|38|47| 15) » (08 IV Le | 6008 || 38 |12.0||63]37 | 34122 | 7 | 28| 6| 3) »| »|21/51) 27) >| 2 Vises: | 3392 | 23 | 8.5//56| 44| 43|12 | 2 43| 1 »| »>|28/26| 46| 1) 4 VE rs | 2344 | 11 | 4.7|66|34 | 33/22 | 12 | 29) 4] » » | 14 | 11 7008400 RE eee 932 | 7 | 24135165| 20/10 | 51153113! »| >| »| 6/15! 75) AI | z f | | | : | Average I . |13.136| 25 | 8.316436 40 |17 | 7 | 26| 7| 2| 1j»|41|44| 15| » [07 II.. (16.404 || 32 ;12.7|51/49| 30 | 14 | 7 | 29| 9 10/0.4| »|38/47| 15| » [05 IIL.. 13.004! 36 ,143|54 46 27 ı6 11 | 27/10! 910.2! »|3053| 17| » lo IV.. \10.140| 39 13.2|47|53 23 14 | 10 | 31/12 10.0.1 > 18/53) 28 ı| 1 V.. | 7.136) 32 |11.1/47|63| 26 13 | 7 |40|12| 2] »; >» 2431/40] 5 105 VI.. | 7.096]| 19 | 7.9153|47| 20 | 20 | 13 | ar 1| »|'»]25| 11| 5661 372 VIL.. || 1536! 5 | 1.812080, 7| 4 10 |.33 >.» »! 2117! 68/441 > STUDIES ON THE VEGETATION OF ICELAND 131 temperate zones, to the south of, or below, the 20 per cent Ch biochore. The A group was again divided into 3 minor groups according to the temperature requirements of the groups. The Al group requires the highest temperature and is only found in subarctic regions. 66° N, lat. in West Greenland was chosen as a practical northern limit. The A2 group does not require so high a temperature, yet it does not occur in the most pronouncedly arctic regions. The northern limit of the group in West Greenland lies south of 76° N. lat. The A3 group is of common occurrence as far north as northern Greenland, hence it is the group that thrives best in the most extreme cold. While cold, i. e. a low temperature, together with a varying amount of heat is indispensable for the A groups, heat is indispen- sable to the E group. In the latter group we may likewise distinguish a series of types according to their temperature requirements. Hence group E was divided into 4 minor groups of which E 1 required most heat, E 4 least. The species of the E1 group have their northern limit in Scandinavia that is to say, they belong to southern Scandinavia. The E 2 group has no northern limit in Scandinavia, but does not occur in Greenland. The E3 group is composed of Icelandic species which occur in Greenland, but south of 66° N. lat. The E 4 group occurs in Greenland north of this line. The distribution of the species groups in the various parts of Iceland as well as in the Icelandic altitudinal zones fully confirms the above described distribution of the groups, both as regards quantity and as regards mere presence. Thus the A group occurs most abundantly and with the greatest number of species in the north and in the highland tracts, whereas the E group is the dominant group in the lowlands and the south country. Of the A sub-groups A 1 prefers the lowland, A 2 the lower tracts of the highland, and A 3 the upper tracts of the highland. Of the E sub-groups E 4 is of common occurrence everywhere, though there is an appreciable decrease in the upper tracts of the highlands, E 8 occurs most frequently in the lowlands. E 2 and especially E 1 occurs solely, and only in scattered specimens, in the 9? 132 H. MØLHOLM HANSEN lowlands. These plants find the most favourable conditions of growth round the hot springs. The circling investigations closely confirm these results. The Å percentage of the formations is higher in the highland than in lowland tracts, and higher in North Iceland than in South Iceland. The same applies to the sub-groups, A 1 showing a steady decrease in quantity from the lowlands to the highlands: at Bjørk and Lækjamôt the average A 1 percentages are 12.1, at Lyngdalur the A 1 percentage is 9.1, and at Arnarvatnsheiöi it is 5.8. A 2 occurs more frequently in the highlands than in the low- lands, and more frequently in North Iceland than in South Iceland, this is the case too with A 3, only in an even more marked degree. The E sub-groups show similar relations. E 4 occurs with equal frequency in the highland and lowland tracts. E 3 occurs most frequently in the lowlands, especially in the south country. The same applies in even greater degree to E 2 and especially to E 1. Table 26 shows the numerical values and their variations accord- ing to altitude and district. Table 26 shows the distribution of the species groups in the scale of moisture. The A group shows the same depression on moderately moist soil as the chamaephytes; from Zone IV the A percentage shows an increase, both upwards in the mo and downwards in the myri. In Zone VII, the flöi, the A percentage reaches its lowest value. The individual sub-groups show different relations; while the A 3 group decreases steadily as we pass downwards in the scale from mo through jadar to myri, the reverse is the case with the two other groups, so that the increase of A in the lower section must be ascribed to A2 and A 1. These relations are most plainly illustrated in the lowland series: Bjork, Lyngdalur, and Lekjamét. The individual sub-groups of E play a very different part in the composition of the vegetation. E 4 occurs in the greatest quan- tity, then successively E 3, E 2, and E 1. While E 4 and especially E 3 must be said to prefer the damper section of the scale, the reverse is the case with E 2 and E 1 which only occur in the mo formations. In the Lækjamôt series, however, E 2 forms an exception to this rule, for, similarly to E 4 and E 3, this group increases with increasing moisture of the soil. Even if the 7 sub-groups cannot perhaps be said to form a continuous scale of adaptation to decreasing temperature, this is at STUDIES ON THE VEGETATION OF ICELAND 133 any rate the case within the sub-groups of each of the two larger groups, and this justifies a linear grouping like the one employed. If now we regard the spectra of the scale of moisture as a whole, as a series-spectrum, it shows a pronounced tendency to form a wedge downwards, produced by a decrease in quantity of the sub- groups of both main groups from without inwards. This wedge shape appears in all the series. The wedge shape of the series-spectrum must be put down to the different temperature conditions in the different sections of the scale. Thus the variations in temperature in the upper part of the scale will be greater than in the lower part since the specific heat of the water will act as a buffer here against changes of tempera- ture. To this must be added the fact that considerably more water will evaporate from the damper than from the drier areas, and since the temperature at which water evaporates, as well as its specific heat, is very high, this will in practice mean a slower and slighter heating of a moist than of a dry area. In the summer, therefore, the temperature will be lower in the former than in the latter area. In the winter the reverse will be the case. If, in addi- tion, the temperature drops below zero, considerable amounts of heat will be liberated within the moist areas, viz. the heat which has become latent by the thawing of the ice, the effect of which will be that a damp soil will freeze slower and not to such depths as a dry soil. In the case of moderately moist soil, one more circumstance must be noted. This zone is relatively dry in the summer, and relatively moist in the winter, which gives it more or less the advantages of dry soil in the summer and of wet soil in the winter. All in all this area will have more favourable temperature conditions than the areas above and below. The interaction of temperature conditions and vegetation in the various zones of moisture will thus be as follows: — A. Melar (Zone I) is in pronounced degree cold in the winter as well as warm in the summer. Hence plants which require much cold (Ch and A 3 species) and much heat (E 2+1 species) thrive well here. In contrast to the other zones of moisture it is, however, bare of snow in the winter. This will further encourage the A 3 species, while the E 2+1 species will decrease in quantity. B. The Mo (Zones II—III) is likewise cold in winter and warm 134 H. MØLHOLM HANSEN in summer, though in less degree than Zone I. Hence the same types of plants occur here. C. Jadar (Zone IV). As previously indicated, this zone must be regarded as relatively warm in winter and warm in summer, owing to the variations in the level of ground-water. Hence the result is that the vegetation consists in marked degree of southern types, EL Th, and E species. D. Myri (Zones V—VI) is warm in the winter but cold in the summer. Hence southern plants requiring much heat (E 2+1 species) and northern plants requiring much cold (A 3 species) thrive badly or are unable to thrive here. As a matter of fact the vegeta- tion consists of southern plants requiring little heat (E 4+3 species) and northern plants requiring little cold (A 2+1 species). E. Flöi (Zone VII). Here the vegetation is covered by so deep a layer of water that the frost hardly reaches it in the winter. Hence it is never exposed to the conditions required by arctic plants; consequently these are absent at any rate in the lowlands and as compared with the myri formations. In the summer, too, the vegeta- tion is covered by water. The heat which benefits the plants on drier soils is latent in the water here. The result is a relatively low temperature which excludes the southern plants requiring more heat. Hence the species group spectrum is compressed to the central parts of the spectrum. Between halla myri and för myri there is a peculiar difference in regard to the species group spectrum. As previously mentioned, the difference between the halla myri and the för myri is this, that halla myri appears where the ground water comes to the surface, while the för myri is dependent for its moisture on the surface precipitation water. While the tem- perature of the water is to a certain extent dependent on the tem- perature of the air in the latter case, the temperature of the water in the halla myri is dependent on that of the ground-water, which again is equal to the annual mean temperature of the locality in question. In the winter there will be a constantly varying amount of relatively warm water in the halla myri to be cooled, whereas, in the för myri, there will be a constant amount of water to be cooled, and the result must be that the temperature of the halla myri in the winter must be higher than that of the for myri. In the summer the reverse must be the case. The heat in the halla myri will have a constantly varying amount of STUDIES ON THE VEGETATION OF ICELAND 135 now relatively cold water to heat, while in the för myri there will be a constant amount of water to be heated, and the result will be that in the summer the temperature ofthe för myri will be higher than that of the halla myri. Which will be best for the vegetation must depend on the relative lengths of summer and winter. Where summer is the longer season, the result will be a relative cooling of the locality in question and a stronger cooling than that which is conditioned by stagnant water. Where winter is the longer season, the locality in question will offer favour- able temperature conditions for the vegetation, even though the summer, short as it is, must also exert its influence. The former conditions prevail in Denmark, the latter in Iceland. For Denmark A. Mentz (1912) has shown that the Paludella bog is tenanted by a series of northern-alpine species not found elsewhere in this country. Thus the Paludella bog offers more favourable growth conditions to arctic plants than other types of bogs. The same is the case in Iceland. In the halla myri at Lekjamot the quantity of A 2 species is considerably higher than in the corre- sponding för myri zones in the south country, while the quantity of A 2 + A 1 species is higher in the halla myri of the valley slopes than in the för myri of the valley bottom. | Hence the cold water peculiar to the halla myri in the summer has even in Iceland a noticeable influence on the vegetation and gives it an arctic character. The effect on the vegetation of the warm water in winter is, however, much stronger. If, in a för myri series, we pass from the drier to the more moist zones, the E 3 percentage has practically the same value throughout the zones until we reach the very wettest, when it shows a very great rise. In the halla myri series the E 3 percentage has its lowest value in the drier zones, whence it rises steadily until it attains its highest value in the dampest zone. In the för myri series E 2 attains its highest value in the driest to moderately moist zones (mo and jadar), whereas, in the dampest zones (myri and flôi), it has decreased much or is entirely absent. In the halla myri, on the other haud, the E 2 percentage rises on the passage from dry to moist soil; where there is the highest degree of moisture, the E 2 percentage is highest. This difference between the halla myri and the för mvriis most naturally explained if we assume that it is H. 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OSU9IALE -_ wnyesonea wnjesinbg os gun eu nog wnsousin wnumoRA fe ee "spe [na LE ‘uw N 5 : Pen RE ee EEE vpnotafurg nuosxie (AS SOE eee SER 138 H. MØLHOLM HANSEN the result of the effect on the halla myri of the warm water in the winter. The Distribution of the Species in the Scale of Moisture. Table 27 shows the distribution of the species in the scale of moisture respectively at Bjørk, on Lyngdalsheidi, and on Arnarvatns- heidi. A special column further shows the average values for these three localities. The Lekjamot series has not been included in the table since the myri formations here differ in several respects from the above mentioned, thus causing some deviations which are not due to the conditions of moisture. On the whole, however, the distribution of the species in the scale of moisture in the Lekjamot series confirms the relations stated below. In order to facilitate a general view the species have been grouped according as they occur with the greater frequency in the lowland formations or in the highland formations, or with equal frequency in both. Within each of these groups the species have then been arranged with the least »moisture-loving« first and the most »moisture-loving« last. Considerations of space have, however, necessitated the exclusion of some more rarely occurring species. The figure marked against a given species in a column is the average F.-percentage of the species in question for the zone of moisture of the locality in question. Thus in the Elyna mo at Bjork, Festuca rubra has the frequency percentages 96, 96, 100, and 96 in the 4 localities there examined. The sum, 388, divided by the number of the localities, 4, makes 97, which is the figure marked against Festuca rubra in table 27, Bjork I. If, next, we consider the distribution of the species in the scale of moisture, it is an extremely variegated picture that meets the eye both as regards quantitative distribution, that is to say, the average distance of the individuals, and as regards the mode of distribution in the scale. Some species show a low F.-percentage (i. e. a great average distance between the individuals), others a high F.-percen- tage (i.e. a small average distance between the individuals). Some species occur only in a small number of moisture classes, others in a larger number or in all classes. Some species only occur in the dry classes, others only in the moderately moist, others again only in the moist etc. But to whichever class or classes a STUDIES ON THE VEGETATION OF ICELAND 139 species belongs, it applies to all species that there is one class of moisture in which the species attains its highest F.-percentage and shortest distance between the individuals, and outside which the F.-percentage de- creases and the distance between the individuals in- creases whether we go up or down the scale of moisture. The distribution of the species in the scale may afford ground for the setting up of a series of types characterised by the magnitude of the F.-percentage, the position of the maximum in the scale, the number of classes in which the species occurs etc. etc., and in time it will be necessary to introduce a terminology in order to charac- terise briefly the relations of a species within an area. At the present time, while such investigations are still in their inception, there is no reason to set up such a system, especially since a good deal of material would be requisite for such a purpose. This part of the investigation must therefore be left until a later period. In this connection it will suffice, as was the main object of our investiga- tion, to establish the fact that a species is closely identified with a definite degree of moisture of the soil. If there is any change in the degree of moisture, no matter in what direction, the F.-percentage of the species will change simultaneously, and the greater the change in the degree of moisture, the greater, too, will be the change in the F.-percentage, until such conditions of moisture are reached as entirely exclude the species. The species reacts identically to changes in moisture wherever it occurs. The table shows how markedly this is the case in the three localities Bjork, Lyngdalur, and Arnarvatnsheidi therein indicated. These three localities have been selected at random from the areas of distribution of the species discussed, and there is no reason to suppose that an investigation in other localities under the same external conditions would give a picture of the relation of the species concerned to the degree of moisture essentially different from that shown in the table. Greater certainty might of course be gained by an increased number of investigations, in that the influence on the magnitude of the F.-percentage of accidental factors, i. e. factors not determined by the degree of moisture, would be precluded or diminished. The distribution of a species in a scale of external factors is just as constant and »good« a character ina species as any morphological or anatomical character. 140 H. MØLHOLM HANSEN TABLE 28. A, B, Cand D denote the different series of types of moisture (cf. text). I II III I\ V VI VII AS Minuartiayerna.«)..2)5.<+2- 9% 16 3 Thymus serpyllum .......... 53 50 32 4 » » Juneusatrindusee:ern UT 41 45 51 6 1 > » Selaginella selaginoides ...... 14 34 63 20 5 2 Cardamine pratensis......... 4 11 41 59 38 10 1 Violaspalustrisre see Te Le > 1 9 31 40 2 » Carex Goodenoughii ......... » 1 47 67 66 53 * Eriophorum polystachyum ... > 14 79 81 100 en ALA ie oie ieee ose a> » » 4 20 36 50 Bb oa ALPINA Er ana: 3 3 10 12 2 1 > Equisetum variegatum ...... 8 17 36 32 26 4 | 4 Polygonum viviparum ....... 68 87 95 93 95 86 | 4 C. Cardamine pratensis......... 4 11 41 59 38 10 1 Deschampsia cæspitosa ...... > 1 16 41 3 » » rer CAPI 22. Ove 2 : > > 8 » > > D. Empetrum nigrum .......... » 94 97 42 52 49 Vaccinium uliginosum ....... » 57 4 26 47 64 PCA RAA 55 » 15 1 1 8 53 » In considering the ecology of a species, a knowledge of both groups of characters is equally necessary. Table 28 shows a selection of types of moisture differing in respect of position and magnitude of the maximum and the number of classes over which the species is distributed. A number of deviating species are given at last. A. The individual species in the series Minuartia verna, Thymus serpyllum . ... (the A series) are characterised by a pronounced maximum differently situated for the different species and at different levels. From the maximum class the F.-percentage decreases equally in both directions or from the edge of the scale towards its middle. B. Poa alpina, Equisetum variegatum, and Polygonum viviparum differ from the above species in that they are equally distributed over all classes of moisture; they differ from each other by the F percentage which is low for Poa alpina, somewhat higher for STUDIES ON THE VEGETATION OF ICELAND 141 Equisetum variegatum and very high for Polygonum viviparum, corre- sponding to a dense growth of Polygonum viviparum, a somewhat more scattered growth of Equisetum variegatum, and a very scattered growth of Poa alpina. C. A third series isrepresented by Cardamine pratensis, Deschampsia ceespitosa, and Carex capitata. These species all have their maximum frequency percentage in class IV; they differ from each other in the magnitude of the F.-percentage. For Cardamine pratensis the F percentage is 59, for Deschampsia cespitosa it is 41, and for Carex capitata 8. They also differ in the number of classes over which they are distributed: Cardamine pratensis occurs in all classes of moisture, I—VII, Deschampsia cespitosa in classes II—V, and Carex capitata only in class IV. D. Most Icelandic species show the above-mentioned regular dis- tribution in the scale of moisture. A small number of species deviate in that they have two maxima with an intermediate relative minimum. These species are represented by Empetrum nigrum, Vaccinium uliginosum, and Betula nana. In a previous section on the distribu- tion of the chamaephytes in the scale of moisture we attempted to explain these facts. The relative minimum is due to annual varia- tions in the water level. Scale of Snow-Covering. Distribution of Species, Species-Groups, and Life-Forms in the Same. For the present it is not possible to set up a scale of snow- covering as minutely graduated as the scale of moisture. The reason is that so far the depth and duration of the snow-covering have not been investigated. In the individual localities it is easy enough to observe the effect on the vegetation of the different depths of the snow-covering, but comparisons between the various localities are rendered difficult by the fact that we have no exact particulars on which to base a comparison between the scales of snow-covering of the different localities. According to Thoroddsen (1914) the snow lies longer and is of greater depth in the north country than in the south-west, and in the south country there may be no snow at all during a long period. In the highland tracts the depth and duration of the snow-covering is greater than in the lowlands. These facts must be taken into consideration in a comparison between the differences in vegetation at the various stations. 142 H. MØLHOLM HANSEN Under the treatment of the formations in the various localities examined, the causes of the differences in vegetation have been more precisely stated. At Bjork in the south country the difference be- tween the Elyna mo and the Arctostaphylos mo was caused, amongst other things, by a difference in the depth of the snow-covering. The Elyna mo has a relatively thin covering of snow, that of the Arctostaphylos mo is somewhat deeper. However, the difference is not considerable enough to cause the appearance of two different types of vegegation. At Nordtunga in the south-west country mo and forest-ground are covered by snow of different depths; while the mo has the snow-covering normally occurring in that part of the country, the forest-ground is covered by a considerable layer of snow throughout the winter. At Lækjamôt in the north country, the mo has likewise the normal snow-covering, whereas the melar is bare of snow. All these localities are lowland localities situated at c. 50—100 m above sea-level. If we pass from the lowlands to the highlands, the difference in the scale of snow-covering will be- come increasingly evident. At Lyngdalur in the south country (c. 250 m above sea-level), three types of vegetation are easily distinguished. The difference between these three types, mosathembur and melar with little or no snow-covering, mo with a normal snow- covering, and geiri with a deep and constant snow-covering, is due to the difference in the snow-covering. In some places a transitional form between mo and mosathembur had developed, with an inter- mediate depth of snow. At Thrasaborgir (c. 400 m above sea-level) the three types mosathembur, mo and geiri were likewise devoloped. On Arnarvatnsheidi near Ulfsvatn at an altitude of c. 500 m above sea-level, the scale of snow-covering was further differentiated. The 5 types of vegetation, melar, Betula-nana mo, the knolly mo, the sides of the snow patches, and the bottoms and north sides of the snow patches, represent 5 different degrees of snow-covering, where the first type has the slightest snow-covering of the shortest duration, the last, the deepest snow-covering of the longest duration, Table 29 gives the distribution of the species in the scales of snow-covering of the 6 localities mentioned above. Within each locality the formation most devoid of snow is given first, furthest to the left, while the formation with the deepest snow-covering is put last, furthest to the right. Bjork a is the Elyna mo, Bjork b STUDIES ON THE VEGETATION OF ICELAND 143 the Arctostaphylos mo. Lyngdalur a, b, c, d, and e are respectively mosathembur, melar, transitional forms between mosathembur and mo, mo and geiri. Thrasaborgir a, b, and c are respectively mosa- thembur, mo and geiri. Lækjamåt a and b are melar and the high mo. Nordtunga a, b, and c are the mo, the vegetation in the forest glades, and the vegetation on the forest-ground. Arnarvatnsheidi a, b, c, d, and e are respectively melar, Betula-nana mo, the knolly mo, the vegetation on the sides of the snow patches, and the vegetation on the bottom of the snow patches with a northern exposure. A comparison of the mean values has been attempted and is likewise given in the table. The scale is divided into three divisions. I represents the types of vegetation bare of snow, melar (I b), and mosathembur (la). II represente types with normal snow-covering, viz. the mo. III represents types of vegetation with a constant snow-covering, i.e. geiri and forest. In the calculation of the mean values the deviating localities have been omitted, viz. Bjork a and ‘b, Lyngdalur c, and Norötunga c. The figures under I a are thus the mean values of Lyngdalur a and Thrasaborgir a; Ib the mean values of Lyngdalur b, Lækjamét a, and Arnarvatnsheidi a. II re- presents Lyngdalur d, Thrasaborgir b, Lækjamôt b, Norötunga a, and Arnarvatnsheidi b and c. III, finally, represents the mean values of Lyngdalur e, Thrasaborgir c, Norötunga b, and Arnarvatnsheidi d and e. The distribution of species in the scale of snow-covering is as the distribution of species in the scale of moisture. Some species attain their maximum F.-percentage in class I, others in class II, others again in class III. Some species have a high frequency per- centage in one of the classes, others in two classes, either I and II or II and III; only a small number of species occur with a high frequency percentage in all classes. A comparison between the different scales of snow-covering shows in what uniform proportions the species occur in the different localities. It may be laid down as a main rule that the species react uniformly to the same changes in respect of snow-covering. A species which, in one locality, attains its maximum F.- percentage where there is a normal snow-covering but decreases if the snow- covering changes no matter in what way, will behave in the same way in all the other localities. 144 H. MØLHOLM HANSEN TABLE 29. The Distribution of the Species i 5 I a II ar, 7 | Average | Bjork | Lyn | Ib (La) Heu | ae a b SANIIRAPANCAESDITOS Aer | 4 3 sers > à : WEA CI EA EE MER ee secs 5 | SEN all » » | 5 Euzulagarcuataeere nee ac. | 6 en Meee oe 3 3 5 Saxitraga oppositifolia.. ...:.... 2. | 14 DS EE 11 ois y 3 ; AMADIS PELLE AE eee eee eue | 18 | alle 5, » > te ila Miri ae Gag eT Male leeres ue | 19 Salle na > 7 I OASOLAU CA tat eee iol ei tolerate e ars 30 10 | + | 7 > A 3 Diyaswoctopetal A EEE RER erates ER] I 03 SRE » » 21 Berastinmealpınume seen SZ SN MIE | ates 13 , 5 18 Silene acaulis SOD NN TC AS iy et 20 7 3 15 Euzwlasspicataeen ee ca cave eo ee) 47 1 37 37 2 26 Tbs serpy 2... aise eek oo | 44 42 6 80 84 » 29 eEStU CAMO NAM an oF fore) sin eee see | AB.) | 32 9 || 38 77 1 42 RENE Su TC EN OPERA | 1 (66) 69 | 73 || 85 71. 92 a SES VE re RES | 37 (55) | 79 66 | 51 | 60 | 14 45 Polygonum viviparum............ | 58 (23) 90 53 65 76 14 62 [HoT ALION IMO oop bp odor Oe one 2205) 21 286 73 | 90 100 2 38 Bestucamribrameen LL... | 26 (27) 89 | 65 97 95 48 45 Thalieirumalpınum. ...........:. | 10 (25) 71 38 | 39 43 41 » Gal um "Normanni. use eee els dea | 14 (3) Die 23 88 53 5 13 Tuneneltiifidus!....u0.ceesaceee | 29 (3) | 50 8 | 45 | 40 1 | 36 EiynasBelländierner ten er cea cae | 7 45 4 | 53 12 » 3 Selaginella selaginoides ........... ge 45 | 14 | 40 17 » 2 Equisetum variegatum............ IE 2 (2) 28 | 5 | 20 19 8 1 == pralense sides. sees I ala) 2311005 18 35 10 » AISETHMESPICAIUME ae | 7 18 2 | 22 7 » 3 Cardamine pratensis sn sanse | 1 11 5 13 8 » » Galinmaboreale eee ee ee en one 1 37 48 26 60 » 3 Equsetunkarvense ain. ccs. ses os | i 20 20 | 10 » » » DEROSESSCAHIMAN. ne. | 18 (1) 67 15 || 95 96 1 46 SAMS OAT CAM este I: 19 30...) a » » 2 Deschampsia flexuosa ............ I) 25 90 | 18 53 » 6 Vaccinium uliginosum............ 4 (+) | 54 15° ||, 28 80 » 8 Violaspalustrisesr Lure seche aie e » 1 rs ag > » » Geranitimy SIIVATIENN mass. an. | » + 25 |, ‘> » » > Aerosbistenliisch 6s vise eee à | > ; 3 23 0.8 il > > GaliImEverumer SE Slade | + 2 20°. 2 4 > 1 Gnaphalium supinum ............ » 1 19 | > » » » Daraxacumkottieinale ern. > + 1871 3 3 » » Callanayal pants. 02.00. Waessenee » 1 12 85 > > Sibbaldia procumbens ...... Play Seater 2 > 12 > » » » RUIMEXMACELOSA RE ee es 1 6 12 | > > 1 2. Luzulasmultlogaun..n en ann > 6 | 10 5 15 » » Hierochloe olorata... „ur. ca. + os » se, 9 » > » >» Vaccine My bs Smee cir » > 7 » » > » Alchemilla ‘alpina. 22, 7... 1 > 4 | » » » 2 Leontodon autumnalis............ > > Gall aes » » » Aillchenillasminors eee teers » > à A, 042 » » » Rubus ‘saxatilis< ee eee > | >» 2 | >» » » > STUDIES ON THE VEGETATION OF ICELAND 145 e of Snow-Covering (cfr. the text). Thrasaborgir Lækjamét Norôtunga | Arnavatnsheidi | | EL 2 b c a b | à b eja b c d lee | | | | | » > > > » > » | 13 » » | » | > > > > 11 » 3 | > mn | » > > |! > > » > » > > || 12 | » 1 » > > |! > > 2 35 > | 7 » > > > > | > > > 8 > » >) 036 > » » » > | > » 23 > » » » | 34 9 4 > » > | » > » | 43 | 24 » > 10 45 | 6 10 > > | > » » || 30 84 » ARS 41 26 26 > » | 1 2 | 50 28 4 » 2 || 43 10 9 > » > | 9 22 > ha ir 62 32 > » | 65 63 50 1 » 7. | 2 24 » 47 62 48 2 » || 69 | 44 62 3 » 15 | » » » 54 88 88 9 » 49 | 8 ji! 4 » 1 2 6 2 46 30 64 38 | 10 | 57 42 12 > 2 54 40 82 74 1 54 72418070 60 » 47 70 | 84 84 38 | 96 96 96 8 66 64 7 » || 59 86 87 | 88 100 28 | 31 88 54 33 98 76 61 24 | 78 | 98 96 | 68 54 97 | 7 60 72 1 92 84 12 16 || 28 93 98 75 50 68 5 86 74 32 92 96 83 As Sae nea 88 39 62 5 9 60 12 24 | 94 80 | 78 60 | 5 76 88 93 » 30 | | 58 4 26 46 68 53 20 4 18 37 28 » 8 4 42 » 9 52 60 27 6 43 40 48 5 > 2 > > 3a 12 86 84 15.1703 6 32 45 | 1 » 12 » 30 24 9 56 40 5 > nl amis: 66 29 » » » 28 2 | 3 30 » rie eS 2 18 | 76 8 16 16 > » » 3 38 52 9 18 su tees SÅ Wee. » a) > » > 12 20 16 6 > 7 11 27 > » 24 » > 3 3 38 » Hy se à 10 1 » 85 met 74 76 » » 72 78 | 40 » » » » » 1 » | 6 2 3 30 16 ay 23 1 26 38 28 66 41 » 92 88 8 80 92 72 | 60 0578 40 | 55 88 Di > » 9 KT UGES » SAMT NE" 8 55 37 55 88 99 | > 64 98 » » 16 | 80 | 98 » » 6: 9774 99 1 4 58 » 68 88 85 | 30 4 76 12 | 85 50 21 > » 48 » > » SR ahi » » 24 26 17 » » 8 » » » RR RTE SN | ewe » » | 95 2 45 > 2 30 » » 12 agp ASS 1» » » | 21 » 15 > 2 2 » » » 53 | 8 | > > » (31 » > » 4 50 | » » » ST LOS ax | » > +r iS 36 23 > > 10 | son » » 8 2 » » > 20 30 59 > » » » | » » » » || » » » | » » > > | » 28 || » » || » » | » » » 2» | 12 22 > > 2 » » a) 4 1 | 8 | » 1 157177272 34 15 » >» 2 PR 1:12. 82 Be » » » > > | > > » || a » > 1 Js he » 22.1428 16 30 > » 6 ur » » » N > » 3. les » > > | > 14 | > > » » i kt Us » > 7 » 4 SE > 4 | » » | » 15 2 » > » > 6 4 3 > 8 » | » | » > > » > » 13 » 5 > > 4 » | » | » 1 » » > » » » | | The Botany of Iceland. Vol, II, 10 146 H. MØLHOLM HANSEN There are, however, a few interesting deviations from the rule. Thus Calluna vulgaris is of common occurrence in the mo at Bjørk. At Lyngdalur it is absent, or practically absent from the mo, whereas it occurs very abundantly in the snow patches. At Thrasaborgir it occurs neither in the mo nor the geiri. Deschampsia flexuosa occurs both in the mo and the geiri in the south country; in the south-west, the north, and the highland tracts it is either entirely absent or occurs only in scattered growth in the mo, whereas it is very abundant in the geiri (and forest). Thalictrum alpinum is a mo plant in the south country but shuns geiri; in the south-west and north country it is still a mo plant, but here it is also met with in the more snow-covered types of vegetation as forest and geiri. It seems natural to suppose that these deviations are due to differences in temperature. Vaccinium uliginosum is another interesting example. Its F.- percentage varies as follows in the scale of snow-covering. In I a (mosathembur) it has an average F.- percentage of 0.5, in I b (melar) 4. Class II, i.e. the mo, has an average F.-percentage of 54 and class III 75. The species is thus a pronounced geiri plant though with strong tendencies towards the mo. At Bjork it plays a promi- nent part in the mo, especially the Arctostaphylos mo, while the Elyna mo is less favourable. In the mo at Lyngdalur it is but sparsely represented, while it is dominant in geiri. The same applies at Thrasaborgir. In the highland tracts, at Lækjamôt and Norötunga, it is not only peculiar to the areas with a deep snow- covering, it also occurs with a high F.-percentage in the mo. On melar it does not occur, however. These peculiarities must no doubt be put down to differences in the scale of snow-covering between the south country on the one hand and the rest of the country on the other. In the high- land tracts and the north country the snow-covering is more constant than in the south country, the mo of which is sometimes covered with snow, sometimes bare. Table 30 shows the distribution of the species groups in the scale of snow-covering. The signatures are the same as in table 23. The average values are given at the end of the table. It appears from the table with all desirable plainness that the A percentage is highest in the class most bare of snow, i. e. in STUDIES ON THE VEGETATION OF ICELAND 147 I a, (mosathembur); from here its value decreases until it attains its minimum together with the maximum of the E per- centage in the class with the deepestsnow-covering. The proportion of the average F.-percentages of the two species groups in the class most bare of snow is as 83 to 17, in the class with the deepest snow-covering as 34 to 66. The variations in the distribution of the individual sub-groups are closely correlated to the variations in the distribution of the main groups. Å 3 attains its highest value in the highest class and thence the F.-percentage decreases steadily as we pass downwards through the classes. It shows the following change: 70 >48 — 35 — 20. The maximum of the A 2 species lies lower in the scale, that of the Al species still lower. The maximum of the latter group is in class II, corresponding to the normal snow-covering of the country. In this class the E species, too, attain their maximum, though not a very pronounced one. The lower E sub-groups, E 3, E 2, and E 1 all have their maxima in class III, corresponding to the fact that the species thrive best where there is a deep and constant snow-covering throughout the winter. Here E 3 is most abundant, E 2 is somewhat less dominant, and E 1 occurs only sparsely. Thus to the 3 classes of snow-covering there corresponds a vegetation quite definitely stamped by its environment. In class I it consists chiefly of A 3 species, less of A 2 species, in class II of A 2, A 1, and E 4 species, and in class III of E 3, E 2, and E 1 species. The snow- bare vegetation of Iceland thus consists of species with a pronounced northern distribution, the vegetation with a constant snow-covering of species with a pronounced southern distribution, and the vegetation with a normal snow-covering is composed of species be- longing to tracts the climate of which corresponds to that of the country. Conditions in the individual localities entirely confirm the facts stated above, both in respect of the quantitative distribution in the main groups and the position of the maximum in the individual subgroups. A decrease in the amount of snow will always tend to render the vegetation more arctic, an increase will render it more southern, 10% 148 H. MØLHOLM HANSEN This distribution is especially very plainly seen in the highland scale. As everywhere else A 3 attains its maximum in the highest class, which is relatively unfavourable to A 2. The maximum of this group is the second or third highest class, while A 1 does not attain its maximun until yet another degree lower in the scale. In the lowest class there is a rise in the A percentage which would seem to suggest that too large an amount of snow restricts the growth of the southern species but promotes that of the arctic species. The Salix herbacea, Sibbaldia procumbens and Anthelia societies previously cited must be assumed to be a development resulting from this fact. The change in the proportion of A and E species as we pass from snowbare to increasingly snow-covered vegetations is the same whether expressed in frequency sum numbers or in the species num- bers alone. This is very plainly evident from the species groups spectra in table 8 which have been calculated from Ingimar Oskarsson’s species lists from Vestfirdir. The series melar — heather and mo > herbfield and birch copse corresponds to the above-mentioned snow- covering classes I—II—III. The percentage amounts of A, A 3, and E 3+2+1 species in the various groups of vegetation are as follows: A per- A3per-- E342-+1 centage centage percentage Hishland'melar: ......... 82 24 4 Iawlandmelar . 20.5... 60 22 23 Heather and mo veg. ... 50 13 32 Herbfield and birch copse 23 fl 48 FLOR ISPHIMES ete Lei: » > 75 Even though the values do not coincide with those given in table 30, the correspondence in the variations of the series of figures is beyond doubt. A comparison between the species group spectra for the various types of vegetation, partly in the different parts of the country, partly at different heights above sea-level, will be of interest. Thus the melar vegetation in the south country has a lower A percentage and A 3 percentage, but on the other hand a higher E 3+2--1 percentage than the corresponding vegetation in the north country and the highland tracts. The numerical values are as follows. SLUDIES ON THE VEGETATION OF ICELAND 149 A per- A 3per- E3+2+1 centage centage percentage Melar in S. Icl....... 60 36 11 sae ZEN Rape eee 75 52 2 —— highland ÉD CET 81 D9 » The corresponding figures for the mo respectively in South Iceland, South-West Iceland, and North Iceland at c. 100 m above sea-level are as follows. A per- A 3per- E 34241 centage centage percentage South Iceland ....... 33 18 34 SW. Iceland: 48 25 19 North Iceland........ 64 39 iL At various heights above the sea the figures in the south coun- try are as follows. A per- A3per- E3+24+1 centage centage percentage AS LOO nf, 204892: 33 18 34 Sr AO 11 ee eg, re I 50 29 25 - 35-400 m ........ 58 33 25 - 500 m (highl.)..... 71 41 3 The figures for the geiri vegetation in the south country are as follows. A per- A 3per- E3+2-+1 centage centage percentage BE AO WAN SST PR et eens 20 12 52 - 3—400 m ........ 36 22 43 HO EN IE RATE 44 24 35 For the mosathembur vegetation, A per- A3 per- E3+2+1 centage centage percentage At 100 m (the Elyna mo)......... 52 30 18 - 200 m (the mosathembur veget.) 74 55 5 - 300m - — — 90 83 3 - 400m - — — 100 100 » The figures all point in the same direction; where the tem- perature conditions are most favourable, the southern species are most abundant, where the cold is predomi- nant, the northern species abound. This relation remains 150 H. MØLHOLM HANSEN the same if the species numbers alone are employed instead of the frequency numbers. The occurrence and quantitative distribution of the species groups in the Icelandic types of vegetation is determined throughout by the temperature conditions prevalent in the locality. The pro- longed low temperature prevalent in the highlands and the north country but especially in localilies where the snow is blown away in the winter, promotes the growth of northern but restricts the growth of southern species, while a prolonged high temperature, as it occurs in the lowlands and the south but especially wherever the ground is covered witha deep and constant layer of snow, restricts the growth of northern but promotes the growth of southern species. This is abundantly confirmed by the vegetation around the hot springs. We are thus fully justified in regarding the species groups asi indicators of: environment, and. the specnes group spectra will then prove an important guide in a more precise analysis of environment. Under the treatment of the distribution of the species groups in the Icelandic scale of moisture, the spectra furnished important holds for an examination of the physical conditions. The legitimacy of the above-stated con- siderations is further confirmed by the distribution of the species groups in the scale of snow-covering, in the types of vegetation of the different parts of the country and the altitudinal zones, and by the vegetation around the hot springs. In two areas, partly in the geiri and partly in the flöi, on soil covered respectively with snow and with water, the E species are unusually abundant. In both places the winter temperature must be supposed to be almost the same, at or below zero. When the snow has melted in the geiri, the heat that is left will directly benefit the plants. In the flöi, on the other hand, a great deal of the heat is latent in the water which still covers the vegetation, consequently the result will be a relatively low summer temperature. The flöi is thus warm in the winter but cold in the summer, while the geiri is warm both in the winter and the summer. The result will be that in both places the species group spectrum is characterised by a high E percentage; on the water-covered soil it is 72, on the snow-covered soil 66. The difference in the summer STUDIES ON THE VEGETATION OF ICELAND 151 temperature appears especially in the E group spectrum in that the lower E sub-groups occur abundantly on snow-covered soil, but are entirely absent from water-covered soil. The E 2 and E 1 species are such as require a high temperature to be able to thrive, and this requirement is only satisfied in geiri and forest. The A group spectrum shows a peculiar difference between the two types of vegetation. The A percentage is 34 in the geiri, 28 in the flöi. In the flöi 20 p. c. of these species are A 1 species, and only 8 p.c. are A 3 and A 2 species, while in the geiri the A1 percentage is only 4, and the sum total of the A 3 and A 2 per- centages is no less than 30. The high A 3 percentage in the snow-covered vegetation and the low A 3 percentage in the water-covered vegetation must be assumed to be a consequence of difference of stability in the covering medium. In the flöi the water is always present, hence the vegeta- tion is never exposed to severe cold. Thus a condition necessary for the growth of A 3.species is not present. Compared with the water in the flöi, the snow in the geiri is less stable. A hard frost may set in before the first snowfall, and frost in the night may affect the vegetation after the snow has melted. This provides a possibility for the growth of the A 3 species, hence compared with water-covered soil the A 3 percentage is high, but compared with snow-bare soil or a vegetation with a normal snow-covering, it is comparatively low. The A 3 percentage is higher in geiri than in forest, respectively 23 and 14, which further confirms the above considerations. Thus the difference between the species group spectra for water-covered and snow-covered vegetation is as fol- lows. The species in the species group spectrum of the water-covered vegetation are largely concentrated in the central part of the spectrum with a marked dominance of E species, corresponding to a favourable and fairly stable winter temperature, and only a slight difference between the winter and summer temperatures, The spe- cies in the species group spectrum of snow-covered soil, on the other hand, though also showing a preponderance of E species, are distributed over the entire scale in con- sequence of a relatively high winter and summer tempe- rature, and greater instability in the winter. As previously mentioned, the species group spectrum for the 152 H. MØLHOLM HANSEN Subularia flag, the water-covered vegetation rich in Th, corresponds closely to that of the flöi: concentration of the species in the central part, and preponderance of the E species. The treatment of the distribution of the species groups and the life-forms in the scale of moisture showed that moderately moist soil (jadar) caused a relative maximum of E species, hemicryp- tophytes and therophytes. This was the case with the vegetation on a gently sloping surface with even transitions from one type of vegetation to another. However, on moderately moist soil there occurs a series of types which, physiognomically, are rather different, both mutually and in relation to the jadar, but which, on close in- spection, prove to be possessed of the pecularities of the jadar vege- tation, though in varying degree, viz. a relatively high H percentage and Th percentage. Of these types the valllendi and flag vegetations have so far been examined. The first of these types develops on the flat cones deposited by the rivulets of melting snow on flat ledges. The valllendi soil is thus saturated with water until the last snow has melted, i. e. until the geiri is bare of snow. In the flag, conditions are otherwise. If it receives any water at all while the snow is melting, it is at most as long as there is snow on the mo. The bare soil of the flag is thus exposed to the effects of the frost (night frost) much longer than the valllendi, which is furnished with fresh water daily. Hence it is hardly accidental that the E species are more dominant in valllendi than in flag. The E percentages for valllendi, jadar, and flag are respectively 75, 53, and 42. The Distribution of the Life-Forms in the Scale of Snow-Covering. Since differences in respect of snow-covering only appear in areas not affected by ground-water, where, as previously mentioned, Ch, H, and Th are the dominant life-forms, it is principally the re- lation of the snow to these which is of interest. Table 30 shows the biological spectra of the various classes of snow-covering in the localities examined by me. At the bottom of the table are given the mean values for all the investigations. It appears from the table with all desirable plainness that Ch are more abundant on snow-bare soil than on soil with a normal snow-covering, and more abundant there than where the soil has a constant snow-covering. For H the case is re- STUDIES ON THE VEGETATION OF ICELAND 1595 TABLE 30. The Distribution of Species Groups and Life Forms in the Scale of Snow Covering. 1. Björk. 2. Lyngdalur. 3. Thrasaborgir. 4. Leekjamot. 5. Nordtunga. 6. Arnarvatnsheidi. 7. Average. 2 |e) 28) A| E|A3/A2 ALEA ESE2|EI Ph. Ch| H| G HH|Th 5 2% As | la 4536 | 29 |11.452|48|30 11 11], 30) 11) 5 | 2 | » |28 | 56 | 16 b 4096 | 30 |13.6/33|67|18| 9 | 6 |33 13/21 0.3| » |39 47 14 0.2 | ~ _ — | — — — fa 2a... |1228| 9 | 24/75/2555 18| 2 |2ı| ı 4 | » |» |10/41 as Ib b... | 3852 | 18 | 5.560 4013619] 5 |30|10| 1 10.2" » [43 | 39 | 18 (atl) ce... | 860 | 27 | 8.6/57|4335|14| 7 |27/10| 6 | » | » | 23) 51) 26 0.5 I d... | 6644 | 34 |13.3|50 | 50 | 29 | 10/11125/14|10| 1 | » | 26/56/17! » |0.3 HI e...| 7418 | 25 | 10.6] 20/80) 12) 3 | 5 |28 126124) 2 | » 135155 |10| » | » Ia 3a... | 1340 | 9 | 22/ 91/9/85) 7 |»|6 >| 3 |»|» 57 8 |35| » | » I ob... 1924) 22 9.6158 42 33 16 9 17 17 8 [0.2|| » | 25 | 56 | 18 0.2 IL c... | 2064 | 31 |10.3/36|65)22 |11| 3 |21 127/16 0.2] » 13449 ı7| » 02 Ib 4a ... | 2058 | 27 | 6.9175 265216 7 24 1 | 1 0.2) » |45|47|5] » | 3 Hb... | 3480 | 39 |17.2164|36 3918| 7 |25| 7 | 4 [0.1] » |35|49|14| » | 2 ee == u u ar res >= = — | = TE > = = | a II 5a... | 1392 | 31 13.948 52/25/15 8 |33| 9 |10| » | » |20/55/16| » |0.3 Mlb... | 4316 | 43 | 10.830 | 70/14 | 10] 5 27/28 11| 4 | » |17| 70) 14] » | » am e 1276 | 23 | 6.4125 75/13/10] 3 17/46/1111] > | 8/75/17! » | » Ib 6a … | 4748 || 27 | 7.9/81| 19/55|20| 6 | 19| » | » | » | » 152136 10 >» | 2 I b... | 5664 | 32 | 11.3) 70| 30||43/24| 3/30) 1 | » | » | » | 48/37/15) » | 1 HM oc... | 7184 | 35 | 14.41/71) 29] 39} 25] 7 124 4 |» | » | » 3847/15 » [0.3 HE d... || 3892 | 32 |13.0/44|56|24|13| 7 |21127| 6 | 2 | » 31/53/16! » |0.2 Ie... || 2000 | 21 |10.048|52|34|13| 1 |24|23| 5 | » | » | 35/43/22] » | » rar 9 SEIFERT | 7. Ia... | 2568 | 9 | 2.3/83/ 17/70) 13| 1 |14| 1 | 4 » |» |27/ 40/33] » | » Ib ... 10.658] 24 | 6.872 2848| 18| 6 |24 4 0.5lo.1]» 47/41/11] » | 2 II ... 26.288 || 32 |13.3\60!40\35|18| 9 |26| 9 | 5 10.2! » 3415016 » | 1 II ... 20:966 | 29 | 10.2 | 34 | 66 | 20 | 10 | 4 |23,30|12 11.5 |» 27/58 16| » 01 versed, this group occurs in greatest quantity on soil with a con- stant snow-covering, while the Th group behaves like Ch. If instead of the values for frequency we use the species number alone, the result will be the same. The Th percentage for snowbare soil, soil with a normal snow-covering, and soil with a constant snow- covering at Vestfirdir, calculated from Ingimar Oskarsson’s spe- cies lists, is respectively 37, 24, and 20. Hence the following rule applies to the distribution of the life- forms in the Icelandic scale of snow-covering. On the most 154 H. MØLHOLM HANSEN snow-bare soil Ch thrive best, the deeper the snow- covering the more does the Ch percentage decrease, while, on the other hand, the H percentageincreases, and where the snow-covering is deepest, H play the most prominent part. This distribution must be regarded as a consequence of the geographical distribution of the life forms. Ch, the arctic life-form, thrive best where the cold has the strongest effect, while the more temperate life-form, H, shows a preference for conditions in which there is the greatest protection from the cold. From this rule of the distribution of the life-forms in the Ice- landic scale of snow-covering there is an interesting, though merely apparent, deviation, as will appear from a close investigation of conditions in the individual localities. In the highlands the rule applies throughout, the slighter the snow-covering, the higher the Ch percentage (though in the very lowest class there occurs an in- crease), and in the lowlands too it holds good if we consider the relation between melar and mo, i. e. between snow-bare and snow- covered soil. In other respects conditions in the lowlands seem to go against the rule, Ch playing the most prominent part where the snow-covering is deepest and of the longest duration, whereas this group decreases when the depth of the snow-covering decreases. The Ch percentage in the Elyna mo, the comparatively snow-bare formation at Bjork, is 28, whereas, in the Arctostaphylos mo, the relatively snow-covered formation, it is 39. In the mo at Lyngdalur the Ch percentage is 26, in the geiri 35, and in mosathembur only 10. At Thrasaborg the values for mo and geiri are 25 and 34 re- spectively. This difference in the distribution of Ch in the highland and the lowland scale of snow-covering is due to the fact that the Ch vegetation in the lowlands consists especially of E species, whereas, in the highland tracts, it consists of A species. This disagreement thus handsomely confirms the distribution of the species groups in the scale of snow-covering. Raunkiær examined the variations in the biological spectra in sections from southern towards northern regions (1908, 1911) and showed that some life-forms, Ph, K, and Th, decrease in quantity, while others, Ch, increase and others again, H, undergo no appre- STUDIES ON THE VEGETATION OF ICELAND 155 ciable change, are indifferent. Passing upwards from the level of the sea to the snow-line in a mountain district, we find the same changes. In Iceland the same holds good for the variation according to altitude: The H percentage remains unchanged throughout the al- titudinal zones, the arctic life-form Ch increases rapidly, while the southern life-forms, Pt, Ph, G, HH, and Th, decrease in the same proportion. These changes in the life-form spectra are connected with, or caused by, a decrease in the warm temperature of the summer and an increase in the cold temperature of the winter. The summer temperature grows lower and the summer of shorter duration, while, on the other hand, the winter grows longer and more severe the further northward we go. If we calculate the biological spectra for the Icelandic types of vegetation and compare the spectra for the types on snow-bare soil, on soil with a normal snow-covering, and on soil with a constant snow-covering, we get the same variations as above on passing from arctic towards temperate regions or from the snow-line towards the level of the sea. "The result will be the same whether we base our calculations on the number of species or on the number of individuals, i. e. on the frequency sum. There is no reason to believe but that, in this case loo, it is the temperature conditions which determine the occurrence and development of the life-forms. The temperature conditions favourable to the artic species are due to the fact that the snow is blown away so that the cold can act with its full force on the vegetation with the result that southern types cannot survive, while arctic types thrive. Where the snow-covering is deep and constant, the case is reversed: here the environment will be unfavourable to arctic but favourable to temperate types because the snow-covering will prevent the extreme variations in temperature from reaching the vegetation. Hence, under conditions where the external factors are not easily observable, the individual life-forms may with full justice be employed, as above, as indicators of environment. Thus, in Iceland, many Ch will indicate severe cold, many Ph, K, and Th relatively favourable temperature conditions. From a scientific point of view, as a means of checking life- 156 H. MØLHOLM HANSEN forms, it will be of interest to have another system of indicators of environment. In the present treatise the geographical distribution of the individual species has been employed as an indicator of en- vironment. A species with a pronounced southern distribution will more certainly indicate a high temperature than a more northern species. The more southern species there occur in an area, and the more prominent the role they play, the more probable will it be that the temperature conditions are favourable. Reversely, it must be supposed that a preponderance of arctic species indicates severe cold. The proportion of southern and arctic species in an area will therefore indicate the temperature con- ditions of that area. In a previous chapter the species groups were dealt with in more detail. At the outset it might be anticipated that the species groups would be more sensitive indicators than the life-forms, and it might be claimed that the two systems of indicators should lead to the same result. An inspection of the tables will show to how great an extent this is the case. A change of environment causing an increase of the Ch percentage will likewise cause an increase of the A percentage, and numerically this increase will be greater than the Ch increase. Table 31 shows the life-form and species group spectra for a series of areas in which the conditions of environment are most clearly illustrated. The localities are arranged in groups of 3 each. The top group 1, comprises the land spectra for Denmark, Iceland, and North Greenland, group 2 the Icelandic zone spectra for the lowlands and the upper and lower zones of the highlands respec- tively, group 3 various zone spectra from Vestfirdir, for the 0— 100 m zone, the 2—300 m zone, and the 3—400 m zone respec- tively, group 4 shows vegetation spectra for snow-bare, normally, and constantly snow-covered vegetation in the same locality, and group 5, finally, gives the mean values for the formation spectra of the various classes of snow-covering. Within each group the coldest area, a, is given first, the warmest, c, last. A closer inspection of the table will show that, compared with the b spectra, all the a spectra have a high Ch percentage, A 3 per- centage, and especially a high A percentage, while the c spectra, on the other hand, have a high (Ph + K— Th) percentage and (E3 + E2 + E1) percentage. The amount of H and (A2+A1+E4) species is relatively unaffected by changes in temperature in any STUDIES ON THE VEGETATION OF ICELAND 157 TABLE 31. Agreement in Variation of Biological Spectra aud Species Group Spectra (cf. Text). or Ch | H |PhKTh | A |A3/A2, Al, E4| E 34241 9/0 2/0 9/9 0/0 || 270 0/0 9/0 Een nd Nes NESS BESES SEES a |35 | 50 15 » 2 uen ee b |15 | 52 33 Brick ie aeehvo ducs c | 3|50 47 Iceland, 8—1200 m. above sea..... a \34 |53 is 80 | 58 38 5 — 2 600 M EE ose co b |21|53 26 52 || 20 49 31 — pi LUE SRE RE c 15152 33 40 115) 41 Vestfirdir, 4—500 m above sea.... a | 43 50 7 93 | 50 | 50 » — A DOONAN. se oc 0e b | 31 |51 18 68 | 27 56 17 — 01005: een c |17|52 31 411115 | 47 38 Snow-bare vegetation Vestfirdir.... a 37 52 11 71 | 32 54 Pee: Normally snow-covered vegetation . b ‚24 55 21 50 | 13 55 32 Constantly snow-covered vegetation c | 20 51 29 |28| 7 45 48 Snow-covering class 1............. a | 47 41 12 172148 47 5 — ØEN) RE b|34150| 16 60/35 51 14 — STE eee eee c |27 158 | 15 134120 36 44 direction; in all the spectra these two groups constitute about half the material. The effect of a changeintemperature is thus the same in both systems of indicators; but it is most marked in the species group system. Hence, when we have elsewhere in this treatise employed the species group and life form spectra when considering the external factors prevalent in the formations, this is quite justifiable; a spec- trum, particularly a species group spectrum, will thus be an im- portant guide in the determination of the external factors which are of importance for the vegetation. Variations in the density and number of species in the scale of external factors bring to light interesting relations. In the 4 classes of snow-covering Ia, Ib, II, and III, the mean density of species is respectively 2.3, 6.8, 13.3, and 10.2, and the mean number of species is 9, 24, 32, and 29; in the 7 classes of moisture the mean density of 158 H. MOLHOLM HANSEN species from class I to class VII is given by the following values: 8.3, 12.7, 14.3, 13.2, 11.1, 7.9, and 1.8 and the mean number of species in the corresponding classes by 25, 32, 36, 39, 33, 19, and 5. It applies both to the number and density of species that they attain a maxi- mum in both scales of external factors, whence they decrease more or less in both directions. The position of this maximum corresponds to the conditions of environment normally prevalent in the country, and practically coincides for both series of figures. The maximum for the scale of snow-covering lies in class II, corresponding to the mo, for the scale of moisture it lies in classes III—IV, corresponding to moist mo and jadar. These types of vegetation must be regarded as the climax vegetation of the country. The rule thus seems to hold good that those parts of the country where the environment is typical of the country and which, there- fore, bear the climax vegetation of the country, have the vegetation which is richest and densest in species. No matter in what direction the external factors are changed, whether in the direction of greater drought or greater moisture, or in the direction of a deeper or a slighter snow-covering, the result will always be a diminution both of the number and of the density of species, and the greater the change of environment, the greater the diminution. Our investigation of the distribution of the species, species groups, and life-forms in the formations, arranged according to in- creasing prevalence of one and the same external factor, has here- with been brought to a close as far as the Icelandic scales of moisture and snow-covering are concerned. Besides extending the investigations to an increased number of external factors, it will likewise be appropriate to divide the flora into groups according to the distribution of the species from Atlantic to more continental regions. It would also seem of interest to divide the flora into groups according to the geographical distribution of the genera, as well as according to the quantitative distribution of the species within their areas. Judging by the investigations given above, such an extension of view-points would lead to a more thorough understanding of the distribution of plants in Iceland, the knowledge of which is essential partly for the question of the genesis STUDIES ON THE VEGETATION OF ICELAND 159 of the Icelandic species, partly for the question of the cultivation of the various Icelandic types of vegetation. Other questions of decisive importance in studies on the di- stribution of the species in the scales of external factors are partly the question of equidistance in division, and partly the question of the determination of the number of external factors bearing on plant distribution. As far as the first question is concerned, in formations with low density of species, the line between two formations is most naturally drawn at the physiognomie boundary line between the two formations, and the areas selected for examination should as far as possible be laid in the middle of the formation. It is pos- sible that the distance between the various localities examined will not in this way become an exact expression of physical equidistance between the localities, or the formations, but merely of ecological equidistance; but since the investigation is primarily ecological, it will suffice if the requirement of ecological equidistance is satisfied, even though physical equidistance would have been desirable. Where we are concerned with the investigation of formations with many species, the requirement of ecological equidistance be- tween the localities examined will be considerably more difficult to satisfy. The present treatise deals principally with formations of this kind, and the examination of them was made in the follow- ing way. On a gently sloping surface the investigator passed so far up and down from one locality that the vegetation had changed appreciably; the second locality was then examined here, whereupon the third locality was chosen and examined in the same way. It is possible that the distances between the localities examined are unequal both physically and ecologically; so much is certain, however, that the sequence of the localities examined expresses a constantly increasing change of environment. If this is the case, however, we have in the proportion of the species points of species occurring principally above, and species oc- curring principally below, the formation in question an aid in determining the question of ecological equidi- Stance between the formations. Another question of equal importance is the question of the determination of the number of plant-distributing factors. This question, however, is only topical in a plant covering rich in species and of uniform physiognomy. If such a plant covering is examined 160 H. MØLHOLM HANSEN by means of Raunkiær's circling method, the flora lists of the in- dividual random samples will furnish a point of departure for the consideration of this subject. This question, as well as the others referred to above, I have, however, been obliged to leave for future consideration, partly for lack of time, partly for want of suitable material. A few more questions, thus some investigations on the acidity of some types of Icelandic vegetation, and some reflections on the relation between plant geography and farming, will be dealt with briefly below. Determinations of the acidity of the soil were made simultane- ously with the investigation of the vegetation. The mode of proce- dure in taking samples of the soil and determining the degree of acidity was that described by Carsten Olsen (1921). For practical reasons the investigation was only made at Bjørk, on Lyngdalsheidi, and on Årnarvatnsheidi. For the various types of vegetation in the above-mentioned localities the acidity expressed in py was as follows: At Bjørk Elvnakm ok SÆLER 6.5, 6.5 average 6.5 Arctostaphylos mo ..... 6.5, 6.5, 6.4 — 65 Calluna-Empetrum mo . 6.4, 6.3 — 64 TEE een; 6.0, 6.0 — 6.0 SAUREN... aan ee 6075.17, 8.7 — 58 Betula nana myri...... 01, 010, 5.2, 2.2 — 54 Koemigia flag... 2:2... 6.6, 6.3 0 On Lyngdalsheidi Mosathembur .......... 6.5, 6.4, 6.3, 6.3 GA MBA ND EE cute 22% 6 6.3, 6.3, 6.2, 6.2 — 6.3 MO a yt sce hae Snes 6.4, 6.4, 6.4, 6.4, 6.3 — 63 N REN IE eae BAR G2, G25 6.2.6.2 Valen dr SS Gi, 022 GAGS 7 — 6.1 AOA ae ne 6.0 — 6.0 Salıx NV pret 5.3 — 5.3 Betula nana myri. 2... 5.3, 5.1, 5.1, 5.0, 5.0, 4.8, 43 za GEL nee ee ee 6.1, 6.41,.6.0 — 6.1 On Arnarvatnsheidi Melar nee 6:9776:8.56.7, 6:6, 6:6 — 6.7 The level no PRE er 6.8, 6.8, 6,4, 6.3, 6.2 — 65 STUDIES ON THE VEGETATION OF ICELAND 161 ane knolly m6 ..:....... 6.8, 6.8, 6.4, 6.2 average 6.5 LUI RS OR ere 6262 6:15 6.1 — -6.2 OT) eee eae G2, 64, 60: 5949-56 — 59 Geiri (Geranium belt)... 6.5, 64 — 6.3 — (bottom veget.).... 6.3, 6.1 _ Thus the Icelandic soils all seem to be slightly acid; no degrees of acidity above the neutral point were measured, nor did any very strongly acid soils occur. The highest value measured in py was 6.9, the lowest 4.8; according to C. Olsen, the corresponding values for Denmark are respectively 8.0 and 3.4. There is this connection between the moisture of the soil and its degree of acidity that in- creasing moisture produces increasing acidity, i. e. decrease in py value. In melar py is about 6.7, in the mo 6.3—6.5, in jadar 6.0— 6.2, and in myri 5.2, 5.5, and 5.9. An increase in the depth of snow-covering shows the same relations: in melar p" is 6.7, in mo 6.3—6.5, and in geiri 6.1—6.3. | The investigations described in the present treatise are not only of phytogeographical and botanical interest, but would also seem to have some bearing on practical matters, partly in agricultural research, and partly more directly in farming. Since, however, these matters have not been subjected to special investigation and are outside the scope of the present treatise, I shall merely make brief mention of a couple of questions connected herewith. Under the treatment of the vegetation the appearance of the surface in the individual types was described. A comparison be- tween this and the species group spectra reveals the following facts. When the E percentage is high, i. e. when the vegetation consists of southern species, the surface is always level, without any formation of knolls, whether the high E per- centage is caused by a deep layer of snow or by the soil being covered with water. If, reversely, the vegetation consists mainly of arctic species, solifluction is always seen. If the vegetation consists of an equal mixture of A and E species knolls will always be met with. This difference between the types of surface connected with the different types of vegetation must be assumed to be a result of the same external factor that determines the differences in vege- tation, in this case the cold. In geiri and flöi (snow-patch and The Botany of Iceland. Vol. IN. 11 162 H. MØLHOLM HANSEN swamp) the soil is protected from the frost and therefore even; in mo, jadar, and (myri) the frozen surface will crack in the spring, as in Denmark, and form greater or smaller polygons which will furnish a foundation for the formation of knolls. How this latter takes place is still uncertain. It seems natural to suppose that it is due to the action of frost which may also be observed in Den- mark when clayey or boggy soil freezes. On such soil, which has been exposed to a long period of frost, the surface will be observed to have been raised in various ways, and the frozen crust will be seen to consist of alternate layers of ice and frozen earth. When the water freezes the whole mass of soil expands upwards, either in the shape of a large cake or as a radiating system of branches of ice and earth. The greater the moisture and the longer the action of the frost, the more marked is this phenomenon. If the Icelandic formation of knolls is a result of the same forces, it may be anticipated to be most pronunced on moderately moist soil and in regions where frosts are frequent. And, as a matter of fact, the formation of knolls attains its handsomest development in jadar in the highlands where precisely these two conditions are present. According to this view the knolls (in mo and jadar) should be a kind of “frost-baked earth-balls”, for which the polygonal soil forms the point of departure. Frost is the agent and water the expanding factor which, on freezing to ice, changes the internal structure of the knoll from a relatively com- pact to a more porous state. In accordance herewith it will, in fact, be observed that the interior of the knolls is peculiarly loose, almost like flour. If there is a continued formation of knolls it will, in regions much exposed to wind, become a starting point for solifluction. The surface of the knolls will break on the side exposed to the wind, and will at last be entirely eaten up by erosion. In areas where the action of the frost is relatively strong, as in melar, knolls will form the starting-point for solifluction. The above considerations are merely of a sketchy nature. On the basis of general observations and the knowledge of external factors drawn from phytogeographical investigations I have attempted to correlate a series of peculiar soil phenomena. By a more me- thodical investigation of these in connection with a simultaneous phytogeographical investigation a better understanding of these fac- tors, so important to Icelandic farming, might no doubt be gained a STUDIES ON THE VEGETATION OF ICELAND 163 By the investigations described in the present treatise it has been shown how, within 3 areas in normal Icelandic physical con- ditions, favourable conditions for southern species are created, and thus a vegetation, the luxuriance of which permits of grazing or haymaking. These areas are either soils protected by water or by snow, or moderately moist soils which combine the favourable temperature conditions in winter of moist soils with the favourable temperature conditions in summer of dry soils. The value of these areas for farming is caused by the fact that southern species and life-forms are larger and more vigorous, pro- duce more matter than northern ones. Hence one of the chief aims in cultivating infertile areas should be to make such changes in the prevalent external factors that from being favourable to Ch they become favourable to H or G, according as the soil to be cul- tivated is comparatively dry or comparatively moist. The means employed for this purpose have been, partly a change in the con- ditions of moisture, partly in the conditions of nutrition. The re- sults have, however, been very varied. The experiments have been most successful in the case of myri, which it has been attempted to eultivate partly by irrigation, partly by draining. It is obvious that irrigation must result in favourable conditions for southern plants, since it increases the medium of protection against the winter cold. If the water is drained off in the summer, this will merely be a further advantage, since a lot of heat which would otherwise be latent in the water now becomes available for the plants. As a matter of fact, the transformation of myri into irrigated myri plays a prominent part in Icelandic farming. The second way in which myri may be transformed is by draining. In that way moist soil is transformed into moderately moist soil, myri to tin. This change in moisture in connection with the addition of manure will have the efffect of gradually re- placing the sedge vegetation of the myri, rich in G, by the grass vegetation of the tin, rich in H — a vegetation identical with the jadar vegetation. Thus draining also produces a more southern vegetation, and the causes have previously been mentioned. In the cultivation of the mo it has especially been attempted to transform it into tin. By treating the soil and adding manure to it, it has been attempted to make the jadar plants grow here, and with some success. Hitherto, however, the object has been to transform a less southern to a more southern type of vegetation à 164 H. MØLHOLM HANSEN but without a simullaneous change of the environment in the same direction. As a matter of fact the result is that “the tin burns” after cold winters and in hot summers, which is due to the fact that in the winter the plants miss the protection afforded by the jadar soil, and in the summer its moisture. Even if a transformation of mo to tün is not as profitable as the transformation of myri to tün, it must, however, on the whole be an advantage to farming. It is, however, questionable whether this is the right way of cultivating the mo. The investigations described in the present treatise have shown that water is the means of protection for southern plants on moist soil, while snow protects southern plants on the drier soils. Hence if a cultivation of the mo equally effective to that of the myri is desired, it should tend to utilise our knowledge of the importance of the snow-covering rather than aiming at the continued transformation into tun. The importance of the snow-covering for the southern plants, and hence for the plants valuable to farmers, has long since been very thoroughly brought home to all parties concerned. When the first Icelanders came to the island, c. 874 A. D., the country was covered with woods “milli fjalls ok fjäru”. This how- ever, is probably an exaggerated statement, says Thoroddsen, “but it is quite certain that the lowlands and valleys must have been more abundantly clothed with copse wood then than now, even if it must be assumed that large stretches of sandar, myrar, and lava fields were also then devoid of woods.” Thoroddsen sup- poses, however, that when Iceland was first settled, the woods ex- tended to an altitude of 600 m above sea-level, and that, at the beginning of the 10th century, they covered an area of 4—5000sq. km. In 1911 the total wooded area had been reduced to 454 sq. km. According to Helgi Jönsson (1900 p. 76), this great reduction has been caused by “reckless exploitation”. But by destroying the trees, the constant snow-covering which was dependent on the pre- sence of wood was also destroyed and, simultaneously, the luxuriant forest undergrowth which was again dependent on the snow-covering, and which formed, entirely or partially, the food of the farm ani- mals. The great decline in old Icelandic culture, which numerically resulted in the population being reduced to half its former number, must no doubt be directly referred to the destruction of the woods. The correlation between these two factors has been outlined above. STUDIES ON THE VEGETATION OF ICELAND 165 APPENDIX: Temperature Conditions in the Upper Soil Strata. Apart from volcanic regions, where the upper soil strata receive heat from the interior of the earth, temperature conditions at the surface are practically determined by insolation. According to the extent of the cloud-covering, a greater or less amount of heat will reach the surface of the earth where part of it will be used for heating the air, another part for evaporation of the water in the soil, and a third part, finally, will heat the upper soil strata. Investigations on the temperature conditions in the upper strata of the soil have been made at a series of stations in the most different climates. An accessible presentation of the questions re- lating to this subject will be found in Ramann, Bodenkunde 1911 and Hann, Lehrbuch der Meteorologie 1926, to which the reader is referred. A series of these investigations are, however, of such great phytogeographical interest in their bearing on the investigations described in this treatise that a brief abstract of the main results will be given in the following. The investigations referred to originate partly, and especially, from Finland, and partly from Russia, and were made by Th. Homén (1894, 1896, 1897) J. Keränen (1920), and H. Wild (1897). The investigations comprise the daily and annual variations in tempe- rature in snow and sandy soil, the temperature of the surface with and without snow-covering, and the daily variations in temperature in different kinds of soil, different in regard to structure, water- content, and plant-covering. As an example of the daily variation in temperature in snow and sandy soil may be mentioned J. Keranen’s investi- gations from Sodankylä of which an abstract is given in table 321—2. The temperature was measured every second hour throughout the 24 hours in the surface of the soil or the snow at different depths, in the case of the snow at depths of 4, 14, 24, and 44 cm. and in the case of the sandy soil at 10, 25, 40, 80, and 120 cm. The temperature of the air is given for each investigation. The temperature of the surface of the snow or the sandy soil is determined by the proportion of insolation and radiation. Ra- diation is greatest in the night, hence the temperature decreases so that the lowest degrees of temperature occur just before sunrise; in N H. MØLHOLM HANSE 166 TABLE The Daily Variation in Temperature in Air, Snow, and Soil at Sodankylä (Finland, 67° 22° N., After Keränen 1920, 3 € me 1. Temperature measurements for snow, made 19—20 March 1917. 26°" 30° 3.) p. 92. 2. Temperature measurements for soil, made 25—29 June 1917, IL. c. 196—197. | | | 0 2 4 6 | 8 10 | 12 14 16 18 20 | 22 24 | M Diff. | | | Baer BE | Air...... . C® | 35.7 | + 37.9) + 39.4 | + 40.4 |x 34.5 | + 20.4 | + 153) + 12.7) + 13.4 | + 16.9) + 26.3 | + 31.9 | 344) 27 6| 27.7 | | | | | | HAN a all elk | 0 em | + 37.7|-+ 38.9 | + 40.0 |+40.1 | + 365,4 24.0 | + 15.9 | + 144|- 20.8! 28.1 4 32.9 | 34.7 | + 36.8) + 30.2| 25.7 [+ 4 - |+300/+ 31.7 | +330) + 33.9; + 32.9) + 25.7 | + 14.7 |-+ 12.0 | + 15.9 +210 + 25.1 |+ 27.6/+ 9296/9251] 21.9 | | | | | | | 1.Snow) + 14 - + 19.0 | + 20.1 | = 21.0 | + 22.0 | = 22.5 | + 22.1 | + 20.1 | + 17.8 | + 166 — 16.6 + 17.5 -18.1/—-190|-194| 59 | | | 1-24 - 1137| + 139 | -- 14.2) + 14,7 | 14.9) 15.7) = 15.1 | + 149 | = 14.712145 = 14.2 | 140 14.04 145] 14 (44 - = 7.9/7 ASE 7,8) 70 ed 7.6 | - Lo OTT ST a Te ead ln | | | | | | | Air : C° | 13.0 2121 120 | 146 16.6 18.5 | 19.1 19.7 19.4 18.: | 17.0. | lbs 13.2 16.0 8.6 || | | || | | = = 0 em | 10.4 9:5, 112918 16.0 | 20.9 | 29.4 | SIS =)" S09) HED YRSEER BEDE 7 | 16.5 12,010 11:07 119.9 22:0 | | -10 - | 16.0 14.7199 12.8 13.0 | 14.6 el 19.0 |.20:0 1720 19/52 7.199 16.6 16.5 7.3 ra a5 me 14.3 13.7 13.0 12.37 | 21.9 12:8 13.2 13.9 14.8 | 152 | 163.) 15.1 13,7 3.4 “. SOl | 240 - | 12.9 13 0 12.9 12.6 12.2 | 11.9 HASSE 32.0 12,8 12.6 129 | 13.2 13.4 12.6 1.6 -80 - | 91 9.2 9.2 9.1 8.7 8.5 8.5 8.6 8.8 9.0 9.2 | 9.3 95 | 8.9 1.0 | | | | 1205 le oe 4.6 4.6 46 4.5 4.5 4.6 4.6 4.7 4.7 | 4.7 4.8 49 | 4.6 0.4 | | STUDIES ON THE VEGETATION OF ICELAND 167 the day, on the other hand, insolation is greatest, and the tempe- rature increases until, simultaneously with or some time after the maximum of insolation, it attains its maximum value. In the course of the afternoon, evening, and night, insolation decreases and with it the temperature until it again attains its minimum at sunrise the next morning. Deviations from these typical relations occur with irregular conditions of cloud-covering. From the heated surface of the earth a current of heat now passes partly upward to the air, partly downward to the deeper-lying strata, and this current of heat is not arrested until the temperature at the surface of the earth has again dropped below that of the surroundings, at which juncture the current of heat begins to change its direction. The surface of the earth now receives heat from the lower strata and, though to a less extent, from the lower layers of the air. The result will then be that shown in table 321—2. The daily variation in temperature is greatest at the surface, thence it decreases upwards as well as downwards until it becomes practi- cally zero, which value is attained at different depths, varying ac- cording to the heat-conducting power of the different kinds of soil. Thus, it appears from table 32 that the daily variation in tempe- rature penetrates far deeper into sandy soil than into snow. In snow the daily variation will as a rule be imperceptible at a depth of 10—20 cm., whereas in sandy soil it is not imperceptible until at a depth of c. 30—50 cm. This agrees well with the much smaller heat-conducting power of the snow. Other kinds of soil show still greater deviations, thus table 35 shows that granite rock has a con- siderably greater heat-conducting power, boggy soil on the other hand, considerably less heat-conducting power than loose sandy soil. Another fact will appear from table 32, viz. the displacement of the moment of incidence of the maximum and the minimum at the various depths. While the temperature at the surface of the snow attains its maximum at 14 o’cl., this will not occur until 16—18 o'clock at 14 cm.s depth, and not until 24 o’clock at 24 cm.s depth. The temperature minimum varies in the same way. The annual variation in temperature is as the daily variation. In the summer an unbroken current of heat will pass from the surface of the soil into the deeper-lying strata, in the winter the current will pass in the opposite direction. The annual amplitude will likewise decrease strongly with the distance from the surface, just as a displacement of the moment of incidence of the 168 H. MØLHOLM HANSEN maximum and minimum will take place at the different depths. Thus the temperature minimum in the lower strata will only occur simultaneously. with the temperature maximum at the surface, and reversely. The daily and annual mean temperature of the surface of the earth is higher than that of the air, just as the daily and annual amplitude is higher for the surface than for the air. TABLE 33. The annual Rise of Temperature in Soils with or without Vegetation or Snow Covering at Pawlowsk (Russia.) The figures give the mean values of a period of 5 years, 189195, After H. Wild 1897: p: 7. 1oW covering cm .. OUdS Fic te eee ir temperature C° atural external surface . indy surface 00em.... + 40 = ol) +160 » » » November egetation or snow covered surface 0.0 cm — 40 = 3 me E Si vo a | 2 a A ler) | 2 ie | 16 31 8.5 8.3 | +674 |=-10.2 6 | 6.6 | 10.4 | 206 OT 9 3.814.290 | I=-10.0 | 7A | 10.3 9.6 6.4 | 2.7 1.2 1.4 0.8 | 1570) 3.0 | +45 143.5 | —-2.4 Ha) 0.8 —-0.7 0.7 1.5 2.6 | April > ©o —— | © > a 2 2 | s|ı5:| | s/s] >.) 7 SEEREN Nn || » » » » » | 6.1| 6.6| 6.6! 70|7.6| 13.4 | 15.9 | 13.8| 8.7 4.0 17.4 | 19.4|15.7| 92135] | 16.7 | 18.91 15.5! 9.0! 3.6| 13.3 | 16.7 | 15.2| 9.8|5.4| 10,1 | 14.1 | 13.9 | 10.3 | 6.9] 6.2 | 10.0 | 11.3 | 10.3 | 8.2) Lo) 14.7| 17.0! 14 2 |. 9.0/4.2] 11.6 | 14.6 | 14.7 111 | 7.3 9.7 |12.6 | 13.5 | 1121023 7.5 10.0 11.6 | 11.0} 9.1) i D —— The facts described above apply to bare homogeneous sandy soil, as invesligated by H. Wild at Pawlowsk, ef. table 33. If, on the other hand, the surface is clothed with a natural vegetation or covered with snow, a case likewise investigated by H. Wild in the same locality and shown in table 33, the facts will be otherwise. A bare sandy surface has a mean annual temperature of 4.0° with an annual amplitude of 29.2, a natural surface has a mean annual temperature of 3.6° and an annual amplitude of 29.2. The surface under snow and vegetation, on the other hand, has a mean annual STUDIES ON THE VEGETATION OF ICELAND 169 temperature of 5.3° and an annual amplitude of 19.4. Thus, while a natural surface is on the whole similar to a bare sandy surface, the presence of a covering of vegetation or snow will cause a re- duction of the annual amplitude of c. 10° and an increase of the mean annual temperature of no less than 1.30. This applies to the surface of the soil, but the deeper-lying strata too are affected by a covering of snow or vegetation, and in the same direction. There will be a decrease in the annual amplitude and an increase in the mean annual temperature. A comparison between the two sides of table 33 will show the numerical values. A covering of vegetation will, in the summer, cause a lower average monthly temperature of the surface below it than the na- tural surface or a bare sandy surface would have done. This difference will, however, only amount to a couple of degrees. In the winter, however, a covering of snow will mean an immense increase of the surface temperature under the snow compared with that above the snow. According to Wild, a snow-covering of 30—45 cm.s’ depth will cause a temperature difference of 8—9° between the surface of the soil and that of the snow. Thus a sandy surface has a January- February temperature of c. + 10°, while the surface below a snow- covering of 30—40 cm. has only a January-February temperature of + 2°; at a depth of 40 cm the values are + 6° and + 1° re- spectively. Very convincing and thorough investigations on temperature conditions in snow have been made by J. Keränen (1920). The investigations comprise two snow-periods 1915—16 and 1916—17, the temperature in the surface of the snow at various depths and at the surface of the soil being measured 3 times daily, at 7 o'clock, at 13, and at 21 o’clock. By means of these figures the average monthly temperature for the respective depths has been calculated. The mean values for the two periods have been given in table 34, where likewise the depth of the snow-covering is given, besides the temperature of the air, and the temperature at various distances from the surface for the year and for each month. The snow-covering during the months November—April has an average depth of 47.8 cm and due to this an average surface tem- perature of + 14.2° can only cause the temperature at the bottom, i.e. at the surface of the soil to drop to -- 2.7°. An investigation of temperature conditions in the snow in the ‚arious months will: also show the varying isolation power of the 170 H. MØLHOLM HANSEN TABLE 34. Annual Variations in the Temperature of the Air, Snow, and Soil in Sodankylå (Finland, 67° 22° N., 26° 39" E.). The investigations cover the period from November 1915 to October 1917 (cf. Keränen 1920, pp. 52—53). - = = a uy IF ara “| 31 2 thofsnowem 47.8 » || 16.11 31.9) 45.8 62.5) 70.5) 68.8 > > » > > > | ‘ipitationmm > » || 52:61 25.8) 23.3) 33.1) 25.5) 36.4| 36.3|49.7/65.3/68.1|74.6| 75.0) 56.6 | SEE accep oe > » 8.2 TE, 8.1 7.7 6.31 7.9! 7.8| 69! 7.0) 8.0) 7.1) 8.31 7.6 perature of AN = 12.110 6 |=8.2|= 17.7 =-14.0 15.0. +-13.6-4.1| 1.2/11.9|14.4/11.7| 4.5/=1.2]=25] wo em EE — 14.2 > +9.6 —18.9 —16.1 17.0 +15.145.9 + » » » > SN USSR » » # 2101-2102 —10.8 —10.4 —3.4 # » » > > UE EPP >} >| + # + 72+ 82+ 8.2+3.0 + »| »| »| à » > | U IR > » * # 49-63 66-26 + > > » » » | SA) 3, 2.00: » > » # + |= 4854 = x ” - >| 4 -50 > » > m ae AGREE # > » ) » > » | 60,9. oF oo. » » » 34 + # » » > > >| » | Far ner Sj" aaa.) Dienst. ee + 2.7132 428+ 4.0 — 3.3 + 28+ 2741.2 1.9/15.3 18.3 14.0 5.105 3.2 (22. 10 > .. ..|s 19122/=11|> 25-2 2.6|< 2.1= 21-+10) -0.9/11:8116.7|13-8/. 6.5), 1.0) 320 Be TEE + 1411.0 +04-- 1.7 2.1 17— 18-10) 04 9.3114.913.0) 7.0 14) 3.1112 ee + 11107 04+ 12+ 18+ 16+ 16-+0.9 0.2 7.914313.1 7.7 2.2) 3.2 116 80 .... | 0.1) 9.0) 13 0.6 0.2=+ 0.6-- 1.0-+-0.8+0.2 5.4111.811.9 8.1) 3.1) 3.2112 EJ Her hr 0.8! 7.2| 24 1.3 0.6 0.3 0.1-—-0.1| 0.0) 1.9! 8.4110.1, 9.5 4.6) 3.2718 ee 1211%6:6.1 22.7 127 0.9 0.6 031 0.1! 0.1! 1.5) 7.0| 9.4| 841 4.9] 3101 snow. At the beginning of the winter when the snow lies lightly, a layer of a certain depth has a greater power of isolation than a layer of the same depth at the close of the winter, at which time the layer has grown more compact. Thus the table shows that the difference in temperature between corresponding layers is greatest at the beginning of a snow-period and decreases progressively until it attains its lowest value at the close of the winter. This fact has a certain practical significance in that the temperature at the surface of the soil will never be very much lower at the beginning of the winter than later on, in spite of the much slighter snow-covering at the beginning of the winter. Investigations on the temperature conditions in soil with a different water content, of a different consistence, and with a different STUDIES ON THE VEGETATION OF ICELAND 171 TABLE 35. Average Maxima, Minima, and Amplitudes of various Soils. After Homen. 1897, pp. 47—48. The investigations cover the period 10—13 August 1893. Granite Sandy heath Bog Diff. | Max. | Min. | Diff. | Max. Min. Diff. Max. | Min. Air temperature C°... | 22.7 | - 9.6 | 13.1 » » » > » » Vegetable covering ... | 32.5 | 12.6 | 19.9 | 37.7 | 6.4 | 31.3 | 328 22 30.7 sr nr. 34.8 | 14.5 | 20.3 | 42.3 | 7.8 | 34.6 | 27.7 | 63 | 214 Sk. aes | 33.1 | 15.2 | 17.9 | 35.9 | 9.7 | 26.2 | 23.9 | 8.9 | 15.3 ne | 31.9 | 15.8 | 16.1 || 30.6 | 11.3 | 19.3 | 20.6 | 111 | 9.6 | + | 304 166 138 247 128 118 167 139 2.8 ee | 28.9 | 17.2 | 11.7 | 22.2 | 14.4 | 7.8 | 16.2 | 148 | 15 eee | 26.1-| 182 | 7.9 | 19.4 | 15.5 | 3.9 | 153 | 149 | 04 er: | 243 | 19.1) 5.2) 17-7 | 15.9 | 1.8 | 143 | 142 0.1 ee... 29|195| 3.4 | 162 | 15.5 | 0.7 | 13.5 | 134 | 0.05 en ne | 21.7 | 19.6 | 2.1 | 15.0 | 148 | 03 | 124 | 124 » N. 200 | 20.9 | 19.6 | 14] 142 | 141! 01|117 16| » clothing of vegetation have been made in Finland by Th. Homén and described in a series of works (1894, 1896, and 1897). Tables 35, 36, and 37 give the chief data of these works. Table 35 com- prises the daily heat maximum, heat minimum, and amplitude for granite, sandy soil, and boggy soil, respectively a solid, a loose, and a damp rock. The figures are the mean values of a series of in- vesligations. Table 36 shows the daily amplitude for various kinds of soil, sandy soil, clayey soil, and boggy soil with or without wood or a covering of cultivated plants (cereals). Table 37 shows the annual mean temperature, the annual variation in temperature, i. e. the difference between the mean temperatures of the coldest and warmest months and the mean temperature of each month at different depths in soils with a different clothing of vegetation, thus at 0.5, 1.0, and 2.0 m for open grassfield, birchwood, and firwood. A comparison between the temperature conditions of solid rock and loose sandy soil shows a much greater current of heat in the solid than in the loose soil. Taking the average of 4 days, the surface of a granite rock will be heated to 34.8° by day. The heat accumulated at the surface will comparatively rapidly spread down- wards so as to make the temperature maximum at a depth of 60 cm no less than 20.9; for sandy soil the same figures are respectively 172 H. MOLHOLM HANSEN 42.3 and 14.2. A comparison between the daily temperature amp- litudes for rock and sandy soil shows, for the same depths, apart from the uppermost layers, a greater amplitude for the solid than for the loose soil. All these figures show that sandy soil is a better isolator than rocky soil. TABLE 36. Average Diurnal Variation of Temperature in different Soils with differing Vegetation. After Th. Homén. Nos. 1—3 (1897, p: 48); 4—14 (1894, ip. 231). Granite BAN Bog Sunny open heath | Forest-clad heath heath F 10 = VER 10— 15/, 10 - 13/3 12 13/5 6 SJ, 12— 137, ir 6—8/, 1893 1893 1893 1892 1892 1892 NP 1 2 3 4 5 6 7 0 cm depth.. | 20.20 34.60 21.40 18.49 29.00 7.19 | 6.39 2 ae 161 19.3 9.6 13.0 132 4.3 3.6 aes Do 13.8 11.8 2.8 94 9.2 PAST | 2.4 10 » > T7 7.8 1.9 64 6.2 1.5 1.3 PAV >: eee 729 3.9 0.4 2.9 Ad 0.7 0.6 40 » SAGE 3.4 0.7 0.05 0.6 0:4 0.2 0.1 Re = = - i i : Clayey Sunny open bog | Forest-clad moor Boggy field =. field 13 — 13/5 c= 8/9 12 —13/, 5—8/9 preserv. | harvest. | 12—13/g 1892 1892 1892 1892 |12-13/,1892! 68/9 1892 | 1892 er! a ee Bee nn —— 24,0 10 IE ieee b> 13 14 ee ee ae ART LENS PR | | | | | Oremaädeptlee NT ar 899 749 |. 1209 | 18.00 a Din > rl 9.5 | 48 4.1 7.4 9.9 6.9 a ee ta 291 9 Te 4.7 4.0 ia Se DEEE JAY eden SE ANR 0.7 11 1.2 eae a Vihear perenne nay a 02 02 | 03 03 | 20 40 » » | 0.04 | 0.04 0.02 +: 0.02 | 0.03 0.03 0.3 | | | | | Il If, next, the dry soil, the sandy heath, is compared with the damp soil, the bog, the above-mentioned deviations are seen to be con- tinual. The surface of the bog only attains a temperature maximum of 27.7°, owing to a great deal of heat becoming latent by evaporation of the water present in the bog. At a depth of 60 cm the maximum temperature is only 11.70. The minimum temperature of the sur- face is no less than 6.3° and is thus the lowest of the temperatures STUDIES ON THE VEGETATION OF ICELAND 173 of the three types of soil. Very striking is the daily variation in temperature, this is not only rather small at the surface, but already at very slight depths it is practically nil. Table 36 shows the average daily variation in temperature for sandy soil, clayey soil, and boggy soil, with or without a covering of vegetation i. e. of cornfield or wood. These investigations show the same conditions as table 35, viz. that sandy soil has a greater daily variation of temperature than boggy soil at the same depth, and that the daily variation in temperature penetrates to greater depths in sandy than in boggy soil. If the soil is covered with vegetation, i.e. wood or cornfields, the result will be in the first place a decrease in the daily variation of temperature. TABLE 37. Annual Variation of Temperature in Soils with different Vegetable Covering in Heinäis, Finland. After Th. Homén 1896, p. 147. Sh int <5 LES ee 5 a1$| 31-4) >| 2] >| 34-e|ala| aie] é nel a | eel ee | se | ee Er trs CR ci a i a le RN P= > | fe = a ae A = ee = === Firwood 0.50 m | 1.6° 12 1.0 1.1 4.1 10.4 12.6 12.8 10.7 6.5 3.7 2.1 5.7 11.8 1.00 > | 23 |18| 1.41.3|2.9| 7.5 10.0 | 11.010.0 |7.3|4.7|3.115.3| 9.7 2.00 > | 3.6 |29| 2.41 2.2|2.6|471 7.0| 85| 871|7.7|5.8|4.3|5.0| 6.5 Birchwood0 50 m | 1.0° 0.4 —0.2 0.3 23 7.5 102 10.9 94 5.6 3.0 1.6 4.3 11.1 1.00 > | 2.0 15| 1.0/0.8|1.8| 4.9| 3.4| 8.7| 8.4 |6.3|4.3 | 2.9/4.2) 7.9 2.00 » | 3.5 2.9 2622123) 3.9| 57| 7.0 7.5|6.8|5.6/4.4|45| 5.3 Grassfield 0.50 m | 1.1° 06 0.3 0.4 1.0 46 85 9.8) 8.7 5.6/3.3 1.63.83 9.5 1.00 > | 2.0 11.4! 10/09/11} 3.3] 65! 81| 7.9)6.1)42|2.7)3.8) 7.2 2.00 > | 3.1 |2.4| 2:011.7|1.6| 2.3| 4.3) 5.8| 6.4) 5.9) 4.9 | 3.83.7) 48 A similar series of investigations on annual variations in tempe- rature and temperature conditions is only found respectively for sunny open and wooded sandy soil, but unfortunately not for damp soil, whether such as is constantly damp throughout the year, or such as is damp in winter but dry in summer Table 37 (after Homén 1896) shows the annual mean temperature at various depths for respectively sunny open and wooded soil, the mean temperature of each month and the difference between the lowest and highest 174 H. MØLHOLM HANSEN monthly mean temperatures. The table confirms the rule previously laid down that the amplitude decreases with the distance from the surface, and further that it is greatest for the sunny open soil, less for the wooded soil. This applies in still greater degree to the mean temperature of the warmest month and to the annual mean tempera- ture. The sequence is as follows: grassfield — birchwood — firwood. From a knowledge of the daily and annual variations in tempe- rature it is possible to determine the heat-conducting power of a rock, this quantity being the less the slower the maximum and minimum spread in the soil, or the quicker the amplitude decreases downwards. After Hann (1926, p. 800) we give the following values for a series of natural rocks (minute, cm.). Sandston eee a een 1.39 Clay with an admixture of sand ........ 0.82 SANT SUISSE EEE RP 0.52 Beas We sranite LE oem cp accrue 1.14 BAUM RE DENDE SEE SEE SES SEERE sub ve Dee 0.32 POON SOME Sohn. ern vite eek e 0.13 IEGOSE SHOW 4..2.....2.% Han bases CRUE 0.16 POMPACE SON 235.5) us Ru nel rer 0.24 |S vgs ae ea Re 0.68 LR EAST earth 5,87 a alc. cys 6, ods eats Re 0.56 EOL EOZEM «sis IEEE ee 0.32 However, the heat-conducting power is not only different for the different rocks, it also varies in the same rock according to the air and water-content. The more solid and moist a rock is, the better is its heat-conducting power. SUMMARY. 1. By investigations on the quantitative distribution of the life- forms in the floras, from temperate to progressively arctic regions, Raunkiær has shown that the chamæphyte percentage is subject to a steady increase from southern towards northern regions. Current conditions in the surrounding seas show an appreciable influence on the course of the individual Ch biochores, a warm northgoing cur- rent causing a decrease of the Ch percentage, while a cold south- going current causes an increase of the Ch percentage. This appears plainly from conditions along the coasts of Greenland and Iceland. 2. If the Icelandic flora is divided into groups according to the northern and southern limits of the species, 7 species groups will result, distributed in 2 main groups. The 2 main groups represent species with respectively a northern and a southern distribution. The sub-groups within each main group differ from each other with re- spect to their northern limit. If the biological spectra of the in- dividual groups are examined, a continued increase of the Ch per- centage from the species group with the most southerly distribution to that with the most northerly distribution will be observed. If like- wise the variation of the biological spectra and the species group spectra in the flora lists of the separate parts of the country and altitudinal zones is examined, the variation is the same in both cases, but greatest in the case of the species groups. Species groups and life-forms may thus be regarded as indicators of environment and may be made the basis of considerations on external factors where these are unknown. 3. Iceland’s Ch percentage ranges it among the boreal hemi- cryptophyte-chamaephyte climates, the Ch percentage for the whole country being 15.2. The 20 p. c. Ch biochore for the country as a whole lies at a level of c. 300 m above the sea. Between this line and the snow-line, which lies at a level of c. 1200 m, it is possible 176 H. MØLHOLM HANSEN to distinguish between a series of zones, a lower and an upper high- land zone, and a nival zone. The lines between these zones can be drawn approximately as follows. The lower highland zone extends from the 300 m curve to the 600 m curve and has a Ch percentage of from 20 to 25; the upper highland zone extends from the 600 m curve to the 800 m curve and at its upper limit has a Ch percentage of 40; the nival zone is the zone between the 800 m curve and the snow-line; it has a Ch percentage of 40—50. Even though the position of the limits of the zones must be taken with some reservation, they agree well with conditions in the adjacent countries. Thus in Scotland the 20 p.c. Ch biochore lies at c. 800 m above sea-level, in the Faeroes at c. 500 m, in Greenland the 20 p. ec. Ch biochore lies at the level of the sea in 60—61° N. 4. An investigation of the peculiarities of the flora in the separate parts of the country and the altitudinal zones shows that the differ- ences are especially due to differences in temperature. The differ- ences in the vegetation are likewise due to this factor. The temperature of the soil differs according to the degree of snow-covering and water-covering, though in different ways. In the winter the geiri vegetation with its constant snow-covering as well as the flöi vegetation with its constant water-covering are protected from the frost. Hence the result in both cases is a vegetation con- sisting principally of southern species, even though the two areas have not one species in common, while the snow-bare vegetation, melar and mosathembur, which is most exposed to the cold of winter, consists principally of arctic species, and the intermediate areas, mo, jadar, and myri, both as regards environment and bio- logical conditions, occupy an intermediate position. In the summer the flöi vegetation has a constant covering of water, the specific heat and evaporating heat of which does not allow of so high a degree of heating as an equal amount of heat produces in the geiri vegetation. The result is, then, that a series of the most heat-loving species do not occur on water-covered soil, but only in the geiri. Soil with a constant water-covering is warm in winter, but cold in summer. The soil with a constant snow- covering in the winter is warm both summer and winter; both these circumstances are strikingly manifested in the composilion of the vegetation. | The sequence dry, moderately moist, and moist soil, or mo, STUDIES ON THE VEGETATION OF ICELAND 177 jadar, and myri, handsomely illustrates the influence of the degree of moisture on the temperature of the surface. — The snow-covering is the same for the three types of vegetation, viz. the normal snow- covering of the country. In winter the dry soil is exposed to the hardest frost, while the moderately moist and especially the moist soil are protected by the moisture of the earth. In the summer, the moist soil cannot, on account of its water content, attain as high a temperature as the dry and moderately moist soils. The last-mentioned is dry in sum- mer, like the mo. Since the moderately moist soil has the advantages of moist soil in the winter, and of dry soil in the summer, it must be the most favourable of these three types for southern plants. This will be confirmed by an examination of table 38. Between dry and moist soils there is a peculiar difference. The dry soil, the mo, is relatively cold in winter but dry in summer, while the moist soil, the myri, is relatively warm in winter and cold in summer. And, as a matter of fact, the result is that the mo has more high-arctic species requiring a low temperature and more species requiring higher temperature than the myri. Conditions in still moister and still drier vegetations than myri and mo, re- spectively, further confirm this difference. The halla myri is another case in point. Owing to the constant supply of ground-water this myri becomes still warmer in winter and still colder in summer than the usual type, the för myri. And the result is a further reduction of the number of species requiring cold and, since the winter lasts longer than the summer, an in- crease of the species requiring warmth. The effect of the cold water in the summer on the composition of the vegetation is likewise appreciable. Since in Iceland it is the temperature in winter and in Den- mark the temperature in summer which determines the formation of the types of vegetation, the halla myri vegetations of the two countries form a peculiar contrast. In Denmark the halla myri is characterised by its high content of arctic plants, but in Iceland by its high content of southern plants. Even in Iceland, however, the cold water in the summer tends to give the vegetation an artic character. Around the hot springs the vegetation consists exclusively of the species requiring most heat. The Botany of Iceland. Vol, 111, 12 178 TABLE 38. H. MØLHOLM HANSEN Species-group spectra and biological spectra of the different types of Vegetation on Iceland, based upon statistical investigations. ss... ss... EORMYrIeE 0e | Bien (01a ee ele a aie) nie Number of Localities examined CRC || Points-sum | 2568 10658 | 2 43908 ‚10140 | 15240 | 4180 1740 5592 404 | 4092 Number of species || Density of 115374 | : | 4852 | species > 6.8 | 72 | 28 113.3 | 53 47 13.2 47 53 |: 9.449 | 51 | 8.3144 56 | 1.9 | 28 | 72 8.6 | 28 | 72 | | 2.0 14 86 9.9 | 58 42 6.925 | 75 | 16 23183 17 114 22 17 | r [9] | 11.0 37 | 63 | 23 | 14 | 38 18 || E |A 3/A 2/A 1|E4 E3 E2 E1 Ch eat] | G HH | Th | | | | a | NE En 13) 1/14| 1) 4) »|27|40|33| » | > 6124| 410.5 0.147 11), (ae | 9|27|10| 90.5131 16) » [0.5 1031|12)1010.1)18'53|28| ı | 1 9/38/12] 1| >»|24|21/49| 5 |02 525/21 11| >| 8/28. 58) 6| 1 20137|136| »| »| 2 76 10| > 4124 26 | 13 |1.1 | 34 16| » |0.1 4/22 37/11] 312 7216| >| 3 | | | »/21)65| » | »|| »/11)18) » | 7 » 115,25 1.4 0.1/13 6012) > | 15 9|20|1836| 213 /67|20| > | 1 | | | Il | 5. The low temperature in winter being the factor which has the greatest bearing on the vegetation, a natural system of the Ice- landic types of vegetation, i.e. a system in which the factors are given in the order of their degree of importance for the vegetation, must give as the first principle of division the conditions of snow- covering, as the next, the conditions of moisture, and so forth. Hence, the types of vegetation investigated in this treatise must be ranged in the following order. I. Vegetation bare of snow. 1. Soil covered with moss 2. Soil covered with gravel II. Vegetation with normal snow-covering. 1. Soil dry 2. Soil moderately moist a. Soil covered with vegetation, level b. Soil covered with vegetation, knolly c. Soil bare, with smallknolls Mosathembur (moss heath, Grimmia heath) Melar (fell field) Mo Valllendi Jadar (grass mo) Flag (clayey flats) STUDIES ON THE VEGETATION OF ICELAND 179 3. Soil moist Myri a. Stagnant water For myri(swampy myri) b. Running water Fét myri c. Springs Halla myri 4. Soil always covered with water a. Stagnant water Flöi b. Running water Fen c. Springs Dy III. Vegetation with a constant and deep snow-covering 1. Normal light conditions, no leaf-fall Geiri (snow patch) 2. Shade and leaf-fall Forest ground 6. Of the individual types of vegetation the following may be mentioned. The mosathembur vegetation is bare of snow in the winter. The surface is covered with a dense and thick carpet of moss in which there occurs a scattered vegetation of high arctic plants poor in species. The amount of geophytes is unusually large. As a cli- matically conditioned type the mosathembur vegetation is confined to the North Atlantic region, in Iceland to the higher levels of South Iceland and especially East Iceland. The melar vegetation is likewise bare of snow in the winter. The surface is covered with gravel and is dry, with polygonal for- mation or solifluction. The vegetation is open, but with a relatively high number of species and density. The mo vegetation, in point of environment, is characterised by a normal snow-covering and by the fact that it is unaffected by the ground water. The surface is knolly and covered with vegetation. The vegetation is both rich in species and dense, and consists of an equal mixture of arctic and southern plants which are either Ch or hemicryptophytes. The jadar vegetation like the mo has a normal snow-cover- ing but is confined to moderately moist soils, i. e. soils dry in sum- mer and wet in winter. The surface has large knolls and is covered with a dense vegetation rich in species (both the number and den- sity of species attain their maximum in jadar). The vegetation con- sists of an equal mixture of arctic and southern species, though compared with the adjacent types the southern species attain a re- lative maximum here. H are the dominant life-form, attaining their 12" 180 H. MØLHOLM HANSEN maximum development in jadar. Ch are of slight importance, while the number of G is on the increase. The valllendi vegetation is a variant developed on the cones deposited by the streamlets of melting snow. There is no knoll formation and the vegetation is that of a more southern environment. The flag vegetation. The surface is a bare clayey flat with scattered knolls and stones. The vegetation is characterised by its high therophyte percentage, though in jadar, too, Th attain a relative though small maximum. Årctic species are more dominant in flag than in jadar or especially valllendi. The jadar vegetation seems to be confined to the Icelandic lowlands, to the jadar or the trans- ition from mo to myri. The myri vegetation is peculiar to moist soil which must not, however, be covered with water all the year round. The surface is knolly. Here the vegetation likewise consists of an equal mixture of arctic and southern plants, but the most arctic and the most southerly either do not occur or their number is much reduced compared with that of mo and jadar. G are the dominant life-form, Ch attain a relative maximum, while the number of H is much diminished. The number and density of the species are appreciably less than in mo and jadar. The types of myri occurring in Iceland are as follows. För myri, which develops in depressions with stagnant water. Halla myri, which develops in places where the ground water comes to the surface, thus especially at the foot of mountains. Fét myri, which occurs near running water, along the banks of rivers, near the sea etc. The flöi vegetation develops where the soil is constantly covered with water all the year round. The surface is level, without knolls. The vegetation is very scattered and poor in species and consists almost exclusively of southern plants. The dominant life- form is G. The hydrophytes or helophytes likewise attain their maximum development in the flöi. The geiri vegetation is confined to soil with a constant and deep snow-covering from early autumn to late spring. The surface is always level, without knolls. The vegetation consists principally of southern plants, notably those requiring the highest temperature which are found in greatest quantity here. The dominant life-form is H, of less importance are Ch and especially G. Both the number and density of species are relatively high, though less than in the mo. . STUDIES ON THE VEGETATION OF ICELAND 181 The forest ground vegetation resembles the geiri vegetation in external factors and in its main features. The density, the number of high-arctic plants, and the quantity of Ch are less in forest ground than in geiri, while the quantity of H is higher. The cause for this may perhaps be found in the differing illumination and the more constant protection from frost in the forest ground than in the geiri. Each of the types of vegetation discussed above comprises a great number of formations which have not, as yet, been more closely examined. 7. Our knowledge of the quantitative distribution of the indi- vidual types of vegetation in the various parts and altitudinal zones of Iceland is as yet rather deficient. Of the percentage of types in the individual altitudinal zones, the following particulars may be given. I. In the lowlands, below the 20 p. c. Ch biochore, the 300 m eurve, the dominant features of the landscape are forest, mo (espe- cially heather mo), jadar, littoral meadow, flag, myri (för myri, halla myri, and fét myri), flöi, dy and fen, and lowland melar. II. In the lower highland zone, 300—600 m above sea-level, the types of vegetation are melar (highland melar), mosathembur, mo (level and knolly), jadar, myri (för myri), flöi, dy, and geiri (in- cluding the Salix herbacea and the Sibbaldia vegetation). III. In the upper highland zone the vegetation is either melar or geiri (especially Anthelia crusts). IV. In the zone between the 800 and 1200 m curves, the nival zone, a very scattered melar vegetation is recorded. The larger or smaller accumulations of snow are another feature of the landscape. Above the 1200 m curve, the snow line, we come to the V. zone, the jökulls, where all higher vegetation is excluded on account of the continuous snow-covering. The forces that go to form the various types of vegetation are, in the lowlands, especially the differences in moisture, in the high- lands, the differences in snow-covering. 8. The investigation of the distribution of species, species-groups, and life-forms in the formations according to increasing prevalence of one and the same external factor has brought to light the fol- lowing facts. In a given scale of one and the same external factor the indi- vidual species attain maximum frequency, i. e. minimum distance between individuals, at some point in the scale. Passing from this point towards either greater or less prevalence of the factor under 182 H. MØLHOLM HANSEN consideration, the frequency of the species gradually decreases, i. e. the distance between individuals grows greater and greater and at last the species entirely disappears. This applies to all species. The individual species may be distinguished with respect to the position of the maximum in the scale, the magnitude of the maximum, and the number of degrees in the scale which the species covers. The proportional distribution of the species in a given scale has proved the same wherever it has been more closely investigated. The distribution of Raunkiær’s life-forms in the scale of ex- ternal factors is the same as that of the individual species. The sequence of the maxima of the life-forms in the scale of moisture from the most moist to the driest section is as follows: HH— G—> H—Ch— (Th). This sequence occurs wherever conditions have been closely examined and remains the same whether the succession is determined by means of the number of individuals (frequency sum) or the number of species. In the scale of snow-covering, Ch occur in greatest quantity in the “sections devoid of snow”, H in the opposite sections. These conditions are repeated wherever the facts have been investigated, and remain the same whether calculated by means of the number of individuals or by means of the number of species. The distribution of the species groups in the scales of external factors would seem to open up new possibilities of determining the factors which are active in the distribution of plants. Fig. 1 is to be found on page 21, the others are printed on plates I—XII. an =.= LITTERATURE Alcenius, O., Finlands kärlväxter, Helsingfors 1919. Anderson G. og H. Hesselman, Verzeichnis der in König Karls Land während der swedischen Polarexpedition 1898 gefundenen Phanerogamen. — Öfvers. kgl. Vetensk.-Akad. Förhandl, Stockholm 1898. — — Bidrag till kännedomen om Spetsbergens och Beeren Eilands kärlväxtflora. — Bihang till K. Svenska Vet.-Akad. Handl. 1898. Ascherson, P. & P. Graebner, Flora des Nordostdeutschen Flachlandes (ausser Ostpreussen). Berlin 1898—99. Asplund, Erik, Beiträge zur Kenntnis der Flora des Eisfjordsgebietes. — Ark. f. Botanik, Bd. 15, Nr. 14, 1919. Blytt, A., Die Theorie der wechselnden kontinentalen und insularen Klimate. — Eugl. Bot. Jahrb. 2: 1—50, 177—184, 1882. — Haandbog i Norges Flora. — Kristiania 1906. Botany of the Færûes, Vol. I —III, Copenhagen 1901—08. The Botany of Iceland, Vol. I—II, Copenhagen 1912—20. Ferdinandsen, C., Undersøgelser over danske Ukrudtsformationer paa Mineral- jorder. Kbhvn. 1918. Fries, Thore C. E., Den synekologiska Linjetaxeringsmetøden. — Flora och Fauna, 1919. Grønlund, Chr., Islandske Naturforhold med særligt Hensyn til Mosvæxtens Be- tydning for Landskabet. — Tidsskr. f. populære Fremstillinger af Naturviden- skaben 5. R. IV.: 321—356, 1877. — Islands Flora. Kbhvn. 1881. — Karakteristik af Planteveksten paa Island, sammenlignet med Floraen i flere andre Lande. — Naturhist. Foren. Festskr. 1884: 107—145. Grøntved, Johs., Formationsstatistiske Undersøgelser paa nogle danske Over- drev. — Bot. Tidsskr. 40: 1-—-71, 1927. Hann, Julius, Handbuch der Klimatologie, Bd. III. 1911. — Lehrbuch der Meteorologie, 4. Aufl. 1926. Hartz, N., Botanisk Rejseberetning fra Vest-Gronland 1889—90. — Medd. om Grønland 15: 1—60, 1894. — Ostgronlands Vegetationsforhold — Medd. om Grønland 18: 107—314, 1895. — Fanerogamer og Karkryptogamer fra Nordost-Gronland, c. 75—70° n. Br. og Angmagsalik, c. 65° 40° n. Br. — Ibid. 18: 315-393, 1895. — and Chr. Kruuse: The Vegetation of Northeast Greenland, 69° 25° lat. n. — 75° lat. n. — Ibid. 30: 333—431, 1911. Hesselbo, Aug., The bryophyta of Iceland. — The Botany of Iceland, Vol. I: 395—678, 1918. 184 LITTERATURE Homén, Theodor, Bodenphysikalische und meteorologische Beobachtungen mit besonderer Berücksichtigung des Nachtfrostphaenomens. — Bidrag til kannedom af Finlands natur och folk 54: 187—416, 1894. — Ueber die Bodentemperatur in Mustiala. — Acta Soc. Scient. Fennicae, XXI, 9, 1—183, 1896. — Der tägliche Warmeumsatz im Boden und die Wärmestrahlung zwischen Him- mel und Erde. — Ibid. XXIII, 3, 1—148, 1897. Hooker, J. D., The Students Flora of the British Islands. 1884. Jessen, Knud, Oversigt over Karplanternes Udbredelse i Danmark. — Bot. Tids- skr. 39: 137—210, 1926. Jönsson, Helgi, Studier over Ost-Islands Vegetation. — Bot. Tidsskr. 20: 17—89, 1895. — Vegetationen paa Snæfellsnæs. — Vid. Medd. Naturh. Foren. 1900: 15—98. — Vegetationen i Syd-Island. — Bot. Tidsskr. 27: 1—82. 1905. Keranen, J., Ueber die Temperatur des Bodens und der Schneedecke in Sodan- kyla. — Ann. Ac. Fennicae 13. 1920. Klinge, Joh., Flora von Est-, Liv- und Curland. Reval 1882. Kruuse, C., Vegetationen i Egedesminde Skjærgaard. — Medd. om Grl. 14: 348— 399, 1898. — List of the phanerogams and vascular cryptogams found on the coast 75°— 66° 20° lat. N. of East-Greenland. — Medd. om Gronland 30: 143—208, 1905. — List of Phanerogams and Vascular Cryptogams found in the Angmagsalik Di- strict on the East coast of Greenland between 65° 30’ and 66° 20‘ lat. N. — Medd. om Grl. 30: 219—287, 1806. Lange, Joh., Conspectus Florae Groenlandicae, I—II. — Medd. om Grl. 3, 1880— 1887. Lindman, C. A. M., Svensk Fanerogamflora. Stockholm 1918. Lynge, B., Vascular plants from Novaya-Zemlya. — Rep. Scient. Result. Norv. Exped. Novaya—Zemlya 1921. Nr.13. 1923. Melan, A.J., Suomen Kasvio. 1906. Mentz, A., Danske Gresser og andre græsagtige Planter. Kbhvn. 1902. — Studier over danske Mosers recente Vegetation. Bot. Tidsskr. 31, Kbbvn. 1912. More, A.G., Contributions towards a Cybele Hibernica. 1898. Nathorst, A. G., Nya bidrag till kannedomen om Spetsbergens karlvaxter, och dess vaxtgeografiska forhallanden. — Kgl. Svenska Vetensk. Akad. Handl. Bd. 20, Nr. 6. 1883. Norman, J. M., Norges arktiske Flora, I—II. Kristiania 1894—1901. Olsen, Carsten, Vegetationen i nordsjellandske Sphagnummoser. — Bot. Tidsskr. 34: 1—44, 1914. — Studier over Jordbundens Brintionkoncentration og dens Betydning for Vege- tationen szrlig for Plantefordelingen i Naturen. Kbhvn. 1921. Oskarsson, Ingimar, Botaniske Undersogelser fra Islands nordvestlige Halvo, Vestfirdir. — Bot. Tidsskr. 39: 401—445, 1927. Ostenfeld, C. H., Skildringer af Vegetationen paa Island. — Bot. Tidsskr. 22: 227—253, 1899; ibid. 27: 111—122, 1905. — Phanerogamae and Pteridophyta. — Bot. Færåes, Vol. I, 1901. — and O. Gelert, Flora arctica I Pteridophyta, Gymnospermae and Monocotyle- dones. Kbhvn. 1902. — Plantevexten paa Færøerne med særlig Hensyntagen til Blomsterplanterne. Kbhvn. 1906. raven i ' | | i | LITTERATURE 183 Ostenfeld, C. H., and Andr. Lundager, List of vascular plants from North- East Greenland (N. of 76° n. lat.) collected by the Danmark Expedition. — Medd. om Grønland 43: 1—32, 1910. — Plants collected during the first Thule expedition to northern most Greenland. — Ibid. 51: 371—381, 1915. — Flowering plants and ferns from Wolstenholme Sound (ca. 76° 30‘ N. Lat.) — Ibid. 64: 189—206, 1923, — Two plant lists from Inglefield Gulf and Inglefield Land (77° 28‘ and 79° 10° N. Lat.), N. W. Greenland. — Ibid. 64: 207—214, 1923. — The Vegetation of the North-coast of Greenland based upon the late Dr. Th. Wulffs collections and observations. — Ibid. 64: 221—268, 1923. — Flowering Plants and Ferns from North-western Greenland collected during the Jubilee Expedition 1920—22 and some Remarks on the Phytogeography of North Greenland. — Ibid. 68: 1—42, 1925. — The Flora of Greenland and its Origin. — Biol. Medd. Kgl. D. vid. Selsk., VI, 3, 1926. Porsild, Morten P., Bidrag til en Skildring af Vegetationen paa Øen Disko. — Medd. om Grl. 25: 89—307, 1902. — The Flora of Disko Island and the adjacent coast of west Greenland from 66°—71° N. Lat. — Ibid. 58: 1926. Ramann, E., Bodenkunde. 3. Aufl. 1911. Raunkiær, C., Vesterhavets Ost- og Sydkysts Vegetation. — Festskrift i Anled- ning af Borchs Kollegiums 200-Aars Jubilæum pag. 312—362, Kbhvn. 1889. — Dansk Ekskursions-Flora. 3. Udg. Kbhvn. 1914. — Planterigets Livsformer og deres Betydning for Geografien. Kbhvn. 1907. — Livsformernes Statistik som Grundlag for Biologisk Plantegeografi. — Bot. Tids- skr. 29: 42—83, 1908. — Formationsundersogelse og Formationsstatistik. — Ibid. 30: 20—132, 1909— 10. — Det arktiske og antarktiske Chamaefytklima. — Biol. Arbejder tilegn. Eug. War- ming, pag. 7—27, 1911. — Formationsstatistiske Undersøgelser paa Skagens Odde. — Bot. Tidsskr. 33: 197—243, 1912. — Measuring-apparatus for statistical investigations of plant-formations. — Bot. Tidsskr. 33: 45—48, 1912. — Om Valensmetoden. — Ibid. 34: 289—311, 1916. — Recherches statistiques sur les formations vegetales. — Biol. Medd. Vid. Selsk. I, 3, 1918. — Ueber das biologische Normalspektrum. — Ibid. I, 4, 1918. — Erindringsord til Forelæsninger over Plantegeografi. Kbhvn. 1920. Resvoll-Holmsen, H., Observations botaniques. — Exploration des nord-ouest du Spitsberg entreprise sous les auspices de s. a. s. le prince de Monaco par la mission Isachsen V. — Résultats des campagnes scientifiques accomplies sur son yacht par Albert I. prince souverain de Monaco. Fasc. XLIV, 5, 1—81, Monaco 1913. — Om Vegetationen ved Tessevand ved Lom. — Videnskapsselsk. Skr. I, Kri- stiania 1912. — Statistiske Vegetationsundersogelser fra Maalselvdalen i Tromsö Amt. — Ibid. 1913. — Statistiske Vegetationsundersogelser fra Foldalsfjeldene. — Ibid. 1914. 186 LITTERATURE Resvoll-Holmsen, H., Om Fjeldvegetationen i det ostenfjeldske Norge. — Archiv f. Math. og Naturvidensk. 37, Kristiania 1920. Rosenvinge, L. Kolderup, Andet Tilleg til Gronlands Fanerogamer og Kar- sporeplanter. — Medd. om Grl. 3, 1892. — Det sydligste Gronlands Vegetation. Ibid. 15: 73—250, 1896. Samsoe-Lund, Vejledning til at kjende Gresser i blomsterlos Tilstand. Kbhvn. 1882. Schouw, Joakim, Frederik, Grundtrek til en almindelig Plantegeografi. Kbhvn. 1822. Simmons, Herman G., The vascular plants in the flora of Ellesmereland. — Report of the second norwegian arctic expedition in the »Fram« 1898—1902. Nr. 2. Kria. 1906. — A survey of the Phytogeography of the arctic american Archipelago with some notes about its exploration. — Lunds Universitets Arsskrift 1913. Smith, H., Vegetationen och dess utvecklingshistoria i det centralsvenska hög- fjällsomraadet. — Uppsala 1920. Stefansson, St., Fra Islands Væxtrige II. — Vid. Medd. D. Naturh. Foren. 1894: 174—212, 1895. — Fléra Islands. Kbhvn. 1901. 2. Udg. 1924. Sälan, Th., A. Osw. Kihlman, Hj. Hjelt, Herbarium musei Fennici I. Plantae vasculares. Helsingfors 1889. Tansley, A.G., Types of British Vegetation. Cambridge 1911. Thorkelsson, Thorkel, Um ürkomu à Islandi. — Bünaôarrit. XXXVIII. Rey- kjavik. Thoroddsen, Th., An Account of the Physical Geography of Iceland with special reference to the plant life. — The Botany of Iceland I, 187—343, 1914. Vahl, M. og G. Hatt, Jorden og Menneskelivet, I. 1922. Warming, Eug., Om Grønlands Vegetation. — Medd. om Grl. 12: 1—245, 1888. — Plantesamfund. Grundtræk af den økologiske Plantegeografi. Kbhvn. 1895. Watson, H.C., Topographical Botany. 1883. Wild, H., Ueber die Differenzen der Bodentemperaturen mit und ohne Vegetations- resp. Schneedecke. — Mém. Acad. St. Petersb. VIII. Ser. Vol. V, Nr. 8, 1897. Willis, J.C. og J. K. Burkil: The phanerogamic flora of the Clova mountains. — Transact. Bot. Soc. Edinburgh 22: 109—125, 1901—04. Jed bya dey 1 THE BOTANY OF ICELAND. VOL. III (H. M@LHOLM HANSEN) Fig. 2. Lyngdalur with Hrölfshölar. In the foreground mo vegetation, further back some narrow strips of mo with mosathembur (the lighter areas). In the background Hrölfshölar with alternating areas of melar and mo. In the depression in centre, a myri. Fig. 3. Thrasaborgir. The light areas in the foreground are mosathembur, in centre, a large patch of snow, geiri, with level surface. The knolly parts between geiri and mosathembur are mo. ‘The picture is taken from the south, looking due north. PLATE THE BOTANY OF ICELAND. VOL. III (H. MØLHOLM HANSEN) Fig. 4. The Mosathembur Vegetation on Lyngdalsheidi. The thick carpet of moss is intersected by long narrow fissures with a special vegetation. The composition of the vegelation is shown in table 9A, p. 40. Fig. 5. The Melar Vegetation on Lyngdalsheidi. The bottom is covered with gravel containing scattered stones, In the background Kalfstindar. The composition of the vegetation is shown in table 10 A, p. 44. II PLATE: III THE BOTANY OF ICELAND. VOL. III (H. MØLHOLM HANSEN) OR IH FRET © me. Fig. 6. The Mo on Lyngdalsheidi. The ground with pronounced knolls. For vegetation, see table 11 A, pp. 48—49. Terre. PR nn we aa hegre Toy ASE: #1 ny = = Fig. 7. Mo on the western Side of Lyngdalur. The knolls on the slope are different from (more elongated than) the knolls on level ground, PLATE IV THE BOTANY OF ICELAND. VOL. III (H. MØLHOLM HANSEN) Fig, 8. The Valllendi Vegetation on Lyngdalsheidi. Surface level, without knolls. For vegetation see table 12 A, p. 52. Fig. 9. Patch of Snow from the western Side of Lyngdalur. The surface of the snow patch is level in contrast to the knolly surface of the sourrounding mo, For vegetation see table 13 A, pp. 56—57, PLATE THE BOTANY OF ICELAND. VOL. HI (H. MØLHOLM HANSEN Fig. 10. Patch of Snow on Lyngdalsheidi. Altitude c,300 m. The picture shows the snow patch distinctly marked off from the sourrounding mo. CERN KT) Fig. 11. Myri at Björk. Surface knolly. For vegetation see table 15 A, pp. 66—67. In the background Lyngdalsheidi and the Björk Farm, PLATE VI THE BOTANY OF ICELAND. VOL. III (H. MØLHOLM HANSEN) Fig. 12. Flag Mo at Lækjaméôt. The picture shows the surface of the flag mo covered with small knolls in contrast to the larger knolls of the mo (left), and the sharp line of demarcation between flag and myri (right). For the composition of the vegetation see table 17 A, pp. 72—73. Fig. 13. A smaller Section of fig. 12. The surface features, the bare clayey ground with small grass knolls and stones, are more distinct. PLATE VII THE BOTANY OF ICELAND. VOL. III (H. MØLHOLM HANSEN Fig. 14. Forest Glade at Norötunga. For the composition of the vegetation see table 21 A, pp. 90—91. Fig. 15. Melar from the Crest of a Hill on Arnarvatnsheidi. The surface covered with larger or smaller stones without solifluction curves. For vegetation see table 22 A, 1—6, pp. 104—105, PLATE VIII THE BOTANY OF ICELAND. VOL. III (H. MØLHOLM HANSEN) Figs. 16—17. Melar from a Slope, viewed from above (fig. 16) and from below (fig. 17). The solifluetion curves are much more conspicuous in the latter than in the former view. Vegetation practically the same as above, see table 22 A, 1—6, pp. 104—105, PLATE IX THE BOTANY OF ICELAND. VOL. III (H. MØLHOLM HANSEN) Fig. 18. The Betula nana-Mo on Arnarvatnsheidi. Surface covered with vegetation but without knolls, For the composition of the vegetation see table 22 A, 7—11, pp. 104—105. Fig. 19. The knolly Mo on Arnarvatnsheidi. Surface knolly. For the composition of the vegetation see table 23 A, 1—5, pp. 107—108, PLATE THE BOTANY OF ICELAND. VOL. III (H. MØLHOLM HANSEN) Fig. 20. The Jadar Vegetation on Arnarvatnsheidi. Surface covered with large knolls and a vegetation the composition of which in table 23 A, 6—10, pp. 107—108. is shown Fig. 21. Picture of a Depression with Myri on Arnarvatnsheidi. The varied composition of the highland myri is illustrated by the collections of water, For vegetation see table 24 A, p. 112, PLATE XI THE BOTANY OF ICELAND. VOL. III (H. MØLHOLM HANSEN) Fig. 22. A portion of the Flöi on Arnarvatnsheidi shown in fig. 21. Surface without knolls. For vegetation see table 23 A, p. 112. Fig. 23. Strip of Snow Patch, on the nortlı aspect of a hill. In contrast to the formations above and below, the surface is comparatively level, For vegetation see table 25 A, 5, pp. 116—117, PLATE XII THE BOTANY OF ICELAND. VOL. III (H. MØLHOLM HANSEN Fig. 24. Large Patch of Snow on Arnarvatnsheidi. Surface level, the vegetation differs on the bottom and sides of the snow patch. See table 25 A, pp. 116—117. Fig. 25. A portion of the Patch shown in fig. 24. Geranium silvaticum in bloom. ae he 2 re est a PE - en LE a kee = k x “ <4 ? {hee FE Te 7. T2 ud el = - i i > ELLE AR à el "ra på SITE x: Ss (= = Det Køl. Danske Videnskabernes Selskab. Biologiske Meddelelser. IX, 2 _ THE SPECIES OF THE GENUS ARIX AND THEIR GEOGRAPHICAL Be, DISTRIBUTION BY . H. OSTENFELD ano C. SYRACH LARSEN ux WITH 35 ILLUSTRATIONS AND 8 MAPS a ee en Br ———— Historisk- filologiske Meddelelser, "Filosofiske Meddelelser, > Mathematisk-fysiske Meddelelser, zu Mee "Kgl. Hof-Boghandel, København. Det Kgl. Danske Videnskabernes Selskab. Biologiske Meddelelser. IX, 2. | EHE SPECIES OF THE GENUS LARIX AND THEIR GEOGRAPHICAL DISTRIBUTION BY FRE OSTENFELD and C. SYRACH LARSEN WITH 35 ILLUSTRATIONS AND 8 MAPS 3 ø KØBENHAVN —…_HOVEDKOMMISSIONÆR : ANDR. FRED. HOST & SØN, KGL. HOF-BOGHANDEL BIANCO LUNOS BOGTRYKKERI A/S 1930 Arbejder fra den botaniske Have i København. Nr. 117. | 0 ULL rec? YORE NICAL X DEN I. Introduction. n the course of an excursion undertaken in 1922, the I eldest among us saw some larch plantations in Roden Forest, in the south-east of the Danish island of Lolland; in most respects they resembled the Japanese Larch (Larix Kaempferi), but differed, nevertheless, from it in several respects, and therefore aroused my interest’. This was the cause of my endeavouring to obtain information regarding, and material from, various larch plantations in this country, for the purpose of ascertaining which forms and species we had taken into culture during the course of the past decades. Arising out of these enquiries, my interest became extended to embrace the whole genus Larix, one result being the present treatise, which considers only the larch in the wild state, and its geographical distribution. It is founded upon a comprehensive study of material from various parts of the globe, as well as of the very copious literature extant upon the subject. Duties of many kinds make heavy demands upon my time, and I have taken as collaborator Mr. C. SYRACH LARSEN, Graduate of Forestry, to whose interest and industry I am indebted, that this paper could be presented in such detail. We have received assistance from many different quarters ; we have had material on Joan from the Arnold Arboretum in Massachusetts, where the East-Asiatic species are very well represented. Moreover, the Larix material in the museums at Washington, New York, Ottawa, Kew and London, as well as that in the Gray Herbarium of Cambridge, Mass., * It is L. Gmelini, var. olgensis. See p. 55. 1* 4 Nr. 2. C. H. OSTENFELD and C. SYRACH LARSEN: has been examined by OSTENFELD on the occasion of his visits to those cities; and the collection of the late Professor HENRY in Dublin has been studied by SYRACH LARSEN, as well as those at Kew and the British Museum. Material has further been placed at our disposal by the kindness of Professor SZAFER in Krakow, Professor B. FEDTSCHENKO and Pro- fessor SUKATSCHEW in Leningrad, and, finally, we have, of course, made use of the museum-collection at the Botanical Gardens here in Copenhagen. OSTENFELD has personally seen L. laricina and L. Lyallii on the spot in Canada, and L. decidua in the Alps, while SYRACH LARSEN has studied the various forms of larch cultivated in England from early times, as well as Mayr’s cultures in Grafrath. We have been fortunate in having been able to make use of the original material of most of the species or varieties described in recent times, namely: L. Mastersiana, L. sinensis (=L. Potanini), L. olgensis (= L. Gmelini var. olgensis), L. Griffithiana, L. occidentalis, L. Lyallii, L. coreensis (=L. Gmelini var. olgensis), as well as L. pendula (=L. decidua X laricina), and specimens from the original localities of L. Principis Rupprechtti (=L. Gmelini var. Principis Rupprechtii), and L. alaskensis (L. laricina), so that we have been enabled to arrive at very fairly definite con- clusions with regard to the conception of the species and their more important varieties. In addition, we have received support from various quarters connected with forestry in this country, numerous owners of woods, and foresters having sent us material; similarly, the director of the Danish Experimental Forestry Service, Professor Dr. A. OPPERMANN, has kindly allowed us to make use of his valuable collection of larches in the Nursery Gardens at Egelund, and has, moreover, evinced warm interest in our work. We have also received The Species of the Genus Larix. 5 great assistance from the Scottish Department of Forestry, Mr. J. M. Murray having on several occasions sent us im- portant material of the Larix species cultivated in Scotland. In this paper, however, as said above, we have restricted ourselves to laying particular stress upon the wild-growing Jarches, that is to say, the genus Larix as it occurs in nature, and have in most cases deferred the treatment of the cultivated forms. We take this opportunity of expressing our gratitude to all those who, in one way or another, have assisted us in our labours. Two maps and a very short summary of some of the results of the results of the present paper were published by us in “Die Pflanzenareale 2. Rh. Heft 7. 1930”, as Karte 62—64. | Il. Larix, Miller. Larix, Miller, is a very well-defined genus. It differs from all the other genera of Pinaceae in being deciduous, and in the dwarf as well as the long shoots being provided with green leaves. Only its near relative, Pseudolarix, also has deciduous leaves, but the latter differs in possessing cones, which drop their scales at maturity. The genus is only found in the northern hemisphere, in the southern part of which it only occurs spontaneously in mountainous regions, while towards the north, and particularly in the Arctic regions, it goes down to the lowlands, where it forms extensive forests. The genus is divided into 10 species and three varieties, some of which are but little known even to-day. They may be classified as follows: — 6 Nr. 2. C. H. OSTENFELD and C. SyRACH LARSEN: Key to the Species and Varieties of Larix. I. Bracts longer than the cone-scales. Leaves slightly or strongly keeled on both sides; the upper-side may, in exceptional cases, be without keel. A. Bracts reflexed. a) Bracts much longer than the cone-scales. The cone 5—11 cms. long..... 1. L. Griffithiana. b) Bracts only slightly longer than the cone- scales. The cone 3—5 cms. long. 2. L. Mastersiana. B. Bracts straight or slightly recurved. a) The cone long and narrow; length to breadth 1,4—1,7; Bracts 0—2 mm.’ longer aia the cone-scales. Leaves deeply keeled on the under-side; slightly less keeled on the upper- side; 192 CS FONG ee ee ee 3. L. Potanini. b) The cone short and broad. Length to breadth 1—1,5, leaves 2,5—4 cms. 1. The leaves are more strongly keeled on the upper- and under-sides than in the case of any other species. The young shoots are particularly densely pilose. The cone - 3,5—5 cms. long: Brits SEAT SER MOLI AGG Se INC, CORTE 4. L. Lyallii. 2. The leaves keeled on the under-side only. The young shoots at first somewhat pilose, finally smooth. The cone 2,5—3 cms. long. The bracts straight or slightly TECULYER. 1. ran eee: 1 5. L. occidentalis. II. Bracts shorter than the cone-scales. Leaves not keeled on the upper-side and frequently flat. A. Thecone-scales reflexed. The leaves broad, deeply keeled on the under-side. Both sides provided =] The Species of the Genus Larix with stomata. The young shoots stout, and of reddish-brown colour............. 6. L. Kaempferi. B. The cone-scales straight or somewhat concave. The leaves flat, or slightly keeled on the under-side. a) The cone-scales distinctly concave. 1. Cones 1,5—2 cms. long. The cone-scales smooth, often shining........ 10. L. laricina. 2. Cones narrow, 3—4 cms. long. The scales pilose, most frequently strongly so on the outer-side of the basal portion; dull... .. 8. L. sibirica. b) The cone-scales straight. 1. Cones 2,5—4 cms. long, narrow. The scales dull, the free edges evenly rounded or slightly emarginate. The bracts are of the same light colour as the cone-scales, which are smooth or pilose on the outer side. The cone is compact. The scales open only sligthly when ripe . . 9. L. decidua. var. polonica. The cone is more frequently smaller, shorter, and thicker. The free edges of the cone-scales are more rounded, and often pilose on the outer- J side. | | 2. The cones up to 2 cms. long; broad. The free edges of the cone-scales are truncate or emarginate. The bracts are darker in colour than the light-coloured, shining, cone-scales. The cone-scales are most frequently smooth on the outer-side, but may be slightly pilose. The cones as a whole 8 Nr. 2 C. H. OsTENFELD and C. SYRACH LARSEN: are of an open, characteristically light construction. The cone-scales open widely when::ripe Vise et 7. L. Gmelini. var. olgensis. The cone longer and more cylindrical. The free edges of the cone- scales are rounded or truncate. The usually straight cone-scales may also be slightly concave or slightly recurved. The first year’s shoots are more frequently pilose, very often extremely so. var. Principis Rupprechtii. The cone is still longer and more cylindrical than in the case of the former variety; length up to about 4 cms. The areas of distribution for the various species differ very considerably in extent; the species with restricted areas of occurrence being indigenous towards the south, particularly in Asia, and appear at the same time to be the oldest forms. Some of the other species have very large areas of occurrence. III. The Species of Larix. 1. L. Griffithiana (Lindl. & Gordon, 1850), CARRIERE: Trait. Conif. 1855, p. 278. — Gorpon: Pin. 1858, p. 126. — WILLKOMM: Forstl. Fl. 1887, p. 157. — REHDER: Man. Trees and Shrubs, 1927, p. 51. — Syn: Abies Griffithiana, LiNDLEY & Gorpon, in Journ. Hort. Soc. V. 1850, p. 214. — L. Griffithii, I. D. Hooker & THOMSON in Cathcart, Ill.. Himal. Pl. 1855, t. 21. — HENKEL & HocHSTETTER: Syn. Nadelh. 1865, The Species of the Genus Larix 9 p. 136. — REGEL, in Gartenfl. XX, 1871, p. 106. — Id. in Act. Hort. Petrop. I, 1871, p. 161. — K. Koch: Dendrol. 1873, p. 264. — I. D. Hooker: Fl. Brit. Ind. V, 1890, p. 655. — SARGENT: Silva N. Am. XII, 1898, p. 4, Note. — MASTERS, in Journ. Linn. Soc. XXVI, 1902 p. 558. — ELwes & HENRY: Trees. Gr. Brit. and Irel. II, 1907. p. 388. — Bot. Mag. 4’ Ser. IV, 1908, t. 8181. — BEIssNER: Nadel- holzk. 1909, p. 305. — PATscHKE in Engl. Bot. Jahrb. XLVIII. 1913, p. 651 (p. p). — REHDER & WILSON: 1914, in Sargent: Pl. Wilson. II. p. 20. — DALLIMORE & JACKSON: Handb. Conif. 1913, p. 286. — Pinus Griffithü, PARLATORE, in De Candolle: Prodr. XVI, 2’, 1868, p. 411. — The English physician and traveller, WILLIAM GRIFFITH, discovered this larch in 1838 in Bhutan, near the village of Woolakoo, a little S. W. of Punakha in the Himalayas; this has subsequently been shown to be one of the most easterly localities within the inconsiderable zone of distri- bution, which extends from this spotin a westerly direction, and is assumed to reach about as far as the source of the Kosi river. The whole extent of the area within the bounds of which it is known is hardly 500 km. at its greatest length (from east to west) and 100—150 km. broad from north to south, and the only specimens seen by us are derived from the easterly section, that is to say, from the most westerly portion of Bhutan, extending a short distance into Nepal, together with the interlying Sikkim, and the southern point of Tibet, which extends between Bhutan and Sikkim. More recent discoveries of this larch have been made in localities situated between the most westerly regions of Bhutan, where GRIFFITH found it, and the Nango Mountains, where it was found by I. D. Hooker in 1848; the only foundation for the report that its zone of distri- bution extends to the source of the Kosi is the statements of the natives. The whole zone is situated within the Himalayas, where it was first found at a height of from 1800 m. 10 Nr. 2. C. H. OSTENFELD and C. SYRACH LARSEN: to 2900 m. above sea-level. Specimens were subsequently found in the Chumbi valley, in the extreme south of Tibet, at an altitude of 3000 m., and in Sikkim it is stated to grow at elevations ranging from 2400 to 3600 m. above sea-level. These facts show it to be indigenous to the Larix Griffilhiana (ESS G)Carr highest tree-clad regions of the eastern Himalayas in the neighbourhood of the forest line, and only in the heart of vallies leading from north and south to the mighty peaks, the final and only mantle of which is the eternal snow. Hooker found it growing over ancient moraines at a height of 3600 m. above sea-level, where it attained its best development. He also found it upon grass-clad or thicket- strewn mountain slopes, but only where the soil was stony and the drainage good. It is thus shown to be a pronounced mountain tree, choosing the fresh, light soil for its abode. It represents the most southerly species of the genus, lat. 27°—28 N. (Map: ]). The Species of the Genus Larix. 11 L. Griffithiana was discovered in 1838, but it was not described in detail until its re-discovery by HOOKER in 1848, who thereupon introduced it into England. Hooker found it only as a small tree, 6—18 m. in height, in the west of Nepal, and it never becomes a tall tree, even although a rather greater height, 19,5 m., has subsequently been reported for specimens in Sikkim, and those found in the Chumbi valley, one of the most recently discovered locali- ies, are possibly a trifle taller still. A tree cultivated at Coldrennick in Cornwall is quoted as being 23,5 m. high, and as such is taller than any noted in their natural haunts. (Gard. Chron. XLI. 1907, p. 130; DALLIMORE & JACKSON, 1923, p. 287). According to I. D. HookeEr’s drawing of a tree in its native habitat in Sikkim (Fig. 1), the crown is broader, the branches differently arranged, and the branchlets longer and more pendulous than in the case of L. decidua, and Hooker also compares it with L. decidua var. pendula (Gard. Chron. XXV. 1886, p. 719). It differs from most of the other members of the genus Larix in possessing cones of great size, reported by Hooker as being 5—7,5 cms. long (Fl. Brit. Ind. V. 1890, p. 655). REGEL (1871; fig. 2 in present paper; same fig. in BEISSNER, 1909) has an illustra- tion of a cone nearly 9 cms. long, and three cones from the already-mentioned tree in Cornwall are between 10 and 11 cms. in length. It is probable that the cones from cultivated specimens have a tendency to become larger than they would be in nature, and when DALLIMORE & Jackson (1923, p. 286) state the size as being 5—10 cms. long, these figures perhaps include specimens from both cultivated and wild individuals. The bracts are longer than the cone-scales, the same being the case with L. Mastersiana, L. Potanini, L. Lyallii, 12 Nr.2. C. H. OSTENFELD and C. SYRACH LARSEN: Fig. 1. Larix Griffithiana (Lindl. & Gord.) Carr. Habit of a tree, from a drawing by Sir Joseph Hooker (Gardener’s Chronicle June 5, 1886). The Species of the Genus Larix. 13 and L. occidentalis, but the difference is greatest in the case of L. Griffithiana; similarly, the free tips of the bracts are reflexed in a manner peculiar to this species and to L. Mastersiana only, which latter, together with L. Potanini, may be said to re- semble it most closely. The beautiful dark violet scales of the immature cone are also characteristic (Bot. Mag. t. 8181). Material of L. Griffithiana collected by I. D. Hooker in Sikkim at an al- titude of 2700—3300 m. above sea- levelis to be found in the »Herb. Ind. Or. Hook. fil. & Thomson«, which gives the following further characteristics. The leaves are placed in bundles containing up to 50, 1,5—3 cms. in length, the under-side being distinctly keeled be- tween the rows of stomata. The first- year’s shoots are very slightly pilose, of a shiny reddish-brown colour, with perhaps a slight, glaucous tinge. The (Lindl. & Gord.) Carr. Cone. From E. Regel, material has been collected shortly ;, Gartenflora 1871. after leafing, the leaves having attained their full length, but a few */s—1 cm. long [male flowers still being present. Pollination has taken place, the pollen- sacs being empty. A female inflorescence has also passed the flowering stage. It is 3'/2 cms. long, and the bracts are so strongly recurved as entirely to cover the remaining portion of the yong cone. It is strongly coloured, and was probably dark purple-red, when fresh. Further original material, No. 4989 of »Herbarium of 14 Nr. 2. C. H. OSTENFELD and C. SYRACH LARSEN: the late East India Company« in »Herb. Bot. Haun«. is part of GRIFFITH's private collection. It has been collected at a rather earlier stage than the preceding, but the female inflorescence in this case also has probably passed the flowering stage, and its length of 2 cms. is almost certainly rather greater than that of the immature female flower. The colour appears to have been the same as that in Hooker’s material, and the specimens show the same long, strongly recurved bracts, which, presumably, are already found before the flowering stage has been reached. The one-year’s shoots have the same colour and the same faint downy covering as in the case of the previously-mentioned specimens. There are only a few leaves attached, which resemble the preceding specimens; the main bulk of loose leaves does not belong to L. Griffithiana at all, but ap- parently to Cedrus deodora. The same is true in the case of some of the unattached female flowers. This confusion need not be attributed to GRIFFITH himself, but to subsequent mistreatment of his material (Vide Bot. Mag. 1908). It is not known with any certainty, whether this species has been introduced into Denmark, as there are no existing specimens of cones from trees grown in this country under the name of L. Griffithiana. Herb. Mat. examined: E. HımaLaya: Bootan, Herb. GrirFirH No. 4989 (Type, Kew) (Hort. Bot. Haun.); Sikkim reg. temp. 8—12000 Feet, Herb. I. D. Hooker (Kew; Hort. Bot. Haun); Sikkim, J. S. GAMBLE 1880 (Kew); Sikkim, SIPUKUNG, Ritu & RHomoo, 1911, (Kew); SMITH & CARE, Jeune Valley, No. 2771, Fl. of Sikkim 1909 (Brit. Mus.); SMITH & Care, Laching, No. 2600, Fl. of Sikkim, 1909, (Brit. Mus.); LACHEN, (= Laching) Sikkim, 1885, J.D. HOOKER (Brit. Mus.); Fl. of Chumbi Phari, leg. DunGBoo, 1879 (Brit. Mus.). Also seen in U.S. Nat. Mus. and in Arn. Arb. from the same localities. 2. Larix Mastersiana, REHDER & WILSON, 1914, in Sargent: Pl. Wilson, II, p. 19. — The Species of the Genus Larix. 15 DALLIMORE & Jackson: Handb. Conif. 1923, p. 292. — REHDER: Man. Trees and Shrubs, 1927, p. 51. — In the west of China, two species of larch are to be found, L. Potanini and L. Mastersiana, of which the former is the commonest, the later having only a very limited area of distribution. L. Mastersiana occurs only inside the zone of distribu- tion of L. Potanini: all in all, it is only known from three localities, lying north and south in the mountains west of the Min river. In 1908—1910, when WILson discovered it, it was quite common in this restricted area, and being greatly in demand on account of its valuable timber, has decreased rapidly, but the inaccessability of its habitat prevents its extermination for the present. It is a small tree, only some 10—20 nı. in height. Its branches of the 2nd order are pendulous, although not so strongly as in the case of L. Potanini or L. Griffithiana, which generally resemble one another in this particular. The one-year’s shoots are smooth, or very slightly pilose; the bark has a fresh, yellowish-brown colour. The leaves are placed in bundles of up to forty in number on the dwarf shoots, and are 1,2—3,5 cms. in length, light green in colour, with two light bands of stomata on the under-side. They present no appreciable difference from those of L. Po- tanini, being distinctly keeled on the under-side in simi- larity with the latter, the keel being less distinct on the upper-side, and only really apparent at the base, The 3—4 cms. long cone is brown, the bracts, which are longer than the cone-scales, are red and recurved. The length is described as being from 3—4 cms., but a cone from an original specimen lying before us (Wırson No. 906) has nevertheless attained a length of 4,5 cms. 16 Nr. 2. C. H. OSTENFELD and C. SYRACH LARSEN: L. Mastersiana is the link between L. Griffithiana and L. Po- tanini. It differs from the former in the size of the cones, which in the case of L. Mastersiana are not more than about half as Fig. 3. L. Mastersiana Rehd. & Wils. Cones from China Western Szechuan. (leg. E. H. Wilson 1908) (Nat. size, upper row dry, lower row wet, the same two cones). long as those of the Himalayan larch. The difference in length between the bracts and the cone- scales is also much more marked in the case of L. Griffithiana than of L. Mastersiana. The two spe- cies differ in point of habitus, the branches of the second order of L. Griffithiana being consider- ably more pendulous than is the case with L. Maslersiana. Compared with L. Potanini, the difference is most pronounc- ed with regard to the orange or reddish-brown bark on the one- vear’s shoots of the latter, tog- ether with the comparatively short, straight, bracts, and the purple-red colour of the cones; in comparison, the bright, yellow- ish-brown shoots, and the longer, strongly recurved bracts, and the red and brown cones of L. Mastersiana, are very distinctive. Following upon his discovery of L. Mastersiana in 1908, WILSON sent seeds to the ARNOLD Arboretum, but the tree is not yet in culture in Denmark. Herb. Mat. examined: W.SzEcHuan No. 906, E. H. Wırson 1908, Type, in Arn. Arb.; also in U. S. Nat. Herb.; Brit. Mus.; Kew Herb.; Hort. Bot. Haun. — The Species of the Genus Larix. 17 3. Larix Potanini, A. BATALIN, in Act. hort. Petrop. XIII, 1894, p. 385. — MASTERS, in Journ. Linn. Soc. Bot. XXVI, 1902, p. 558. — Gard. Chron. 3. Ser. XXXIX, 1906, p. 178 (cum icon.). — ELwes & HENRY: Trees. Gr. Brit. and Irel. IJ, 1907, p. 391. — Beıssner: Nadelholzk. 1909, p. 307, (cum icon.). — PATSCHKE, in Engl. Bot. Jahrb. XLVIII, 1913, p. 651. — REHDER & WILSON, 1914, in Sargent: Pl. Wilson, II, p. 18. — REHDER, in Journ. Arnold Arb. IV, 1923, p. 121. — DALL1- MORE & JACKSON: Handb. Conif. 1923, p. 297. — Wırson in Journ. Arn. Arb. VII, 1926, p. 46, — Hsen-Hsu-Hu & Woon-Younc-Cuwn: Icon. Plant. Sinicarum, 1927, Pl. 2 — REHDER: Man. Trees and Shrubs, 1927, p. 50. —. Syn L. chinensis BEISSNER in Mittl. d. dendr. Gesellsch. 1896, p. 68. — DIELS, in Engl. Botan. Jahrb. XXIX, 1901, p. 216. — MASTERS, in Journ. Linn. Soc. Bot. XXVI, 1902, p. 558. — ELwEs & HENRY: Trees. Gr. Brit. and Irel. II, 1907, p. 346. — BEISSNER: Nadelholzk. 1909, p. 303, (cum icon.). — PATSCHKE, in Engl. Bot. Jahrb. XLVIII, 1913, p. 651. — L. tibetica, FRANCHET, in Journ. de Bot. XIII, 1899, p. 262. — Dies, in Engl. Bot. Jahrb. XXIX, 1901, p. 216. — MASTERS, in Journ. Linn. Soc. Bot. XXVI, 1902, p. 559. — L. Griffithii, Masters, in Journ. Linn. Soc. Bot. XXVI, 1902, p. 558. — PATSCHKE, in Engl. Bot. Jahrb. N 1913, p. 746. — Non: Hook. f. & THOMSON. — L. Potanini occurs in a belt extending from the north- west of Yunnan, where it is broadest, northwards through Szechuan to a short distance into the interior of Kansu. Thence it follows the great mountain chain of Tsinling- shan eastwards to the extreme south-west corner of Shensi. The majority of finds has been made in Szechuan and in the north-west of Yunnan, where, generally speaking, it is common, and is a valuable forest tree. It is to be found there from an altitude of 2500 m. above sea-level and higher, until it finally disappears at the forest-line. Wırson Vidensk. Selsk. Biol. Medd. IX, 2. 2 18 Nr. 2. €. H. OSTENFELD and C. SYRACH LARSEN: (No. 903) found it in 1908 north-east of Ta-tsien-lu at an altitude of 3300—4800 m. above sea-level, and no higher- lying locality has as yet been reported. ce: 1: 3.000.000. ny Map. II. © ---— Larix Polanini, Batalin .——; >: Fe Mastersiana ,Rehd. 8 Wils. The first material was discovered by ARMAND DAVID at Shensi, and was described by FRANCHET in 1884 as pr The Species of the Genus Larix. 19 Larix spec. POTANIN found the material for BATALIN's type in the neighbourhood af Ta-tsien-lu in 1893, and the majority of the subsequent finds originate from this locality. Specimens were found by Purpom in 1910—1911 in Kansu and Shensi, and by Rock in 1922 and 1924 as far south as the mountains around Yangtsze in the north-west of Yunnan (Journ. Arnold Arb. VII. 1926, p. 46). Several other finds had already been made in the north-west of Yunnan by HANDEL-MAZZETTI in 1914—18, but they were first re- ported in 1929 (HAnDEL-MAZZETTI; Symbolae Sinicae, VII, 1, 1929). HANDEL-MAZZETTI also reports its occurrence from the south of Szechuan, and as far west as the mountains between Salween and the Irrawady in the extreme north- east of Burma. It is found in the greatest abundance, forming forests, at an altitude of about 3000 and 3400 m. above sea-level, and in scattered groups down to 2700 m. above sea-level. | The material for BEıssneEr’s L. chinensis was found in 1893—94 by Father GiuserrE GirRALDi at Tai-pei-shan in Shensi, and Purpom’s discovery originates from the same locality. This, together with the fact that the original material of L. Polanini agrees with BEıssneEr’s illustration (Fig. 70 in Nadelholzk. 1909), proves that the two species are identical. FRANCHET's L. tibetica, which was found by Prince Henry d’Orleans near Ta-tsien-lu, where so many finds of L. Potanini have subsequently been made, also coincides in every respect with the latter. The length of the cone varies from 2,5—7,5 cms. Two cones from the already-mentioned highest known locality, north- east of Ta-tsien-lu, 3300 to 4800 m. above sea-level (WILSON No. 903) measure 2,5—3 cms. Two other cones from Wırson’s material collected from about the same district, 9% 20 Nr. 2. C. H. OSTENFELD and C. SYRACH LARSEN: west and south-west of Ta-tsien-lu, from 3300—4000 m. above sea-level, are 3,5—3,7 cms. long. WILLIAM PURDOM’s No. 760 from the south of Kansu, 3000—3300 m. above sea-level, should be mentioned as representing material from a northern locality; six cones from this collection vary from 3 to 3,5 cms. in length. REHDER & WILSON estimate the average length of the cones taken from the intermediate and most northern localities to be 3—4,5 cms. (Pl. Wils. 1916, p. 19), but specimens from more southerly regions show that it can be considerably greater. Among GEORGE FORREST’s material from Fig. 4. L. Potanini Batal. Cones from China, Northern part. (W. Purdom No. 760). (Nat. north of Yunnan (GEORGE For- size, upper row dry, lower row REST: No. 6745. 1910. lat. 27° 2 3 5 x wet, the same two cones). i 35’ N.), there are cones up to the Likiang Range in the extreme 5 cms. in length (Kew Herb.), and Rock's specimens from the same neighbourhood (1922—24) are, according to REHDER, 6—7 cms. long (Journ. Arnold Arb. VII, 1926, p- 46. See also f. australis Henry apud Handel-Mazzetti, 1929, |. c.). In this connection it should be stated, that FRANCHET had already described this species from Yunnan, and this accounts for his quoting a length as great as 5 cms. for ordinary cones (R. P. DELAwAy). The large cones, which demonstrably exist, give it a point of simila- rity with L. Griffithiana, and explain the reason for MASTERS and PATSCHKE attributing this species to Szechuan on the The Species of the Genus Larix. 21 basis of PRATT's discovery (Journ. Linn. Soc. Bot. XXVI. 1902, p. 558; Engl. Bot. Jahrb. XLVIII, 1913 p. 746). FRANCHET, however (Journ. de Bot. XIII, 1899, p. 262), cor- rectly identified PRATT’s discovery with L. tibetica (= L. Potanini Bat.). The distinguishing characteristics of L. Potanini from L. Griffithiana and L. Mastersiana are best demonstrated by an examination of the cones. In the case of the former, the bracts of the mature cone are not more than 2 mms. longer than the cone-scales, and are straight, while, in the case of the other two latter species, they are relatively longer, and strongly reflexed. The cone is violet with red bracts, that of L. Mastersiana being brown with red bracts. The first-year’s shoots are of a deep reddish-brown colour (Wırson, No. 903), or orange-brown (WILSON, No. 910), with prominent, lighter-coloured stigmata. The leaves are placed in bundles of up to fifty on the dwarf branchlets, 1,5—3 cms. in length, and are similar to L. Mastersiana in being distinctly keeled on the under-side, the keel on the upper-side being only noticeable at the base. All three south-asiatic larches (L. Griffithiana, L. Master- siana and L. Potanini) have a prominent keel on the under- side of the leaf, and are also partly keeled on the upper- side; but none of them can be compared to L. Lyallii, the leaves of which are prominently keeled on both sides. The leaves of L. Potanini have been described as four- sided when seen in tranverse section, being keeled on the upper as well as the under-side (DALLIMORE & JACKSON: Handb. Conif. 1923, p. 297); but we have been unable to observe this dissimilarity from L. Mastersiana and L. Griffi- thiana in the specimens we have examined. In the localities where the tree altains its best growth, 22 Nr. 2. C. H. OSTENFELD and C. SYRACH LARSEN: it reaches a height of 25—30 m., according to REHDER & Witson, but A. E. PRATT observed specimens west of Ta- tsien-lu as high as 40 m. (Engl. Bot. Jahrb. XLVIII, 1913, p. 746). The crown is more slender in shape than that of L. Griffithiana, the branches of the first order being des- cribed as rather short. Branches of the second order are, on the contrary, pendulous in both species. Single individuals of the species attain their best growth in the fertile, lower-lying, forest districts, but it only occurs scattered among other conifers and deciduous-leaved trees, and is more specially found along the sides of water- courses. It becomes more and more common as the ground rises, and in the highest-lying districts whole forests are composed of it. It was introduced into Germany in 1899 under the name of L. chinensis. Seeds of it were sent to BEISSNER, and plants were successfully raised (BEISSNER: Nadelholzk. 1909, p. 305; vide ELwes & HENRY: Trees Gr. Brit. and Irel. II, 1907, pp. 346—347). It was subsequently introduced into England, when Witson in 1904 sent seeds from Szechuan to Veitch’s Nursery Gardens. It is not found under cultiva- tion in Denmark. Herb. Mat. examined: W. SZECHUAN, No. 910, E. H. Witson 1908 (Arn. Arb.; U. S. Nat. Mus.; Kew.; Brit. Mus.; Hort. Bot. Haun.). — Lichiang Range lat. 27° 35’, 1910, Forrest No. 6745 (Brit. Mus.; Kew). — W. China, Hung-Sha, No. 3009, E. H. Wırsonx, 1904 (Brit. Mus.; Kew). — N. China, No. 760, Arn. Arb. Exp. Won. Purpom (Kew; Brit. Mus.; U. S. Nat. Mus.; Arn. Arb.; Hort. Bot. Haun.). — Cam. SCHNEIDER, Iter chinense 1914, SzEcHUAN austr., Kapala- Linku, 3800—4000 m. (Kew). — Kansu, T’ao River basin, 10—11000 ft. I. F. Rock, 1925, No. 12803. — SHEnsı sept., monte Kuon-tan-san 1894, ded. BEISSNER (Part of Type collection of L. chinensis; Kew). — 4. L. occidentalis, Nurrazz: North Am. Silv. III, 1849, p. 143, t. 120. — Le. The Species of the Genus Larix. 23 SARGENT: Silv. N. Am. XII, 1898, . 11, t. DXCIV. — REHDER: Man. Trees and Shrubs, 1927, p. 51. — Syn: Pinus Nuttallii, PARLATORE in De Candolle, Prodr. XVI, 2. part, 1868, p. 412. L. occidentalis together with L. Lyallii are representatives in North America of the type of larch characterised by possessing cones, the bracts of which are longer than the cone-scales, even when the cones attain maturity. Both species are indigenous to the most westerly parts of North America, where they are vicarious, L. occidentalis being a native of the mountains at an altitude of between 600 and 2100 meters, while L. Lyallii is an alpine tree, holding itself to the neighbourhood of the forest line between 1200 and 2400 m. above sea-level. L. occidentalis is a valuable tree, which can attain very considerable dimensions under suitable conditions, namely, on fertile, deep soil in vallies. It occurs in Western Canada (British Columbia), and reaches its highest pitch of devel- opment in a section of the most north-easterly part of the State of Washington, the extreme west of Montana, and the northern parts of Idaho, where whole forests of it are often to be met with; while it is often found growing among Thuja plicata, Pseudotsuga mucronata, Tsuga Alber- tiana, Picea Engelmanii, and Abies grandis. In the most suitable localities, it can attain a height of 50—80 m. (Sar- GENT: Silv. N. Am. XII, 1898, p. 11; REHDER, 1927, p. 51), but as a rule it is less than 50 m. high. The girth may also be considerable, and trunks are mentioned having a diameter of up to 2 m. (Henry & Erwes: 1907, p. 394), and about 2,5 m. (SARGENT: 1898, p. 11). Such girths are, of course, considerable, but not so enormous in relation 24 Nr. 2. C. H. OSTENFELD and C. SYRACH LARSEN: to the great height, and L. occidentalis in its habitat also grows slender, regular trunks with short lateral branches, and slender, pyramid-shaped crowns. In April 1826, Davin DouGLas made a journey up the Columbia River, and in the district lying in the fork made by the junction of the River Spokon and the Columbia, on his way to Fort Colville, he entered the great, fertile pine-forests, where L. occidentalis attains its greatest devel- opment. He did not differentiate it from L. decidua, which is later described, but he admired its imposing dimensions and the excellence of its timber, writing in his journal: »I measured some thirty feet in circumference; and several which had been levelled to the ground by the late storms, were one hundred and forty-five feet long, with wood per- fectly clean and strong«, and he also states that they were the commonest conifers met with in the district (Com- panion to the Bot. Mag. II, 1836, p. 109). The tree is a splendid one, surpassing all the other species of larch in height and girth where it attains its best development, and possesses a Shape and timber as valuable as the best of the other species. Its area of distribution lies like a ring around the lowland, formed by the central part of Washington and the northern of the Oregon up to the northern side of the Blue Mountains. This is the Great Plain of the Colum- bia River. It is most extensively distributed towards the north-east in the Rocky Mountains; the line then takes a north-westerly direction towards the Cascade Mountains, which it follows southwards until a little south of the Columbia River, where it bends eastwards and continues — in somewhat straggling groups, it must be confessed — until it again reaches the Rockies. Map. III. e ---- Larix oceidenlalis, Null. .---—-- Larix Lyallic, Parl. 26 Nr. 2. C. H. OSTENFELD and C. SYRACH LARSEN: Its cone is 2,5—3,5 cms. in length, and the open form with the long, visible bracts, which are straight or only slightly recurved, make it easily recognisable. The scales Fig. 5. L. occidentalis Nutt. Branch and cone from Montana, Glacier National Park, Lake Mac Donald, ca. 1000 m (leg. I. G. Jack, Sept. 1921). (Nat. size, left wet, right dry, the same branch). are thin, and their free tips are straight, or slightly recur- ved. The basal portion of the outer side is finely pilose. The female inflorescence are deep red with green mid-rib and mucro (U. S. Nat. Herb.), and the male flowers are rather long. The young shoots are brown and pilose, becoming smooth at a later period, the leaves 2,5—4,5 cms. long; they are green, and not blueish-green. Vigorous ” AJ] The Species of the Genus Larix. “ shoots of young trees are provided with particularly long leaves, giving them the characteristic appearance, which by itself alone renders them distinguishable from the other Fig. 6. L. occidentalis Nutt. Cones from cultivated trees. Botanical Gardens, Copenhagen 1928. (Nat. size, upper row dry, lower row wet, the same two cones). cultivated species. It was introduced into Europe (Kew) in 1881, and thrives well under cultivation in Great Britain, developing the same fine form of growth as when found in its native surroundings, but is attacked by Dasyscypha Willkommi, with which it has also been badly beset in Denmark (Hæsede Nursery at Gisselfeld, Dr. BoRGESEN’s garden in Hellebæk, the Nurseries of the Danish Experi- 28 Nr. 2. C. H. OsTENFELD and C. SYRACH LARSEN: mental Forestry Service at Egelund; vide A. OPPERMANN: Cultivation of the Larch in Denmark in Det forstlige For- sogsvesen i Danmark, VII, p. 276). In forests and gardens its occurrence is as yet rare. Herb. Mat. examined: Brit. Columbia.: Deer Park, Lower Arrow Lake, 1890, Macoun (Gray Herb.). — Upper Arrow Lakes, 1889, Dawson (Ottawa Herb.). — Between Lower and Upper Arrow Lakes, 1890, Macoun (Ottawa Herb.) — Sicamous, 1889, Macoun (Ottawa Herb.). — Colombia Slope, 1834, Herb. Nuttall, Type collection (Brit. Mus.). — Columbia River from lat. 48°—49° N., several specimens, Dr. LyaLt, 1860 (Kew; Gray Herb.), — Columbia River 1890, JoHN Macoun, (Brit. Mus.). — Selkirk Flora, 1905. Cuas H. SHaw, a) Wood W. of Nelson, b) Hills near Howser Lake (Brit. Mus.; U. S. Nat. Herb.; Gray Herb.). — Washington: Blue Mts. Colum- bia Co. 1897 (Gray Herb.). — Swank River, 750—1800 m., SHARPLES, 1913, (Gray Herb.). — Near Kettle Falls and in the Rocky Mountains, 1826, Davip DoucLas (Kew). — Cascade Mts., T. S. BRANDEGEE, 1882, Ex Herb. Univ. Calif. (Hort. Bot. Haun.). — Suksdorf, Fl. of Washington, Mt. Paddo, ADAMS 1883 (Brit. Mus.; Gray Herb.).— Oregon: Union, Col. Casıck 1882 (Kew). — Petty’s Canon, 1880, S. Warson (Gray Herb.). — Big Fork, 1908, J. CLEMENTS (Gray Herb.). — Clear water (Gray Herb.). — Near Mt. Hood, WALPOLE, 1898 (U. S. Nat. Herb.). — Montana: Columbia Falls, 1893, WırLıams (U. S. Nat. Herb.). — Lower valley of Clarks Fork, 650 m. J. B. LEIBERG, 1895 (Gray Herb.; U. S. Nat. Herb.). — Fl. of Idaho, Craig Mts. near Lake Waka, 1892 (Brit. Mus.; Gray Herb.). — Fl. of Idaho, Payette Lake, 1899. Marcus Gray Jones (Brit. Mus.). — 5. L. Lyallii, Parlatore, in Enum. Sem. Hort. Reg. Mus. Flor. 1863. Journ. Bot. I, 1863, B. 35, and, in Gard. Chron. 1863, p. 916. — SARGENT: Silv. N. Am. XII, p. 15, t. DXCV. — REHDER: Man. Trees and Shrubs, 1927, p. 51. Syn: Pinus Lyallii, PARLATORE in De Candolle Prodr. XVI. 2. 1868, p. 412. | L. Lyalli, has for its area of distribution two regions divided from one another, one towards the east in the Rockies, and one to the west in the Cascade Mountains. The Species of the Genus Larix. PAS Within both areas, it goes southwards to about lat. 45°N., that is to say, as regards the western area, a trifle south of the Columbia River, and north again to about the Fig. 7. Group of L. Lyallii, forming forest line above Lake Louise, Al- berta, Canada. Ca. 2000 m. (Aug. 1924. C. H. Ostf. phot.). boundary line between Washington and British Columbia; in the eastern area, it follows the boundary between Bri- tish Columbia and Alberta northwards to the neighbourhood of Mount Hooker. On the west, it runs a little nearer to the coast than, and on the north-east, a little beyond the 30) Nr. 2. C. H. OSTENFELD and C. SYRACH LARSEN: limits of, L. occidentalis. This area of distribution corre- sponds with the more alpine character of L. Lyallü, which is therefore found at higher altitudes than the latter on the great mountain chains bounding their mutual domains. (See Maps III & VIII). L. Lyallii, in contrast to L. occidentalis, is of very small importance as a forest tree. Under favourable conditions, it succeeds in reaching a height of 20—25 m., but is frequently lower. It grows but slowly in the harsh climate of the upper forest-line, where it has its home; BRANDEGEE counted as many as 562 annual rings in a trunk about 50 cms. in diameter. From the taxonomic point of view, L. Lyallü and L. occidentalis resemble one another closely, and it is also prob- able that their characteristics can vary to such an extent, that they overlap. Even so, they are, nevertheless, so dis- similar, that they must be regarded as two different species. The cone is larger than that of L. occidentalis (3,5—5 cms. in length), but has the same open form, and the long, vis- ible bracts which characterise the latter. The scales are more pilose, and become a little more recurved at maturity. The cone at the flowering-stage has dark red, rarely green, scales, while the bracts are of more pronounced red shade. The long mucro of the bract is also deep red, in contrast with L. occidentalis (U. S. Nat. Mus.). The male flower is long, the young shoots are strongly pilose, the hairs light brown; the leaves are 2,5—4 cms. in length, and blueish- green; the transverse section shows them to be rhomboid, and considerably thicker than those of L. occidentalis. The leaves, which may be as long as those of L. occidentalis, are more quadrangular than those af any other species, which fact, together with the densely pilose young shoots, The Species of the Genus Larix. 31 makes L. Lyallii easily recognisable, even without the cones. The wings of the seeds are stated to be of a faint red colour in contradistinction to those of L. occidentalis, É Fig. 8. L. Lyallii Parl. One year’s Fig. 9. L. Lyallii Parl. Cone shoot showing dense pilosity. from British Columbia, Tecamo- Montana, Glacier National Park, res (leg. John Macoun, July 1889). Piegan Purs, 2100 m. No. 2204 (leg. (Nat. size, upper dry, lower wet) J. G. Jack, Sept. 1921). | where they are brown; but the material of L. Lyallii from i Glacier National Park (2100 m. above sea-level) in Montana, | and from Tecamores in British Columbia, presents this difference to a slight degree only, and it can, no doubt, be entirely absent. In recent times (1893 and later), trials have been made 32 Nr. 2. C. H. OSTENFELD and C. SYRACH LARSEN: in England with the cultivation of L. Lyalli, but it thrives very poorly; the attempts have only resulted in raising a few isolated specimens, which, however, only grew for a short time. In Denmarks no attempts at cultivation have been made. Herb. Mat. examined: Alberta: Silver City 1885, Jonx Macoun (Brit. Mus.). — Near Banff, W. C. Catia, 1899 (Kew). — Selkirk Mt. 1904, Summit of Burgess Trail, H. PETERSEN (Brit. Mus.; Gray Herb.). — Lake Louise, 1905, EDITH M. Farr (Brit. Mus.; Gray Herb.). — Above Lake Louise, 1924, C. H. OSTENFELD (Hort. Bot. Haun.). — Lake Agnes & Mt. Piron, Frances C. Princes 1900 (Gray Herb.). — Lake Agnes, 6800 ft., C. S. SARGENT, 1897 (Gray Herb.; U. S. Nat. Herb.). — Near Lake Agnes, 7400 ft., MAcoun, 1904 (Ottawa Herb.). — Pipestone Valley S. of Summit, Headwaters of the Saskatchewan and Athabasca River, STEwART & Brown, 1908 (Gray Herb.). — Sheep Mt., Macoun, 1895 (Ottawa Herb.). — Brit. Colum- bia, Tecamores, JOHN Macoun, 1889, Ex. Herb. Geol. & Nat. Hist. Surv. Canada (Hort. Bot. Haun.). — Kicking Horse Lake, JoHN Macoux, 1890 (Brit. Mus.). — Kootanie Pass., Dawson AuG. 1881, and Macoun 1890 (Ottawa Herb.). Kootanie Valley, Dawson July (Gray Herb.). — Kanashir Summit, R. M., 7000 ft. Dawson, July, 1884 (Ottawa Herb.). — Washing- ton: Cascade Mt. to Fort Colville, Dr. Lyarr, 1860 Type collection (Kew, also in Gray Herb.). — Fort Colville to Rocky Mountains, Galton Range, Dr. Lyarr 1861, (Kew). — Near Mt. Stewart, T. S. BRANDEGEE, 1883, Ex. Herb. Univ. Calif.; (Hort. Bot. Haun.; Kew; Brit. Mus.; Gray Herb.), — Yokima Region, 6200 ft. 1883. — Forest Reserve, 5700—5800 ft., 1897. Mt. Stuart, 1898; Wanalschee Mt. 1901 (U. S. Nat. Herb.). — Fl. of Mon- tana, Marcus E. Jones: a) Hamilton, Bitter Root Valley 1905 (U. S. Nat. Herb.); b) Darby 1909 (Brit. Mus.). — Glacier Nat. Park, 2100 m., Arn. Arb. Journey to Montana, No. 2204 (Hort. Bot. Haun.). — Horse Pass, Montana, 200 m. (U. S. Nat. Herb.). — . 6. Larix Kaempferi, (LAMBERT, 1824), SARGENT: Silv. N. Am. XII, 1898, p. 2. Note. Wırson: Conif. and Tax. Jap. 1916, p. 30. — REHDER: Man. Trees and Shrubs, 1927. p. 51. — Syn: Larix conifera nucleis pyramidatis, foliis deciduis, Engelbertus, Kaempferus: Amoenitarum exoticarum, 1712, p. 883. — The Species of the Genus Larix. 33 Pinus Larix, CaroLus PETRUS THUNBERG: Flora Japonica, 1784, p. 275. — Non L. 1753. — Pinus Kaempferi, LAMBERT: Genus Pinus, II, 1824, p. V. — Abies leplolepis, SIEBOLD & ZuccaRINI: Fl. Jap. II, 1842, p. 12, a, — Larix japonica, CARRIERE: Trait. Conif. 1855, p. 272. — Non Murray, 1863. — L. leptolepis, GORDON: Pinetum, 1858, p. 128. — Murray: Pines and Firs, Jap. 1863, p. 89. — BEIssNER: Nadelholzk, 1909, p. 307. — O. G. PETERSEN: Forstb. 1920, p. 247. — A. OPPERMANN, in Det forstl. Forsagsv. i Danmark, VII, 1923, p. 266. — DALLIMoRE & Jackson: Handb. Conif. 1923, p. 288. — The Japanese Larch is only found in the wild state in the interior of Hondo at about the same latitude as Tokio, while it is cultivated in the north and south, and also upon the large islands of Hokkaido, Schikoku, and Kiuschiu. Its area of distribution runs roughly east and west across Hondo from the province of Kaga in the west, through Shinano to the district around Nikko in the province of Shimotsuke, where it reaches its most easterly and most northerly point of occurrence. The area forms a belt 80— 100 km. wide, and 250—300 km. long (see Map V). It is common within these limits, and grows at an altitude of between 500 and 2300 m. above sea-level, keeping to the volcanic soil. On Fuji-Yama it occurs right up to an altitude of 2900 m., but, at the extreme limit, only as a stunted bush hardly Im. high (Murray: 1863, p. 97). 1.G. VEITCH was the first to draw attention to this form, which Murray in 1863 described as a separate species, L. japonica (non Carriére). After its subsequent introduction to the Arnold Arboretum in 1892, it has been demonstrated that it does not retain its dwarf growth, and does not deviate from the species in any important characteristic. WILSON has given a detailed description of its occurrence Vidensk. Selsk. Biol. Medd. IX, 2. 3 34 Nr. 2. C. H. OSTENFELD and C. SYRACH LARSEN: upon the basis of his own observations (Wırson: 1916, pp. 30—31), and he states that is has a tendency to form pure growths of considerable extent, otherwise occurring only in company with other conifers such as Pinus densi- flora, Abies homolepis, A. Veitchti, Picea jezoensis, Tsuga diversifolia, and deciduous foliage trees, such as oak, birch, hornbeam and beech. SırasawA, however, states that it most frequently occurs in mixed forests (SırasawA: 1910, p. 307). As a rule, it attains a height of 25—26 m. with a girth of 2—3 m.; but it can, under exceptional circums- tances, reach 33 m. with a girth of 4 m. In speaking of its occurrence upon Fuji-Yama, Wırson remarks, that Pinus pumila as a rule is not found here, and consequently the light-loving L. Kaempferi is allowed to dominate in these greater altitudes, where otherwise Pinus pumila is the only ruling tree or shrub. The recurved cone-scales, which are generally very distinctive, make L. Kaempferi an easily recognisable larch. It varies in size, and large cones are common in cultivated specimens. Mayr, who may be supposed to have been intimately acquainted with the species in its native country, states that the cones only attain a length of 1,5—3 cms. in their natural habitat, becoming as long as 3,5 cms. under cultivation (Mayr: 1890, p. 65). He mentions the illustrations in SIEBOLD & ZUCCHARINI: Fl. Jap. II, 1842 (Plate 105), which reproduce two cones 3,5 cms. in length, as an example of a cultivated specimen with large cones. Under culture in Denmark, this tree has produced cones as long as 4 cms. (Strodam near Hillergd, and Tinning Forest near Friijsenborg). The female cone in the flowering stage is violet; the bracts have a green mid-rib; the species seems to vary The Species of the Genus Larix. vo very little. Pale flowers are not mentioned, and flowers only a trifle lighter in shade are found in cultivated spec- imens (Egelund Nurseries under the Danish Experimental Forestry Service). The first-year’s shoots are stout, yellow 8" onifers and Taxads of Japan, 1916). H. Wilson, C = 4 4. rom | == + Larix Kaempferi (Lamb.) Sargent. (E 10. Fig. 36 Nr. 2. C. H. OSTENFELD and C. SYRACH LARSEN: to reddish-brown, most frequently a fresh chestnut-brown, and may be smooth or pilose. The leaves are 3—3,5 cms. long, blueish green in colour, with stomata on both sides, and have a prominent keel on the under-side. Wırson describes the crown as narrow and somewhat pyramidal, the branches numerous, thin, and short. Usually Fig. 11. L. Kaempferi (Lamb.) Sarg. Cones from cultivated trees. Den- mark, the Garden of Forest Botany, Charlottenlund, 1922 (*/s nat. size, upper row dry, lower row wet). they project horizontally from the trunk, but are sometimes bent upwards or downwards; this description is confirmed by an illustration of a group of older trees (Wırson: 1916, Plate XV). (Fig 10). Under culture in Europe, L. Kaempferi seems to have a tendency towards developing a broader crown with stouter, longer branches, than those of L. decidua, but as there are at present only young trees up to 60 years of age in culture, there is some hope that, as time goes on, they will adopt a — from the forestry point of view — more satisfactory form, and one more in keeping The Species of the Genus Larix. 37 with Wırson’s description of them from their home. Although the Japanese Larch was mentioned by KAEMPFER already in 1712, it was first described by LAMBERT in 1824, and first introduced into Europe in 1861, when JoHn GouLD VEITCH sent seeds to the Nursery Gardens near London. It came to Denmark in 1889 (The Garden of Forest Botany at Charlottenlund), and is now, thanks to its vigorous early growth, and stout, picturesque appearance, a tree in common use in forests and gardens. Herb. Mat. examined: Yokohama, 1862, Maximowicz (Brit. Mus.). — Chinsenji, Nikko, Binet, 1877 (Brit. Mus.). — Nippon, Jizogatake 1903, Faure, No. 5344 (Brit. Mus.). — Nippon, Asamayana, 1904, FAURIE (Brit. Mus.). — Aomori, culta, 1905, FAURIE (Brit. Mus.). — Also seen in Kew etc. — Numerous cultivated specimens from Denmark, etc. 7. Larix Gmelini (Ruprecht 1845), GORDON: Pinetum 1858, D. — Herb. Fl. Ross., Mus. Bot. Acad. Imp. Petropol. edit. 1912. — Conf. MIDDENDORFF in Middf. Reise, IV, 1. 1867 p. 527, Note. — Syn: Abies Gmelini, RUPRECHT, in Beitr. Pflanz. Russ. Reich. 2. Lief. 1845, p. 56. — Abies kamtschatica, RUPRECHT 1845, 1. c. p. 57. — Pinus dahurica, FıscHEr, in Schtschagl. Anz. f. Entd. in d. Phys. Chem. Natur. u. Techn. VIII, 3’. 1831 (nomen nudum). — TURCZANINOW, in Bull. de la Soc. Imp. Natur. de Mosc. XI, 1838, p. 101 (nomen nudum). — Id., Fl. Baical. Dahur. I. 1842—45. p. 14, (nomen nudum). — ENDLICHER: Syn: Conif. 1847, p. 128. — Lepr- pour: FL Ross. III, 1846—51. — TRAUTVETTER in Act. Hort. Petrop. V, 1877, p. 111. Pinus Kamtschatica, EnpLicHer: Syn: Conif. 1847, p. 135. (Species inquirenda). — Leprsour: Fl. Ross. III, 1846—51, p. 673. — Larix dahurica, TRAUTVETTER: Pl. Imag. Descrip. Fl. Russ. III. Fasc. 7, 1846. p. 48, Tab. 32. — Turczaninow, in Bull. de la Soc. Imp. des Natur. de Mosc. 1838, p. 101 (nomen nudum). — TrAUT- 30 Nr. 2. C. H. OSTENFELD and C. SYRACH LARSEN: VETTER in Middf. Reise, I, II, 4’, 1847, p. 148. — CARRIERE: Trait. Conif. 1855, p. 270. — TRAUTVETTER & MEYER in Middf. Reise, I, II’, 2’, 1856, p. 88. — Maxım.: Prim. Fl. Amur. 1859, p. 262. — RADDE, in BAER & HELMERSEN: Beitr. Kennt. Russ. Reich. XXIII, 1861, p. 608, — HENKEL & HOCHSTETTER: Syn: Nadelh. 1865, p. 138. — Mip- DENDORFF, in Middf. Reise, V, 1’, 1867, p. 527. — Fr. ScHMIDT, in Mém. Acad. Imp. Sci. St. Petersbourg, Sér. 7, XII, No. 2. 1868, p. 63. — REGEL, in Gartenfl. XX, 1871, p. 104, et in Act. Hort. Petrop. I. 1871, p. 159. — K. Koch: Dendrol. 1873, p. 261. — MASTERS, in Journ. Linn. Soc. Bot. XVIII, 1880, p. 522. — WILLKOMM: Forst. Fl. 1887, P. 155. — HERDER, in Act. Hort. Petrop. XII, 1892, p. 98. — SARGENT: Silv. N. Am. XII, 1898, p. 4. Note. — CAJANDER, in Act. Soc. Sci. Fennice, XXXII, No. 3. 1904, p. 8. — Mayr: Fremdl. Wald- und Parkb. 1906, p. 299. — ELwEs & HENRY: Trees, Gr. Brit. and Ireland II, 1907, p. 379. — BrIssNER: Nadelholzk. 1906, p. 319. — PATSCHKE, in Engl. Bot. Jahrb. XLVIII, 1913, p. 651. — A. OPPER- MANN, in Det forstl. Forsggsv. i Danmark VII, 1923, p. 271. — Oxapa, in Bot. Mag. Tokio XXXVIII, 1924. — Komarow, in Acad. Sci. Publ. Foederat. Soviet. Social. 1927, p. 101. — HuLTEN, in Kungl. Sv. Vetensk. Handl. Ser. 3, V. 1928, p. 68. — Larix Kamtschatica, CARRIERE: Trait. Conif. 1855, p. 279. — MIDDENDORFF, in Middf. Reise, IV, 1. 1867, p. 529. — Erwes & Henry: Trees, Gr. Brit. and Irel. II, 1907, p. 343. — L. sibirica, MAximowicz, apud REGEL: Veget. Skitz. Amur. 1856, p. 495. — Id. in Bull. Acad. St. Petersbourg XV, 1857, p. 226. — HERDER, in Act. .Hort.:Petrop. XII, 1892, p. 102 (pp). = Masters, in Bull. Herb. Boiss. VI, 1898, p. 272. — PATSCHKE, in Engl. Bot. Jahrb. XLVIII, 1913, p. 651 (p.p.). — Non LEDEBOUR. — L. decidua var. rossica, HENKEL & HOCHSTETTER: Syn: Nadelh. 1865, p. 133, (p.p.). — Non REGEL. — L. dahurica var. japonica, MAxIM., apud REGEL, in Gartenfl. XX, 1871, p. 105, cum icon. — MIYABE, in Mem. Boston Soc. Nat. Hist. IV, 1890, p. 261. — PATSCHKE, in Engl. Bot. Jahrb. XLVIII, 1913, p. 651. — Wırsox: Conif. and Tax. Jap. 1916, p. 33. — MiyaBe & Kuno: Icon. Ess. For. Hokkaido 1920, p. 23. — READER: Man. Trees and Shrubs, 1927. p. 52. — L. intermedia, K. Kocu: Dendrologie, 1873, p. 260 et 261 (pp.). — L. kurilensis, Mayr: Monogr. Abiet. Jap. 1890, p. 66. Pl. V. — ELwes & Henry: Trees, Gr. Brit. and Irel. II. 1907, p. 383. — BEISSNER: Nadelholzk.1906, p.321.— Dati. & Jackson: Handb. Conif. The Species of the Genus Larix. 39 1923, p. 287. — A. OPPERMANN, in Det forstl. Forsogsy. i Danmark VII, 1923, p. 275. — L. dahurica var. kurilensis, SARGENT: Silv. N. Am. XII, 1898, p. 4, Note. — L. Cajanderi, Mayr: Fremdl. Wald- und Parkb. 1906, p. 297. — ELwes & Henry: Trees, Gr. Brit. and Irel. II, 1907, p. 346. — Datu. & Jackson: Handb. Conif. 1923, p. 279. — L. dahurica var. pubescens, PATSCHKE, in Engl. Bot. Jahrb. XLVIII, 1913, p. 651. — L. dahurica var. kamtschatica, MıyaBE & Kuno: Icon Ess. For. Hokkaido, 1920, p. 26. — Kuno, in Jap. Journ. Bot. II, 1925, p. 52 et 217. — L. Gmelini (L. dahurica) is a very common tree through- out the entire forest-clad regions of Eastern Siberia, vast tracts being often entirely composed of it, especially in the north, where it alone forms the forest line (See Map V). Its most northerly point of occurrence is near the Cha- tanga and its tributary, the Novaja, at lat. 72°—721/:° N, (Middf. Reise IV, 1867, pp. 595 and 604), and further eastwards, at the mouth of the Lena, it reaches nearly as far north as lat. 72°N. (CAJANDER in Act. Soc. Sci. Fennicae, XXXII, No. 3, 1904, p. 32). From these outposts in the extreme north, it extends southwards through the whole of Eastern Siberia, and reaches its most southerly point of occurrence at about the same latitude as Vladi- vostok, where it goes over to var. olgensis, which car- ries the area of occurrence further southwards. In the southern parts of the area of distribution, it goes westwards to Lake Baikal, the northerly part reaching as far west as the district around the mouth of the Jenisej. Near Lake Baikal, and along the banks of the Lena from Kirensk to Oleminsk, forms are found intermediate between the typical L. Gmelini and L. sibirica; the same phenomenon might also conceivably be observed 40 Nr. 2. C. H. OSTENFELD and C. SYRACH LARSEN: further north in a belt, where the two species meet one another (CAJANDER; ibid p. 8). Similar forms probably occur in the extreme north near the mouth of the Jenisej, contradictory reports existing regarding the larch species in these districts. SCHEUTZ states that L. sibirica is the only larch near the Jenisej, also attributing the most northerly, stunted specimens between Dudino (Lat. 69° N.) and the Arctic Sea to this species (Kgl. Sv. Vet. Handl. XXII, No. 10, p. 41). MIDDENDORFF, who devoted special attention to the relation between the two larches, and endeavoured to fix the boundary between them during his sojourn near the Jenisej, came, on the other hand, to the result, that the dividing line between L. Gmelini and L. sibirica must be looked for between lat. 67'/2° and lat. 68'/2° N., and that only L. Gmelini at any rate was to be found at lat. 69/2" N. He also suggested the possibility of the existence of a transition belt with intermediate forms between the two species (1. c. pp. 530 and 595). MippENDORFF supposed that L. Gmelini formed the forest line as far west as about the spot where the Ob empties itself into the Arctic Sea (l. c. p. 538). His statements here are not based on personal observation, and L. Gmelini has never subsequently been found so far west; SCHEUTZ too (l.c. p. 47) only found L. sibirica there. The relation between the two species will be seen from the foregoing to be still insufficiently illuminated, but as already stated, it appears reasonable to suppose that a transitional zone lies in this district as well, and that in all probability the boundary lies somewhere in the neighbourhood of the mouth of the Jenisej. Eastwards, L. Gmelini is found as far as the coast bor- dering the Sea of Ochot, the only localities where it does not occur being the coast of Kamtschatka and the northern Fog The Species of the Genus Larix. 41 section of the gulf between Kamtschatka and the mainland. It extends further to the small islands along the coast, passes over to Sachalin and to the most southerly of the Kurile Islands, viz., Shikotan and Etorofu. On the north-east, it reaches its extreme limit near the Anadyr River, which, however, it only follows for a short distance south of lat. 65° N., never overstepping lat. 65° N. and long. 172° E. Finally to its area of distribution must be added the isolated occurrence in the interior of Kamtschatka. The limit for its occurrence on the north-east towards the Sea of Ochot, as well as the northern boundary, is given on our map in accordance with MIDDENDORFF'S detailed accounts (1. c. pp. 530—535). The occurrence in Kamtschatka is reproduced from the map of HULTÉN (Kgl. Sv. Vet. Handl. V, No. 1, p.284), and Komarov (Acad. Sci. Phil. Foederat. Soviet Social., 1927, p. 101), and with regard to the localities on Sachalin and the southern Kurile Is- lands, several detailed notes exist, the most exhaustive of which has been supplied by MıppEnporFrF (1867), Fr. Scumipt (1868), Mayr (1890), and MıyaBE & Kuno (1920). Within this extensive area of distribution, between .lat. 43° N. and lat. 72'/2° N., and between long. 85° and 172°E., the species undergoes considerable variations in habit. It is found in every possible form, from low, stunted speci- mens in the most northerly localities, to shapely trees in the southern vallies 80 to 100 feet high. MIDDENDORFF, who has given the, hitherto, most detailed description of this species on the basis of his own observations, has supplied several sketches of types varying from the fine, single- trunked tree near the Aldan River at lat. 61'/:° N., to the century-and-a-half old stunted, zig-zag bent specimens from the River Novaja at lat. 72'/2° N. (Fig. 12). 42 Nr. 2. C. H. OSTENFELD and C. SYRACH LARSEN: A little to the south of the most northerly localities with the quite dwarf, stunted specimens, more or less open forest is found, becoming denser and better formed the further south it approaches. The growth everywhere in the northern localities is slow, ‘and the average size small. Thus, the larch in the Arctic circle seldom exceeds 12 m. in height at the Lena, and the trees are all more or less stunted. The forest is so open, that the branches hardly touch one another, and rejuvenation is very slow. CAJAN- DER, Who described the forest there also, examined a number of trees in the neighbourhood of Shigansk on the Lena, close to the Artic circle, and as the measurements give a good impression of the slowness of growth, they are given here: — Height Girth Age ae eae er 190 cms. = about 85 years I Py eee a = 26 cms. 0 NOTE PES 310, = betes EW ee hn he, 5 Ban =: pe UDE RR aa 100 FE — 136.4454 4 FPE yo = 13048 LESE ees: Mak Tow — 120925 WINE En, MOSS 41 cms. 1508 LCR TR 990 — _ 16042 De BÆRE 2 Bi 1100. ,— ale 150% The following three younger trees, however, were measured at the same time and in the same locality: Height Girth Age Lis AE ae es 350 cms. 13 cms. 17 years EN NX HOUR Bi 38. = ih ere ©" 155257 DA = BAT == [he Species of the Genus Larix. 43 These three trees as well as those in the first table show that the rate of growth can vary considerably, even within the same area, but, taken as a whole, the figures indicate only a slow rate of growth, agreeing well with the descriptions (CAJANDER: 1904, 1. c. p. 23). MIDDENDORFF supplies information with regard to the appearance of the larch near the Aldan River and its tri- Fig. 12. L. Gmelini (Rupr.) Gordon. very old, stunted specimen, from lat. 72'/2° N., river Novaja. From Middendorff, Reise, 4. Vol. p. 605. butary, the Milja, from about lat. 60° N. His illustration (Vol. IV, 1867, p. 538 reproduced here as Fig. 13) of a tree near the Aldan River, bears witness to good shape, and his measurements of trees on the Milja at lat. 60° N. (1. c. p- 539) indicate considerable size as well. One of the tallest trees found was 80 ft. high, the girth of the trunk 3”/4 ft. above the level of the ground being 6 ft. 4 inch., and at a height of 56 ft., 2 ft. 4 inch.; from the district] around Jakutsk eastwards through the Stanowoj Range, the East- Siberian larch also develops into a valuable forest tree. The tallest trees mentioned by MippeNporrr were found on the west slope of the Stanowoj Range, and were 80—100 ft. high. In a more southerly direction, in the neighbourhood 44 Nr. 2. C. H. OSTENFELD and C. SYRACH LARSEN: Fig. 13. L. Gmelini (Rupr.) Gordon. Tall tree at the river Aldan, lat. 607/2°N. From Middendorff, Reise, vol. 4. p. 538 (Abt. 80 feet high). of the Amur River and its tributaries, it probably attains an even greater height, both Fr. SCHMIDT and MAXIMOWICZ describing the occurrence of large, fine specimens with a diameter of up to 4 ft. (Maxim. 1859, pp. 393—394). The Species of the Genus Larix. 45 It appears to be an extremely common tree in all distriets within its extensive area of distribution, and in the localities in the extreme north, it predominates over all other kinds of trees. Thus CAJANDER, on his journey down the Lena, noticed that the spruce disappeared a little to the north of Jakutsk, the fir being still found a few degrees further north, while the larch was supreme from about lat. 64° N. right up to the forest-line at the mouth of the Lena at lat. 72° N. (CAJANDER: 1904). A good im- pression of how dominating, nay, supreme, it becomes in comparison with other trees in wet, tundra-like districts, may be gained from Okana's description of its occur- rence on Sachalin (Okana: 1914), where the larch is able to form whole forests on tracts that are so wet, that the undergrowth is composed, inter alia, of Ledum, Myrica, Vaccinium, Andromeda, and Oxycoccus. Finally, it is met with in the „high moor formation”, although certainly only as small individuals (vide Scumipt, 1868, p. 14; BEISSNER, 1909, p. 320, and REGEL in Gartenfl. XX, 1871, p. 105). We have seen that L. Gmelini reaches farther north and farther out on the flat, wet areas than other coniferous trees; it possesses also a marked propensity for withstand- ing the foggy, inclement climatic conditions prevailing in the regions abutting the Sea of Ochot, which it closely approaches on the Kurile Islands, as well as on Sachalin and the mainland, from about lat. 61° N.; further south- wards, it goes out on the many small islands along the coast. It not only contrives to exist under the inclement con- ditions, high winds and a cold, damp atmosphere, to which it is exposed, but can also develop into a tree of consider- able dimensions. Thus Wırson gives its height on Sacha- 46 Nr. 2. C. H. OSTENFELD and C. SYRACH LARSEN: lin as being 20—30 m., while Mayr found it at its best on Etorofu in the Kurile Islands, and measured specimens as high as 22 m. with a girth up to 1 m. breast-high above the level of the ground; in the exposed localities on Shi- kotan it only occurred as small, stunted specimens, 10 ft. high. While its growth and outward form suffer under exposure, the influence of the damp atmosphere endows it with fine, luxuriant foliage, and the transition between the normal, well-developed larch forest, and the stunted, wind-swept, but luxuriantly green shrub of the coast local- ities, may be exceedingly abrupt (MıDDENDORFF: 1867, p.606). Departing from the coastal districts inland into the mountain ranges, L. Gmelini is again found growing in the most inaccessible spots and in the very highest tree-clad regions. In the north this fact is very pronounced, the only other tree accompanying it to its highest points of growth being the low, creeping Pinus pumila; Miıp- DENDORFF has supplied an exhaustive description of this circumstance in the Stanowoj Range, especially in the district around the source of the little Ujan River, 1200 m. above sea-level (1. c. 1867, p. 616). Further south, indeed, the larch contrives to force its way high up among the mountains, but only occurs scat- tered among Abies sibirica and Pinus cembra var. sibirica at the extreme limit, which, on Sokondo, south-east of Lake Baikal, reaches 2000 m. above sea-level (RADDE in BAER & HELMERSEN: Beitr. Kennt. Russ. Reich. XXIII, 1861, pp. 468—472. Vide Mıppr. 1867, p. 622). L. Gmelini is thus the dominant tree, outnumbering all others far northwards out upon the flat, wet tracts, and in part also, upon the upper tree-clad mountain regions, and, finally, outwards to the coast, but it by no means The Species of the Genus Larix. 47 attains its best development in these localities. The protected spots on the slopes of vallies with the fresh, well-drained soil are those where the finest examples are found, even though they appear to demand a greater degree of humidity on the more southerly than the {more northerly situated localities (Maxim. 1859, pp. 393—394, and Mippr. 1867, p. 540). The fact that L. Gmelini is most common in localities shunned by other trees, is in agreement with its light- loving characteristic. It may be expressed as follows: it is excluded from richer soil by coniferous trees more tolerant of shadow (Abies sibirica, A. sachalinensis, Picea obovata, P. jezoensis, P. Glehnii, Pinus silvestris, P. cembra var. sibirica, and P. pumila), and is only deserted by them under the most unfavourable growing conditions, which the larch has greater capabilities of withstanding than the other species. Pinus pumila is its closest competitor, and may perhaps even be said to surpass it with regard to the elevalions at which it can exist. TRAUTVETTER’S first detailed description of L. Gmelini with illustrations is based upon specimens collected by MIDDENDORFF near Novaja at lat. 72'/2° N., and thus ori- ginates from „Die an der äussersten Baumgränse stehende Lärche des Taimyrlandes”, as MippENpDORFF himself ex- presses it (l. c. p. 748, Note), that is to say, from the same region as MIDDENDORFF’sS illustration (reproduced here) of the most stunted specimen. A just estimation of L. Gmelini as a valuable forest tree widely distributed in Eastern Siberia, and not merely as a dwarf growth on the forest-line towards the Polar Sea, as Mayr still regarded it when he described the larch on the Kurile Islands (Mayr: 1890, p. 99), has been arrived at from the descriptions given by Mippenporrr himself, and from the accounts of 48 Nr. 2. C. H. OSTENFELD and C. SYRACH LARSEN: Maxımowicz, Fr. SCHMIDT, WILSON, MIYABE & Kuno, Okana, and others. Beyond varying in its form of growth, L. Gmelini evinces certain modifications in other particulars, but never to such an extent as to warrant their not being included under one species within the limits adopted in the present paper; it must, nevertheless, be regarded as one of the most variable species £ of the genus Larix. The cones may vary in size from quite short (1 cm. or less Fig. 14—15) to almost double the size (2 cms.), but all possess the characteristic straight cone- scales, not incurved, but rather sligthly recurved, truncate or Fis: 14 L Gmelini. (Rupr.) Gordon, small coned (so-called L. kurilensis from cultivated tree. Denmark, Egelund plantation 1923. (Nat. Mayr). Cones size, upper row dry, lower emarginate at the free edge. The straight cone-scales give the cone a characteristic appearance of lightness, specially pronounced row wet.) in the case of dried specimens. The one-year’s shoots vary from reddish-brown to light coloured, and their degree of pilosity, often very pronounced, varies likewise, and may be completely absent. Reddish- brown and distinctly pilose shoots are stated by Mayr as being characteristic for the larch on the Kurile Islands, and this was generally accepted, until the exhaustive investigations of MıyaBE & Kuno (1920, p. 24) showed that this fact alone did not warrant the differentiation between the larch on the Kurile Islands an that on Sachalin. Mayr also described the larch on the Kurile Islands as possessing purple-red female cones when flowering, but MıyABE & Kuno, in common with Wırson, have shown that the flowers of The Species of the Genus Larix. 49 the Larix on the Kurile Islands and Sachalin were not constant in colour, but that the bright, green colour could also occur (MıyaBE & Kuno: Plate 7; and f. ochrocarpa, Wırson 1916). It is possible that the one-year’s shoots of the larch in Kamtschatka, the Kurile Islands, Sachalin, Fig. 15. L. Gmelini (Rupr.) Gordon. Cones from cultivated specimens. Denmark, Forestry Botanical Gardens, Charlottenlund, 1922. (*/s nat. size, upper row dry, lower row wet). Skantar, other lesser islands, and tracts of coast of the mainland, are rather more reddish-brown, and that the colour of the female cone is more often red there than in other localities, but there is not sufficient basis to warrant this larch being classed as a separate variety, and still less for the retention of a distinct species, viz., L. kurilensis Mayr. There is likewise no reason for separating Mayr’s L. Cajanderi from L. Gmelini. The “dichter weissgelber, lockiger Haarschopf”, which appears simultaneously with the new leaves, has the same form as that described for the cone- scales of L. Gmelini, and there is no deviation in other particulars. Mayr stated that is was found scattered among L. Gmelini, along the course of the Lena, from the outlet Vidensk. Selsk. Biol. Medd. IX, 2, 4 50 Nr. 2. C. H. OSTENFELD and C. SYRACH LARSEN: of its tributary, the Aldan River, and still farther northwards, L. Gmelini occurring alone to the south of it. Mayr based his opinion upon material collected by CAJANDER in the course of his journey along the Lena from its source to its estuary; but CAJANDER himself described all the larches along the lower course of the Lena as L. Gmelini. Comparing Mayr’s illustration of L. Cajanderi (Fremdl. Wald und Parkb. 1906, Fig. 88) with TRAUTVETTER’S L. dahurica (Pl. Imag. Descrip. Fl. Russ. Ill. Fasc. 7, 1846, Plate 32), one may well go so far as to say that Mayr’s specimens represent a very typical L. Gmelini; it originates, moreover, from a northerly locality (North of lat. 63° N.) similar to that from which TRAUTVETTER derived his material (lat. 72'/2° N.). — L. Gmelini is stated to have been introduced into Europe in 1827, and put into culture in Denmark in 1889 (or earlier), where attempts have been made to utilise it in the forests (A. OPPERMANN: 1923, p. 271). To judge by its occurrence on the cold, foggy coasts of the sea of Ochot, it is reasonable to suppose that it possesses forest-forming capabilities in other unfavourable localities, of which we have a pronounced example in the Faeroe Islands. Besides the variations which we do not think are worth keeping as special varieties (L. kurilensis and L. Cajanderi), the species-complex L. Gmelini has two geographical varieties of more systematic value, viz., var. olgensis and var. Principis Rupprechtii, both of which occur south of the area of occurrence of the real L. Gmelini. Herb. Mat. examined: Ad. fluv. Boganida 72'/2°, MippENDoRFF (Hort. Bot. Haun.); type col- lection to L. dahurica. — Sib. Orient. Udskoi, Exp. Acad. 1844 (Kew). — Ochotsk Sea, C. WRIGHT, Coll. U. S. Explor. Exp. 1853—56 (Kew). — Amur, Maximowicz, ex Herb. Hort. Petropol. — Maximowicz, Iter secund, 1860. Manchuria austro-orient. ad. fontes fluv. Fundim (Kew). — Manschur. The Species of the Genus Larix. o1 austr. orient. ad Usuri sup., c. 1860, Maximowicz (Brit. Mus.). — Jap. Hakodate, cult. Maximowicz, Iter secund. 1861. — (Kew) Dr. ALBRECHT, Jap. Ins. Jezo circa Hakodate, 1861 (Kew). — Sachalin, Fr. SCHMIDT (Kew). — Ad. flum. Kolyma, leg. AuGustimowicz (Kew). — Sibiria, ScHOCKLEY, 1900, a) Cape Suffein b) Turumcha Crest (Brit. Mus). — Kaborowsk, C. S. SARGENT, 1903 (Kew). — Border of swamps near Srychensk, C. S. SARGENT, Aug. 1903 (Arn. Arb.). — SacHauın, 1907, FAURIE (Brit. Mus.; Arn. Arb.). — V. Komarow, Iter Kamtschatic. secund. leg. V. Komarow, No. 247, 1909 (Kew). — Kamtschatka, V. Komarow, Iter Kamtsch. secund. 1909 (Kew). — Prov. Transbaicalia, sept. lacus Baical. Herb. Fl. Ross. 1912 (Hort. Bot. Haun.). — Sachalin, 1914, E. H. Wırson, No. 7364 (Brit. Mus.). — Sachalin, 1914, E. H. Wırson No. 7331: L. dahurica var. japonica f. ochrocarpa, Wırson (Brit. Mus.). — Tschapina, Nikolki, Kamtschatka, leg. R. Maraıse, 1921, Svenska Kamtschatkaexp. No. 3468 (Hort. Bot. Haun). — Open country near Togoliara shrine, Sachalin, 1914, E. H. Witson, No. 7333 (Arn. Arb.). — Cult. HEINRICH Mayr, Grafrath, Bayern, 1927, C. SyracH Larsen (Hort. Bot. Haun.). — Det forstlige Forsogsvesen, Egelund Planteskole, Denmark. — Copenhagen, Bot. Gardens. — Forestry Botan. Gardens, Charlottenlund, Denmark. 7 b. Larix Gmelini, var. olgensis (Henry 1915) Ostr. & Syracu L., in Pflanzenareale. II. 7. 1930. Syn.: Larix sibirica, Maxımowiıcz, 1860, in herb. et apud KomMArow, in Act. Hort. Petrop. XX, 1901, p. 194. — PATScHkE in Engl. Bot. Jahrb. XLVIII, 1913, p. 692. — Non LEDEB. Larix dahurica, KoMARow, in Act. Hort. Petrop. XX, 1901, p. 190. — Nakal, in Journ. Coll. Sci. Imp. Tokio, 1911, p. 382. — Non TRAUTV. — Larix olgensis, HENRY, in Gard. Chron. 27. Febr. 1915, and in Trans. Roy. Scot. Arb. Soc. 1915, p. 147. — Komarow, in Act. Hort. Petrop. XXXIX, 1923, p. 23 et 126. — DALLIMORE & Jackson: Handb. Conif. 1923, p. 295. — Larix koreensis, RAFN, nomen nudum, in Tidsk. f. Skovv. XXVII, 1915. — O.G. PETERSEN: Forstb. 1920, p. 247. — A. OPPERMANN in Det forstl. Forsogsv. i Danmark, VII, 1923, p. 273. — Larix dahurica, var. koreana, NaKkaï, in Tozawa & NAKAI, Atlas ill. geogr. Distrib. of Korean woody Plants & Bambo os. 1.1. 1929. In 1860, Maximowicz found a larch near Olga Bay on the coast of the Amur district, which he classified as L. 4* 52 Nr. 2. C.H. OSTENFELD and C. SyRACH LARSEN: sibirica. It was subsequently described by Henry in 1915 on the basis of the same specimens together with fresh ones from Olga Bay as a new species, L. olgensis. Map IV. ————— Larix Gmelini,[Rupr) Gord. LEERE var olgens is, (Henry) nob. Saar FN 9999 98 Prineipis Rupprechtii, (Mayr) nob, © Ty pe Locality. When constituting the new species, HENRY specially relied upon the strongly pilose one-year’s shoots, and the shape of the cone. As regards the first character, MıyABE The Species of the Genus Larix. 726406 (27) au farm avy « 9 (FN yet S2dIoutdg CS mu D you (Aauspy)*s78u2870 uva 97 ‘7 ‘A den 29242928 x zauspzun °° 00000 ‘paon [Hana 24217249 + ‘9 ‘gP27 “999479798 27407 2) 54 Nr. 2. C. H. OSTENFELD and C. SYRACH LARSEN: & Kuno have shown that this pilosity of the shoots cannot be used as characteristic for the larch at Olga Bay as opposed to L. Gmelini, having found on Etorofu examples of the latter just as pilose. The cone is long with well- rounded cone-scales, giving it a certain superficial resem- blance to that of small-coned L. decidua or L. sibirica, also to L. Kaempferi; it devi- ates to such a marked extent from the hitherto-known type ofL. Gmelini, that there is warrant for supposing it to be a variety of the latter. It is found over a tract of country Fig. 16. Lariv Gme- extending from Olga Bay and Vladimir Bay lini. Rupr. var. o- southwards through Kirin and the north of gensis (Henry) Ostf. __ IT i Korea, continuing further on the peninsula, & Syrach L. Cone in natural size. (from as shown on the map (Naraı, 1911, p. Te Se 382, Tozawa & Nakai, 1929). On the Febr. 27,1915). north it passes over to typical L. Gmelini, the transition zone presumably lying in the neighbourhood of Vladivostok, but in such a manner, that L. Gmelini extends furthest to the south inland, while var. olgensis reaches furthest north along the coast. There is even a possibility that some of the large-coned Larix found on the coast around the Bay de Castries and the mouth of the Amur by Maxımowicz in 1854 ought to be classified under this variety. Maximowicz first classified it as L. sibirica, but subsequently altered his classification to L. Gmelini (Maximowicz: in Bull. Acad. St. Petersburg, XV, 1857, p. 226; Id., Prim. Fl. Amur., 1859, pp. 393— 394). L. G. var. olgensis has been cultivated in Denmark under the name of L. koreensis, Rafn, nom. nud., and has been shown to possess such good qualities, that the stock is being steadily increased (A. OPPERMANN, 1923, p. 273). The e The Species of the Genus Larix. cultivated trees show the same characteristic type of cone, the colour of the cone when flowering varying from tree to tree from red through pale pink to green; the shoots vary Fig. 17. L. Gmelini var. olgensis (Henry) Ostf. & Syrach L. Cones from cultivated specimens’. Roden forest in Denmark 1922 (*/s nat. size, two upper rows wet, two lower rows dry). from pale to a light chestnut-brown, the majority at all events appearing to be smooth. The oldest examples known in Denmark are to be found in a plantation, Roden Forest, near Aalholm (Lolland), already mentioned in the preface. 1 The method of photography in this illustration differs from that adopted in most of the others, and the specimens are, therefore, not well suited for comparison with figs. 16 and 18. 56 Nr. 2. C. H. OSTENFELD and C. SYRACH LARSEN: They were planted out in 1902 as three-year-old plants, and can be traced back to a seed-merchant in Yokohama. Herb. Mat: examined: Manschuriæ austr.-orient. St. Olga, Maxımowicz, 1860, Type (Kew); Co-type (Brit. Mus.). — V. Komarow: Fl. Manschuriæ, No. 80, 1897, Distr. Musang, trajectus Pzao-sieng, Korea sept. (Kew). — Korea, Ma-Mi- hint, F. N. MEYER, 1906, No. 169 (Kew). — Arnold Arb. Exp. 1917—18: Korea, Prov. N. Kankyo, 1917, Nos. 8948, 8962, 8977 and 9044 (Snow Mt.). Fig. 18. L. Gmelini var. olgensis (Henry) Ostf. & Syrach L. Cultivated in Denmark, Egelund Plantation, 1923. (Nat. size, upper row dry, lower row wet). Prov. S. Kankyo 1917, Nos. 9151 and 9152 (all in Kew and Brit. Mus.). Prov. N. Kankyo, No. 8893 and 9037 (Arn. Arb.) — Culta in Dania, ins. Lolland, Roden Skov (seeds sown 1899, plants coll. 1922); ins. Sjælland, Egelund (seeds sown 1914, plants coll. 1923). 7 c. Larix Gmelini, var. Prineipis Rupprechtii (Mayr 1906) Ostf. & Syrach L., in Pflanzenareale II. 7. 1930. Syn: L. dahurica, HANCE, in Journ. Bot. IV, 1875, p. 138. — BRET- SCHNEIDER, in Peterm. Mittl. 1876, No. 46, p. 37—39. — MASTERS, in Journ. Linn. Soc. Bot. XVIII, p. 522. — PATSCHKE, in Engl. Bot. Jarhb. XLVIII, 1913, p. 706. — Non: TRAUTVETTER. L. sibirica, FRANCHET: Pl. David I, 1884, p. 97. — PATSCHKE, in Engl. Bot. Jahrb. XLVIII, 1913, p. 706. — Non: LEDEBOUR. L. Principis Rupprechtii, Mayr: Fremdl. Wald- und Parkb. qn ml The Species of the Genus Larix. 1906, p. 309. — ELwes & HEXRY: Trees. Gr. Brit. and Irel. II, 1907, p. 346. — DALLIMORE & JACKSON: Handb. Conif. 1923, p. 298. — L. dahurica var. Principis Rupprechtii, (Mayr) REHDER & WirL- son, 1914, in SARGENT: PI. Wırson II, p.21 (p.p.). — REHDER, in Journ. Arnold Arb. IV, 1923, p. 121. — REHDER: Man. Trees and Shrubs, 1927, p. 52. — Hsen-Hsu Hu & Woon-YounG CHUN: Icon. Plant. Sinicarum, 1927, Pl. 1. Inhabiting an area which is now completely separated from that of L. Gmelini and var. olgensis, another variety of L. Gmelini is found, namely, var. Principis Rupprechtii. Its area of distribution extends over the mountains west and north of Peking through the provinces of Shensi and Chili. No forest is found north of the Yellow Sea. (Maps IV og V). The province of Shonking, north of the Yellow Sea, was once rich in forests, which in earlier times probably formed the link between the two now widely separated forest tracts, containing respectively L. Gmelini var. olgensis and var. Principis Rupprechtü. The separation has taken place partly in recent times, and has been caused by extensive afforestation, which in that district has produced a wide extent of country devoid of forest (W. PATSCHKE in Engl. Bot. Jahrb. XLVIII, 1913, p. 705). In 1903, HEINRICH Mayr discovered in Wutaishan, one of the most southerly localities in its area of distribution, the material on the basis of which he put forward the species L. Principis Rupprechtü. Mayr’s cones (Fig. 94 in Fremdl. Wald- und Parkb.) are very large, and present many points of difference from those of L. Gmelini. The larch which Wma. Purpom found in 1909 in the same district — near some temples in the village of Wutai — has rather smaller, or much smaller, cones (Arnold Arbor- etum Expedition to the north-west of China, 1909, No. 58 Nr. 2. C. H. OSTENFELD and C. SYRACH LARSEN: 161 a and 161 b), and together with other specimens, shows modifications towards var. olgensis. The types of the two varieties have been taken from localities lying as far apart as possible, and for this reason it is only natural that careful investigation within the Fig. 19. L. Gmelini var. Principis Rupprechtii (Mayr) Ostf. & Syrach L. China, Shansi, Wutai village (leg. W. Purdon, 1909), (large-coned). (Nat. size, upper row dry, lower row wet). radius of distribution has led to the discovery of material showing less pronounced differences than the types, but which, on the other hand, illustrate the transitional stages from the one to the other. BREITSCHNEIDER found var. Principis Rupprechti during his ascent of the mountain Po-hua-shan on the west of Peking, where, apart from its having been planted near the temple on the summit of the mountain at a height of about 2200 m. above sea-level, it was also found scattered on the slopes of the mountain (Peterm. Mittl. 1876, No. 46, pp. 37— The Species of the Genus Larix. 59 39). Mayr’s account of its occurrence in 1903 includes an isolated specimen near a temple, and some old trees on a slope of a neighbouring mountain. Together with these, the oldest, accounts, Purpom’s observations, showing that the tree has now become very rare on the mountains west of Peking (Pl. Wils. II, p. 21), give the impression of a rapidly declining tree, and one which, at any rate, is now found for the most part scattered in the higher mountain regions, 2000—3000 m. above sea-level. Neither does it appear to be a particularly tall tree, the greatest dimensions given being 20—25 m. high with a girth of 2 m. The cone is cylindrical, being longer, and possessing considerably more cone-scales, than either L. Gmelini or L. G. var. olgensis. The shape and number of the cone-scales are reminiscent of L. sibirica, with which FRANCHET also classified it on the basis of Davin’s speci- mens. It differs, however, quite distinctly from L. sibirica in its smooth, thinner cone-scales, which are not incurved along the free margin, and are more openly arranged, thus giving the cone that appearance of lightness and openness characteristic of L. Gmelini and its varieties, and which is especially apparent when dry. Mayr’s cones, which seem to be of unusual size, are 4,2—4,3 cms. in length; cones from 2400 m. above sea-level in Wutai-shan (Purpom, No. 161 b) are 2—3 cms. long, while others from 2550 m. above sea-level in the same district are only 1'/2—2'/4 cms. in length, but they are all more slender and narrower in comparison with the length than the cone of L. Gmelini. The, relatively, still larger size of the cone is the only point of difference between it and var. olgensis. The cone when flowering is red with a pale midrib in the bracts, according to Wm. Purpom’s specimens in the U. S. National 60 Nr.2. C. H. OSTENFELD and C. SYRACH LARSEN: Herbarium, but other information with respect to the colour is lacking. This larch is not found in cultivation in Denmark, where everything bearing a resemblance to it almost certainly has its origin in Korea, and belongs to var. olgensis. DALLIMORE & JACKSON (Handb. Conif. 1923, p. 298) are incorrect in citing REHDER & WILSON as the authors of the species L. Principis Rupprechtii; REHDER & WILSON were the first to classify it as a variety of L. dahurica, while Mayr must still be accounted the author of the species, if it is to be maintained as such. On the occasion of the Arnold Arboretum Expedition to the East in 1917—1918, WiLson discovered a larch with a peculiar cone,- which he has named L. dahurica var. Principis Rupprechtü f. viridis. Two trees of unknown origin have been planted near the monastery of Yutingi in Kongo- san in the province of Kogan in Korea. The cones of the specimen lying before us (No. 10508) vary in length from 2,5 to 3,5 cms., and in breadth from 2,3 to 2,6 cms. (open and dry). The cone-scales are faintly emarginate, of a reddish-brown colour, with a distinct blue bloom. The bracts are blue-black, and are visible between the cone- scales. The light, open structure of the cone characteristic of L. Gmelini and its varieties is absent; in its place there is a close, solid structure which, together with the long, cylindrical cone, is reminiscent of L. decidua. It is impos- sible to come to any definite conclusion with regard to this form; further researches on the spot and cultivation are necessary. Herb. Mat. examined: Po hua shan, China bor. 1876, BRETSCHNEIDER No. 14480 (Kew; Brit. Mus.). — Wutai shan, Wutai village, temple grounds, Shansi prov. 1909, Te en et = The Species of the Genus Larix. 61 Wo. Purpom, Arn. Arb. Exp. N. China, No. 161 a and 161 b (Arn. Arb.: U. S. Nat. Mus.; Brit. Mus.; Hort. Bot. Haun.). — Hsiae, Wutai shan, Chili, China, 1913, F. N. MEYER (Kew). — Chili, Arn. Arb. Herb. J. Hers, Nos. 2018 and 2116 (Kew). — West-Weichang, North Chili, 1909, Wn. Purpom (Arn. Arb.). 8. L. sibiriea, LEDEBOUR, Flora Altaica, IV, 1833 p. 204. CARRIERE: Trait. Conif. 1855, p. 274. — TRAUTVETTER, in Middf. Reise ‚I, 2’. 1. 1847, p. 170. — TRAUTVETTER & MEYER, in Middf. Reise, I, 2’. 2. 1856, p. 88. — HERDER, in Act. Hort. Petrop. XII, 1892, p. 101. — SARGENT: Silv. N. Am. XII, 1898, p. 3. Note. — KÔPPEN: Geogr. Verbr. Holzg. europ. Russl. II. 1889, p. 489. — Printz: Veget. Sib. Mong. Front. 1921, p. 112. — ELwEs & HENRY: Trees, Gr. Brit. and Irel. II, 1907, p. 374. — REHDER: Man. Trees and Shrubs, 1927, p. 51. Syn: Pinus Larix Europe, PALLas, Fl. Ross. I, 1784, p. 1, Tab. 1, ona. B EC. — Pinus intermedia, FISCHER, in Schtschagl. Anz. f. Entdeck. 1831 (nomen nudum). — TURCZANINOW, in Bull. Soc. Imp. Nat. Mosc. XI, 1838, p. 101 (nomen nudum). — L. europaea var. sibirica, Loupon: Arb. & Frut. Brit. IV, 1838, p. 2352. L. intermedia, TURCZANINOW, in Bull. Soc. Imp. Nat. Mosc. XI, 1838, p. 101. (nomen nudum). — K. Kocu: Dendrol. 1873, p. 260. — Abies Ledebourii, RUPRECHT in Beitr. Pflanz. Russ. Reiches, 2 Lief. 1845, p. 56. — Pinus Ledebourii, ENDLICHER: Syn. Conif. 1847, p. 131. — L. decidua var. Rossica, HENKEL & HOCHSTETTER : Syn. Nadelh. 1865, p. 132. — REGEL in Gartenfl. XX, 1871, p. 101, and in Act. Hort. Petrop. I, 1871, p. 157. — L. decidua, var. sibirica, REGEL, in Gartenfl. XX, 1871, p. 101, and in Act. Hort. Petrop. I, 1871, p. 156. — Korsuinsky, in Mém. Acad. Imp. Sci. Mosc. 8’ Ser., VII, 1898, p. 493. — L. Rossica, TRAUTVETTER, in Act. Hort. Petrop. IX. 1884, p. 212. We have seen the manner in which L. Gmelini occurs in Eastern Siberia; L. sibirica presents the parallel in Western Siberia and the north-east of Russia, where it is a common forest tree. Its area of distribution extends unbroken from Lake Baikal in the east to the White Sea, 62 Nr. 2. C. H. OSTENFELD and C. SYRACH LARSEN: terminating in the west quite near to Lake Onega (CAJANDER). Its most northerly point reaches Jenisej, where, according to SCHEUTZ (1888, p. 41), it is to be found right up to the Arctic Sea (see under L. Gmelini in this paper, p. 40). From this point, lat. 69°—70° N., it may be found growing everywhere southwards to the Altai Mountains, and the area reaches its southern extremity in two isolated localities a little more to the south on the southern slopes of the Sair Mountains at lat. 46°—461/2° N. and near lat. 45° N. (Price & Simpson in Journ. Linn. Soc. Bot. XLI, 1913, p. 444). On the south-east point of the Kola peninsula there is an isolated, presumably wild, specimen. It is about 31/2 m. in height, and is supposed to be more than 150 years old. It is situated 3 km. from the sea, and 2 km. from Ssosnowka (TOLMATCHEW in Sy. Bot. Tidskrift, 1925, p. 523)! (See Map V). The border-line of its occurrence has been drawn on the map according to several different sources. In European Russia, KouznETsov’s revision of KÔPPEN’s map has been adhered to in the main (Körren; Geogr. Verb. Holz. 1889, Map IV, and KouzneETtsov in “vol. jubil. a I. P. Boropin” 1927) (see our Map VI), and also Bromovıst (Finsk Forstf. Medd. 1887, pp. 152 and 153). Towards the east, more particularly north of the Urals, the line has been extended farther out towards the Arctic Sea in agreement with MinDENDORFF (Midd. Reise, IV, Part I, p. 531), who gives the most northerly point of occurrence in Europe as being about the source of the Kara in the extreme north of the Urals at lat. 68° N. Further eastwards, the boundary is likewise MIDDENDORFF’S (l. c. pp. 531—532), and has only been moved close to lat. 70° N. near Jenisej, as already stated, in conformity with SCHEUTZ, MIDDENDORFF having placed it a little more to the south, attributing the occur- The Species of the Genus Larix. 63 Larix sibirica, Leds. From: Kouznelsov. (927. Cajande r, 1900. Tolmatehe w, (925. Map VI. rences of larch in the extreme north to L. Gmelini (for which we refer to L. Gmelini). Towards the east, it is bounded by the belt of intermediate forms, also mentioned under 64 Nr. 2. C. H. OSTENFELD and C. SYRACH LARSEN: L. Gmelini (L. Czekanowskiü, SZAFER), and we find the reports of the most easterly occurrence of L. sibirica within this belt, where CAJANDER found it on the Lena almost as far east as Oleminsk (Act. Soc. Sci. Fen. XXXII, No. 3, p. 8). In a southerly direction, it has been collected in the forest east of Urga and north of the river Tola (C. W. CAMPBELL, 1902, Kew Herb.). In determining the borderline towards the south, we have the exhaustive reports of PRINTZ (Veget. Sib. Mong. Front. 1921), and the already- mentioned observations of PRICE & Simpson for the eastern section; but. from this point, where we are without their observations in the south of Russian Siberia, and until we reach European Russia, special investigations regarding the larch are lacking. The most probable boundary is the one given here (according to Zon & SPARHAWK: Forest Resources of the World, 1923, p. 286), as it undoubtedly everywhere constitutes one of the farthest-reaching forest outposts. Its occurrence in the Urals has been investigated by both Körren and Korsuinsky, and their observations, have been followed here. Their statement, that L. sibirica is not to be found on the western side of the Urals towards the north right up to the source of the Petschora, has, nevertheless, been somewhat modified, the boundary having been fixed at a rather less northerly point. KöPrpEn also mentions a more southerly line than Korsnınsky. The boundary line in the southern outposts of the Urals has been drawn according to KorsHinsky’s and KOUZNETZOV’S maps, which are the most detailed; the two isolated occur- rences on the south-east of the Urals are included in the general are of distribution. In the north of Russia and in Siberia, the West-Siberian larch is, as a rule, only a small tree, but along the sides The Species of the Genus Larix. 65 of the rivers, where it is protected, and where the soil is fresher, it may develop better; in the extreme north, however, where it occurs on the forest-line, only stunted individuals are met with (Mıppr. |. c.; GOREDKOv, 1926, Ref. in Bot. Centralbl. XX, 1927, p. 246). In northern European Russia, the larch does not reach the forest-line, which chiefly consists of Picea obovata, but the situation changes as it approaches the Urals, where it becomes the only tree among the forest outposts, and this continues to be the case farther east (RıkLı in Vierteljahrs- schrift, Nat. Gesell. Zürich, XLIX, 1904, p. 132; vide CAJAN- DER, 1903). The tree is of common occurrence and one of value in the entire southern area; it is seen at its best in the Urals and the mountains towards the south-east in the western part of Altai. Krassnorr (1886, Ref. in Engl. Bot. Jahrb. IX, 1888, pp. 53—67) has investigated the occurrence of the larch in the western part of Altai, and particularly discussed the problem of its natural regeneration, which only takes place with difficulty in these regions. Further towards the east in Altai, in Tannu-ola, and other portions of the extreme north-west of Mongolia, its occurrence has been described by Price & Simpson (l. c. pp. 391 - 398). The best and most recent description of the West-Siberian Larch in its natural surroundings is PRINTZ's detailed account of its occurrence and development in Tannu-ola and the Sajan Mountains and the adjacent steppes. The area is an interesting one, the larch being described in all its forms, from the highest development in the fertile, fresh mountain- soil, to its isolated, decrepit appearance on the steppes. Under the most favourable circumstances, it may attain a height of over 40 m. with a diameter of about Vidensk. Selsk. Biol. Medd. IX, 2. 5 66 Nr. 2. C. H. OSTENFELD and C. SyRACH LARSEN: 1,5 m. A warm, fresh soil is especially favourable to its srowth, and in such localities it forms more or less pure groups, while it is otherwise met with in forests scattered among Pinus silvestris, Picea obovata, Abies sibirica, and Pinus cembra var. sibirica. On the forest steppes the larch is the dominating tree. On the steppe between the Sajan Mountains and Tannu-ola, small sporadic specimens of the larch are found along the upper course of the River Jenisej. West of the Sajan Mountains, on the Abakan steppes, it is found where the ground rises in low ridges, and it also occurs along the courses of the rivers and on the small islands lying in their beds. Here it is often mingled with Pinus silvestris, birch (B. pendula), and poplar (P. laurifola, P. tremula, and P. nigra) (PRINTZ, 1921, p. 112). Good illustrations of L. sibirica are to be found in Printz’s book, and in B. A. KELLER’s paper: Im Berg und Tal des Altai I, 1914, Plate 5 (see Fig. 20). Of the other species of larch, L. sibirica most re- sembles L. decidua, of which it has sometimes been regarded as a variety (Loupon, REGEL, and KORSHINSKY). In the absence of flowers or cones, they are also diffi- cult to distinguish; their leaves are similar, although those of L. sibirica are somewhat longer than those of the latter; the light-coloured bark is another point of resemblance. Under cultivation, the young tree of L. sibirica is characterised by its crown, which is remarkably narrow, but the young tree is perhaps most easily recognised by the sweet, pleasant scent which becomes apparent under dry conditions, and which is not found in the European larch. The cone of L. sibirica is, when flowering, green, or The Species of the Genus Larix. 67 faintly rose-coloured, varying to a deeper red, in which case the colour approaches that of L. decidua. Material taken from the province of Irkutsk (Herb. Fl. Russ, 1907, Fig. 20. Larix sibirica Ledeb. Trees of good size from Altai. (From KELLER, Altai I. 1914). No. 2545), and from a forest east of Urga and north of the river Tola in Manchuria (C. W. CAMPBELL, 1902, Brit. Mus.) shows flowering cones of just such a colour, but, as a rule, they are of a lighter red, or almost green. The cone is 3—4,5 cms. long, composed of numerous scales, 30—40 in number, and is in this particular reminiscent 5° 68 Nr. 2. C. H. ÖSTENFELD and C. SYRACH LARSEN: of the cone of L. decidua or L. Gmelini var. olgensis. Its incurved cone-scales, with their inflexed free margins nevertheless constitute L. sibirica a well-defined species, and its characteristics do not appear to vary much, Fig. 21. L. sibirica Ledeb. Kuretj on the western side of Lake Baikal, in mixed forest, leg. Sukatschew, 1928. (Nat. size, upper row dry, lower row wet). although it shows some transition into L. decidua in the most westerly area of occurrence, L. decidua var. polonica being a stage approaching L. sibirica. The outer-side of the cone-scale is, moreover, faintly pilose to closely matted, chiefly at the base. At maturity, the cone-scales open more than is the case with L. decidua, but not so much as L. Gmelini, and the wing of the seed does not reach quite as far as the free margin of the cone-scale. un. The Species of the Genus Larix. 69 L. sibirica was introduced into Denmark by SCHÂFFER, and it was planted in the Castle Garden at Horsholm in 1796 (A. OPPERMANN, 1923, p. 257), but is has never become common, although it is to be found in several dendro- logical collections, and experiments are still being made with it in forestry, but on the whole it does not seem to grow well with us, and is usually strongly attacked by Dasyscypha Wilkommi. Herb. Mat. examined: Altai, LEpEBouR (Kew). — Altai (Brit. Mus.). — Sasan Gebirge, Chonna Engate, STUBENDORFF 44. (Brit. Mus.). — Little Atlim and Jum- bemjol, Siberia, c. 1880, CH. Hace (Hort. Bot. Haun.). — East Mongolia, forest E. of Urga and N. of Tola River 1902, C. W. CAMPBELL (Brit. Mus.). — Prov. Irkutsk, distr. Balagansk, in insula fl. Angara pr. Sczer- baczewa, 1907, Herb. Fl. Ross., Mus. Bot. Acad. Imp. Petropol. edit. (Hort. Bot. Haun.). — Mongol & Turkestan Exp. 1910, M. P. Price, Gloucester. Kobdo River, Mongol.; several other specimens from the same Expedition without locality (Kew). — Kasnezky, Alatau reg. flum. Tom. 1909, B. KroroTtov (Kew). — Pl. of Siberia, F. N. Meyer. Near Sajansk, S. W. Siberia, 1911 (Kew). — Pl. of Siberia, F. N. Meyer. Near Ak-selan, Altai 1911, (Kew). — St. Irkutsk, W. SukATSCHEw, 1928 (Hort. Bot. Haun.). — The Bays Kurkut and Koty, Mt. Chargana and at the village Kuretj, all on the western side of Baikal lake, W. SUKATSCHEW, 1928 (Hort. Bot. Haun.). 9. L. decidua, MILLER: Gard. Dict. 8’. 1768. K. Kocu: Dendrol. 1873, p. 258. — KIRCHNER, LOEW & SCHRÖTER: Lebensgesch. Blütenpfl. Mitteleuropas I, 1906, p. 155. — REHDER: Man. Trees and Shrubs, 1927, p. 51. — Syn: Pinus Larix, LINNÉ: Spec. Pl. 1753, p. 1001. — LEDEBoUrR: Fl. Ross. III, 1846—51, p. 672. — Abies Larix, PoıRET in LAMARcK: Dict. VI, 1804, p. 511. — L. europea, DE CANDOLLE in LAMARCK: Fl. Franc. III. 1805. p. 277‘. — CARRIÈRE: Trait. Conif. 1855, p. 276. — ELwEs & HENRY: Trees, Gr. Brit. and Irel. II, 1907, p. 349. — Beıssner: Nadelholzk. 1909, p. 311. — DALLımorE & JACKSON: Handb. Conif. 1923, p. 281. ' On the title page is given 1815, but it should be 1805; according to a note from A. DE CANDOLLE. Conf. ELWES & HENRY, Il, 1907, p. 349. Note. — 70 Nr. 2. C. H. OSTENFELD and C. SYRACH LARSEN: Larix larix, KARSTEN: Pharm. med. Bot. 1882, p. 326. — Sar- GENT: Silv. N. Am. XII, 1898, p. 3. Note. — AscHERSON & GRAEB- NER: Synop. 2’. I, 1913, p. 313. The European Larch, L. decidua, extends from Dauphiné and Provence northwards and eastwards through the Alps to a point 40—50 km. south-west of Vienna, where its main area of occurrence reaches the most extreme northwesterly point. In the north-west corner of Yugo- Slavia and the north-east corner of Italy it reaches southwards to lat. 46° N., extending to lat. 441/2° N. in the west (WILLKONM: Forstliche Flora, 1887, p. 144), and probably even a trifle further southwards to between lat. 44*/2°—44° N. It also occurs spontaneously towards the north-east in the southern district of the Sudetic Mountains and Tatra, and there may be two isolated localities in the Transylvanian Alps. The occurrence of the larch in the French Alps has been mentioned sufficiently frequently (GRENIER & GODRON: Fl. France, III, 1855, p. 156; HONORÉ ARDOINE: Fl. Alp. Maritim, 1867, p. 346; Rouy: Fl. France, XIV, 1913, p. 359), but a detailed description, such as, for example, Curist’s account of the species in Switzerland, is wanting. It is found in Savoy, Dauphiné, and in the Provincial Alps and no doubt extends somewhat into the Maritime Alps, its southern limit being probably, as already stated, between lat. 44° and 44'/2° N. BRIQUET's account of the larch in the French Alps which approach the Lake of Geneva (BRIQUET in Ann. Conserv. & Jard. Généve, III, 1889, pp. 46—146), indicates an occurrence in larger or smaller quantities at an elevation of 600—1800 m. above sea-level, and points to the fact that the natural forests have been greatly over-exploited, and finally, that it is The Species of the Genus Larix. 71 partly being superseded by other kinds of trees. In all probability, a similar state of affairs holds good for its distri- bution in a southerly direction, where it is nevertheless found growing higher up in the mountains: Thus it is found forming dense woods at an elevation of 2300 m., and can be seen in small groups as high as 2400—2500 m. above sea-level (FLAHAULT in Coste: Fl. France, I, 1901, and in Rev. Eaux et Foréts, 1901). The border-line of distribution in the present paper has been drawn in accordance with Curist’s map of the occur- rence of the larch in Switzerland (Curist: Pflanzenl. Schweiz, 1879, Map II), and is continued in an easterly direction in conformity with the statements of KERNER and CIESLAR (KERNER: Pflanz. Donauländer, 1863, and CıEsLar in Cen- tralbl. Forstw. 1904, pp. 2—9). Of these the latter is one of the most recent and detailed descriptions of the geo- graphical distribution of the European Larch, and is the work which has been most closely adhered to here. The small area of occurrence north of the Danube near Pögg- stall and Jaurling has, nevertheless, been included on the authority of KERNERS' positive statement that it grows wild in this locality (KERNER: I. c. p. 158). The area of distribution in Czeko-Slovakia on the south-easterly frontier of Bohemia, and the south-easterly portion of the Sudetic Mountains, is drawn according to CIESLAR and HAyEK (HAYEK: Die Pflanzendecke Österr. Ung. I, 1916). Hayek remarks, that it is hardly possible to define with any degree of certainty the area of distribution where the larch grows wild, and the same is undoubtedly the case with regard" to the other area on the Bohemian frontier. There appears, however, to be no doubt that the larch exists in the wild on 74 Nr. 2. C. H. OSTENFELD and C. SYRACH LARSEN: state in both these areas; the only point of uncertainty is the extent of the two localities in question. Of the two smaller localities still further eastwards, the most southerly lies in Tatra, where the larch occurs scattered on the slopes towards the valley of the Waag (CIESLAR: l. c. p.4; Hayek: l. c. pp 343 and 395; and SAGORSKI and SCHNEIDER: Fl. Centralkarpathen, I, 1891, p. 569). The forest-line here is formed of stunted larches, which in the, highest parts grow at an elevation as high as 2000 m. above sea-level. The other locality north-west of Tatra lies in Babia göra on the frontier between Czeko-Slovakia and Poland (VIERHAPPER in Oster. Bot. Zeitschr. LXI, 1911, p. 229. Vide CIESLAR in Centralb. ges. Forstw. XL, 1914. p. 182, Note). Beyond the area of distribution mentioned here, L. decidua has also been reported far out towards the south-east in the Transsylvanian Alps, where Hayek cites two localities, one to the south (see Map VII), and the other to the west of Kronstadt, in the Cibin Mountains, where it is found in the neighbourhood of the Zood valley at an elevation of 1400 m. above sea-level and upwards. The first-mentioned locality has also been described by Maack (Zeitschr. Forst. Jagdw. XXXVI, 1904, p. 644), who gives a detailed account of forest remains, including specimens of considerable dimensions in the mountains, growing at altitudes from 1300—1600 m. above sea-level, and mentions that timber for the castle at Sinai was fetched from this spot. The larch in both these localities is undoubtedly the original species; the only point not decided being whether the tree is the typical L. decidua, as there seem to be reasonable grounds for believing that it may be L. d. var. polonica. The colour of the young shoots and the colour of the 1 O1 The Species of the Genus Larix. leaves is reminiscent of the West-Siberian Larch, which, in the coneless state, is most easily distinguishable from L. decidua by the scent of dried specimens, absent in the case of the latter, as mentioned under L. sibirica. The young shoots are smooth and yellowish, the leaves 2—3 cms. long, of a fresh, green colour. The bracts, which are of a deep purple-red are, during the flowering season, much longer than the green, or faintly red, cone-scales, which they entirely cover. This purple-red colour is absent from the bracts only in exceptional cases, the whole female cone being then green or whitish instead. The last-mentioned form (flore albo, Loudon, 1838) is found in Wallis, the Engadine, and in the neighbourhood of Flühelen in Switzer- land (Curist: 1. c. p. 225; AscH. & GRAEB. I. c. p. 314). The cone is long and cylindrical, consisting of a large number of scales — 30 to 40 — and is generally 2,5—4 cms. long, but specimens as long as 6 cms. have been collected by Coaz in the Münster valley at Graubünden (BEıssnEr: 1909, p. 312, Note). The cone-scales are straight and thin at the free margin, which is broad and rounded, or slightly incurved. The seed-wings are as long as the cone-scales, and reach their extreme edges, so that they are, relatively, a trifle longer than in the case of L. sibirica. The exterior of the cone-scales is smooth or pilose, but seldom so pro- nounced as in the case of L. sibirica, and the bracts of the mature cone are visible at the extreme base of the cone, being wholly covered on the other parts. During the younger period of growth, the tree is pyra- midal in shape, but the appearance becomes less pronounced the older it becomes. The bark of old trees becomes furrowed, and sheds in larger or smaller plates, thus exposing por- tions of the reddish-brown inner bark. The heart-wood is -n 16 Nr. 2. C. H. OSTENFELD and C. SYRACH LARSEN: handsome, strong, and of great durability; its value is further increased by the trunk being frequently straight, Fig. 22. L. decidua Mill. Cones of cultivated specimens from Denmark, 8 different collections (”/4 nat. size, all wet). and often attaining considerable dimensions. The greatest height observed is presumably 53,7 m., or perhaps a trifle higher (OPPERMANN: 1923, p. 216; vide ELwEs & HENRY: II, 1907, p. 349). The corresponding diameter was 1,1 m., I I The Species of the Genus Larix. which indicates a well-formed tree, but far greater girths combined with less height have been observed. Fig. 23. L. decidua Mill. Cones of cultivated specimens from Denmark, 8 different collections. (”/4 nat. size, the same cones, all dry). L. decidua often varies in its growth, and several well- pronounced forms have been found — pendulous, globular, and so on —. CıesLar has differentiated the larch found in the Sudetics as a separate form with more slender trunk 78 Nr. 2. C. H. OSTENFELD and C. SYRACH LARSEN: and crown, thinner branches, later leafing, and earlier fall (CIESLAR: 1. c. 1914, pp. 171—174; vide SCHREIBER in Cen- tralb. ges. Forstw. 1921, p.p. 1—30 and pp. 76—99), and the larch which has been grown in Scotch forests for the last two hundred years is also regarded as a separate form with good qualities from the forestry point of view (G. SCHOTTE, 1917; A. OPPERMANN, 1923). The height of 53,7 m. with a corresponding diameter of 1,1 m. was found at Jägerndorf in the south of the Sudetic Range, which shows it to have been discovered within the area indicated by CIESLAR as being the district for the good Sudetic Larch. The European Larch is one which has been cultivated for a long period; it was introduced into Danish forests by v. LANGEN in 1763, or even perhaps in 1745, and is nowa common forest tree. One of the finest plantations is to be found in Tinghus Plantation in Grib Forest. It originates from 1777, and in 1923 the largest tree had attained a height of 34,5 m. with a girth of 85,5 cms. 1,3 m. above the level of the ground, this and other trees in the plan- tation being of particularly good shape (A. OPPERMANN, 1923). Herb, Mat. examined: Numerous cultivated specimens from Denmark, Sweden, Norway, Scotland, North America etc., in different herbaria. 9 b. L. decidua, var. polonica (Racızorskı 1890) OSTF. & SyracH L., in Pflanzenareale II. 7 1930. Syn: L. polonica, RACIBORSKI: Kilka slow omdrzewiu w Polsce, (Einiges über die Lärche in Polen) 1890, and in Z. Woycıckt: Obrazy reslinnosci Krolestwa Polskiego (Vegetationsbilder aus dem Königreich Polen) 1912. — SZAFER, in Kosmos XXXVIII, 1913, p. 1298. — SUKATSCHEWw: Entwicklungsgeschichte der Gattung Larix in Lesnoje Djebo 1924 (Ref. in Bot. Centralb. V, 1925, p. 297). L. europea, KüPPEN, Geogr. Verb. Holzgw. europ. Rusl. II, 1889, p. 484—487. — ASCHERSON & GRAEBNER: Synop. mitteleurop. Fl. 1, I, 1897, p. 203. — ELwes & HENRY: Trees, Gr. Brit. and Irel. II, 1907, p 352—353. — Non D.C. The Species of the Genus Larix. 19 L. sibirica, CziHak & SzaBo in Flora, 1863, p. 278. — JANKA, in Oestr. Bot. Zeitschr. 1868, p. 665. — Kanıtz: Pl. Roman. 1879—81, p. 139. — Branpza: Prod. Fl. Roman 1879—83, p. 433. — GRECESCU: Consp. Fl. Roman. 1898, p. 539. — Pantu & PROCOPIANU-PROCOPO- vıcı, in Bull. Herb. Inst. Bot. Bucarest, 1901, p. 131. — HORNUZAKI, in Oestr. Bot. Zeitschr. LXI, 1911, p. 407. — VIERHAPPER, ibid, 1911, p. 228—231. — AscHERSON & GRAEBNER: Synop. mitteleurop. Fl. 2’. I, 1913, p. 314. — Propan: Fl. Roman. I, 1923, p. 29. — Non Ledeb. Outside the area of distribu- tion hitherto treated of, the European Larch appears also in Poland as a special race. Körren has given a detailed Fig. 24. Larix decidua Mill. var. polonica (Racib.) Ostf. & Syrach L. Cones of the typical (KôPPEN: lI. c. II, 1889, pp. 484 form. Nat. size. (From Szafer 1913). description of its distribution —487), and has also cited some localities where fossil remains are found, north and east of the existing remnants of the primitive larch forests in Poland, thereby proving that the larch enjoyed a wider distribution in prehistoric as well as early historic times than it does at the present day. All these forests of wild larch, however, were classified by KÔPPEN as well as by all other botanists of an earlier date as L. decidua, until Racısorskı in 1890 showed that the larch from the old Polish stock differed morphologically from the typical European Larch, and bore a close resemblance to L sibirica, for which reason he classified it as an independent species, L. polonica. SZAFER in 1913 went closely into the question regarding the justification of its being regarded as an independent species, and gave the first detailed description of its charac- teristics, at the same time examining it on the spot. The result of his observations convinced him, that the classi- fication was justified, and that its systematic characteristics 80 Nr. 2. C. H. OSTENFELD and C. SYRACH LARSEN gave it a place between L. decidua and L. sibirica. With regard to its distribution, he showed that the larch in Tatra and Babia göra (West Beskiden) in reality is true L. decidua, while on the contrary, the larches found in the wild state on the north-east of this locality in Poland all belong to the Polish Larch. Its intermediate position between the other two European representatives of larch is clearly shown by material from its natural habitat, and from SzAFER’s analysis of the flowers and cones (SzAFER: |. c. Plates I and III). The shape of the cone is strongly remini- scent of a small-coned specimen of L. decidua, but the cone- scales are more rounded, resembling those of L. sibirica, and less emarginate at the free margins than those of L. decidua. The cone is truncate like that of L. sibirica, and not so pointed as that of L. decidua. The reason for the cones being, as a rule, small, may possibly be, that they are taken from very old trees. It seems to be a fact that the cone of var. polonica is smaller than that of either L. sibirica or L. decidua. SzAFER differentiates two types, f. typica, and f. pienina, the former of which has completely rounded cone-scales, those of the latter having a slight emargination, thus resembling L. decidua. He further differ-. entiates between two forms according to the colour of the flowering cone, namely, f. rubriflora and f. viridiflora, so that both colours can occur here just as in the case of the European Larch: but the green colour, which is the exception with L. decidua, is described as common in the case of the Polish Larch. As far as it is possible to judge from well preserved material and SzaArEr’s detailed treatment, there do not appear, however, to be sufficient grounds for maintaining it as an independent species, as its close resemblance to The Species of the Genus Larix. $1 Fig. 25. L. decidua var. polonica (Racib.) Ostf. & Syrach L. A very old tree in Chedmowa Gora reservation in Poland (photo. by W. Szafer). L. decidua makes it more natural to consider it as a variety of the latter. L. d. var. polonica is only found in the remains of forests, and then as a rule only in small groves. Most of Vidensk. Selsk. Biol. Medd. IX, 2. 6 82 Nr. 2. C.H. OSTENFELD and C. SYRACH LARSEN: the specimens are old individuals, and young trees are not common. The photographs kindly sent by SZAFER certainly bear witness to trees of considerable size, but unattractive in shape (Figs. 25 and 26). The first plantations visited by Racı- BORSKI are said to have been very beautiful, and CIESLAR was Fig. 26. L. decidua var. polonica (Racib.) Ostf. & Syrach L. Natural forest, Chedmowa Göra reservation, Poland. (photo. by W. Szafer). thus induced to suggest a trial with the Polish Larch in forest culture, as he thought it would prove to have the same valuable properties as the larch in the Sudetics (CIESLAR IL. c. 1914, pp. 182 and 183). The systematic position of the Polish Larch having been demonstrated, as an intermediate form between the European Larch and the West-Siberian species, a possibility is obtained of being able to explain the systematic position of the larch in its spontaneous occurrences in Rumania, where it has been classified alternately as L. decidua and L. sibirica, but the question is still incapable of a full explanation. The Species of the Genus Larix. 83 In Rumania as it is at present, the larch is cited as occurring spontaneously in five different localities; WILLKOMM has mentioned a sixth near Bistritz (l. c. 1887, p. 144), but mt] iw ’ - Y +9 € EUR RU y; N Fig. 27. Larix decidua var. polonica (Racib.) Ostf. & Syrach L. Poland, Chelm at Nowa Slupia. (From Szafer 1913). this has never subsequently been confirmed, and is therefore not taken into account here. WiLLKomm thought it probable that the European Larch reached its extreme south-easterly limit in the districts round Kronstadt, but CıesLar did not consider that sufficiently reliable evidence of its occur- 6* 84 Nr. 2. C. H. OSTENFELD and C. SYRACH LARSEN: rence east of Tatra had been produced. Our own opinion is that ihe five localities mentioned here can be relied upon. As already mentioned (p. 74), the two most southerly localities are those cited by Hayek, and classified as L. decidua, namely, the Cibin Mountains and the mountains to the south of Kronstadt, and as we have no material at our disposal regarding these two localities, they must for the present be regarded as L. decidua, even though their geographical position renders it probable that they may belong to L. decidua var. polonica; the three localities in the north must, in fact, be classified with this variety (see Map VII). The facts regarding these three localities are as follows: CziHak & SzaBo make a reference to L. sibirica in Rumania in 1863 (Flora 1863, p. 278), and in 1868 JANKA gave a detailed description of his discovery of L. sibirica at Ceahlau (Ostr. Bot. Zeitschr. 1868, pp. 365, 366). These statements as well as others of still older date (1835 and 1842) are quoted by Kanirz in support of the discovery of L. sibirica in Moldavia (Kanıtz: Plantas Romaniae, 1879—81, p. 139). Later Rumanian botanists as well as others are agreed that the tree is L. sibirica (BRANDZA, GRECESCU, PANTU & PROCO- PIANU-PROCOPOVICI, HORNUZAKI, VIERHAPPER, and PRODAN). Other botanists have had doubts as to its being L. sibirica (Ascus. & GRAEBN. 1897, and Erwes & Henry, 1907). ASCHERSON & GRAEBNER, having in their first edition adopted a sceptical attitude, state in the second edition, that they are now satisfied that the tree in question was the true L. sibirica. The light-coloured flowering cones and their pilosity have been specially quoted as being an indication that the tree found at Ceahlau in Moldavia (the most south-easterly ————— ss m ic The Species of the Genus Larix. 85 of the three Transylvanian localities where var. polonica occurs), and in Bukovina near Krasna-Ilska (the most north-easterly), is L. sibirica, but this is insufficient for classifying them as such. Specimens in the Fl. Roman. exsicc. No. 331 b (Kew.; Brit. Mus.; Hort. Bot. Haun.) show that the larch at Ceahlau belongs to the intermediate type between L. decidua and L. sibirica, and the same is the case with the specimens (No. 331 a) from the Transylvanian district, Turda-Aries, Trascau, 1924. The last-mentioned locality lies a little to the south-west of Klausenberg (the most south-westerly of the three Transylvanian localities for var. polonica). The larches at Ceahlau and near Turda must accordingly be classified as L. decidua var. polonica, and the third locality just to the north of them in Bukovina should undoubtedly receive the same classification, while the classification of the two southern localities remains an open question until material comes to hand. Herb. Mat. examined: Fl. Roman. exsicc. Nos. 331 a and 331 b (Kew; Brit. Mus.; Hort. Bot. Haun.). — Forest of Maijouv, near Kielce, Poland, 1921, A. Henry (Herb. A. Henry, Dublin). 10. L. laricina (Du Roi, 1771) K. Kocn: Dendrol. 1873, p. 263. — BRITTON & Brown: Ill. Fl. U.S.& Canada, I, 1913, p. 60. — SuDWORTH in Bull. Agric. No. 680, 1918, p. 3. — SARGENT: Man. Trees. N. Am. 2’ed. 1921, p. 31. — REHDER: Man. Trees and Shrubs, 1927, p. 52. — Syn: Pinus laricina, Du Roı, Observationes Botanicae, 1771, p. XLIX. — WANGENHEIM: Beytr. Nordam. Holz. 1787, p. 42, cum icon. — P. Larix Americane, ParLas: Fl. Ross. I, 1784, p. 2. Tab. 1, Fig. E. — P. intermedia, Du Roı: Harbk. Baumz. II, 1800, p. 114. — > a * 86 Nr. 2. C. H. OSTENFELD and C. SYRACH LARSEN: Larix americana, MıcHaux: Fl. Bor. Am. II, 1803, p. 203. — REGEL in Gartenfl. XX, 1871, p. 105 et in Act. Hort. Petrop. I, 1871, p. 160. — SARGENT: Silv. N. Am. XII, 1898, p. 7, cum icon. — Pinus microcarpa, LAMBERT: Genus Pinus, I, 1803, p. 58, cum icon. — PursH: Fl. Am. Sept. II, 1814, p. 645. — Larix microcarpa, DESFONTAINES: Hist. Arb. II, 1809, p. 597 — CARRIERE: Trait. Conif. 1855, p. 275. — Gorpon: Pinetum, 1858, ty ee Pinus pendula, Pursu: Fl. Am. Sept. 1814, II, p. 645. — HooKEr: Fl. Bor. Am. II, 1840. — DE CANDOLLE: Prodr. 1848. — Non So- LANDER. — Larix pendula, MACNAB, in Quart, Journ. Agric. V, 1834—35, p. 601. — Hooker: Fl. Bor. Am. II, 1840. — Non SALISBURY. — L. intermedia, LAwson & Son, in Agric. Man. 1836, p. 389. — L. decidua var. americana, HENKEL & HOCHSTETTER: Syn. Nadelholzk. 1865, p. 133. — L. alaskensis, W. F. WIGHT, in Smiths. Misc. Coll. L. 1907, p. 174, Tab: XVII. — The small-coned American Larch has a very wide area of distribution. The boundary-line extends unbroken from the extreme east of Newfoundland westwards over Canada and the northern U. S. A. to the Rockies, and north-west to the mouth of the Mackenzie River. From this point there is a gap in the line from the water-shed in the northern spur of the Rockies to the interior of Alaska, where it re-appears along the banks of the Yukon River, its tributaries, and lesser streams. The most northerly point is situated at the mouth of the Mackenzie, and a little to the east at the Anderson River; it nearly, buth never quite, reaches lat. 70° N. (see Map VIII). The most south- erly localities lie to the south of the Great Lakes, reaching lat. 40° N. south of Lake Michigan, and a trifle more southerly nearer east (about lat. 39° N.). Supworrn’s state- ments regarding its occurrence on the extreme north of the coast of Labrador right up to Baffin Land (U. S. Bull. The Species of the Genus Larix. 87 Agric. No. 680, 1918, Map 7) are very improbable, and we have been unable to discover any evidence in support of them, either in the shape of other records or specimens from Baffin Land. Within such wide bounds, it is only natural that the tree should vary somewhat in growth from the good to the poor localities, and from south to north, but it seems otherwise to be a very uniform species, varying but little morphologically. It attains its best development on well- drained ground around the Great Lakes, but here, just as elsewhere within the wide bounds of its occurrence, it is not the dominating tree where the soil is richer and also appeals to other more shadow-enduring species. Most frequently it will be found relegated to low-lying, damp soil, where other trees cannot follow it, and also in the extreme north it becomes the dominating tree. It succeeds in thriving and forming extensive, dense forests even in the very damp areas. In the north it reaches the extreme forest-line together with Picea mariana, P. canadensis, and other species of trees, or it is found forming the forest-line alone. In the most northerly localities, where it grows together with others, it is the most vigorous species, suc- ceeding in developing as a small tree when other kinds only manage to exist as creeping, stunted individuals. With regard to temperature and humidity, L. laricina is capable of growing under very widely differing conditions. HUTCHIN- SON States its powers of existing with or without water to be three times as great as those of Alnus incana (Hur- CHINSON, 1918, p. 482). On marshy ground and in the extreme north, it certainly does not grow as large as in the best localities, but on the marshes in the southern portion of the area it can still 90 Nr. 2. CG. H. OSTENFELD and C. SYRACH LARSEN: attain a height of 12—15 m. (SARGENT: 1918, p. 9), andin Alaska a height of about 10 m. is reached (KELLOGG in Forest Serv. Bull. No. 81, 1910). Statements from Minne- sota are extant of its attaining a height of 35—40 m. in the districts around the Great Lakes, where, as already stated, it grows best; HENRY has there measured a specimen 24,3 m. in height with a girth of about 1,4 m. (HENRY & ELwes, II, 1907, p. 393), but as a rule, its extreme height is given as being only 18—20 m. (SARGENT: 1921, p. 31; REHDER: 1927, p. 52). The tree possesses both in its earlier and its later years a pyramidal crown, owing to the shortness of its lateral branches. Branches of the second order are generally pen- dulous, and contribute towards giving the tree its charac- teristic appearance. The bark presents a peculiarity in peeling off in small, thin flakes in a manner somewhat similar to that of Picea abies. The leaves are green, or a light blueish-green, narrow, and 2,5—3,5 cms. in length. The pronounced keel on the under-side gives them a triangular appearance, seen in transverse section. The young shoots are light-coloured, smooth, or with a slight down, the cones when flowering varying in colour from light red to green. The mature cone presents the most pronounced charac- teristic of the species, and varies only to a very slight degree. The cone-scales are thick, bright, smooth, and distinctly arcuate, 12—15 of them together forming the 1,5 cms. long cone. The bracts are '/1—*/2 as long as the cone-scales, and vary somewhat in shape, the mucro being either rather shorter or rather longer, and the angle between it and the rest of the free margin of the bract more or less pronounced; the angle is often a distinct right-angle. The Species of the Genus Larix. 91 On the basis of specimens from Tanana on the Yukon River, WIGHT has distinguished the larch in Alaska as a separate species, Larix alaskensis (W. F. WIGHT: A new Fig. 28. Marsh with L. laricina and some Picea. Canada, Ont. Holland River near Toronto. Aug 1924. (C. H. Ostf. phot.). Larch from Alaska. Smiruson. Misc. Coll. L., 1907, p. 174, Table XVII). Of the characteristics which are said to distinguish it from L. laricina, the following are the most important. The bracts are more evenly pointed than in the case of L. laricina, where they are described as „more 92 Nr. 2. C. H. OsTENFELD and C. SYRACH LARSEN: broad-shouldered“ — alluding to the right-angle between the „mucro“ and the remaining free margin of the bracts. The cone-scales are fewer in number, longer, and narrower in the case of the Alaskan Larch, and, finally, the shorter Fig. 29. L. laricina (Du Roi) Fig. 30. L. laricina (Du Roi) Koch. Koch. Cones from Canada, Cones from cultivated tree; Den- Ontario, Lake Superior (leg. mark, Bellevue near Beldringe, K. Heimbürger, 1928). (Nat. Præstø. (Nat. size, upper row size, upper row dry, lower dry, lower row wet). row wet). leaves and slower growth are stated to be characteristic for the latter. An investigation of the material from Fort Gibbon (lat. 65° N., long. 152° W.) which lies on the Yukon River, and is very close to Tanana, from which WicxT's type came, confirms WIGHT's description, and there is no doubt that it fits the larch in Alaska. But this is not sufficient to separate it from L. laricina. In a large collection of cones from Lake Superior kindly sent us by Mr. K. Heın-. BURGER 1927, several cones are to be found which exactly correspond to those from Fort Gibbon, and this will prob- ably always be the case whenever there is abundant The Species of the Genus Larix. 93 material to hand. It must finally be stated, that in the analysis of the cone-scales and bracts of L. laricina, as given by Britton & Brown, the bracts have exactly the form described by WIGHT for L. alaskensis (Britton & Brown: Ill. Fl. 2nd. Ed. I. 1913, p. 60). Therefore L. alas- kensis, WIGHT, cannot be maintained, either as a species or variety; it can only be regarded as a form of growth, influenced by inclement external conditions; a similar form will presumably be found further east- a £ wards on the extreme northerly limit for the area of L. laricina. We have material from Fort Churchill, Hudson Bay, which supports this supposition. Finally, it should be adduced for the sake of completeness, that HENRY (Gard. Chron. LVIII, 1915, p. 179, Note) pig. 31. wrongly classifies L. alaskensis, with (DuRoi) Koch. Cones of L alaskensis from Fort Gibbon, Alaska. deviate from the small-coned L. Gmelini U.S. Nat. Mus. No. 866498. (Nat. size, upper row dry, lower L. laricina L. Gmelini, supposing that it does not from Eastern Asia. Larix laricina is found in a few earwciweb) old Arborets in England, where it has long been cultivated, but has never become common. In Denmark it is stated as planted in the Arboretum at Aalholm in 1832 (WeEırsacH: Notes, Bibl. Hort. Bot. Haun.). A tree at Bellevue near Præstø which still exist probably dates from the same time and was in 1924 24,5 m. high with a girth of 1,5 m. (1,3 m. above the ground). The oldest mention of American Larch in forest culture in Denmark from about the year 1800 (OPPERMANN, 1923) we regard as not applying to L. laricina, but to 94 Nr. 2. C. H. OSTENFELD and C. SyRAcH LARSEN: the supposed hybrid, L. pendula, our opinion being based upon still-existing specimens from that period. (See below under Hybrids). Herb. Mat. examined: In uligin. Am. Sept. (Brit. Mus.). — Labrador: Geol. & Nat. Surv. of Can. No. 24990, Fords Harbour, R. BELL, 1884 (Ottawa Herb.); Ana- totak Secounn 1928, 364 (Hort. Bot. Haun.). Ungava River, Fort Chino, SPREADBOROUGH, 1876 (red coned), (Ottawa Herb.), Ungava Bay, L. M. TURNER, 1884 (Gray Herb.); Sandwich Bay, White Bear River, 29. July 1926 (red coned) (Gray Herb.); Fl. of the Labrador Peninsula, Saguenay Co.; Archipel Quapitagone, H. St. Jonn, July 1915 (Ottawa Herb.). — Canada, Miss. BRENTON (Kew). — Forest ou nord du Fort Carlton, BOUGEAU, 28. Maj 1858 (Kew). — Brouagne, H. Sr. Jons, Aug. 1915 (red coned) (0. H.); also colls. from Labrador in U. S. Nat. Herb. — New Foundland: Bay of Islands, North Arm, FoGG, 1926 (Gray Herb.). — Strait of Belle Isle, 1924, FERNALD etc. (Gray. Herb.). — In the Gray Herb. 8 other colls. of New Foundland. Colls. also seen in U. S. Nat. Herb. — Flora des Iles St. Pierre et Miguelon (Gray Herb.). Fl. of Newfoundland no. 157, St. Johns, 1894, ROBINSON & SCHRENK (Ottawa Herb.; Kew; Hort. Bot. Haun.). — Fl. of W. Newfoundland, Bay of Island, 1910, FERNALD & WIE- GAND, no. 2408 (Brit. Mus.). — Fl. of Newfoundland, Valley of Exploits River, Grand Falls, 1911, FERNALD & WIEGAND, no. 4417 (Kew; Hort. Bot. Haun.). — Interior Newfoundland, Ep. BRENTON, 1912. (Kew). — Prince Edward Island, Brackley Point, Macoun, June 28, 1887 (Very small coned, the new cones red) (Ottawa Herb.). Magdalen Isles, Fr. JOHAN- SEN, July 1917 (Ottawa Herb.). — Fl. of Prince Edward Island, Queens County, Brackley, Point Road, 1912, FERNALD, Lanp & JoHn (Ottawa Herb.; Brit. Mus.; Hort. Bot. Haun.). — Fl. of Magdalene Island, Que- bec, 1912, FERNALD & WIEGAND, no. 6716, Grindstone Isl. — (Further Fragm. from N. B. Maine, Mass. Michigan), (Brit. Mus., Gray Herb. and U. S. Nat. Herb.). — New Brunswick, CAMPBELLTON, 1876 (Ottawa Herb.). — Gaspé Co., Mt. Albert, FERNALD & Coruıns, July 1906 (red coned), (Ottawa Herb.). — Montmorency Falls, Macoun, June 1915 (red coned) (Ottawa Herb.). — 7 colls. from Quebec (Gray Herb.). — Quebec, Flamand, leg. K. HEIMBÜRGER, 1926, C.H. OSTENFELD: Canadian Plants, no. 626 (Hort. Bot. Haun.). — Ontario: 3 colls. in Ottawa Herb. — Massachusetts, 1 coll. (Gray Herb.). — Rhode Island: 1 coll. (Gray. Herb.). — Newport, Nova Scotia, June 18, 1918, J. G. Jack. (Arn. Arb.). — Arctic Canada, Churchill, Hudson Bay 16-7-1923., Hort. Bot. Haun.; BIRKET SMITH (5. Thule Expedition 1921 — 24, red cones). — St. Thomas, Ontario, 1906, Geo. L. FiscHer (Arn. Arb.). — Churchill, Hudson Bay, 1910. J. M. Macoun (red coned, rather few scales in the cone). (Ottawa Herb.). — Manitoba, Near Branden, Macoun, 1896 Ps u ay SA The Species of the Genus Larix. (very small coned). (Ottawa Herb.). — Ohio: 1 coll. (Gray Herb.). — Buffalo, G. W. CLINTON (Brit. Mus.). — Maine, Dr. A. Gray, 1877 (Kew). — Maine, J. BLAKE (Brit. Mus.). — BROwNVILLE, Maine, Aug. 29, 1895, J. G. Jack (Arn. Arb.). — New Hampshire, 5 colls. in Arn. Arb. at Gray Herb. — Adirondacks Mt. New York, T. S. BRANDEGEE, 1884, Ex. Herb. Univ. Calif. (Hort. Bot. Haun.). 1 other coll. of New York (Gray Herb.). — Near Port Huron, St. Claire Co. Michigan, C. K. Dopge, October 11, 1891 (Arn. Arb.). — North of College, Agricultural College, Michigan, 1898 (Arn. Arb.). — Roadside near Douglas Lake, Cheboygan Co., Michigan, J. H. Exvers, July, 7, 1917. (Arn. Arb.). — Michigan, 3 colls. one red coned (Gray Herb.); also in U. S. Nat. Herb. — Wisconsin: 3. eolls. (Gray Herb.). — Illinois (Gray Herb.). — Maryland, Pennsylvania, New Jersey and Indiana (U. S. Nat. Herb.). — Saskatchewan, North of Prince Albert, Macoun, 1896 (small coned) (Ottawa Herb.). — N. W. Ter., Lat. 61° Long. 104°, TyrELL, 1893 (Ottawa Herb.). — Lake Huron, Dr. Topp (Kew.). — Winnipeg Lake, 1884, Jas. M. Macoun (Ottawa Herb. ; Brit. Mus.). — Lake Superior, HEIMBÜRGER 1928 (Hort. Bot. Haun.). — Heron Bay, C. H. OsTENFELD, 1924 (Hort. Bot. Haun.). — Charlotte, Ver- mont, 1877, C. G. PRINGLE (Kew). — Mac. Cubbins Lake, Minnesota, E. P. SHELDON, May, 1895. Ex. Herb. Univ. Calif. (Hort. Bot. Haun.). — Swamps at Mineral Springs 1913, Ove Pautsen (Hort. Bot. Haun.). Dease River, Northern Brit. Col., Dawson, 1887 (Brit. Mus.; Ottawa Herb.). — Kokomo Creck, 40 ml. north of Fairbanks, Alaska, L. M. PRINGLE, Aug. 17, 1909. (U. S. Nat. Herb. et ex U. S. Nat. Herb. in Hort. Bot. Haun.). — Fort Gibbon Alaska, A. G. MapprEw, Ex. Herb. U. S. Nat. Herb. (Hort. Bot. Haun.). — Fort Gibbon along the Yukon River, A. S. Hircucock, 1909 (U. S. Nat. Herb.). — E. KoExxE : Herb. dendrologicum (Hort. Bot. Haun.). IV. Hybrids. There are three areas where two different species of larch meet in nature. In two cases, those of L. Potanini—L. Ma- stersiana, and L. occidentalis—L. Lyallii, the species are so little known and so closely related, that it has hitherto been impossible to distinguish hybrids between them. In the third case, however, where the question is one of two widely differing species, L. sibirica—L. Gmelini, it is evident that hybrids are produced in the areas where their respec- tive boundaries meet. 96 Nr. 2. C. H. OSTENFELD and C. SYRACH LARSEN: Hybridisation has undoubtedly taken place several times under cultivation, when two or more species have been brought together, and it is probable that a considerable number of crossings might be made artificially, but deli- berate experiments of this nature have not been mentioned hitherto in the literature extant upon the subject. L. Gmelini x sibirica, SZAFER in Kosmos, XXXVIII, 1913, p. 1297. Syn: L. Czekanowskii, SZAFER |. c. This hybrid is probably found on a broad belt stretching from Lake Baikalnorthwardstoabout the mouth of the Jenisej. It has been described by Szarer, and investigated by SUKATSCHEW in 1928 in the district round Lake Baikal, where it seems to grow extensively. He has kindly sent us abundant specimens of cones taken from a large number of trees, and these specimens give evidence of many different intermediate stages between the supposed parent species (see figs. 32—33 showing some of the cones). MIDDENDORFF (Middf. Reise IV, I, Teil, pp. 530 and 595) and CAJANDER (Act. Soc. Sci. Fennicae. XXXII, No. 3, 1904, p. 8) have both previously stated that no well-defined difference existed between the two species, and this belt with its hybridogenous intermediary forms is the natural explanation of their assertions. The matter has been dealt with in greater detail under L. Gmelini. Herb. Mat. examined: Maretuj, Cape Ulan (3 samples); the village Listwenicznoja, and the bays Kurkut (5 samles), Koty (3 samples) and Krestowka (1 sample), — altogether 14 samples from 14 different trees, all from the western Side of the Lake Baikal, W. SUKATSCHEw, 1928 (Hort. Bot. Haun.). — L. decidua x larieina, A. HENRY, in Gard. Chron. Ser. 3. LVIILL).191 5" 9.178 «O —1 The Species of the Genus Larix. REHDER: Man. Trees and Shrubs, 1927, p. 52. — Syn: Pinus pendula, SOLANDER, in Aiton: Hort. Kew. III, 1789, p.369. — Non Pursh. — Larix pendula, SALISBURY, in Trans. Linn. Soc. VIII, 1807, p. 314. — Non McNab. — L. dahurica, ELWES & HENRY: Trees, Gr. Brit. and Irel. II. 1907, p. 379—382, pro parte. Non Turcz. (Conf. HENRY, in Gard. Chron. Ser. 3. LVIII, 1915, p. 178, Note). — Fig. 32. L. Gmelini X sibirica. Kurkut on the west side of Lake Baikal. (Leg. Sukatschew, 1928). (Nat. size, upper row dry, lower row wet). L. americana, forma, OPPERMANN, in Det forstl. Forsogsv. VII, 1935. p. 190 and 278. (Cum icon.). — Non Michaux. There has been a good deal of uncertainty with regard to the origin of this Larch. From the time when it was first described as L. pendula (1789) until 1915, it was always regarded as indigenous to North America, where the statements regarding it were certainly very diverse and Vidensk. Selsk. Biol. Medd. IX, 2. 7 98 Nr. 2. C.H. OSTENFELD and C. SYRACH LARSEN: usually of a very summary character, usually based only on the accounts of others. Of the many statements regarding its occurrence in North America, there are only two authors who could Fig. 33. L. Gmelini X sibirica. Kurkut on the west side of Lake Baikal, (leg. Sukatschew, 1928). (Nat. size, upper row dry, lower row wet). have based their records on personal observations. The one MacnaB (in the Quart. Journ. Agric. V, 1834—35, pp. 594 —605), simply mentions one species of larch (Larix pendula) observed by him in the neighbourhood of Lake Ontario, and his description coincides entirely with L. laricina, thus being of no value as regards the present question. The other description, which strikes one as more convincing, is given by PursH (Flora Americae Septentrionalis, II, 1814, The Species of the Genus Larix. 99 p. 645). According to the title-page, he relies upon "twelve , years travels and residence in that country”, and, describing L. pendula, Lambert, and L. microcarpa, Lambert, jointly, he says positively that MicHaux is mistaken in including them under one species, adding: “I never saw them both growing in the same place, or even near one another.” We have, nevertheless, no doubt at all, that this is wrong, and that his remark considers only L. laricina, the occurrence of which in two forms is due in the main to the different characters of the growth localities. The description of the two “species”, as far as it concerns their habitats, sounds extremely im- probable. L. pendula is said to be “a beautiful tree, res- embling the European Larch”; and grows “in low cedar swamps”, while L. microcarpa, which certainly “resembles the preceding L. pendula” has its home “on high mountains”. Finally, L. pendula — which must, at any rate have been less common than the other, as no subsequent attempts to find it in North America have been successful — has been provided with American popular names (Tamarack, Hackmatack), no American name being given to L. micro- carpa (laricina), which otherwise is known under these names. As already mentioned, we have no doubt that there is only one species of larch of that group in North America, and that Pursn’s description is clearly influenced by LamBert’s account (in Genus Pinus, 1803), in which two “species” are mentioned, but which, in part at all events, is based upon material from specimens cultivated in England. In SOLANDER’s Notes (Brit. Mus., unpublished), its habitat is given as follows: — ,,Habitat in New Foundland insula Amer. septentr. Latitud. 48 gr. ubi hiems perquam aspera”, but in SOLANDER's description in Arron: Hort. Kew., there 7“ 100 Nr. 2. C. H. OSTENFELD and C. SYRACH LARSEN: only stands “Nat. of North America. — cult. 1739 by PETER GoLLınson”. Thus it appears from the oldest descriptions that the tree was to be found in Newfoundland as well as in culture. FERNALD in 1915 answered an enquiry from the British Museum with regard to L. pendula in New- foundland, by sending herbarium specimens (Herb. Brit. Mus.) from various localities on the island, but all of them distinctly belong to L. laricina, and he knows only one species. The tree as cultivated in England (CoruLınson, Mill Hill), which has been described as Pinus pendula, is posi- tively stated as having come from America. We do not, however, think that any proof exists of its having been found in North America in the wild state. Morphologically, it occupies an intermediate position between L. decidua, and L. laricina. The type specimen in the British Museum gives the length of a cone as 25 mm., and two still immature cones are 23 mm. and 19 mm. respectively. The immature cones are distinctly reddish- mauve, and in this point they resemble L. decidua. The lowest cone-scales are larger than those of L. decidua, and in this point they show a decided approach to the type of L. laricina, as well as in the fact of the cone-scales being thicker and brighter than those of the European Larch. LAMBERT reproduces material from COLLINSON’s tree at Mill Hill (Genus Pinus, 1803, Pl. 36). On account of its intermediate position between the European Larch and the American Larch and also of the fact that it is found in culture, we agree with HENrRy’s explanation, wherein he describes it as a hybrid, produced in cultivation, between L. decidua and L. laricina (Gard. Chron. LVIII, 1915, p. 178). | f The Species of the Genus Larix. 101 A. OPPERMANN has shown, that a group of peculiar- looking larches about 125 years old is to be found in Den- mark (Folehave), and he classifies them as “a kind of L. americana which has larger cones than the pronounced L. microcarpa” (A. OPPERMANN: Cultivation of Larch in Den- mark, 1923, p. 319). We regard them as being L. pendula, Fig. 34. L. decidua X laricina? (L. ,,pendula’’). Cultivated, Denmark Fole- have, 1922. (*/s nat size, upper row wet, lower row dry.) viz., hybrids between L. decidua and L. laricina, but have to add, that it is extremely difficult to decide whether such trees, which are found in culture among many forms of L. decidua, really are L. pendula, it being possible to find among L. decidua specimens of great similarity, but it is at least evident that the said specimens are not L. laricina. Herb. Mat. examined: Culta; SOLANDER, Type specimens, no locality, no year (Brit. Mus.) — Woburn Abbey, Bedfordsh., England, Oct. 1928, C. SyracH LARSEN (Hort. Bot. Haun.). — ? Denmark, Folehave on Sjælland (1922). L. Kaempferi x decidua, Coaz, in Schw. Zeitschr. Forstw. LXVIII, 1917, p. 12. 102 Nr. 2. C. H. OSTENFELD and C. Syrach LARSEN: L. leptolepis X decidua, HENRY, in Irish Times, June 24, 1919. — Henry & FLoop, in Proc. Roy. Irish Acad. XXXV, B, 1919, p. 55. — REHDER, in Journ. Arn. Arb. I. 1919, p. 52. — DALLIMORE & JACK- son: Handb. Conif. 1923, p. 280. — REHDER: Man. Trees and Shrubs. 1927, p. 51. — Syn: L. Marschlinsi, Coaz: 1. c. 1917. L. eurolepis, HENRY: 1. c. 1919. — HENRY & FLoop: I. c. 1919. — DALLIMORE & JACKSON: 1. c. 1925. — REHDER: ]. c. 1927. — L. Henryana, REHDER: I. c. 1919. — Coaz can only be understood to mean, that he believes he has observed the cross L. Kaempferi X decidua; but others are of the opinion that it is L. Kaempferi X sibi- rica (HENRY & FLoop: l.c. p. 57; vide HENRy’s notes: ibid. p. 66; DALLIMORE & JACKSON: 1. c. p. 292). Coaz’s observations are based upon specimens of seed from a L. Kaempferi in the neighbourhood of Morat in Swit- zerland. L. decidua and L. sibirica were both found close by, but, as already stated, Coaz believes the European Larch to be the male parent in the supposed cross; it seems, nevertheless, as though there might be some doubt as to whether it was the one or the other. If, however, any regard is to be paid to his observations, it can only be in the present shape; perhaps it would be best to neg- lect them entirely. The oldest specimens of the hybrid L. Kaempferi x decidua recognised with certainty originated about 1900 upon the estates of Dunkeld and Murthly in Perthshire, Scotland, and the first detailed report by Henry & FLoop in 1919 was based upon material derived from this source. It is an easily recognisable form, intermediate between the two widely different parent trees. The cone is more cylindrical than that of L. Kaempferi, the cone-scales being at the same time less recurved. The one-year shoots are The Species of the Genus Larix. 103 something between the reddish-brown, stout shoots of the Ja- panese Larch, and the light-coloured, slender shoots of the European species. In the seed-bed, one-year plants of L. Kaempferi are distinguishable by being considerably smaller than those of L. decidua, and in this particular too the one-year hybrid plants occupy an intermediate position. From the forestry point of view, the European Larch has a better shape, but is, upon the other hand, extremely susceptible to the attacks of Dasycypha Willkommit, which the Japanese Larch is not. The hybrid combines the good shape of the one and the powers of resistance against canker of the other, and is therefore now the subject for larger experiments in forests. The second and third hybrid generation has also been raised, and is now being experi- mented with. In Denmark, one specimen is known from Dr. BorGE- SEN’s garden at Hellebæk, and young plants of L. Kaempferi from various Danish forests show signs of being hybrids with L. decidua. Herb. Mat. examined: Buffalo Park, Murthly, Scotland, 1923, J. M. Murray (2 samples). — Scotland, 1923, J. M. Murray. — Dunkeld, Scotland, September 1926, C. SYRACH Larsen. — Denmark, the Garden of Dr. BørGEsEn at Helle- bæk 1925, C. H. OsTENFELD. — Denmark, Strødam, near Hillerød (specimens sent from Scotland). The reciprocal cross, Larix decidua X Kaempferi, has been observed in the Frijsenborg Forest District, where the first hybrid generation was planted as one-year plants in 1925. The seed was collected from a 90—100-year-old L. decidua in »Frijsenborg Lystskov«, where the Japanese Larch stands a little to the west and south-west of the former. The seed yielded only a minimum of hybrids, the Nr. 2. C. H. OSTENFELD and C. SYRACH LARSEN: 104 = FEAT NN = Les Ÿ if / | \ N Å 3 £ {À \ x N u‘ >: AA mn. X hr years old, from Folehave, Denmark. From A. Oppermann Forstl. Forsøgsvæsen 1923. Fig. 35. L. “pendula” Soland. Cultivated trees about 125 majority of plants being pure L. decidua. This seems to is attended . decidua X Kaempferi indicate that crossing L with more difficulty than the reverse hybridisation. rw nee X, 2. The Species of the Genus Larix. 105 V. Summary. In the present paper the areas of distribution of the various species of larch are dealt with in detail, but only as far as the distribution concerns the wild-growing - plants; the cultivation of the larches, which in many regions is of rather considerable economic interest, has mostly been omitted. The authors recognise 10 species of larch and three geographical varieties. According to the international rules of nomenclature, the following names are valid: L. Griffithiana, L. Mastersiana, L. Potanini, L. occidentalis, and L. Lyallii, which five species constitute a natural sub-genus, characterised by the bracts of the cone being longer than, and reaching out of, the cone scales. All these species have restricted areas of distribution, being mountain trees from the great mountain regions of western N. America and south-eastern Asia respectively. Of these, only L. occidentalis has any considerable economic value, but none of them have hitherto been taken into culture on a large scale. 3. The five other species are L. Kaempferi (L. leptolepis) L. Gmelini (L. dahurica) with the varieties olgensis and Principis Rupprechtii, L. sibirica, L. decidua (L. europaea) and L. laricina (L. americana). Of these, L. Kaempferi has a small area of occurrence on Hondo, Japan, while L. decidua has a medium-sized area. L. Gmelini, L. sibi- rica, and L. laricina, on the other hand, have very large areas, the last inhabiting the northern temperate and sub-arctic zones of N. America from Newfoundland to Alaska. L. Gmelini and L. sibirica divide Eurasia between them, L. Gmelini being found in Eastern Asia, and as 106 Nr. 2. C. H. OSTENFELD and C. SYRACH LARSEN: far west as from Lake Baikal northwards; L. sibirica in the area west of L. Gmelini as far west as N. E. Europe. The differences between the species and their variability have been considered under each species, and their synonymy and the records of specimens upon which our conclusions are based are cited in full. The geo- graphical varieties of L. Gmelini, namely L. olgensis and L. Principis Rupprechtii, form a kind of transition to the first-named sub-genus, and their areas of occurrence also cause them to approach the Chinese species of that sub-genus. The variety of L. decidua, var. polonica, is a link between that species and L. sibirica, and is a form which appears to be not far from extinction. The species of the second sub-genus are of importance as forest trees, and several of them are objects of extensive cultivation. Between the species which meet in nature, hybrids are found as regards the combination L. Gmelini X sibirica, while the combinations L. Lyallii X occidentalis and L. Mastersiana X Potanini have not yet been recognised. When cultivation brings two species together, hybrids also arise. L. decidua X laricina has been known for a very long time, but is usually misinterpreted; L. Kaempferi x decidua is much more recent, but seems to be of economic value, and will probably become much commoner; L. Kaempferi X sibirica has been reported, but is not definite. When L. Gmelini becomes more used in cultivation, this most valuable species will no doubt hybridise with several of the other species. CONTENTS a rear 3 an a Bees, eue 5 CL LE SES MES PRE RP en tole nig ee DSSS wee 8 LL. ARNO NE E CO ee sou Soon > wie ve ein 9 nm ee due 15 END pee SR CC EE PR EU DE 17 RE CR ie tar Fm Spoke pT 22 un. ra, ur Ru 28 ee RE ae ne clea) oy ttn se EE ERE då 32 rues 37 am. i. Gmelini var olgensis............. RER ay Var kore 51 Der Gmelin var. Principis Rupprechtü .......:..--.2.- 56 oy er er PE OT REE PR Re 61 ne ee 69 Bere FEAH VAR DOSER M... NOR. 78 ee ee RE ES BØED sok mes 85 Eee eo Sie anaes RE sk gO 95 ST SETS oy a eS oe ne ee hi vue 105 Forelagt paa Modet den 3. Maj 1929. Ferdig fra Trykkeriet den 30. Juni 1930, Mr FRI PU Så „an JE 1% i Auto 2478 = ie = eres J K ae BIOLOGISKE MEDDELELSER UDGIVNE AF 6. BIND (Kr. 18,10): 1. LuNDBLAD, O.: Zur Kenntnis der Quellenhydracarinen auf Møens Klint nebst einigen Bemerkungen über die Hydra- carinen der dortigen stehenden Gewässer. Mit 7 Tafeln und I RN er. 2. BØRGESEN, F.: Marine Algæ from the Canary Islands, especially from Teneriffe and Gran Canaria. II. Phæophyceæ. 1926 .. 3. OSTENFELD, C. H.: The Flora of Greenland and its Origin. ENTE I RET SEES SD NES RER RES 4. FIBIGER, JOHANNES and MØLLER, PouL: Investigations upon Immunisation against Metastasis Formation in Experimental Cancer. With 5 plates. 1927......... ELLE EL et, NENNE 5. Linp, J.: The Geographical Distribution of some Arctic Mi- NT a A ER ‚6. BØRGESEN, F.: Marine Algæ from the Canary Islands, espe- cially from Teneriffe and Gran Canaria. III. Rhodophycee. Part.1. Bangiales and Nemalionales. 1927................... ; 7, LINDHARD, J.: Nogle Undersøgelser over den respiratoriske | Kvotient under kortvarigt Muskelarbejde. 1927 ............. BER | 7. BIND (Kr. 14,85): - +4. RAUNKIÆR, C.: Dominansareal, Artstæthed og Formations- ” DR EN RO MR A a NR 1 2, "PETERSEN, C. G. JoH.: On some Biological Principles. 1928 . Ss 3. VIMTRUP, Bu: Undersogelser over Antal, Form, Bygning åg vs Overflade af Glomeruli i Nyren hos Mennesker og nogle Patte- 4 Bexsev R. R. og Vimrrup, By.: Undersøgelser over de Rou- a ‘get’ske Cellers Funktion og Struktur. En Metode til elektiv eo Marva at My oh briller. 1928 44,0... > THOMSEN, Otur: Die Erblichkeit der vier Blutgruppen des ka Menschen, beleuchtet durch 275 Nachkommenschaftsindivi- u — duen in 100 AB (IV)-Ehen (nebst 78 Kindern, von denen nur "> ~~ der eine (AB)-Elter bekannt ist). 1928 ..,.......:.:......... 6 "KROGH A. and HEMMINGSEN, A.M.: The Assay of Insulin on © - Rabbits and Mice. 1928...... AAT N, REN Do RAL a 2 7. JOHNSSON, J. W.S.: L’Anatomie mandchoue et les Figures de jet Th. Bartholin, étude d’ iconographie comparée. 1928......... se 2, Kemp, TAGE: Om Kromosomernes Forhold i Menneskets soma- REE RETRO UID. eo aise es SA ha Weis, Fr.: Fysiske og kemiske Undersøgelser over danske Hedejorder. Med særligt Henblik paa deres Indhold af » Kolloider og Kvælstof. With a Resumé in English. 1929 . DET KGL. DANSKE VIDENSKABERNES SELSKAB Kr. 8. 1.00 1.00 0.70 2.00 1.75 8.25 A . 1. BoRGESEN, F.: Marine Algæ ar Pili Aue islander’ cage 75 cially from Teneriffe and Gran Canaria. III. Rhodophycez. LENS Part II. Cryptonemiales, Gigartinales and Rhodymeniales. Les Mélobésiées par M€ Paul Lemoine. Avec 4 planches. 1929. . 2. THOMSEN, OLUF og KETTEL, KARSTEN: De menneskelige Isoag- glutininers og tilsvarende Blodlegemereceptorers Styrke 4. | forskellige Levealdre. Med 1 Tavle. 1929........ Spee patie # à 3. KRABBE, Knup H.: Recherches sur l'existence d'un œil parietal ” rudimentaire (le corpuscule pariétal) chez les mammifères. Avec 11’ planches (22 figures). 1929.44 ST ue yaa 1 "4, Rosenvince, L. KoLpErup: Phyllophora Brodiæi and Actino- SUR coccus subcutaneus. With one plate. 1929 ............... ZAC iS is 5. THOMSEN, OLUF og KETTEL, KARSTEN: Kvantitative Under- as my, enters over de SEE Isoagglutininer | Anti-A. og N ‘LUNDBLAD, O.: Die rente der Insel Bornholm. mate rey 9 Tafelnund ‘1 Textfigur. (1930: SPA STENENE ER Ba Ba, ©. 00.8. LINDHARD, J. and MÖLLER, Jens P.: On the Origin: of the Initial | Heat in Muscular ER: 1930 BESS RE BI uty 9 BIND eo Pressen): NE BR. ler: 2 BORGESEN, Få Marine, Algæ from the Canary islander espe- 4 … cially from. Teneriffe ‘and Gran Canaria. HI. Mhedo payne ga us N BOSCH. Ceramiales; 1930 ......... BE ART A 7.90 rata Bs OSTENFELD, C. H. and SYRACH (LARSEN, €: The species of ere Genus: Larix: and their. ap nk distribution. FN 35 i Fr } … STRAY CONTRIBUTIONS TO THE = FLORA OF GREENLAND I-V BY MORTEN P. PORSILD (WITH 8 FIGURES IN THE TEXT) ARBEJDER FRA DEN DANSKE ARKTISKE STATION PAA DISKO Nr. 13 SÆRTRYK AF MEDDELELSER OM GRØNLAND LXXVII i ns à | KOBENHAVN > BIANCO LUNOS BOGTRYKKERI A/S ER io 1930 D & (4 a Arbejder fra den Botaniske Have i København. Nr q — BOTANISK HAVES BIBLIOTHEK GOTHERSGADE 130 KØBENHAVN (COPENHAGEN) DANMARK he Botanical Library of the University of Copenhagen takes pleasure in sending you the following = tes Jon LEK Golan Mari; 7 FAR a Mb, LI ME containing the results of work done at the Bota- nical Garden and reprinted from Danish scientific journals. | The Botanical Library will be glad to receive copies of publications from your Department in exchange. Arbejaer Ira den Botaniske Mave I NODENMAVE, | Distributed from the Botanical ‘ danske botaniske Have i Københa vr Arbeider fra d Regarding tae n Len Botaniske Litterat: indy. Luvdager >) Some Germ Ir Lind“ Dani. EB Carl Christen- sen: Dean Bug.Warming: Obser tae Arbeider fra den Botaniske Have i Kgbenham. m +h + £ ice Tit a Theat from the Botanical Library of the University in C Regarding tne nos. 1 Botaniske Litteratur 18t -XXI (Arbejder ke Have i København, Nr.72) concerning the Vegetat and. North-east nen represented in the Herbariur taniske Litteratur 1560-1911. x fi : la Valeur systematique de = : n / des aliuvions mediterranecnnes gy of arctic Flowering ed during the first Thule Expe- st Greenland. and Biology of arctic Flowering Caprifoliaceae do do II,4. Primul eae teaabningerne hos Griselinia littoralis og Campanula vidali Wat atomiske Bidrag. Planteanatomiske bidrag II. Snes Uvella Stein og nogle andre F. Børgesen & C.Raunkiær: Mosses and Lichens collected in the former Danish Vest Indies. Ernst Østrup: Fresh-Water Diatoms from Iceland . ericanae. Fr .‚Kränzlin: Orchidaceae quaedam i,Cstenfeld: A List of Arctic Caryuphyllaceae. H D k he Structure and Biology of Arctic n lants. Caryophyllaceae Ove Paulsen: Studies on the vegetation of the Transcaspian Lowlands. the vegetation of Pamir. < Lichen Flora and Lichen vegetation of STRAY CONTRIBUTIONS TO THE FLORA OF GREENLAND I-V BY MORTEN P. PORSILD (WITH 8 FIGURES IN THE TEXT) ARBEJDER FRA DEN DANSKE ARKTISKE STATION PAA DISKO Nr. 13 SZ RTRYK AF MEDDELELSER OM GRØNLAND LXXVII KØBENHAVN BIANCO LUNOS BOGTRYKKERI A/S 1930 Arbejder fra den Botaniske Have I København. Nr, 118 Page Introduehiane. LE TERESA 3 I. The Flora of South Greenland, 60°—62° N. Lat., Addi- tions and Bangeaiistensions ed. een 8 11. 2Galıum "Biandeseer Gray. on 28.0% ar en anne 24 III. The Genus Andromeda in Greenland................ 32 iy ine Greenland: Cranberry. tr os “Ace yc. ee toes an 38 V. Ranunculus pygmaeus var. Langeana Nath........... 42 50 a ARIC AL GARDER INTRODUCTION rs høg a person who has lived many years in the Arctic and become acclimatized to it, what, if anything, he finds wanting of the ordinary life of his more genial mother country, he will respond that he misses something, sometimes so much that he is heartsick with longing, such things as fresh strawberries, the shade of trees, or good music. For the last, quite lately radio has been a good substitute, but the other things will probably for all time be unattainable. It had been the writer's wish for many years to make a trip to southernmost Greenland, that peculiar section, part of a big Arctic land, but not Arctic itself, or rather, with the Arctic keynote modified by a nuance of something more genial. It is a country where trees still are seen; where Eric the Red and his people had their farms, churches and cloisters; and where now their Eskimo victors, their seals having gone, are trying to establish a living by cattle- and sheep-ranching, in the fashion of the old Norse and on their very farm-sites. But the short Arctic summer too often made such a trip impossible. The fact that all connection with the outer world is limited to three months, condenses to the same short period all administrative and clerical work. Also, the steamers do not touch the ports of the whole coast, and even if such a rare event should happen, one would be without means of transportation in the working field if they were not taken along from the starting point. In 1924, the Danish Government had granted the Arctic Station a new motor-boat, the “A. Holck”, named in memory of the man through whose generosity the Danish Arctic station was founded in 1906. Built as a yawl of 15 tons burden, with a 12 H. P. engine, it was stronger and more sea-worthy than that which the station had pre- viously possessed. It arrived in the autumn, too late for an extended experimental cruise that year, but during the winter the southern trip was prepared for. As the ships in the spring of the next year brought no visitors to the station, there seemed to be no obstacle, and the long desired trip was started. 1* 4 Morten P. PorsiLp. With the writer was his son Mr. A. E. PorsiLp as “second in com- mand” on deck or in the engine-room, as circumstances would require, and as botanical assistant in the field. In addition there were two Eskimo hunters, the writer’s usual companions on boat trips, and lastly, Master Ove STEN PorsıLp, the writer's youngest son, who acted in the capacity of “odd-job-boy”. We started from Godhavn on July 6th in the after- noon, went, watch by watch, to Sukkertoppen and Frederikshaab, reaching Ivigtüt the morning of July 12th. Having visited the cryolite mine, we explored the fertile Björnedal the next day, and continued to “Nyboes Canal”, in which the boat was trapped, until the next tide mercifully released it; we then proceeded to Julianehaab, arriving on July the 16th. Leaving the next day, we had two very unpleasant days across Juliane- haab Bay, where we were forced to encounter fog, heavy sea, drifting ice and the danger of rocks all at once, until we reached Nanortalik on July 19th. From there we went through the picturesque sounds of Torssukatag and Prins Christians Sund, stopping, because of darkness, at Igdlorsuit and arriving at our farthest point, Nunatsuk on the east coast, on July 21st. From here we rounded the theatrical Walkendorf Islands, explored the fiords around Ilua, and went over Frederiksdal to Nanortalik on July 25th. The next days were spent in the Tasermiut Fiord and on July 28th we left Nanortalik and went to Agdluitsoq Fiord. Having finished there, we passed along Lichtenau and Sydpröven to Julianehaab on Aug. Ist. After having prepared and dried our collec- tions, we set out, on Aug. 4th, for the Qaqortog and Igaliko Fiords, and on Aug. 11th we sailed on our way out of Brede Fiord and Torssukataq. When we came out, on the 12th, a strong southerly gale with ugly eddy- squalls met us and forced us farther out from the coast, until, after a watch of 12 hours, we found shelter at Tigssaluk. Though the next day was foggy, we came to Neria, Narssalik and Frederikshaab, and continued on the 15th, still with fog, to Avigait, where we stayed for the night. The next day being better, we continued homeward and reached Godthaab, the capital of Greenland, on Aug. 17th. A few hours later the s.s. “Hans Egede” came from Denmark and in it Mr. HauGe, Minister of the Interior and as such, the highest official of Greenland, and with him Mr. DauGaarp-Jensen, Director of the Administration of Greenland. As an inspection of the Danish Arctic Station was in their program, the rest of our trip was a race with the s. s. “Hans Egede”, with too long watches, until we reached our home on Aug. 22nd. On this maiden-trip of 48 days the “A. Holck” had been running one-third of the time, as shown by the exact figures of her log-book, and had covered over 2000 miles. She had experienced nearly all the features and surprises an Arctic coast can give, and proved herself Stray Contributions to the Flora of Greenland I—V. 5 a very sturdy and reliable boat, giving her crew safe transportation under all conditions, and cosy quarters and working room when an- chored. The southernmost region, especially the district of Julianehaab 60°—61° N., is one of the best botanically explored sections of Green- land. We owe our knowledge of the flora to a long line of well-trained experts: M. WORMSKJOLD, 1813; F.C. Rasen, 1823; J. Vani, 1828—-30; A. BERLIN, 1883; P. EBERLIN, 1883—85; Tu. Horm, 1886, (Frederiks- haab district only); L. K. ROSENVINGE, 1888; N. Hartz, 1889; and to a still larger number of skilful amateurs, geologists and surveyors or officials residing in the country, among whom may be mentioned: A. KorneErup, C. Petersen, P. L. P. SyLow, N. O. Host, L. SCHIØDTE, A. Jessen, and Mrs. ELEONORA LUNDHOLM. All results so far are, for the flora of the vascular plants, incorporated in L. K. RosEnvinGe’s "Andet Tillæg til Grønlands Fanerogamer og Karsporeplanter”, Medd. om Grl. III. Forts. III. 1892, in which paper, besides additional localities for other sections of Greenland, there is the best list of plants occurring in the southern part. The same author has published an elaborate study on the geographical and ecological conditions of the flora: “Det sydligste Grønlands Vegetation”, (with a resumé in French), Medd. om Grl. 15., 1898. Since the issue of these two important papers, large collections have been made by Dr. J. Linpuarp (Ivigtüt-distriet) and by Dr. H. DEICHMANN, and especially by Dr. G. MeLporr (Julianehaab- distriet), which are deposited in the herbarium of the Botanical Museum at Copenhagen, but which have not been published. There was thus no great probability that new researches would yield results worth the expenses nor had we any ambition in that direction. Our aim was simply “these wonders to behold” and to obtain research material for comparison with plants from other sections. And when, nevertheless, we can add some additional localities for some of the rarest species, it only shows how difficult it is to obtain a complete knowledge ot the flora of so vast a country as Greenland. Here follows a list of the localities visited by us, and their geo- graphical latitude. Frederikshaab district. Frederikshaab, 62°5’. Eqaluit in Kuanersôq, 62°5'. Thickets of Salix and Betula. 6 Morten P. PorsiLn. Narssalik Island, 61°38’. Neria Island, 61°35’ (collections by J. EuGEntus). Ivigtüt, 61°13’. Thickets and fertile slopes. Björnedal, 61°15’. Sea shore, dry grass-fields, thickets of Salix, Betula, Alnus, Sorbus. Julianehaab district, northern part. Julianehaab, 60°43’, around the colony. Qagssiarssuk in Tunugdliarfik Fiord (Eric the Red’s estate “Brattahliö”, 61°10’. Sea shore, grass-fields. Kiagtüt, i. e., somewhat south of that place, opposite the former loc- ality, 61°10’. Dry alluvial ground, water courses, bogs, thickets. Narssaq at Tunugdliarfik Fiord, 60°55’, near the village. Qaqortoq, near the Norse church ruin, 60°49’, grass-fields. Tasiüssaq, in Qaqortoq Fiord, 60°50’. Heaths and bogs, thickets and fertile slopes. Igaliko (the ancient Norse episcopal seat “Gardar’’), 60°59’. Dry and barren fields, overgrazed meadows. Qagssiarssuk, Igaliko fiord, 60°53’. Sea-shore, dry Dryas- and Cladonia- heath, ponds in thickets, brooks. Eqaluit, Igaliko fiord, 60°47’. Thickets, bogs and ponds. Sydpröven, 60°26’ and Lichtenau, 60°30’, around the villages. Amitsuarssuk, at the head of one of the branches of Agdluitsoq-fiord, 60°45’. Birch and Sorbus-thickets, heath with Ericaceae and Lichens, lake-shores, rocky brook-bed. Julianehaab district, southern part. Nanortalik, 60°7’, around the village. Taserssuaq in Tasermiut Fiord (in botanical literature often called “Kinguadalen”’), 60°16’. The biggest birch “forest” of Greenland, covering the bottom of a valley and the lower parts of the surrounding hills; lake shores, slow streams, thickets, bogs and swamps. “Uiluvit”. (The place visited is at ab. 60°28’, on the eastern shore of Taser- miut Fiord. The name was taken from a map and is used on the labels of the duplicates distributed. But it is a mistake, as Uiluvit is, in fact, located on the west side). Sea shore. Frederiksdal, 60°0’. Grass-fields, bogs, water-courses and ponds. Sangmissoq, 59°58’. manured soil, near the village. Kangikitsog in Ilua Fiord, 60°18’. Sea-shore, heath, bogs, ponds, thickets. Stray Contributions to the Flora of Greenland I—V. 7 Igdlorsuit, head of eastern branch of Ilua Fiord, 60°21’. Luxuriant growth of shrubs and herbs around the Norse ruins. Alluvial sands near the front of the glacier. Igdlorsuit, Prins Christians Sund, 60°10’. Fresh moraine, sea-shore, fertile slope. Nunatsuk on the east coast, 60°4’. Heath, meadows, bogs, fertile slopes, hillsides. In one respect the higher flora of southmost Greenland still needs investigation, namely in regard to the alpine parts of the districts. The highest tops surpass 2000 m., rising with steep and bare walls and wild, rugged peaks. Very little is known about the composition of the flora here, what is known we owe mostly to A. KornErup and to a few moderate ascents made by L. K. RosenvinGe. Several plants of a more alpine or high-arctic type have been casually noticed in the lowland, where they seem to be foreigners, and probably there will be found a decided alpine life-zone above the subarctic lowland-zone. Also, more observations on the occurrence or lack of drift on the mountain tops and plateaus are needed. When we started, we had the best of intentions to climb the hills, but partially they were difficult to ascend, partially we generally had to anchor in rather unsafe places and could not make our two Eskimos responsible for the big boat’s safety for too long a time, all the more so because they were quite unacquainted with the region. Therefore we never found time enough to make an ascent. The following list is to be understood as a supplement to ROSEN- VINGE’S list mentioned above. Generally only new localities are men- tioned and when we did not find plants already known, this is also stated, as it gives an impression of how scarce or local such species are. I owe sincere thanks to Dr. H. Danistept, Stockholm, for identifying the collections of Taraxacum and Hieracium, and to Dr. J. G. Gunnarsson for revising and naming the Betula-specimens. Also to Prof. C. H. OstenreLp and Dr. C. Curistensen, Copenhagen, Dr. SELIM BIRGER, Stockholm, and to Dr. Tu. Horm, Clinton, Md. I owe thanks for valuable hints and corrections. Whoever travels in Greenland will appreciate the great and valuable help he receives from the local officials, through their hospitality as well as by their knowledge of the local difficulties and dangers to be avoided. For this a well as for other things, not to be mentioned here, we thankfully remember the chief magistrates of the districts we visited, CO Morten P. PorsiLp. Messrs. C. LanGskov, Sukkertoppen; C. Simony, Godthaab; P. IBSEN, Frederikshaab; O. Hastrup, Julianehaab; and L. MATHIESEN, Na- nortalik. Disko, Greenland. February, 1928. T, THE FLORA OF SOUTH GREENLAND, 60°—62° N. LAT., ADDITIONS AND RANGE EXTENSIONS Woodsia ilvensis (L.) R. Br., common. Cystopteris fragilis (L.) BERNH., common. — montana (Lam.) Desv. (det. SELIM BIRGER). New to Greenland. This interesting and unexpected addition to the flora was found S. of Kiagtüt, growing in thickets on alluvial soil. The plant is generally considered a strict calciphile; the surrounding rocks are here sodalite- and nephelin-syenites and diabases. Besides in northern and central alpine Europe the plant occurs in North America, from Labrador to Alaska, but seems nowhere to be common. The nearest stations are S. Labrador in 59° N., the St. Lawrence region of Quebec and one station on Newfoundland. Dryopteris Filix mas (L.) ScHoTT, quite common in thickets. — spinulosa (MüLL.) Kuntze var. americana (Fiscx). WEATHERB. (see FERNALD: Rhodora 1915, p. 144 and 1926, p. 146), common. According to information (in litt.) by our well-known fern-authority Dr. C. CHRISTENSEN of Copenhagen, all the Greenland material which has hitherto passed as Lastrea spinulosa 8 intermedia LANGE Consp. p. 187 belongs to this variety, the history of which is given by FErnALD l. c. Dr. CHRISTENSEN continues: The Icelandic specimens also belong here, only one specimen slightly approaches the European form, but the Faeröese are European. In Lapland both forms seem to occur and in Denmark we have the stout typical form with blackish scales in the woods, whereas in bogs, on Alnus-stumps, a smaller form with lighter coloured leaves and light scales occurs. To me they seem rather to be forms from sunny situations, and it is but natural to find such north of the wooded area... . (in litt.). Stray Contributions to the Flora of Greenland I—V. Q Dryopteris Phegopteris (L.) C. Cur., common. — Linnaeana C. Cur., common. Polystichum Lonchitis (L.) Rorx, common. Athyrium sp. An immature set of specimens was found at Kangkitsog. An indusium is present, which would bring the plant to A. Filix femina (L.) Roru, heretofore not observed in Greenland; but the fronds are so young and undeveloped that a definite identification is impossible. From 6 localities on the southern part of the east coast, be- tween 60° and 61° N., has been found an Athyrium which has passed as A. alpestre (Hoppe) RyLanps. It was also found once in the Ilua Fiords of the west coast. In 1917, Fr. K. Burrers has shown (Rhodora 1917, p. 203) that the American material forms a very distinct variety americanum Burt. Having applied to Dr. C. CHRISTENSEN, he kindly revised the material and wrote: In the Copenhagen herbarium there are only 5 sheets of A. alpestre from Greenland. Most of them are not well developed and difficult to identify de- finitely, but at least the specimens from Kuteq, 60°41’ N. (Egerrın), and Nenese, | 60°18’ N., (J. VAHL), are undoubtedly v. americanum as described by BuTTers. The Icelandic specimens all belong to the European typical form, only one frond from Husavik (East-Iceland leg. H. Jonsson) approaches much to v. americanum. Our specimens from America, especially specimens from Québec, show that the variety is very well characterized by Burrers. (in litt.). Asplenium viride Hups., not seen. Botrychium Lunaria (L.) Sw., common. A monstrous form with sporangia on upper parts of the sterile fronds was noticed at Qagssiarssuk, Ig. F. — boreale MILDE, Prins Christians Sund; Taserssuaq, Tas. F.; Igd- lorsuit, Il. F. | — lanceolatum (GMEL.) AANGSTR., seems to be rare in this section. | By us only found S. of Kiagtät. Equisetum arvense L., common. — silvaticum L. seems to be quite rare in this section. From Tasers- suaq, Tas. F. it has been taken by all previous collectors. We also took it here where it was very abundant, and from two other places in the same fiord. From Tunugdliarfik F. it has once been collected, (ROSENVINGE), and we found it here S. of Kiagtüt. Finally it was found at Eqaluit, Ig. F. 10 Morten P. PoRSILD. FERNALD states (Rhodora 1918, p. 129) that out of 194 sheets of North American specimens, 188 sheets have quite glabrous branches, while in two sheets only the branches bear minute tri- chome-like spicules, characteristic of the great bulk of European specimens. For the glabrous phase, the name, var. pauciramosum MILDE, is given, as this plant in the northern parts of its range generally is lesser branched than the type. A f. multiramosum FERN., however, occurs also in the southern parts of the American range of the glabrous variety. All the plants taken by us belong to the glabrous few-branched variety, but a specimen taken by N. Hartz Sept. 6th, 1889, at Tassersuaq, Tas. F., is distinctly scabrous and, at the same time, “multiramosum’’, 1. e., the typical European form. Equisetum hiemale L. not seen. — variegatum SCHLEICH., common. Lycopodium Selago L. common. — annotinum L. common, especially in the var. pungens Desv. — alpinum L., common. — complanatum L., not common; found by us at Björnedal; Eqaluit, Ig. F.; Amitsuarssuk; Taserssuaq, Tas. F.; Kangikitsoq. — clavatum L. Taserssuag and Uiluvit, Tas. F. Selaginella selaginoides (L.) Link, probably common, Eqaluit, Ig. F.; Tasiussag, Qag. F.; Kiagtüt, Tun. F.; Igdlorsuit, Il. F.; Prins Christians Sund. Isoetes echinospora Dur. Igaliko; Amitsuassuk; Tasserssuaq, Tas. F., abundant; Prins Christians Sund. Juniperus communis L. v. nana (WuLp.) Loup., common. Sparganium hyperboreum Laesr., Ivigtüt; Igaliko; Qagssuarssuk and Eqaluit, Ig. F.; Amitsuarssuk; Taserssuaq; Kangikitsoq; Flow- ering and fruiting specimens seen. — affine SCHNITZL. not seen. Potamogeton filiformis Pers. Igaliko; Qagssiarssuk, Ig. F.; flowering specimens seen. — groenlandicus HÄGSTR. not seen. — alpinus Bars. Qagssiarssuk, Ig. F.; sterile. — gramineus, L. Igaliko and Qagssiarssuk, Ig. F.; Taserssuaq, abun- dant; Frederiksdal; all seen by us were sterile. Stray Contributions to the Flora of Greenland I—V. 11 Triglochin palustre L. probably common. Anthoxanthum odoratum L., very abundant at all places visited in the northern fiord region of the Julianehaab district, not seen in the southern region. Hierochloé alpina (Sw.) Roem. & ScHuLT., common. Phleum alpinum L., common. Alopecurus aequalis SoBoL. var. natans (WAHL) FERN. Qagsserssuaq, Tun. F.; Qagsserssuaq, Ig. F.; Tasiüssaq, Qag. F.; Amitsuarssuk, Ig. F.; Taserssuaq, Tas. F.; Frederiksdal. Agrostis stolonifera L. Neria; Qagssiarssuk, Ig. F.; Tasiüssaq, Qaq. F.; Amitsuarssuk. — canina, L., common. — borealis HARTM., common. Calamagrostis Langsdorfit (Link) Trın., common. — hyperborea LANGE, common. — neglecta (EHrH.) FL. D. Wert. var. borealis LANGE seems to be much rarer than in the middle parts of West Greenland; new lo- calities: Neria; S. of Kiagtüt. — purpurascens R. Br. The continuous range of this species is from 73° to about 64° N. South of that it has once been found in Tunugd- liarfik Fiord at Kiagtüt, 61°12’, by Kornerup, and once at the end of the Frederikshaab Glacier, 62°30’, by Horst. Kornerup’s specimens are quite immature, but still they show the essential characters of the species; the woollen tufts on the leaves at the joint, the well developed lacerate ligula, the short hairs of the florets and the long awns. Probably in both cases the specimens were representatives of an alpine floral element washed down with the torrents. We searched for it, but in vain. Deschampsia alpina (L.) Roem. & SCHULT., common. — flexuosa (L.) Trın., common. Trisetum spicatum (L.) Ricut., common. A revision of its numerous variations in Greenland is needed. Although FERNALD, in his revision of N. E. American forms, also mentions specimens from Greenland (Rhodora 1916, 195), he unfortunately does not consider the varieties described by Lance, some of which will probably be identical with American forms. Poa alpigena (Fr.) Linn. (P. pratensis AUTT.), common. _ — nemoralis L., common. — glauca VAHL, common. — alpina L., common. A revision of the numerous Greenland forms, (and hybrids?), of the four species mentioned, in the light of the 124 Morten P. PorsiLp. recent studies of C. A. M. LınpmaAn, in HoLMBERG: Skandinaviens Flora H. 2, p. 198, and in Rep. Sc. Res. Norweg. Exp. to Novaya Zemlya 1921 etc. is much needed. Poa annua L. Sangmigssoq, abundant around the settlement. Phippsia algida (Sou.) R. Br. Only noticed at Ivigtüt. Puccinellia an retroflexa (Gurt) Home. subsp. borealis Hotms.? A well sized, more or less erect Puccinellia-species was quite common. It probably belongs here. — maritima (Hups.) PARL. searched for without success. — phryganodes (Trin.) Scripn. & Merr. Björnedal; Tasermiut F.; Kangikitsoq; Igdlorsuit, Il. F.; Prins Chr. Sund. Festuca ovina L. sens. latissimo, common. — rubra L. s. latiss., common. Also the Greenland species and varieties of Festuca need a revision. Nardus stricta L., very abundant in the Tasermiut- and Ilua Fiords, also seen at Nunatsuk on the east coast, but here confined to moist depressions, and growing exactly to the limit of the lasting snow in winter. Agropyron violaceum (Horn.) LANGE. Björnedal; Amitsuarssuk; Taser- ssuaq; Tas. F. Elymus arenarius L. var. villosus E. MEY., common. Eriophorum Scheuchzeriı HorpE, common. — angustifollum Roru, common. Scirpus caespitosus v. callosus Bıc., common. — pauciflorus LIGHTF., Qagssiarssuk, Ig. F. Heleocharis uniglumis (Link). SCHULT., not seen. Carex nardina Fr. Kiagtüt; Tasiussaq, Qaq. F. — capitata L., Eqaluit, Ig. F.; Qaqortoq; Tasiussaq, Qaq. F. — gynocrates DreJ., Kiagtüt. — scirpoidea MıcHx., common. — microglochin Wauu., Prins Christians Sund. — incurva LIGHTF., rare, Qagssiarssuk, Tun. F. — Macloviana d’Urv., common. — pratensis DREJ., Qagssiarssuk, Ig. F.; Qaqortoq. — Lachenalii ScHK., common. — glareosa WAHL., common. — canescens L., common. — brunnescens (PERS.) Porr., common. — bicolor ALL., not seen. — rufina DREJ., not seen. — rigida Goop., common. Stray Contributions to the Flora of Greenland I—V. 13 Carex Goodenoughii Gay., probably common in the northern part of the Julianehaab distriet, additional localities: Qagssiarssuk, Tun. F. — subspathacea WORMSKJ., not seen. a — salina WanL., Qagssiarssuk, Ig. F.; “Uiluvit”’; Nunatsuk; all our specimens were immature and cannot be definitely identified; at “Uiluvit” they were growing in great abundance along the border of a lagoon, forming zones. The plants of the innermost zone, growing between willows, are tall and approach var. Aaitegatensis Fr. Others seem to be identical with C. groenlandica LANGE or C. hyperborea Dres. The plants from Nunatsuk grew in a swampy depression near the sea, but with no other halophilous plants be- tween. They are nearer the type than the others, (suggestions by Dr. Tu. Horn). — Lyngbyei Horn., not seen. — alpina Sw., common. — Buxbaumii WAHL., not seen. — stylosa C. A. Mey., common, also in the interior of the fiords. — atrata L., common. — deflexa Horn., Kvanefjord; Kiagtüt; Tasiussaq, Qaq. F.; Taser- ssuaq, Tas. F.; Kangikitsoq. — supina WAHL. seems to be much rarer than in the middle sections of West Greenland. Formerly, it had been recorded only from Qagssiarssuk, Ig. F. where we found it again; also at Igaliko and Kiagtüt. — rariflora (WAHL.) SM., common. — panicea L., not seen. — capillaris L., common. — Oederi Rerz., hitherto only recorded from Igaliko; we found it at Qagssiarssuk, Ig. F. — rostrata Stokes, heretofore only from Igaliko and Taserssuaq where we found it again, in the last place covering a very wide area; also at Qagssiarssuk, Ig. F. — rotundata Stokes is probably common, additional localities seen: Narssalik; Qagssiarssuk, Tun. F.; Eqaluit, Ig. F.; Qaqortoq; Taser- ssuaq, Tas. F.; Frederiksdal; Nunatsuk. Juncus filiformis L., Eqaluit in Kuanersoq; Qagssiarssuk and Eqaluit, Ig. F.; Qaqortoq; Taserssuaq, Tas. F.; Kangikitsoq. — aretieus Wırv., S. of Kiagtüt, Tun. F.; Qagssiarssuk, Ig. F. Ta- sermiut F., several places; Igdlorsuit, IL F. — nodulosus Waut., additional locality: Eqaluit, Ig. F. — squarrosus L., not seen. 14 Morten P. PoRrsiLD. Juncus bufonius L., abundant at Igaliko where it has been collected before. Also at Narssaq, Tun. F. — albescens (LANGE) Fern. (J. triglumis Autrt. de. fl. Grl., non L.), Björnedal; S. of Kiagtit, Tun. F.; Taserssuaq, Tas. F. — trifidus L., common. Luzula parviflora (Euru.) DeEsv., common. — arcuata WAHL., not seen. — confusa LINDEB., probably rare. — multiflora (RETZ.) Les., common. — frigida (Bucu.) Sam., probably common. — spicata (L.) Lam., common. Tofieldia palustris Hups., common. Streptopus amplexifolius (L.) De., Neria; Björnedal; Qaqortoq; Amit- suarssuk. Orchis rotundifolia Banks., by us only found at Qagssiarssuk, Ig. F. where it has been found before. The specimens were abundant in a very dry Dryas-Lichen-heath as well as in swampy depressions among mosses under willows. Habenaria straminea Fern. Rhodora, 1926, p.174 (H. albida Autt. de. fl. Grl. non M. albida (L.) R. Br.), common. FERNALD has shown that the plant which has passed as H. albida in Newfoundland, Greenland, Iceland and the Faerö Islands is specifically distinct from the European. Our plants have a very distinct scent of vanilla, whereas the Swedish and Alpine plants are described as, “faintly scented’. — hyperborea (L.) R. Br. (Limnorchis hyperborea, Ryps., Bull. Torr. Bot. Cl. 28, 1901, p. 620). The small plant with the slender spur, equalling typical material from Iceland, seems, in Greenland, to be confined to the area of the larger birch. We found it abundant at Igaliko, Qagssiarssuk, Ig. F., I have also specimens from Lichtenau and Ivigtüt. Where it occurred, generally there were no specimens of the much commoner subsequent variety. — hyperborea var. major LANGE (Limnorchis major RyDe. |. c., p. 617), common. Also this plant is fragrant, recalling the scent of Dianthus. Listera cordata (L.) R. Br. Probably common; additional localities: Björnedal; Amitsuarssuk, abundant; Kangikitsoq; Igdlorsuit, [lua F. Coralliorrhiza trifida CHAT. seems to be rare; Neria. Salix herbacea L., common. — Uva Ursi Pursx., Björnedal. Stray Contributions to the Flora of Greenland I—V. 15 Salix chloroclados Fron. (S. groenlandica (AND.) LunDstr.), noticed in nearly all places visited but, as has already been said by Rosen- VINGE, markedly less abundant than in the middle parts of West Greenland. — glauca L., everywhere. The more or less erect willows forming thickets in South Greenland seemed to us rather different from what we generally supposed to be S. glauca at higher latitudes. According to Froperus, (Medd. om Grl. 63, 1923), probably no pure i.e. S. glauca free of hybridogenous admixture, is to be met with in Greenland, but these approach very close to the definition of what pure S. glauca should be, as it is given in FLoperus’ work, p. 122. Alnus crispa (Aır.) Pursn. (A. Alnobetula (Euru.) HARTIG, var. repens (WormskJ.) WINKLER). Neria; Björnedal, abundant. Betula. The southern part of Greenland is, as is well known, charac- terized by one dwarf-birch B. glandulosa Micux. and one higher and stouter species allied to B. pubescens EnrH., which on its best localities becomes tree-like, at its northern limit and in higher altitudes only shrubby. Also, hybrids between them have been suggested by previous writers. Our collections have brought nothing new as to the distri- bution, but they were handed over to Dr. J. G. GuNNARsson, the author of the very elaborate study of the birches of Scandinavia. (J. G. Gunnarsson: Monografi över Skandinaviens Betulæ, Arlöv | 1925). Dr. Gunnarsson’s naming of the tree-birch and its several hybrids with B. glandulosa is now at hand, but will no doubt be published by the author elsewhere. Rumex domesticus HARTM., not seen. — Acetosa L., no additional localities. — Acetosella L., common. Oxyria digyna (L.) Hırr., common. Koenigia islandica L., common. Polygonum viviparum L., common. — heterophyllum Lindm. var. boreale (LANGE) LinpM. emend., Sv. Bot. Tidsskrift. 6. 1912, p. 67. (Syn. P. avieulare L. var. borealis LANGE: Consp. Fl. Grl. 1880, p. 105; P. islandicum MEIssN. sec. Autt. Americ.), no additional localities, but quite common in inhabited places. Atriplex (an glabrisculum Evmonst.?) was found by N. Harrz at Taser- 16 Morten P. PoRrsiILD. miutsiaq, Tas. F., very distant from the present settlements, but not very far from Norse ruins. We found it again on the same shore of the fiord, but farther outward, at about 62°28’ N., where it grew very abundantly. Hartz’ as well as our specimens are immature and cannot be definitely identified. Prof. C. H. OstEn- FELD suggests (in litt.) that they belong to A. longipes (DREJ.) emed. TURESSON. Montia lamprosperma Cuam., Narssag and Qagssiarssuk, Tun. F.; Amitsuarssuk; Frederiksdal; Sangmigssoq. Stellaria media CYR., very common, in inhabited places, but observed nowhere else by us. — longipes GOLDIE, much rarer than farther north. — humifusa Rorrs., common. — borealis Bic. (St. calycantha BonG.), common. Cerastium cerastioides (L.) BRITTON, common. — alpinum L., common. — caespitosum GiL., Eqaluit; Kuanersôq. — caespitosum subsp. alpestre (LinpBL.) HARTM., probably common; additional localities: Qagssiarssuk and Eqaluit, Ig. F. Sagina nodosa (L.) FENZL. Igaliko and Qagssiarssuk, Ig. F. — caespitosa (J. VAHL) LANGE, no additional localities. ; — intermedia FENZL., Taserssuaq, Tas. F.; [gdlorssuit, Il. F.; Nunatsuk. — saginoides (L.) DALLA Torre (SX. Linnaei PRESL.), Neria; Nunatsuk. — procumbens L., not seen. Minuartia biflora (L.), not seen. — rubella (WAHL.) GRAEBN. Qagssiarssuk, Tun. F.; Amitsuarssuk; Taserssuaq, Tas. F.; probably common. — groenlandica (Retz.) OSTENF., no additional localities. Honckenya peploides (L.) Eurn., v. diffusa Horn., Tasermiut F., several stations; Kangikitsoq; Igdlorssuit; Prins Christians Sund; probably common in suitable places. Viscaria alpina (L.) Don., very common. In the southern districts white flowered specimens are more common than pink-flowered. Silene acaulis L., common. Coptis trifolia (L.) SALISB., common. Ranunculus reptans L., Qagssiarssuk, Tun. F.; Qagssiarssuk and Eqaluit, Ig. F.; probably common. — hyperboreus Rotrs., Narssalik; Qaqortoq; Amitsuarssuk. — pygmaeus WAHL., Julianehaab (MELDoRF); Nunatsuk. Stray Contributions to the Flora of Greenland I—V, 17 Ranunculus acris L., very common, also on the east coast, at Nu- natsuk. — confervoides (Fr.) AscH. & Gr., Qagssiarssuk, Ig. F.; Amitsuarssuk; Taserssuaq, Tas. F. Thalictrum alpinum L., common. Papaver radicatum Rorrs. (an incl. P. nudicaule L. em. Lunpstr.?), rare; Frederikshaab; Neria; Ivigtüt; Narssaq, Tun. F.; Qagssi- arssuk, Ig. F.; Amitsuarssuk (white-flowered). Subularia aquatica L., found again at Taserssuaq, Tas. F.; Frederiksdal. Cochlearia officinalis L. var. groenlandica (L.) GELERT and v. oblongi- folia (Dc.) GELERT, common. Roripa islandica (OED.) Sch. & THELL., very rare: Ivigtüt (LinpHARD); Qagssiarssuk, Ig. F. Cardamine pratensis L., var. angustifolia Hoox., Björnedal; Qagssiar- ssuk, Tun. F.; Qagssiarssuk, and Eqaluit, Ig. F.; Amitsuarssuk; Taserssuaq, Tas. F. — pratensis var. palustris Wımm. & GRAB., Qagssiarssuk, Tun. F. — bellidifolia L., not seen. Capsella Bursa pastoris L., only seen at Narssaq, flowering specimens, where it has also previously been found, f. inst. by MELporr: big, fruiting specimens. Draba incana L., very common. — stylaris GAY, not seen. — aurea M. WAHL, common. — nivalis LILJEBL., not seen. Arabis alpina L., not very common. — Holboelli Horn., not seen. Drosera rotundifolia L., not seen. Rhodiola rosea L., common. Sedum villosum L., no additional localities. — annuum L., common. Parnassia Kotzebuei Cu. & Scuv., no additional localities. Saxifraga Aizoon Jacg., common. — oppositifolia L., common. — stellaris L., common. — nivalis L., less common than farther north. — tenuis (Waut.) H. Smrrn, Kiagtüt, Tun. F., amongst the preceding species (KORNERUP). LXXVII 2 18 Morten P. PorsiLp. Saxifraga aizoides L., local: Neria; Björnedal; Taserssuaq, Tas. F.; Prins Christians Sund. — cernua L., rare, at least in the lowland: Amitsuarssuk; Taserssuaq, Pas: Te — rivularis L., also quite rare in the lowland: Neria; Qaqortoq; Tasiussaq, Qaq. F.; Nunatsuk. — groenlandica L., less abundant at lowland stations than farther north. Sorbus decora (SARG.) C. K.Scun., in all Alnus- and Betula-thickets visited, but nowhere dominant. Rubus Chamaemorus L., not seen. — saxatilis L., known from a single spot in Tasermiut F. only. We searched for it without success. Comarum palustre L.; rather rare, noticed at four localities of which two are new: Amitsuarssuk; Nunatsuk. Here not seen in lakes or ponds as it occurs farther north, but only in patches of Sphagnum in the thickets. Potentilla maculata Pourr. (P. Crantzit BECK), common. — pacifica Howe Lu (P. anserina 8 groenlandica SER.), not rare. — anserina L. (typica), not seen. Sıbbaldiopsis tridentata (SoL.) Ryps., very common. Sibbaldia procumbens L., not abundant, at least in the lowland. Dryas integrifolia M. VAHL, very scarce, at least in the lowland; Neria, rare (according to EuGeEnıus’ labels); Igaliko; Qagssiarssuk, Ig. F., very abundant; not seen in the southern parts. Alchemilla alpina L., very common. — minor, subsp. filicaulis (Bus.) Linps. Fır., Eqaluit in Kuänersög; Björnedal; Julianehaab (MELDoRF); Kangikitsoq; Igdlorssuit, Il. F.; Prins Christians Sund; probably common. — glomerulans Bus. apparently rarer than the preceding species: Neria; Björnedal; Nunatsuk. Vicia Cracca L., at Igaliko, its only occurrence, it grew abundantly amongst grass in an overgrazed meadow. The plants were dwarfish and sterile. Lathyrus maritimus (L.) Bic. Except in the Tasermiut Fiord, present everywhere from the Tunugdliarfik Fiord to Nunatsuk, often very abundantly. Geranium silvaticum L., only found once, not seen by us. Callitriche verna Kürz., not seen. Stray Contributions to the Flora of Greenland I—V. 19 Callitriche hamulata Kürz., Björnedal; Taserssuaq, Tas. F.; Frede- riksdal. — anceps FERNALD, Kangikitsoq. Viola Selkirkit Pursu, Eqaluit in Kuänersôq. — palustris L., common. — montana L., Qagssiarssuk, Tun. F.; Igaliko and Eqaluit, Ig. F.; Tasiussaq, Qaq. F. — labradorica SCHRANK, Eqaluit in Kuänersôq; Neria; Eqaluit, Ig. F.; Amitsuarssuk. Epilobium palustre L. var. labradoricum Hausskn., additional localities: Neria and Narssalik, where it is common; Amitsuarssuk; Prins Christians Sund. — anagallidifolium Lam., common. — lactiflorum Hausskn., Neria; Amitsuarssuk; Taserssuaq, Tas. F., very abundant; Kangikitsoq; Igdlorssuit, Il. F.; Prins Christians Sund; probably common. — Hornemanni REICHENB., seems to be less common than the prece- ding species, additional localities: Neria; Tasiussaq, Qaq. F.; Uiluvit. Chamaenerium angustifolium (L.) Spacu, var. intermedium (WORMSKJ.) LANGE, common. — latifolium (L.) SPACH, common. — latifolium f. elatior Hausskn., Björnedal; Prins Christians Sund. Myriophyllum alterniflorum De., found in three places, of which Taser- ssuaq, Tas. F. seems to be a new locality. Hippuris vulgarıs L. Quite common. Ligusticum scoticum L. Quite common; additional localities: Björnedal; Amitsuarssuk; Frederiksdal. Archangelica officinalis Horrm., common. Cornus suecica L., very common. — canadensis L., searched for in vain. Empetrum nigrum L., common. — var. purpureum (Rar.) De. Redfruited crowberries have been reported several times from Atlantic North America and from North Greenland and Ellesmere- land. They have sometimes erroneously been considered identical with the South American species. FERNALD and WieGanD have shown that in Atlantic North America, besides 2. nigrum, there occur 9% 20 MorTEN P. PorsiLp. two redfruited species, E. Eamesii and E. atropurpureum, which are distinct from the South American species but nearer allied to them than to E.nigrum. And lately FERNALD has found again the redfruited form of E. nıgrum. The several very interesting stages in the development of our knowledge of these plants and their history are given in the following papers. M. L. Fernarp: The Chilian Empetrum in New England. Rhodora 1902. p. 147. H. G. Simmons: The Vascular Plants in the Flora of Ellesmereland, 1906, p. 43. — A revised list of the Flowering Plants and Ferns of N.W. Greenland 1909, p. 59. M. L. FERNALD & K. M. Wiecanp: The Genus Empetrum in North America, Rhodora 1913, p. 211. M. L. FERNALD: Empetrum nigrum f. purpureum (RArF.) n. comb. From West Greenland redfruited crowberries have never been reported, and I have for many years searched for them in vain. Berries which do not attain full maturity before the frosts set in, will the next spring remain on the shrub in a discoloured, reddish-brown state, and have an acid taste. This case is very common. Amongst plants dried and sent by Mr. J. Eugenius, 1925, was a set of Empetrum nigrum, taken on Narssalik Island, 61°38’, on Aug. 23nd, with partially unripe and greenish, partially ripe and purplish fruits, but in all other respects a typical E. nigrum. Pirola rotundifolia L. var. arenaria Mert. & Kocu. As to the disting- uishing characters separating this plant from its nearest allies: P. rotundifolia, typical, P. grandiflora and P. americana see LANGE: Consp. Fl. Grl. 1880, p. 84; Warmine: Medd. om Grl. 36, p. 60, 1912; FERNALD»D: Rhodora 1920, p. 121; FernaLp: Ruopora 1904, p. 197; H. ANDRES: Österr. Bot. Zeitschr. 1913 (not accessible to me, quoted in Hecı: Ill. Fl. v. Mittel Europa vol. V. 3. T., p. 1587). According to the last mentioned author, the plant should be scent- less, which is doubted by BRAUN-BLANQUET, who treated the Pirolaceae in Heats Flora. And, as a matter of fact, on the labels of specimens from Newfoundland (Gray Herbarium Nr. 6000) expressly stated “fragrant”. This plant seems to be very rare in Greenland. From the district here treated I have seen a specimen from Ivigtüt (leg. Norman) and one from Neria (leg. EUGENIUS). — grandiflora Rapius, very rare, at least in the lowland, by us only seen S. of Kiagtüt, Tun. F., sterile specimens. It has been taken twice, both times flowering, in the same fiord by KornErUP, one set from an altitude of 1000 ft.; the other in a bog. Stray Contributions to the Flora of Greenland I—V. 2 Pirola minor L., common. Ledum groenlandicum OED., common. Rhododendron lapponicum L., common. Loiseleuria procumbens (L.), DEsv., common. Phyllodoce coerulea (L.) Bas., common. Harrimanella hypnoides (L.), Cov., quite scarce in the lowland, but, according to ROSENVINGE, common on the hills. Andromeda glaucophylla Link., Narssalik (see: part III, p. 32). Oxycoccus quadripetalus GiL., v. microphyllus (LANGE), (see: part IV. p- 38). Vaccinium uliginosum L. var. alpinum Bic. (= subsp. microphylla LANGE) and var. pubescens Horn. are both common. Most of the lowland plants belong to the last-mentioned. The two varieties seem to be different, not only in morphology, but also in distribution, flowering time and in the fruits, and a renewed study of them is needed. — Vitis Idaea L., var. minus Lopp. (= var. pumilum Horn.), very rare, not seen by us. Diapensia lapponica L., rather scarce. Primula stricta Horn. Only once recorded for the section, not seen by us. — egaliksensis WORMSK., very sparingly at its type locality: Igaliko. Statice maritima MILLER, quite common on sea-shores. — sibirica (Turcz.) LEDEB. (an = St. labradorica (WALLR.) Huss. & BLAKE?), very rare, at least in the lowland. Gentiana nivalis L., common, also with white flowers. — aurea L., numerous localities, known before; Igdlorsuit, IL F. — serrata GUNN., only seen at Igaliko. Lomatogonium rotatum (L.) Fr., seen, but no additional localities. Menyanthes trifoliata L., only seen at Igaliko. Thymus arcticus Durand (= Th. Serpyllum v. prostratus Horn.; see Ronnicer: Contributions to the knowledge of the genus Thymus. Rec. Bot. Exch. Cl. 1923, p. 237). Common. Limosella aquatica L., only once reported in the section, not seen by us. Veronica alpina L. sens. latiss., very common, most of the plants from this section seem to belong to the var. villosa (WorMmsKJ.) LANGE. 22 Morten P. PorsiLp. The Greenland forms of this species still need a revision, as F. W. PENNELL’s treatment: “Veronica” in North and South America, Rhodora 1921, is very insufficient and by lack of descrip- tions other than those given in the keys, not convincing. PENNELL considers the northern V. alpina different from the species in the Alps of Gentral Europe, and gives the range of the former as Scan- dinavia, Scotland and East Greenland, whereas V. Wormskjoldu R. & Sch. (= v. villosa) is said to be confined to West Greenland. Such a difference in distribution would certainly strengthen the author’s opinion, but, unfortunately, the specimen quoted from “Flora Danica” as well as the single Greenland specimen of V. al- pina he has seen, both came from Disko, which is not located in East Greenland. Veronica fruticans JACQ., common. Euphrasia arctica LANGE, common. Bartschia alpina L., common. Alectorolophus groenlandicus (CHAB.) OSTENF., common. — groenlandicus var. Drummond-Hayı (Bucu. WHITE) OSTENF. (= A. borealis STERN. an = Rhinanthus oblongifolius FERN.?). Rarer than the preceding species and not growing in company with it. S. of Kiagtüt, Tun. F.; Igaliko and Qagssiarssuk, Ig. F.; Sydpröven; Lichtenau; Taserssuag, Tas. F.; Igdlorsuit, Il. F.; Frederiksdal. Including the two stations mentioned by OstEnrELn (Bot. of the Färöes, p. 95) the total range in Greenland is from 60°30’ N., on the East Coast, to ab. 61°10’ N., on the West. Pedicularis flammea L. According to ROSENVINGE, common, which we cannot corroborate. South of 60°30’ we only found it, very sparingly, at Taserssuaq, Tas. F. Pinguicula vulgaris L., common. Utricularia minor L., not seen. Plantago juncoides Lam., v. glauca (Horn.) Fern. (incl. P. maritima Autt. de Fl. Grl. and P. borealis LANGE, see: FERNALD: The Maritime Plantains of North America, Rhodora, 1925, p. 95). Galium Brandegeei Gray, probably not rare; (see part II, p. 24). — triflorum Mcux., quite common in willow- and birch-thickets and on fertile, grassy slopes. Linnaea borealis L., var. americana (Fors.) REeuper. Neria. Only two localities previously known in the section. Stray Contributions to the Flora of Greenland IV. 23 Campanula uniflora L., not seen. — rotundifolia L., common. Erigeron compositus Pursu., not seen, probably alpine. — uniflorus L., emend. VIERH., quite scarce, at least in the lowland. Neria and Frederikshaab; Taserssuaq, Tas. F. — borealis (VIERH.) SIMM., common. Antennaria groenlandica PORSILD, quite common. — ? intermedia (ROSENVINGE) PorsıLv, Igdlorsuit, Ilua-F.; not typical, perhaps another species. — alpina (L.) R. Br., rare or probably alpine. Neria; Prins Chr. Sund. Gnaphalium supinum L., quite common. — norvegicum GUNN., common. — uliginosum L., not seen. Achillea Millefolium L., f. nigrescens E. Mey. (A. nigrescens RYD8.), seen at several localities, but none new. Matricaria inodora L., var. grandiflora (Hoox.) Ostenr. (= M. i. v. phaeocephala Rupr.), only seen at Igaliko, where it was known before. Leontodon autumnalis L., no additional localities. The specimens col- lected belong to the f. asperior WAHL. TARAXACUM AND HIERACIUM I have to thank Dr. H. Dautstept of Stockholm for his most valuable help in identifying our specimens of these genera. Un- fortunately, our collections here were very. insufficient, mostly because the season was so unfavourably late, that the HigerRacium species, H. alpinum excepted, were just coming into flower when we had to leave the district. Still it would seem that especially the Taraxacum-flora in southmost Greenland deserves a closer investigation than we could undertake. Taraxacum. Group Ceratophora. — brachyceras Dautsr., S. of Kiagtüt, Tun. F.; Qagssiarssuk, Ig. F. According to Dautsrepr (Arkiv f. Bot. B. 5. Nr. 9, p. 20, 1906) formerly known from Arctic Europe, Spitsbergen and N. E. Green- land. — leptoceras Dautst., n. sp., Qagssiarssuk, Ig. F. Group Spectabilia. — croceum Dautst., Narssalik; Björnedal; Qagssiarssuk, Tun. F.; Eqaluit. Ig. F.; Igdlorsuit, Il. F.; Prins Christians Sund, Probably common. — pseudonaevosum Dantst., n. sp., Uiluvit, Tun. F,; Kangikitsoq. — maurostylum Dantst., n.sp., Eqaluit, Ig. F. 24 Morten P. PorsıLD. Hieracium alpinum L., common. — livido-rubens Aımo., Taserssuaq, Tas. F.; Prins Christians Sund. — hyparcticum ALMQ., Eqaluit in Kuänersôq; Björnedal; Amitsuar- ssuk. — groenlandicum ALMQ., Prins Christians Sund. — groenlandicum subsp. silvaticiforme Dauıst. ad int., Taserssuaq, Tas. F. Specimen very imperfect. — ? amitsokense ALMQ., Qagssiarssuk, Tun. F. — rigorosum (Lst.) ALMQ., Qagssiarssuk and S. of Kiagtüt, Tun. F. Noticed on numerous other localities, but as not yet flowering, not collected. Probably common. LE GALIUM BRANDEGEEI GRAY. A very tiny species of Galium was first found in Greenland by J. VAHL, at Julianehaab, 61° N., and Godthaab, 64°10’ N. HORNEMANN identified it as G. uliginosum in Mk. Pl. vol. 2, p. 128, from which work it was taken over in Hooker’s, “Outlines of the distribution of Arctic plants”, 1861, in spite of the fact that VAHL had identified and distributed it with printed labels under the name of G. palustre. When Jon. LANGE, 1857, published a list of Greenland plants in the appendix to Rınk’s Gronland, vol. II, he called it G. palustre, v. minus, the varietal name, only as a “nomen nudum’. In his “Conspectus’’, from 1880, he adds, p- 92, the diagnosis: 2—3 pollicare, foliis obovato-lanceolatis, obtusis, minutis (5—6 mm. longis) ; cyma depauperata, saepe ad florem unicum reducta. Habitus fere G. trifidi L., quod tamen pedicellis capillaribus, corollis trifidis etc. distinguitur. Later, the small Galium has been found and published with LANGE's name from Igaliko, 61° N., (BERLIN); from Sydpröven, 60°26’ N., (Hartz); Tunugdliarfik Qingua, 61°15’ N., (Rosenvince). The latter author has also seen specimens taken by J. VAHL at Kapisilik, 64°20’ N. And lastly, and somewhat unexpectedly, it was stated by KRUUSE to be found on the East Coast, at Tasiussaq, 65°37’ N. During the winter of 1924—25, A. E. PorsıLp was preparing him- Stray Contributions to the Flora of Greenland I—V. 25 self for an intended collecting trip to South Greenland, studying her- barium specimens of types not occurring in the sections of Greenland where he had formerly been. As to the small southern Galium, we had only specimens (duplicate) from Kruuvse’s collection mentioned above. In comparing these with some European material of G. palustre, he realized that the East Greenland plant must be specifically different. One of its most important differ- ences had already been noticed by KRUUSE, namely the trimerous flowers. About his plants KRUUSE says (Medd. om Grl. 30, p. 255): Found butin one place on the edge of a pond among moss and grass, but here very numerous. 3—10cm. long, richly branched, creeping shoots with four-leaved whorls. The joints of the stems 0.7—1 cm. long. The leaves 1—5 mm. long. ca. 1.5 mm. broad. The flowers 1—4 in cyme, abt. 1 mm. broad, the corollawhite, tripetalous, the fruit 0.5—0.8 mm. in diameter. Flow- ers from the 10th of July till the 10th of August, in fruit on the 20th of August. Of course, the species first to suggest itself would be G. trifidum, which occurs in Iceland, but as the East Greenland specimens seemed rather different from European ma- terial of this species, we turned to American literature and soon found that the specimens fairly matched the description of G. brevipes Fern. Fig. 1. Galium Brandegeei Gray from 3 East Greenland, Tasiussaq, 65737" N., & Wieg. leg. C. Kruuse; slightly enlarged. LANGE's remark, that G. tri- fidum should differ from his “palustre, var. minus” by its trifid corolla, can only mean that he had actually seen a tetramerous flower. We were therefore prepared to meet any small-sized Galium occurring in Northern Europe or America, trimerous as well as tetramerous. We hunted many times for them in vain, until we got the first, growing in Sphagnum and other mosses along the borders of lakes and ponds. This and all subsequent ones were, however, G. Brandegeei, according to our excerpts and notes, and we did not succeed in finding any tetramerous species. We found G. Brande- geei at the following places: Agdluitsoq Fiord at Amitsuarssüp Qingua, 26 Morten P. PorsiLp. 60°45’ N., in Sphagnum at the border of lakes under birches and willows; galiko Fiord at Qagssiarssuk, 60°53’ N. under similar conditions; Tunugd- Fig. 2. Galium Brandegeei Gray, from Quebec, Matane County, FERNALD Pass leg. M. L. FERNALD, LupLow Griscom, K. K. Macxenzig, A.S.PrAse and L. B.Smiru. Natural size. liarfik Fiord at Qags- siarssuk, 60°10’ N. and Sydpröven, 60°26’ N., in ponds near the settlement, probably the same place where N. Hartz found it. In all places, where seen, it grew plenti- fully, in Agdluitsog, f. inst., over miles at a stretch, and, on closer investigation than time would permit us, it will certainly prove to be more common. As the tiny stems project barely 1—2 cm. above the moss, it is very inconspi- cuous and it has to be expressly searched for every suitable place. A. E. PorsıLp took all our material to Copenhagen. Prof. M. L.FERNALD generously supplied authentic American material of G. Brandegeei and re- lated species. Having compared our plants with the available ma- terial, he reports: Without much doubt I should say that all earlier collections from West- Greenland are uniform with ours, i.e., belong to the G. Brandegeei Gray, and not to G. palustre or G. trifidum either. Still Kruuse’s plants seem to me to be somewhat different. From Iceland only three poor sets occur in the Copenhagen herbarium. They Stray Contributions to the Flora of Greenland IV. 27 are surely not typical G. trifidum, but the material is too scanty for a definite iden- tification. All Scandinavian material I have seen is G. trifidum, and later from America he adds: Having now seen a large material of G. Brandegeei in the Gray- and Ottawa- herbaria, I am somewhat in doubt about the taxonomic unity of that species or about its range in variation. As Linnaeus’ G. trifidum came from Canada, a careful comparison between the European and American material of this species as well as with the related species probably should be suggested.*) A. E. PorsiLp (in litt.). The type of G. Brandegeei came from New Mexico, Valley Rio Grande on Los Pinos Trail, (Ab. 37° N.), 9000 feet altitude. It was described by Asa Gray in Proc. Am. Ac. 1877, p. 58. Caespitose-depressum, parvum, glabrum, laevissimum. Radicibus fibrosis, foliis quaternis obovatis vel spathulatis fere aveniis lin. 1—3 longis. Pedunculis “unifloribus solitariis binisve nudis. Flore albido semi-lineam longo. Fructu laevi glabro. — Twenty years later, K. Wırcann published an extensive revision of the Nth. American Galium-species, allied to G. trifidum, in Bull. Torr. Bot. Cl. 24, p. 389—403, 18972) His description runs: Perennial and caespitose, forming dense mats, stems low and prostrate or ascending (5—12 cm. long), slender and rather densely leafy, smooth or nearly so; branches when present solitary; leaves in fours, unequal, obovate-spathulate, small (10 mm.) or less; rounded at the apex, cuneate at the base, somewhat fleshy, dull on both surfaces, veins indistinct, margins and midribs glabrous; flowers lateral, commonly geminate, on glabrous arcuate pedicels which are as long or longer than the leaves, corolla of med. size, white, 3-parted, lobes broadly ovate, obtuse, fruit glab. Endosperm spherical hollow, annular in cross-section. The specimens from our collections agree very well with the des- criptions given and with specimens from Québec and Newfoundland, only our plants are somewhat more branched. In American literature the plant is said to grow in springy places, whereas we took ours in Sphagnum, but in one specimen from the Tabletop Mts. in Québec, 1100 m. alt., (Gray Herbarium N. 26020), the roots were entangled in a clump of Sphagnum. 1) Already Ruprecur noticed that American and Russian specimens were slightly different. Fl. Samojed. Cisural., Beitr. Pfl. Russ. Reich. Lief. 2., St. Petersb. 1845, p. 38. 2) I have had no access to these papers, only the quotations having been copied for me. bo CO Morten P. PorsiLp. The specimens from East Greenland collected and described by KRUUSE (see above) are smaller than ours and in habit, branch- ing and dimensions come nearest to G. brevipes, Fern. & WIEGAND, but stems, leaf margins and midribs, as well as the peduncles, are per- fectly glabrous, so it must be a dwarfish form of G. Brandegeei. Fig. 3. Galium Brandegeei Gray, from South Greenland, Amitsuarssoq 60°45’ N., leg. A. E. PorsıLn & M. P. PorsiLp, slightly enlarged. What is Galium brevipes FERN. & WIEG.? The original description of this plant runs: humile valde implicatum, caulibus 0.5—3 dm. longis ramosissimis glabrescentibus vel paulo retrorso-scabris, internodiis longioribus 1—3 cm. longis; foliis plerumque 4is subinequalibus oblanceolatis vel oblongo-lanceolatis obtusis cuneatis 2—10 mm. _longis 1-nerviis glabris vel margine et subtus in nervo scabris; floribus axillaribus solitariis vel binis; pedicellis arcuatis glabris demum 0.5—4 mm. longis; corollis minutis albidis, lobis 3 obtusis; fructu glabro, carpellis maturis 0.8—1 mm. diametro, endospermo in sectione transversali annulare. (Rhodora 1910, p. 78). Stray Contributions to the Flora of Greenland I—V. 29 The type came from an exsiccated marlpond near the mouth of the Grand River, Gaspe County, Quebec. Beyond this, two localities from Maine and one from Minnesota are known. Quite recently, FER- NALD has withdrawn this species, making it a synonym under G. Brande- geei, (“Persistence” etc., p. 283, in a footnote, without giving reasons for the transfer). Due to the courtesy of Prof. FERNALD, I have been able to investigate good specimens, also of the type collection, over twen- ty individuals, and they are all, seen under micro- scope,minutelyretrorse- scabrous on stems and leaf margins (see Fig. 5a). As G. Brandegeei is best defined from all the others by its glabrous stems, leaves and peduncles, a transfer to this species therefore cannot be effected without changing the definition of G. Brandegeei considerably. In its richly branched stem G. brevipes recalls dwarfish specimens of G. trifidum, and we learn that the au- thors of it first considered it, at least partially, as the var. subbiflorum WıEG. of Fig. 4. Galium brevipes FERNALD & WIEGAND, G. trifidum. But, on the from Maine, Aroostock County, New Limerick, leg. M. L. Fernauo. Slightly enlarged. other hand, the peduncles and the shape of the leaves in G. trifidum are widely different. One part of the variety subbiflorum was later transferred by Wırsann to G. Claytoni Micux., (Rhodora 1910, p. 228), and, certainly, as will be seen from the key below, G. ES Ré = u ho EN ee ee | mm Figs. 5a. Galium brevipes, part of stem showing spines, drawn from type specimen, Grand River, Gaspé County, Québec. b Fruits of the same. 30 Morten P. PoRSsILD. brevipes rather closely approaches that variety. Perhaps it would be best to keep @. brevipes as a distinct species until more observations of it can be obtained. To show the relationships and to facilitate the search for eventual new occurrences, I have annexed an Analytical Arrangement of the small Galium-species of N. Europe, Greenland and N. Atl. America. I. Corolla tetramerous. A. Leaves in whorls of 6—8, linear-lanceolate, with distinct mucro, 5—10 mm. long, 1—2 mm. broad. Mature fruits warty, ab. 1 mm. in diam. Erect, 1.5—3 dm. high, retrorse-scabrous, with apical, richly flowered inflorescences. Not blackening when dried. Wet bogs, meadows and lake-borders in temp.-bor. Europe and Iceland, (not in America). G. uliginosum L. Fig.: Fl. D. 1509; Rchb. 1193; Hegi: VIST. tab. 248. fig. 4; Lindman: pag. 505. B. Leaves in whorls of 4, linear-lanceolate to oblanceolate-spatulate, obtuse, without mucro. Fruits glabrous. a. Inflorescence forming small dichotomous cymes with se- veral flowers, the peduncles of which become gradually hori- zontally distant. Plant erect, 2—5 dm. high, sparingly branched, retrorse-scabrous, blackening in drying. Leaves 10—12 mm. long, 2—4 mm. broad. Fruits united nearly to the top, 2.5—3.3 mm. in diam. Wet meadows, temp.-bor. Europe, (not in Iceland), temp.-bor. N. America to Québec and Newfoundland. G. palustre L. Fig.: Fl. D. 2764; Rchb. 1185, I; Hegi: VI, 1. tab. 248,3; Lindman: p. 503; Gray Man.: p. 749. In Europe several varieties are discerned; see f. inst., Neuman & Ahlfvengren p: 107: b. Flowers in single pairs or in very few-flowered cymes. a. Leaves normally erect, 15—25 mm. long, faintly scabrous on margins and midribs of lower side. Stem erect, 1—8 dm. high, freely branching from base. Peduncles not horizontally distant. Fruits 2.5—3.5 mm. in diam. | | | | 8. Leaves soon reflexed, 5 Stray Contributions to the Flora of Greenland I—V. 31 Damp, shaded woods in E.N. America to Quebec; (not in Europe). G. tinctorium L. Fig.: Gray Man. p. 750. 15 mm. long, distinctly scabrous on margins and midribs of lower side. Plant erect, 0.5—3 dm. high, from capillary rootstocks. Inflorescence as in the pre- ceding species, flowers rather larger, but fruits much smaller, 1.0—1.5 mm. in diam. In mossy Larix- and Thuja-swamps of bor. N. America to 8. Labrador; (not in Europe). G. labradoricum WIEG. Fig.: Gray Man. p. 750. II. Corolla trimerous. A. Stems distinctly retrorse-scabrous. a. Flaccid and weak, freely branching, often densely matting. Flowers solitary or geminate on capillary, arcuate, 0.5—2 cm. long peduncles. Leaves narrow, linear-lanceolate, often re- flexed, their margins and midribs as well as the peduncles re- trorse-scabrous. Fruits 1.25—1.50 mm. in diam., only halfway united. Bogs, mossy woods and wet lake-shores in bor.-subarct. N. America to Labrador, bor.-subarct. N. Europe, Iceland (?), Styria (one locality). G. trifidum L. Fig.: Fl. D. 48; Rchb. 1198, Il; Hegi: VI. 1. p. 223; Gray Man. p. 750. Stouter, suberect. Flowers in terminal cymes of 2’s or 4’s, on thick, straight and glabrous peduncles. Leaves spatulate, retrorse-scabrous on margins and midribs. Swamps and damp places in Pac. N. America, Cordilleras, and E., temp.- bor. N. America to Québec and Newfoundland; (not in Europe). G. Claytoni Micux. Fig.: Gray Man. p. 750. B. Stems indistinctly scabrous or glabrescent; leaves scabrous on margins and midribs. a. Flowers solitary or paired, on straight or arcuate, axillary, very slightly prickly peduncles. A glabrescent form of the pre- ceding, more boreal in distribution and especially from brackish and lime-stone localities in E. N. America to S. Labrador. G. Claytoni var. subbiflorum Wine. Morten P. Porsıu». © DD b. Very small, richly branched and densely matted. Flowers solitary or geminate on very short, 0.5—4 mm. long, glabrous, curved peduncles. Fruits very small, 0.8—1.0 mm. in diam. Wet swamps in Coniferous woods in E. N. America: Minn., Me. and Quebec. G. brevipes FERN. & WIEG. Fig. nostra 4, 5b. C. Stems, peduncles and leaves glabrous. a. A form of G. trifidum, from which it only differs in the glabrous stems, peduncles and leaves. Fruits slightly larger, 1.50—1.75 mm. in diam. Brackish marshes in E. Atl. N. America, from Me. — Québec. G. trifidum var. halophilum Fern & Wiec. b. Sparingly branched, suberect, 5—15 cm. high. Flowers lateral, solitary or geminate, on arcuate pedicels, as long or longer than the leaves, (10 mm.). Fruits 1.”—2 mm. in diam. Springy places and wet moss in New Mexico, alpine; bor.-atl. America: Gaspé, Newfoundland and Labrador; 8. Greenland. G. Brandegeet GRAY. Fig. nostra 1—3, 5a. JØDE THE GENUS ANDROMEDA IN GREENLAND During his extensive travels throughout the settled coast of West Greenland, Jens VAHL found no Andromeda. The first to report it was J. TAYLOR, surgeon on whaling ships, who states A. polifolia for Disco, 69°10’ N. and Wilcox Point 74°18’ N. (Trans. Bot. Soc. Edinb. Vol. VII. Part II, 1862). H.C. Hart, botanist on the NARES expedition, claims Abbreviated titles used in the key. FI. D. Icones Florae Daniae, Hauniae 1761—1880. Not seen. Rchb. Reichenbach: Icones Florae Germaniae, 1834—67. Not seen. Gray Man. Robinson & Fernald: The Gray Manual or Handbook of Flowering Plants and Ferns . . . N. U.$. and Canada. 7. 1908. Hegi: Illustrierte Flora v. Mittel-Europa, Vol. I—VI. not finished. Lindman: Svensk Fanerogamflora, 2. uppl. 1926. Neuman & Ahlfvengren: Sveriges Flora, 1901. Stray Contributions to the Flora of Greenland I—V. oun NAS, fin ww to have collected the same species, 1875, on “S. Disko, E. of Godhavn”. (Journ. Bot. London 1880). According to H. G. Simmons, who studied the plants of Tayror and Harr in the herbaria of the British Museum, there are, however, no Andromedas among them. The identifications must consequently have been erroneous, as was often the case with the said authors. As to the last locality the present writer may remark that, after twenty years of botanizing “E. of Godhavn, S. Disko”, he has found no Andromedas there. In 1878, an Andromeda was picked up by the geologist A. Kor- NERUP, at the head of the small fiord Tiningnertôq, 62°20’, just south of the great Frederikshaab glacier. The plant was identified by Jon. LANGE as A. polifolia and the specimens were preserved. They were dwarfish, growing in Sphagnum, showing barely two years growth overtopping the moss, each year’s growth 15—20 mm. long and with 3—4 leaves. Young flowers are present, but no fruits. Later this section of Greenland — not the locality itself — has been investigated by the very experienced collectors L. K. Rosenvince and N. Hartz, but without adding new stations for Andromeda. In 1925 I had made a collecting trip to the southernmost parts of Greenland, accompanied by my son, A. E. Porsitp. On our return we stopped for two hours at the settlement of Neria, 61°33’ N. to visit the native catechist J. EuGenius, who for some time has been collecting herbarium specimens for me. In looking over his harvest, we noticed a fine set of a dwarfish Andromeda, matching very well the plants of Kornerup of which I have a small duplicate from LanGe’s herbarium. Eugenıus’ plants were taken on moist, boggy ground on the island of Narssalik, 62°38’ N. Since, I have twice got specimens from the same locality. A week later we arrived at Egedesminde where we met the or- nithological expedition of Mr. E. Lenn Scuioier, of which Mr. Jo- HANNES LARSEN, well known to all for his artistic skill and his thorough knowledge of bird-life, was a member. But he is also known to his friends as having a great knowledge of Danish plants. He told me that he had seen an Andromeda on the small island of Manitsoq, 68°47’ N. the day before. Mr. Larsen took no specimens but only wondered why he had not seen that plant before in the different sections of South Greenland the expedition had visited. I rather doubted the identification of his find, as it seemed surprising to me to get two new stations for a genus only found once before, and this station was so far north; so I proposed a few other names, as Loiseleuria, Phyllodoce, etc. These were unknown to Mr. Larsen, whereas he would not let himself be saddled with the suspicion of having made a mistake about Andromeda. So we started at once to see the plants in doubt. LXXVII 3 34 Morten P. PorsiLp. Under Mr. Larsen’s guidance we went straight to the plant. It grew between mosses — no Sphagnum — in company with Myrtillus uliginosa, Ledum decumbens, Betula nana, species of Carex and Juncus ete., on morainic soil. The island consists totally of gneiss and granite. The area occupied by the Andromeda was barely more than 50 m. across. It was in full flower, on Aug. 22nd, and we found a few fruits from the year before. In identifying plants from West Greenland it is quite appropriate to look up the status of the species in question in Northern Atlantic America. In regard to Andromeda, M. L. FERNALD has shown, (Rhodora 1903, p. 67) that here are two species, viz., the common A. glaucophylla Link. and the much rarer A. polifolia, restricted to arctic-alpine situa- tions. For the history and nomenclature of A. glaucophylla see FER- NALD’S paper, as well as a later article by the same author in Rhodora 1916, 100. Of the first species, I had a specimen from Nova Scotia (Gray Herbarium N. 24289, leg. M.L. Fernaıp and B. Lone.) showing a fruiting shrub 2—3 dm. high with leaves up to 33 mm. in length; thus, in habit and size very different from all the small Greenland specimens. As my partner on the trip, A. E. Porsitp, wanted to leave Greenland to go to America that autumn, I was forced to label our collections of the trip somewhat hurriedly, as he wished to compare some critical plants with the large collections in the Copenhagen herbarium. The Andromedas from both of the new localities were thus labelled “A. poli- folia L.” and duplicates with that name issued. At Copenhagen, however, A. E. Porsitp found ample material of A. glaucophylla, by which he could prove that the Andromedas from all the southern localities in Greenland really belonged to this species, whereas the specimens col- lected at Manitsoq, six degrees farther north, were A. polifolia L. After a renewed investigation of the specimens I quite agree with him. Before going into detail, I have still to mention that WARMING in his “Biology of Arctic Plants” (Medd. om Grl. 36, p. 29) studied the morphology and biology of the flowers of A. polifolia, chiefly on Danish and Norwegian material. He also mentions material from West Green- land, of which he says, in describing the flowers: “I do not find any important difference between Green- land and European individuals.” As the plants of Kornerup, at that time, were the only ones known, this statement must refer to those specimens, i. e. herbarium specimens with but few and quite young flowers. Stray Contributions to the Flora of Greenland I—V. os or The anatomy of the Ericales, in the same work, is given by H. E. PETERSEN (l. c., p. 107, 1917). Dr. PETERSEN made his sections from the KORNERUP plants, labelled by LANGE A. polifolia L., and described them in a comparison with what was known about the anatomy of A. polifolia in Europe. He probably was not aware that any related species might be taken into consideration. PETERSEN found nothing in the anatomical features which “would serve to discern”’ arctic speci- mens from temperate ones, except that he states repeatedly: that the fine pubescence on the lower surface of the Greenland plants does not occur in any European plant. The absence of those hairs on specimens Fig. 6. a. A. polifolia; b. A. glaucophylla, slightly enlarged (after FERNALD). from Arctic Norway might have suggested to the anatomist that he had a specific and no ecologic character before him. The North American species of Andromeda are described by FER- NALD (Rhodora 1903, p. 70—71 and Gray Manual 7. edit. 1908, p. 634— 35) thus: A. polifolia. Low shrub, with elongate creeping base; stem simple or with ascending branches, 5—30cm. high; leaves linear to narrowly oblong, either flat or revolute, glabrous, generally whitened beneath with a varnish-like coat, later often green; bud-scales scarcely glaucous; pedicels in terminal umbels, filiform, straightish 2—4 times exceeding the nodding flower and erect fruit; corolla pink or white; calyx with pale or usually reddish slightly ascending lobes; capsule brown or reddish, obovoid or subglobose, as high as broad. A. glaucophylla Link. Similar in habit; leaves white beneath with close fine pubescence; branchlets and bud-scales glaucous; flowers on thickish curved pedicels rarely twice their length; calyx-lobes whitish, usually spreading; capsule depressed, turban-shaped, glaucous. The Greenland specimens of A. polifolia L. have all leading charac- ters in common with the description above, but the plants are very small. The stems are freely branching in the mosses or humus of decayed 3* 36 Morten P. PorsiLp. leaves and provided with fine-branched and mycotrophic roots right up to the lowermost leaves. Only the tops of the branches are visible above the “soil”, they are hardly over 1 em. long, with very short internodes, bearing 6—10 leaves, and an inflorescence with 3—5 flowers. The leaves are 8—11 mm. long, 1—1.5 mm. broad, in rare cases shorter and broader. The pedicels are 10—15 mm. long, the flowers overtop- ping the uppermost leaves. The plant when in flower is quite conspicuous, but without, it would easily be overlooked. Even in this dwarfish state, the inflore- scence 1s characteristic of the species, as is the waxy coat and Fig. 7. a. A. polifolia from West Greenland, the total absence of hair on the 68°47’ N., with young fruits, Aug. 22nd, 1925 leg. Jouannes Larsen; b. A. glauco- lower surface of the leaf. Also in phylla from West Greenland, 61°22’ N., Europe dwarfed forms are men- Aug. 2nd, 1925, leg. J. Eucenıus. tioned from extreme localities, f. inst., var. acerosa Hartm., but they are probably forms of no taxonomic value. _ As already stated the Greenland specimens of A. glaucophylla Link are likewise, dwarfish, even more than its calciphile variety, iodandra Fern. (Rhodora 1916, 100). The tips of the branches overtopping the moss or the soil are from 1.5—3.5 cm. long, bearing from 8—25 leaves on short- ened internodes. The mature leaves are 10 —18 mm. long and are very involute; in most cases the involute parts of the blade are closely pressed to the midrib. Therefore it is often difficult to see the hairs on the lower surface, as there are none on the whitish midrib. The hairs (fig. 8) are short, one-celled, hyaline, and divergent, forming a very fine and close, but thin, tomentum. They are barely visible under a strong lens, but easily seen in sections under the microscope. The hairs alone are sufficient for discerning the species. But in the dwar- fish state, too, the inflorescence is quite characteristie with its short Fig. 8. Sections of the leaves of A. glaucophylla, showing the hairs on the lower surface; a. typical form from Newfoundland; b. from West Greenland. Stray Contributions to the Flora of Greenland I—V. 37 and thick pedicels, and its tendency to become (see fig. 7) spirally bent. The flowers of the Greenland plants are not oblate subglobose, like the var. iodandra, but distinctly urceolate, light pinkish, distinctly paler than in Greenland forms of A. polifolia. Anthers — in herbarium spec- imens — are brownish, but not pale-brown as is said about the main form. I have not yet seen mature fruits, but only found a very few old ones, showing that the -plant fruits in Greenland, at least in favour- able seasons. Besides the differences given by FERNALD and quoted above, there seems to be yet another. In A. polifolia, as it is described from Europe and as specimens at hand from Europe and Alaska show, the stems are very richly provided with roots, arising as WARMING I. c. has shown, in the axils of the leaves. The Greenland specimens are root-bearing right up to the lowermost leaves. The Greenland specimens of A. glau- cophylla do have roots on the subterranean parts of the stems, but in markedly less degree, and in two herbarium sheets from America there are none at all. One sheet (Gray Herbarium Nr. 24289, from Sphagnous boggy swale bordering a lake in Nova Scotia) shows stems without a single root, measuring 21—25 cm. up to the lowermost leaf. In the other (Gray Herbarium Nr. 26926, from turfy and peaty knolls in limestone barrens in New Foundland, leg. M. L. FERNALD, B. LONG, and B. H. Dunsar) there are none either. The bare parts of the stems under the lowermost leaves are 3—6cm. long. These last specimens are without flowers, but probably belong to the variety iodandra, as the habit matches well with the description and as they came from the same region and kind of soil as the variety. The geographical Distribution of the Species. In America A. polifolia is generally considered an arctic plant, extending very locally south to the Adirondack Mountains, Lake Huron and southern Alaska. Mostly the floras give the distribution quite broadly: “from the Atlantic to the Pacific and to the Arctic Ocean”. From literature available here a few really arctic occurrences may be mentioned: the Atlantic coast of Labrador, Kotzebue Sound and St. Lawrence Island, to which may now be added West Greenland, in 68°47’ N. But in Eurasia this species cannot correctly be labelled arctic. Generally speaking, in Europe and Asia it occupies the northern belt of Coniferous woods and most of the deciduous forest regions. South- wards, it stops when the steppe-belt begins, or it is only to be met with in isolated alpine or boggy situations, see, f. inst., BRAUN-BLANQUET in his treatment of the Ericales in Hear: Illustr. Flora von Mittel- 38 MorTEn P. PorsiLp. europa vol. V. 3, p. 1652, where he states the occurrence to be coin- cident with that of Trientalis europaea, for which a map is given in the same volume p. 1862. Northward, it stops where the forest stops and the tundra begins. At its northern limit it is a lowland plant, in Norway only ascending to low or moderate altitudes (NoRMAN), and only on the most favourable points it reaches high latitudes, f. inst., in Norway and in the Lena valley, up to 71° N. If, indeed, the climatic require- ments of the American and Eurasian stock of A. polifolia are different, a renewed investigation of their identity might be appropriate.’ The arctic Andromeda of America may, with the Greenland plant, constitute an undiscerned form, making Andromeda analogous to such species as Vaccinium Vitis Idea of which Greenland and America have only the variety pumilum, or of Saxifraga comosa, the nearest relative of which S. stellaris is in Europe and South Greenland, but not in America. For A. glaucophylla, FERNALD, l|.c., gives the distribution: Ailik Bay 55° N. in Labrador, west to Lake Winnipeg, south to Minnesota, Pennsylvania and Northern New Jersey. A remarkable extension is Southwest Greenland 62°20’—38’ N., but it has a great number of parallels, f. inst., Carex pratensis, Streptopus amplexifolius, Orchis ro- tundifolia, Anemone Richardsoni and some 30 others. It seems easiest to interpret the small and isolated Andromeda occurrences in Greenland as the dwindling remainder of a more genial postglacial optimum- climate when probably the areas were much larger. IV. THE GREENLAND CRANBERRY. In the southern part of West-Greenland, from the Godthaab Fiord region, in 64°32’ N., and down to the southernmost point, a cranberry is quite common. By J. VAHL, in his printed labels, and by Jon. LANGE, in his “Conspectus Fl. Grl.”, 1880, p. 90, it was simply called Oxycoccus palustris Pers., but A. BERLIN identified plants collected by himself as O. palustris *microcarpus Turcz., and claimed this subspecies to be new to the Greenland flora (Ofv. K. Vet. Ak. Férh. Stockholm 1884, Nr. 7, Stray Contributions to the Flora of Greenland I—V. 9 p- 93). However, BERLIN’S specimens were all sterile and his identifi- cation therefore not very well founded. The name has later been used by HESSELMAN who investigated the mycorrhiza on BERLIN’S specimens (Bih. K. Sv. V. Ak. Handl. Stockh. B. 26, Afd. III, Nr. 2, p- 27). Lance took up BERLIN’S localities in the appendix to his Con- spectus, 1887, p. 267, but did not recognize BERLIN's identifications. But instead, LANGE named the Greenland plants “f. microphylla’, foliis plerisque quam in forma typica minoribus; pedunculis puberulis ‘ and adds, p. 268: Foliis saepius minutis nonnihil accedit ad var. mierocarpam (Turcz.) cui tamen propter pedunculos pubescentes adnumerari non potest. Foliorum magnitudo ceterum, bene observantibus cll. Bertin et WARMING, variabilis est, quare potius forma borealis quam varietas constans habenda est. By L. K. ROSENVINGE in his second appendix to the “Conspectus”, 1892, p. 692, the name microphylla LANGE is also dropped with the remarks: Pedunculi semper puberuli. Folia plerumque minora quam in forma typica (f. microphylla Lee.) ceterum haud diversa. Forma typica haud raro in locis fertili- oribus invenitur, formis intermediis cum f. microphylla conjuncta. Oxycoccus microcarpus Turcz. was probably founded on specimens from the Baical-Dahurian region in Siberia. The species has since been kept separate by nearly all Russian authors. In European floras it ap- peared sometimes as a variety, sometimes as a subspecies, or, it was entirely neglected, but in the latest and most modern Scandinavian floras, f.inst., NEUMAN & AHLFVENGREN, LINDMAN, HJELT, etc., it has, based on closer researches in the field, been given full specific value. Quite recently G. SAMUELSSON, in revising the Swiss herbaria, also found the species quite common in the European Alps. About its taxo- nomic status he says (Vierteljahrschr. Naturf. Ges. Zürich 67, 1922, p. 256): Oxycoccus quadripetalus ist bekanntlich eine ziemlich polymorphe Art. Ihre Ab- grenzung gegen O. microcarpus macht jedoch selten Schwierigkeiten. Das am leich- testen fassbare Merkmal von O. mierocarpus liefert der kahle (oder fast kahle) Blü- tenstiel, (bei O. quadripetalus deutlich behaart!). Die Kleinheit aller Teile, wie Blätter, Blüten, Früchte usw., ist gewöhnlich sehr auffallend. Die Blattform ist auch dadurch etwas abweichend, dass die Blätter ihre grösste Breite fast an der Basis haben und ausgeprägter zugespitzt sind. Die Blüten haben eine gewöhnlich stärker rote Farbe, und die Früchte sind deutlich verlängert (birnen- oder zitronen- förmig). Blütezeit und Fruchtreife fallen ein bis zwei Wochen früher als bei O. quadri- petalus. Zusammen sind diese Merkmale hinreichend, um ©. microcarpus als eine gute systematische Einheit zu bezeichnen. 40 Morten P. PORSILD. Besides the characters mentioned above, there are several of less value, because they seem to be less constant, viz.: O. quadripetalus Git. O. microcarpus Turcz. (= O. paluster PERS.) several flower-stalks single or in pairs pubescent bracts glabrous ciliate calyx-lobes glabrous pubescent on edges, naked filaments pubescent all over on outer side longer than the tubes or fila- anthers shorter than the tubes or fila- ments. ments. It is of far more importance, however, as also SAMUELSSON empha- sizes, that the two species are ecologically different. According to E. Metin, ("Studier Over de Norrländska Myrmarkernas Vegetation’, etc. Uppsala 1917, p. 124 ff.), ©. mierocarpus is bound to a certain, well-defined association of species having Sphagnum fuscum and a few other xerophilous species of Sphagnum as its substratum. O. mi- crocarpus is thus what Braun-Blanquet!) calls “gesellschaftstreu” (in French: “exclusif”), whereas ©. quadripetalus is at most “gesellschafts- hold” (préférant), or even “gesellschaftsvag” (“indifférent”), as it grows on several, ecologically widely different species of Sphagnum, as well as on Hypnaceae or other substrata. Plants with some of the characters verging towards O. quadripe- talus have sometimes been supposed to be hybrids, but SAMUELSSON states (1. c.) that actual hybrids are very rare: Obgleich ich beide hundertmal gesehen habe, so bin ich in der Natur nur einmal auf eine wahrhaft kritische “Zwischenform”, und zwar betreffs aller oben bespro- chenen Merkmale, gestossen, und sie kam tasächlich mit beiden Arten zusammen vor, weshalb ihre Bastardnatur sehr wahrscheinlich ist. O. microcarpus Turcz. is quite common in Northern Europe, from Iceland to Russia, also in the Alps, and in Northern Asia to Sachalın. From America, I have not seen it reported, but a specimen from Wrangel, Alaska, collected by Fr. V.CovıLıe and Tx. H. Kearney (Har- RIMAN Expedition Nr. 436) undoubtedly belongs here. In well-in- vestigated countries, as the Scandinavian peninsula and Finland, O. microcarpus evidently ranges somewhat farther north and to higher altitudes than O. quadripetalus. 1) For the explanation of these terms see f. inst., BRAuN-BLANQUET: Prin- zipien einer Systematik der Pflanzengesellschaften auf floristischer Grundlage. Jahrb. St. Gall. Naturh. Ges. 57. II. 1921 and E. RuEBEL: Ueber die Entwicklung der Gesellschaftsmorphologie. Journ. of Ecology 8. 1920, where numerous other papers on this subject are mentioned. Stray Contributions to the Flora of Greenland I—V. 41 Students of the flower-biology of O. quadripetalus (SPRENGEL, KERNER, LINDMAN, WARMING, KIRCHNER)!) do not think that self- pollination ever takes place in this species. The flower. is slightly protan- drous and the style is elongated, so that the mature stigma is well re- moved from the anther-tubes. The dry pollen-tetrads will easily drop out, but owing to the position of the expanded flower they do not touch the stigma until a humble-bee attaches itself to the flower, and by its weight bends it vertically downwards. Other insects are said to be unable to eflect pollination. The flower-biology of the Oxycoccus from Greenland and Arctic Norway has been investigated by WARMING (Biol. of. Arct. Pl. vol. I, p. 54. Medd. om Gril. 36, 1912). He had evidently also material of O. mi- crocarpus, but he did not recognize the difference between this species and the Greenland plant?) WARMING found that in the flowers of the northern cranberries the anthers were already open and shedding pollen in the bud, as has been observed in many other Arctic Ericaceae. Further, the style in the mature state barely overtops the anther-tubes and he thinks that, in the northern plants, self-pollination regularly takes place. This statement of the length of style fits best with O. mi- crocarpus. The flowers of the Greenland plant, as seen by the pre- sent writer, are fully expanded, with the corolla fully reflexed before the style even protrudes between the anther-tubes, and overtopping stigmas are only seen when the flowers begin to wither. Thus the northern forms of the cranberries may, genetically, be- come pure lines. The Greenland plant. Having before me numerous specimens of 16 different collections and notes from others, kept in the Copenhagen herbarium, I cannot subscribe to the statement by ROSENVINGE, quoted above, that also typical O. quadripetalus occurs in Greenland. To me, they represent a very uniform type which, in brief, can be characterized as different from ©. quadripetalus in all its dimensional characters, as well as in the colour and biology of its flowers. With O. microcarpus, it has the dimensions in common, but it differs in the fruits and the flower-stalks being even more pubescent than in the type. If typical O. quadripetalus did really exist in Greenland, a designation of the dwarfish state as a “forma’’ would be fitting. As it is now, it seems 1) See: Kincuner, Loew u. Scuroeren: Lebensgeschichte der Blütenpflanzen Mitteleuropas. Lief. 23—24. Stuttgart 1923, p. 124. 2) On p. 56 is an obvious “lapsus calami” when W. ascribes “downy” instead of glabrous pedicels to O. microcarpus. 49 Morten P. PoRrsILD. more appropriate to consider it a local variety, fixed genetically, and hence I propose as its name: O. quadripetalus GiLie., var. microphyllus (LANGE) n. c. It differs from the main form chiefly in its dimensions: free, leaf- bearing shoots, generally 2—3 cm., only exceptionally (when not growing on Sphagnum) up to 2 dm. long. Leaves with strongly revolute margins (more than in the type) (3—)4—5(—7) mm. long, 2—2.5 mm. broad, elliptic-ovate. (In O. microcarpus the leaves are nearly of the same size but different in form, being distinctly broadest near the base and more pointed). Peduncles single, rarely in pairs, brownish-red, (10—)12—15 (—18) mm. long, densely covered by short whitish hairs, especially upwards, nearly as dense as in ©. macrocarpus Pursu. Calyx-lobes with red margins, finally entirely red, faintly ciliate, at the top de- pressed and in the median line apiculate. (WARMING l.c., fig. 96 D). (In the type they are evenly rounded-obtuse (WARMING I. c., fig. 57 A), often green throughout). Flowers about half the size of the type, equal- ling those of O. microcarpus. Petals deep red, (in O. quadripetalus whitish with a not well-defined pink midline; in ©. microcarpus this line is deeper coloured and sharper defined). Filaments dark chocolate, pub- escent on margins. Anthers brown, glabrous, tubes slightly longer than the anthers, shiny, golden-bronze-coloured. Style red, in the expanded flower shorter than the tubes but finally barely overtopping them. Berries deep red (like those of Vaccinium Vitis Idaea, v. pumilum), al- ways globular, ab. 5mm. in diameter. V. RANUNCULUS PYGMÆUS WAHL. VAR. LANGEANA NATH. From alpine situations in Gaspé County, Québec, M. L. FERNALD has described (Rhodora 1917, p. 137) a peculiar variety of R. pygmaeus which is called var. petiolulatus n. var. foliis radicalibus pedatim divisis, foliolis 3 petiolulatis rhomboideo-obovatis pal- matis laciniis 3—5 oblongis vel valde divisis; capitulis fructiferis 5—7.5 mm. longis Stray Contributions to the Flora of Greenland I—V. 43 In its basal leaves the new variety is said to be quite like the rare Rocky Mountain species, À. Grayi Brirron, but differing in the floral parts. And in FERNALD’s recent work: “Persistence of Plants in Unela- ciated Areas, etc.’’, Mem. Am. Ac. Sc. 15. III, 1925, p. 299, the plant is considered a strict endemic, characterizing the unglaciated summits of the region mentioned. This plant is, however, also known from Greenland, where it was detected by A. G. Natruorst, 1883, at Unartuarssuk on the east coast of Disko, and described under the name of R. pygmaeus var. *Langeana, (Ofv. K. Vet. Ak. Förh. 1884, N. 1, p. 46), and good photographs were given in the annexed plate. LANGE included the plant in his Conspectus Florae Groenlandicae, pars II. 1887, p. 254, and translated Naruorst’s original Swedish description into Latin: 1—4” alta, caespitosa, foliis radicalibus trisectis, segmentis magis minusve longe petiolatis, sursum latioribus, intermedio saepius 3—4-fido, lateralibus 2—4 fidis, foliis caulinis subsessilibus, ad basin usque 3—5-fidis, laciniis laceolatis v. sublinearibus The plant was found again, in 1890, by N. Harrz at Qutdligssat 70°3’ N., and several other places on East Disko, (Medd. om Grl. 15, 1894, p. 52), and by the present writer at its type locality in 1898 and later. It also occurs on West Disko in Mellemfiord at Kuänit, 69°45’ N., (M. P. P.), and at Qasigigssat, 69°52’ N., (A. E. P.). On the eastern coast of Greenland var. Langeana has been mentioned by Hartz and Kruuse (Medd. om Gril. 18, p. 331, 1895 and ibd. 30, p- 167, 1905) from three localities lying between 70°30’ and 71°40’ N. All Greenland localities, so far, are in the sedimentary sections of Green- land, not in the Archean. In spite of the widely different shape of the leaves NATHORST doubted that his plant was a separate species, as in typical R. pygmaeus, too, the basal leaves show some tendecy to become more deeply cleft. This doubt was emphasized by Hartz and Kruuse who state that the var. Langeana is connected with the main form by intermediate forms. Hartz, especially, mentions such forms from Ritenbenk, in W. Greenland, 69°44’ N., which is in the gneissic area. And a similar statement has been made by myself (Medd. om Grl. 50, p. 375, 1912) from plants collected in W. Greenland, 71°—73° N., in the gneissic area. My statement, however, was a mistake; the plants in question are only somewhat luxuriant forms of typical À. pygmaeus. Having at present no access to the specimens of Harrz or Kruuse, I must for the subse- quent remarks be contented with my own observations from Disko. Lastly, K. Jessen has made an elaborate study of the morphology, anatomy and biology of the arctic Ranunculaceae in Medd. om Gril. 36, 44 Morten P. PorsiLp. p. 383, 1912. Here the variety is also mentioned, but new facts regarding its taxonomic position were not brought forward. Compared with A. pygmaeus, the var. Langeana Natu. is less tufted, the stems are slender erect, 10—15 cm. high, mostly with two stem leaves. Typical A. pygmaeus is densely tufted, more or less prostrate — ascending, but, when growing in moss, the stems be- come longer, 10—12 cm. The leaves are distinctly lighter-coloured and a trifle thinner. JESSEN gives the average thickness of the leaves of À. pygmaeus as 0.27—0.30 mm., whereas sections of the variety Langeana, made by me, averaged 0.22 mm. in thickness. The anatomy of the leaves and the disposition of the stomata are practically the same. Also in var. Langeana, the roots are mycotrophic. NATHORST suggests that the pedicels of the variety seem to be more pubescent than in the typical form, but I have not been able to find any difference when they were of equal maturity. The achenes are practically equal in size and shape. Generally, however, the styles of var. Langeana are straight or nearly so, whereas the styles of R. pygmaeus are distinctly recurved (see Jessen Le. p.382, WAnLENBERG Fl. Lapp., tab. VIII), but straightish styles are also sometimes seen in this species. In spite of the slight difference, except in the form of the leaves, var. Langeana Natu. seems not to be a mere ecologic form, but rather a geographical race, hitherto known from Greenland and alpine Gaspé, Québec. If it were only a form adapted to growth amongst mosses, it would certainly have been noticed long ago in Northern Scandinavia, where R. pygmaeus has been known for nearly 200 years; and then one should easily find it everywhere. But such is not the case, here at least. On many suitable spots it has been searched for in vain, whereas at its type locality, where also typical R. pygmaeus is abundant, it is always easily found. BIANCO LUNO A/S, KBHVN + . ‘ PE @ + Arbejder fra a bötaklake Haye i København. Nr ! "n -HistorisK-flotogiske: Messe " Filosofiske Meddelelser, 2.27... my Mathematisk-fysiske Meddelelser, É DE RÅDNE! Meddelelser NAR Det Kgl. Danske Videnskabernes Selskab. Biologiske Meddelelser. X, 2. THE REPRODUCTION OF AHNFELTIA PLICATA BY L. KOLDERUP ROSENVINGE KØBENHAVN HØVEDKOMMISSIONÆR: ANDR. FRED. HØST & SØN, KGL. HOF-BOGHANDEL BIANCO LUNOS BOGTRYKKERI A/S 1931 Arbejder fra den botaniske Have i København. Nr. 119, Ve MIN AU WIDRKAKN NEW YORK SOTANICAL GARDEN 1. Introduction. Al he relationship and delimitation of the genus Ahnfeltia have always been and are still very uncertain. The genus was first given a tolerably natural delimitation by J. G. AGARDH who distinguished it from the genus Gymno- gongrus near which it was placed (comp. Spee. g. o. II, 1851, p. 310). In his Epicrisis (Sp. g. o. III, 1876, p. 205) this author gives the genus the same position and refers to it 6 species which he divides into three sections: Ahnfeltia, Dictyogenia and Dia- nema, distinguished by differences in the ana- tomical structure of the frond. Nemathecia and cystocarps are mentioned or shortly and incompletely described in some of these spe- cies, but two kinds of reproduction are never recorded in the same species, and it is there- fore doubtful whether all these species really belong to the same genus, even when taking into consideration the anatomical differences Fig. 1. Ahn- mentioned above. Scumirz in his paper on yeltia plicata. Actinococcus (1894, p. 396, see also Scumirz End of frond with nema- and HAUPTFLEISCH in ENGLER u. PRANTL 1896, es De. p. 366) took the genus in a narrower sense, cember. = , : . Fisted, comprising only J. AGARDH's section Ahnfellia, 2'/» while he maintained that the other two sections must be united with Gymnogongrus. According to SCHMITZ, not con- 1? 4 Nr. 2. L. KOLDERUP ROSENVINGE: sidering the nemathecia, no organs of reproduction are known in the genus as founded by SCHMITZ; sex organs and cystocarps are entirely unknown. I can confirm this for the common European species A. plicata (Huds.) Fries of which I have examined numerous specimens from the Danish waters gathered in all seasons without detecting any trace of reproductive organs besides the nemathecia. As the nemathecia have no parallel within the Floridex and as they have been variously interpreted, a closer ex- amination of their structure and development is needed. 2. Earlier Investigations on the nemathecia. The nemathecia of Ahnfeltia plicata seem to have been early observed, but it cannot always be seen from the short descriptions of the earlier authors whether the tubercles mentioned by them refer to the nemathecia or to the fre- quently occurring warts of vegetative character. The lower- most tubercle depicted in English Botany tab. 1089 (1803) agrees well with the nemathecia and undoubtedly represents such an organ. LyNGBYE mentions (1819, p. 42) that the tubercles are in particular met with in spring, which is in good accordance with the behaviour of the true nemathe- cia; he did not observe any spores. C. AGARDH (1822, p. 313) names them nemathecia and states that they are composed of articulate filaments. The following authors (GREVILLE, Harvey, J. AGARDH) confirm that and declare that they have not observed any spores, especially no tetraspores. KirzinG (Tab. phyc. 19, tab. 66) pictures a section through a nemathecium and, more enlarged, the radiating filaments, which are said to be composed of “Kettensporen”. They are represented as long rows of very small oblong cells of The Reproduction of Ahnfeltia plicata. 5 equal size, but these cells are not the spores. These were first described in 1893 by BurrHam and Scumirz, who found that the nemathecial filaments produce at the end each a sporangium which. gives rise to one monospore. BurFHAM observed the escaping monospores which were ellipsoid, about 15 x long, and 7 « thick, thus much larger than the cells of the nemathecial filaments. He gives good figures of these organs (1893, figs. 43, 44). As cited by BUFFHAM from a letter from BORNET, this prominent French algologist had observed such spores as early as 1857. SCHMITZ's observations on the spores agreed with those of BurFHAM, but he also studied the structure of the nema- thecia of this and the related species A. sefacea, and arrived at the conclusion that the nemathecia were not organs of the Ahnfeltia but that they belonged to a parasite, which he called Sterrocolax decipiens, growing on the surface of Ahnfeltia and penetrating into the cortex of the latter with numerous “Senker”. The author admits, however, that the phenomena here described, which he had observed most distinctly in A. selacea, were not easy to observe in A. plicata. SCHMITZ's inference as to the parasitical character of the nemathecia was only founded on the presence of the said processes penetrating into the cortex, and not on the study of the development of the nemathecia. His in- ference is, therefore, not conclusive, for the processes might also be explained as secondary formations developed from the base of the nemathecium produced by the Ahn- feltia. If the nemathecia were not organs of Ahnfellia, it must be concluded that no kind of reproductive organs had ever been observed in these Algæ. Scumirz indeed draws this conclusion for the whole genus Ahnfeltia (1894, p. 397, 1896, p. 366), but this is a priori highly improbable, in 6 Nr. 2. L. KOLDERUP ROSENVINGE: particular for Ahnfeltia plicata which has been so often examined and is of such common occurrence and so easily propagated though it has no vegetative means of propagation. For the elucidation of this question I have examined 1) the development of the nemathecia and 2) the germination of the spores. 3. Development of the nemathecia. At the coasts of Denmark the nemathecia arise in Sep- tember. They are not of parasitical origin but appear as Fig. 2. First origin of nemathecia. September. 670 : 1. small low cushions arising from a group of superficial cells growing out simultaneously and dividing by cross walls (fig. 2). In September I found the cushions very low, only 1—2 cells high. In the middle of October they reach a considerably larger size (fig. 3). The extension may be up to '/s of the circumference of the frond, and this extension is accomplished by the continued production of new nema- thecial filaments at the margin. The cells of the nemathecial filaments are longer than those of the cortical layer, usually 2 to 3 times as long as broad and thinner, often only 2 to 3 w thick; the limit between the cortex and the nema- thecium is, however, not always distinct. At the border of the nemathecium the filaments are shorter and bent some- what outwards. The cells all contain one nucleus; the end- AJ The Reproduction of Ahnfeltia plicata. cells are scarcely different from the others except that they are richer in protoplasm. At this period two kinds of cells different from the others appear in the nemathecial filaments. Some cells ter- minal on radiating cell-rows, usually directly on cortical cell- rows, become flask-shaped, being attenuated upwards, Fig. 3. Nemathecium, October. A, vertical section. 244 : 1. B—D, upper ends of nemathecial filaments with generative cells. 670 : 1. thus reminding one of carpogonia and like these staining deeply with hæmatoxylin, but their content is homogeneous and the nucleus is usually not or scarcely visible. They often appear in great number at the bottom of the nemathecium, arresting the growth of the filaments on which they are terminal (figs. 3 and 4); but they are also to be found at higher levels, even near the surface, I have, however, never seen them protruding above the surface. Only in one case, in a wart from a plant having grown in an aquarium from > r fe) Nr. 2. L. KOLDERUP ROSENVINGE: May to October, I found numerous similar carpogonium- like cells terminal on most of the filaments of the wart, Fig. 4. Nemathecium, October. A, vertical section of nemathecial fila- ments showing flask-shaped cells below and generative cells above. B, upper end of primary nemathecial filament. C, flask-shaped cell. 1080: 1. in several cases protruding above the surface (fig. 5). In some of them a small nucleus was found in the lower or Fig. 5. Vertical section of cushion (anomalous nemathecium?) arisen in a plant kept in an aquarium from May to October. 860 : 1. in the upper part of the cell. These cells might better be considered as sterile hair-cells though such hairs have not The Reproduction of Ahnfeltia plicata. g been met with on the fronds. Hyaline hairs have certainly been observed in the young disc-shaped germlings (see below p. 20, fig. 17), but they were long and had the typical cylindrical shape, not being attenuated upwards. It Fig. 6. Vertical sections of nemathecia, October, showing groups of gener ative cells and horizontal or obliquely upward growing cell-rows spring- ing from them. 625:1. The group of generative cells in fig. B is situated at the boundary between the nemathecium and the cortex. is doubtful whether this wart was a nemathecium or only a sterile wart; at all events it was not normal, but de- generated in the middle. The first described included car- pogonium-like cells may perhaps also be considered sterile, undeveloped hair-cells. The fact that they are never borne on particular cells comparable to carpogonial filaments but 10 Nr. 2. L. KOLDERUP ROSENVINGE: always situated at the end of ordinary nemathecial fila ments or cortical cell-rows, and the absence of a well devel- oped nucleus make it highly improbable that they should be comparable with carpogones. The other kind of cells differ by their greater thickness and by richer contents. They arise at the upper end of the nemathecial filaments, terminal or lateral, singly or usually in small groups which seem to arise by division Fig. 7. From a nemathecium, October. A, vertical section of the border; the outer portion of the nemathecium is built up entirely of generative cells and their derivates. B, generative cells giving rise to horizontal cell-rows. C, generative and flask-shaped cells. A 960 : 1. Band C 1080:1. of a single cell. They have the character of generative cells. Some of them, at least, grow out, in particular in a horizontal direction, between the nemathecial filaments, where their course may be rather irregular. The cells of these filaments are much larger than those of the nema- thecial filaments and they become poorer in contents and therefore often rather hyaline. Fig. 6 shows a horizontal filament running just within the cuticle, and fig. 7 the border of a nemathecium the outer portion of which is exclusively composed of large cells of the same origin. In The Reproduction of Ahnfeltia plicata. 11 fig. 6B is shown a group of generative cells, situated at a low level in the nemathecium, at the limit towards the cor- tex, from the upper cells of which group new branched cell-rows growing obliquely upwards are produced; these cell-rows are thicker than the nemathecial filaments be- tween which they penetrate. In specimens collected in the middle of November the nemathecia had grown thicker and had also increased in circumference, the marginal part growing along the surface CT \A \\\ a ; VA) Fig. 8. Vertical section of nemathecium, November. 160: 1. of the frond from the insertion of the nemathecium, and the nemathecial filaments being here directed outwards. The outermost (lowermost) filaments are close to the sur- face of the cortex but not coalescent with it, and the cuticle of the frond remains easily discernible (fig. 8). No connections between the nemathecial and the cortical cells take place here. The large generative cells found in Oc- tober are found again in the lower portion of the cushion, partly immediately over the limit towards the cortex, partly at a somewhat higher level. They are easily recognisable by their greater size, their irregular shape, their dense cell- contents and their high staining power with hematoxylin. A lively development of cell-filaments like that shown in fig. 6 B has taken place, a great number of upward growing 2 Nr. 2. L. KoLDERUP ROSENVINGE: cell-rows issuing from them. It seems probable to me that all or nearly all the cell-rows situated over the large cells in figs. 9 and 10 have been produced by these cells. These cell-rows resemble the primary nemathecial filaments but are at any rate at first thicker than the latter; they form new nemathecial filaments, continuing their way towards the sur- Fig. 9. Vertical section of lowermost part of nemathecium, November. The irregular cells rich in plasmatic contents are situated at the level of the surface of the frond *. 1080 :1. face of the nemathecium. The content of the generative cells is homogeneous and stains intensely by hematoxylin, but the nucleus is usually not very distinct or scarcely visible. The irregular shape of the cells depends partly on the fact that fusions often take place between cells of different cell-rows. The “Senker’ mentioned and figured by Scumirz (1. c. p. 393 fig. 11 and 12) and interpreted. by this author as haustoria penetrating from the supposed parasite into the host plant, are undoubtedly groups of the ‚here described generative cells. The obconical shape of The Reproduction of Ahnfeltia plicata. 13 these groups of cells, in particular of those situated at the lowermost level of the nemathecia (figs. 6, 8, 9), is the same as that of the “Senker”. The marginal portion of the nemathecium is composed of horizontal cell-rows not connected with the cortex; these cell-rows have probably all taken their origin from the generative cells or their derivates, like those shown in fig. Le == Ce es COCA ae © Van = à Ce | DITITD nr. Den @ Fig. 10. Vertical section of nemathecium, near the border, December. 610,213 7A, and they must therefore be considered as secondary nemathecial filaments. The development of the primary nemathecial filaments is, at all events to a great extent, stopped by the form- ations of the flask-shaped cells and the appearance and further development of the just described generative cells, and they are then replaced by the secondary nemathecial filaments produced by the latter. This arresting seems not only to be caused by the fact that the uppermost cells of the filament have developed into flask-shaped cells or generative cells, for the growth of other filaments also seems to be checked without producing generative cells. On the other hand, primary filaments seem in 14 Nr. 2. L. KOLDERUP ROSENVINGE: some cases to continue their way to the surface of the nemathecium without any connection with the generative cells, e. g. fig. 16E. That, however, is a point that de- serves further investigation. Fig. 10 drawn from a specimen gathered at the end of December favours the view that the nemathecial filaments situated over the generative cells are only or principally produced from them. The narrow cells of the secondary nemathecial filaments Fig. 11. From a nemathecium from Kerteminde, November (Flemming, Heidenhain). End-cells of (secondary) nemathecial filaments showing nu- cleus and chromatophores. The nucleus in A—D has a feebly stained homogeneous central body surrounded by a well limited halo. In E the substance of the nucleus is more condensed but shows no distinct chro- mosomes. In F the limitation of the nucleus is indistinct, a group of 4 chromosomes is situated to the right of the central body. 1800: 1. contain a small nucleus and one or more chromatophores. The apical cell has more plasmatic contents and a larger nucleus situated in the middle of the cell; it is at first not or scarcely thicker than the others, especially when the cell is still dividing (fig. 14 4, F, 15 B). Later on, when the apical cell gradually develops into a monosporangium, it takes an oblong, ovate or obovate shape. Ripe or nearly ripe spores may occur already in November, but the pro- duction of spores continues till May. The resting nucleus The Reproduction of Ahnfeltia plicata. 15 of the end-cell has a large nucleolus or central body, glob- ular or usually somewhat depressed. It is homogeneous in structure and stains intensely or, with a high degree of dif- ferentiation, more feebly by hematoxylin after HEIDENHAIN. The material was fixed in FLEMMING’s weaker solution or after NAWASHIN’s method, but equally good results were obtained with material preserved many years ago in strong alcohol by Dr. HENNING E. PETERSEN. In some cases, in specimens preserved in FLEMMING’s solution or in alcohol, Fig. 12. Same material as fig. 11. Four end-cells from the same section showing nucleus and chromatophores, the latter apparently partly fusing together. 1800 : 1. the chromatophores could not be observed, but usually they were very distinct in a number of 2 or 4 or rarely more. The shape of the chromatophores is very variable, ribbon-shaped, rod-shaped, linear with attenuated ends, sometimes very long and curved or spirally twisted. Their staining power after HEIDENHAIN’S method is considerable, often greater than that of the nucleolus, The most remark- able feature in the young monosporangia is the fact that the chromatophores are not unfrequently found lying in pairs close together along their long axis as shown in several of the figures. When two chromatophores are exactly of the same length and are placed very close together, they 16 Nr. 2. L. KoLDERUP ROSENVINGE: would seem to be the product of a longitudinal divi- sion (figs. 12, 13, 15), but as such a division of chromato- phores has not hitherto, to my knowledge, been ascertained, Fig. 13. From a nemathecium from Kerteminde, November (Nawaschin). The end-cells are swollen and show very distinet chromatophores, partly paired. The nucleus is indistinet in the three first figures. The cell be- neath the monosporangium is short, deeply stained. 1015: 1. further proof must be demanded. On the other hand, the paired chromatophores might be supposed to be on the point of fusing together along the longitudinal axes, and this supposition is more in accordance with the cases Fig. 14. Vertical section of nemathecium. Photograph. About 120:1. where the paired chromatophores are of different lengths. This interpretation is corroborated by the fact that the ripe spores seem to contain one single chromatophore. Paired chromato- phores were observed in end-cells which were still eylindrical and in more or less obovate, nearly ripe monosporangia. As mentioned above, the resting nucleus in the terminal The. Reproduction of Ahnfeltia plicata. 17 cell has a distinct outer limitation and a large homogeneous nucleolus or central body staining more or less intensely with hematoxylin (Heidenhain). In other cases the central body is differentiated into small grains which stain in- tensely with hematoxylin. The number of these grains, which must be supposed to be chromosomes, was often seen Fig. 15. From a nemathecium from Frederikshavn, Henn. Petersen, May (Alcohol, Heidenhain). End cells of nemathecial filaments showing very distinct chromatophores, partly paired, and nucleus. A, group of four end-cells; in 7 the nucleus is in the resting stage, in 4 apparently in the first dividing stage, in 2 the nucleus has lately divided and the two daughter nuclei show each four chromosomes but are still without nuclear membrane. Dividing stages further represented in figs. B, C (2), K. In fig. I the nuclear body is rod-shaped, homogeneous without nuclear membrane. A—G, 1015:1. H—K, 1800: 1. to be 4 (fig. 15). Dividing nuclei were rarely observed, most distinctly in the second cell from the left in fig. 15 A; two groups of 4 chromosomes each are here situated near one another in the axis of the cell, evidently arisen by division Vidensk.Selsk. Biol. Medd, X, 2. 2 18 Nr. 2. L. KoLDERUP ROSENVINGE: of a nucleus like that in the cell to the right of it. The two daughter nuclei are still without nuclear membranes, Another division stage is shown in fig. 15 K, but here the chromosomes are not distinct. The nuclear divisions ob- served were evidently all mitotic. No indication of a synapsis ss i ED CRD Fig. 16. A—F, from the same material as fig. 14. The chromatophores not distinct in figs. A—C. One end-cell in B contains two nuclei. Ripe monospores are present in C. D, the last cell contains a nearly ripe spore, a younger spore is developing in the cell beneath it. E, a spore has been exhausted to the right and a new monosporangium is develop- ing beneath it. The narrow, clavate intensely stained cells are perhaps end-cells of primary nemathecial filaments. F, ripe monospore not yet set free showing nucleus and two chromatophores. G, living, ripe spore set free in May. A—D, 670:1. E—F, 1080:1. G, 670:1. stage or a heterotypic division was ever met with. The formation of the monosporangia is thus not preceded by a reduction of the number of chromosomes, and this is in accordance with the fact that no fertilisation process has The Reproduction of Ahnfeltia plicata. 19 been ascertained. The number of chromosomes in the young still dividing end-cells of the nemathecium being four, it must be supposed that the vegetative cells of the nema- thecium and probably also of the frond have the same number of chromosomes, but owing to the small size of the vegetative nuclei, the chromosomes are very difficult to distinguish. Some observations seem, however, to show that there are really four chromosomes in the nuclei of the cortical and the medullary cells of the frond'. The nemathecia ripen in winter and are still to be found with ripe spores in May, but then they die and in summer Ahnfeltia is always sterile. The ripe nemathecia are hemi- spherical or usually elliptical or obiong, their long axis being parallel to the axis of the frond (fig. 1). The colour is yellowish’. The ripe monosporangia are ellipsoidie or obovate, but the spores set free are globular, about 8.5 w in diameter. They contain numerous small refractive bodies (starch) and one single yellow-brown chromatophore, situated a little excentrically, and beside it a hyaline round spot the nature of which was not ascertained (nucleus or vacuole?) (fig. 16). 3. Germination of the spores. Spores were sown in May 1927, fronds of Ahnfeltia with ripe nemathecia being put down on slides, partly sand- blown, at the bottom of glass-vessels filled with sea-water from the Great Belt, where the fronds had been collected, and placed in a room facing north. The presence of the 1 I am indebted to Dr. C. A. JØRGENSEN, to whom I have shown some of my slides, for having called my attention to such nuelei, but the observations still need confirmation. ? GREVILLE (1830 p. 150) described them as dark coloured. 20 Nr. 2. L. KoLpErup ROSENVINGE: evacuated spores was ascertained, but the first stages of the germination were not observed. About three months after the sowing, small violet orbicular discs composed of a single layer of cells appeared, the smallest ones consist- ing of about 30 cells, the largest of much more. In several cases the discs bore single hyaline hairs (fig. 17). The young plants were kept alive for two years, but in the latter part KS RO AD IR vas sas NR SØ 1 py W Fig. 17. Germlings obtained by sowing monospores in May 1927 on slides. A—C about three months old, in B a young hyaline hair springs from a marginal cell, in C a long hair springs from the disc. D), a two years old germling. A—C, 625:1. D, 350: 1. of this period they did not thrive well and finally perished. They had then increased considerably in circumference and were growing thicker in the middle owing to horizontal cell-divisions, but they showed no trace of an upright shoot. These small crusts agreed exactly in colour and structure with the expanded discs from which the upright shoots of Ahnfeltia spring (fig. 18), and there can be no doubt as to their identity. It must be emphasised that the basal discs The Reproduction of Ahnfeltia plicata. 21 of Ahnfeltia plicata in Nature often reach a considerable size before the formation of upright shoots takes place, — The development of the disc-shaped young plants from the germinating monospores thus tells directly against SCHMITZ's hypothesis. 4. Conclusions. Fig. 18. Young frond springing The reproduction of Ahnfeltia plicata (and related species) is very peculiar and different rom an ex- from that of all other Florideæ. Antheridia, panded disc. carpogonia, cystocarps and tetrasporangia are N wanting. No organs of reproduction are known apart from the nemathecia. These bodies are different from other nema- thecia known by their development and their function. While other nemathecia produce seriate tetrasporangia in the nemathecial filaments, those of Ahnfeltia produce mono- sporangia only in the last cell of the nemathecial cell- rows. But the cell-rows producing the monosporangia are not identical with the primary nemathecial filaments. These arise in autumn as outgrowths from a group of superficial cells of the frond dividing by transverse cell-walls. In these cell-rows two kinds of particular cells are early produced (in October): 1) flask-shaped cells arising from the end-cells of the cell-rows, most frequently at the bottom of the nema thecium and consequently often terminal on the cortical cell-rows. These cells remind one of carpogonial cells by their shape and like these stain deeply with hæmatoxy- lin, but this coloration touches only or in particular the cell-wall, whereas the content is feebly developed, homo- geneous and apparently slightly stained and the nucleus not or scarcely visible. These cells are further terminal on ho Nr. 2. L. KOLDERUP ROSENVINGE: vegetative cell-rows, not at the end of particular carpo- gonial filaments lateral on the latter, as in other Florideæ, and they are always included, not with protruding end. It must therefore be concluded that they cannot be con- sidered as more or less modified carpogonial cells. They might better be compared with the sterile hairs occurring near the carpogonial branches in Ptilota (comp. Davis, Bot. Gazette, 22, 1896). They are doubtless reduced organs without function, not giving rise to any new formation. 2) The other kind of particular cells, the generative cells, as they have been named above, are, in contra- distinction to the flask-shaped cells, productive. They arise at the top of the primary nemathecial filaments, by trans- formation of the end-cell or as a lateral outgrowth, they are rich in protoplasm and divide early with the conse- quence that they form small groups of active cells at the surface of the young nemathecium. From these cell-groups new cell-rows spring in a horizontal direction or directed upwards, with the result that numerous upward growing cell-rows are produced, forming a system of secondary nemathecial filaments issuing from an irregular layer situ- ated near the bottom of the nemathecium. The cells of this layer are irregular of shape. The nemathecium is thus built up in two distinct phases. The primary nemathecium is a rather low cushion composed of closely placed pri- mary nemathecial filaments of moderate length, being im- mediate continuations of the cortical cell-rows; at the border the cell-rows are shorter and diverging outwards. By the further development of the nemathecium the upper portion arises, exclusively or mainly, from the generative cells, or their derivates, and the secondary nemathecial filaments are, therefore, not continuations of the primary ones. The whole The Reproduction of Ahnfeltia plicata. 23 complex of cells arising from the generative cells must be considered as representing a new generation, comparable to the sporophytic generation (Actinococcus) of Phyllophora Brodiæi (comp. K. ROSENVINGE 1929) though there are es- sential differences. The Actinococcus generation arises in a fertile segment of the frond from an auxiliary cell, in a similar manner to a gonimoblast, which process, according to H. CLauszEn (1929) and Kyrın (1930 p. 27) must be supposed to have been preceded by a fertilisation, so that the nuclei of the sporophyte are diploid (8 chromosomes) whereas those of the gametophyte are haploid (4 chromo- somes). The secondary (fertile) nemathecial cell-rows in Ahnfeltia arise from several, perhaps numerous, generative cells produced in particular organs: the primary nema- thecia. The question then arises, what morphological significance must be attributed to the generative cells. Some would perhaps prefer to consider them as organa sui generis without any relation to other reproductive cells in the Florideæ, but this view, I think, is not satisfactory. The young groups of generative cells offer some resemblance with the incompletely developed procarps which occur so frequently in Phyllophora Brodiwi (K. ROSENVINGE 1929 fig. 10) and it appears not unlikely that they are, like these, reduced procarps, though differentiated carpogonia and auxiliary cells have never been ascertained. If this interpretation is right, it must be assumed that there are a great number of starting points for the secondary nema- thecial filaments in the same nemathecium, though perhaps not so many as might be supposed because several of the cell-groups may be produced by the horizontally running cell-rows (comp. fig. 6) and a number of the cell-groups do not perhaps produce nemathecial filaments. By this € r Fr 24 Nr. 2. L. KoLDERuP ROSENVINGE: multiple origin of the sporogenous cell-rows the nema- thecium of Ahnfeltia differs essentially from that of Phyllo- phora Brodiei, where the whole complex of nemathecial filaments normally derives from one auxiliary cell.” Further, as mentioned above, the nemathecial filaments of Ahnfeltia differ by not producing tetrasporangia but monosporangia which are not seriate but develop only in the end-cells. The question of the morphological signific- ance of the monosporangia is no easy matter to solve. The fact that they occur in nemathecia suggests that they might be interpreted as originating from tetrasporangia which have failed to be divided owing to the wanting reduc- tion division of the nuclei. Such a division at any rate does not take place in the monosporangia and it seems too to be precluded at any earlier moment; its occurrence seems further to be improbable as a fertilisation or an -Ug'apomictic process has not been ascertained, The secondary nemathecial filaments may also be inter- preted as gonimoblast cell-rows arising by apogamy from the generative cells, and the whole complex of secondary nemathecial filaments would then be a compound cysto- carpium, the gonimoblast filaments issuing from numerous generative cells. According to this view the monospores are to be regarded as carpospores: the nemathecia repre- sent the carposporophytic phase and the tetrasporophytic phase is wanting. Such a compound cystocarp is not other- wise known among Florideæ. The fact that the spores are terminal on sterile cell- ! It seems, however, that a large Actinococeus nemathecium may sometimes arise by fusion of primordia of nemathecia issuing from two or perhaps more contiguous auxiliary cells (comp. K. ROSENVINGE 1929 p. 22 plate figs: V—VIII). The Reproduction of Ahnfeltia plicata. 25 rows does not seem favourable to this view, as cystocarps of such a structure do not occur within Gigartinales to which the genus Ahnfeltia is usually referred. The interpretation of the secondary nemathecial filaments as gonimoblast filaments would be in better accordance with the facts known supposing that Ahnfeltia were related to the Cryp- tonemiales where both sexual and sporophytic nemathecia occur, and where cystocarps with a structure showing some resemblance to that of the nemathecia of Anfeltia are known (e. g. Polyides). The frond and the young, primary, nema- thecia can be regarded as the gametophyte with modified procarps: the generative cells, which produce the secondary nemathecial filaments representing the sporophytic phase. The number of chromosomes is four in the nuclei of the spores as well as in the nuclei of the secondary nema- thecial filaments from which they arise, and probably the same number occurs in both phases of Ahnfeltia. This number must be the haploid number as no reduction of the chromosome number occurs and no fusion of nuclei has been ascertained, although not rarely fusions of cells occur in the first (gametophytic) phase as well as the sporo- phytic phase. One or the other interpretation may be right, the nema- thecium of Ahnfeltia will in any case remain a very peculiar formation otherwise hitherto unknown among Florideæ. (3 2 r © r . 26 Nr. 2. L. KOLDERUP ROSENVINGE: Postscript. The researches of which the present paper gives an account were completed in the spring of 1930 and were in- tended to be embodied in the fourth part of my publication: The Marine Algæ of Denmark, which I hoped to complete at the end of 1930. As an illness prevented me from wor- king for a long time, I preferred to publish my investigations on this subject in a separate paper which I succeeded in finishing and sending to the Academy for publication at the end of October 1930. It was only in November that I became acquainted with the note af B. D. GREGORY: New light on the so-called parasitism of Actinococcus aggregatus, Kütz. and Sterrolax decipiens, Schmitz (Annals of Botany, vol. 44, no. 177, July 1930), which the author has kindly sent to me. To judge from the short account of this note, the results of GREGORY seem in the main to be in accordance with mine. The author maintains that Sterrocolax is not of parasitical nature but that the development of the cushions begins with a localized hypertrophy of the cortical tissue of Ahnfeltia. Within such a tissue he found filaments “terminated by darkly-staining somewhat pointed apices, and it is believed that these filaments give rise to the extra- matrical tissue of Sterrocolax”. It seems not improbable that these filaments or their darkly-staining apices might be identical with the generative cells described above. The author observed fusions between the medullary cells in the The Reproduction of Ahnfeltia plicata. 2 SJ neighbourhood of the nemathecia and he thinks it possible that they represent a very much reduced sexuality, a view with which I cannot agree. Monospores were grown in £ culture, but "after three to five months, only rudimentary disc-like structures have been obtained”. GREGORY found in the medullary cells both a four and an eight chromosome complex, but he adds that it is not yet known whether the eight chromosome condition bears any relation to the cell-fusions. There is some evidence that there are eight chromosomes in the apical cells and in the monospores of Sterrocolax decipiens’. As mentioned above, I found four chromosomes in the apical cells of the nemathecia; when eight chromosomes were observed in such a cell, it was shortly after the division of the nucleus. The author concludes that the mode of origin of Sterrocolax decipiens and its similarity in structure to Ahnfeltia plicala suggest the pro- bability that it is the asexual biont of its so-called “host”. At the same time appeared another paper treating the same subject, namely E. CHEMIN: Ahnfeltia plicata Fries et son mode de reproduction. Bull. de la soc. bot. de France, t. 77 p. 342-354. The author examined the structure of the nemathecia but he did not observe the “Senker” of SCHMITZ. He points out that Scumirz did not say anything about the origin of the parasite and emphasizes the continuity of the cell-filaments at the boundary between the cortex and the nemathecium, but the photograph (plate IV) representing a vertical section of a nemathecium' also shows numerous cells intensely stained with haematoxylin in the bottom layer of the nemathecium. It seems probable that these cells are identical with those which I have described above as flask-shaped, though CHEMIN, who has observed them, 1 Not a gall, as erroneously said at the foot of the plate. « > 5 = - 28 Nr. 2. L. KoLpErup ROSENVINGE: does not mention their shape. The photograph further shows, at a higher level, in particular to the right, groups of darker cells which might possibly be identical with the generative cells mentioned above and their derivates. In examining the germination of the monospores, CHEMIN observed the first stages of the young plants which I have not seen. He found that the germinating spore produced a short articulate cell-filament giving rise at its distal end to a disc which after two weeks might consist of some twenty cells. Though the smallest discs observed by me were only slightly larger than these, I have not observed any trace of such a germinating filament. The rare hyaline hairs observed in my cultures have nothing in common with it. It is remarkable that CHEMIN did not meet with any trace of chromatophores or phycoerythrine in the spores, while I found a distinct yellowish chromatophore. After one month the greatest discs measured 40 x in diameter and were thicker in the middle than at the border. After two months the discs were only slightly more developed but they had multiplied by proliferation. CHEMIN concludes that the discs are probably the beginning of Ahnfeltia. The Reproduction of Ahnfeltia plicata. 29 Bibliography. C. A. AGARDH (1822), Species Algarum. Vol. I pars posterior. J. G. AGARDH (1851), Species genera et ordines Algarum. II pars 2. — (1876). — Pars III (Epicrisis). T. H. BurrHam (1893), On the Antheridia, etc. of some Floride:e. The Journal of the Quekett Microscopical Club, Vol.V, ser. II. HuGo CLAUSZEN (1929), Zur Entwicklungsgeschichte von Phyllo- phora Brodiaei. Ber. d. Deutsch. Botan. Gesellschaft. Bd. 47. English Botany. Vol. 16. 1803. R. K. GREVILLE (1830), Algæ Britannicæ. L. KOLDERUP ROSENVINGE (1929), Phyllophora Brodiæi and Actino- coccus subcutaneus. K. D. Vid. Selsk. Biologiske Meddelelser. 8. Bind, 4, Kobenhavn. F. T. Kirzine (1869), Tabulae phycologicae 19. Bd. Nordhausen. H. Kyrın (1930), Über die Entwicklungsgeschichte der Florideen. Lunds Univ. Arsskrift. N. F. Avd. 2, Bd. 26, Nr. 6. H.C. LYNGBYE (1819), Tentamen Hydrophytologiæ Danicæ. Hafniæ. Fr. SCHMITZ (1894), Die Gattung Actinococcus Kütz. Flora. Fr. 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Elektrolyters Indflydelse paa Difteritoksinets og det anti- x MIRE Serums Stabilitets- og Neutralisationsforhold med 10. BIND. (under nn JENSEN, AD.S.: Der grosse europäisch-sibirische Kreuzschnabel- zug 4927, 1930 ...... RE, ests RY At ere EDITED Se ws » ‚BY ) , ig | L.KOLDERUP ROSENVINGE ae PH. D. Res ERBE ÅR AND | EUG. WARMING (})_ bela sk PH. D., SGD. A N ve IL PART tLe.) 4 "POUL LARSEN: = NGI OF ICELAND 000000 L VEN ve? AT DAC N EN a RES cr ag de OM CE OUR) SN”! BY THE AID OF THE CARLS LE HOZ aah a +4 4 Ri B er BA FR AT 1% ARBEJDER FRA DEN BOTANISKE HAVE I KØBENHAVN. NR. 120. = 1 eee UNG! OF ICELAND BY POUL LARSEN WITH 19 FIGURES IN THE TEXT AND A COLOUR CHART r ne u es b . L ka lid 7 Qf bé À 86 v RW YOR: ROTANICAL GARDEN PREFACE i 1921 I was requested by the editors of this work to make a journey to Iceland for the purpose of investigating the fungi of that country, more particularly the Icelandic Hymenomycetes, among which especially the Agaricaceae occupied a less important place in previous works on the fungi of Iceland than their supposed number would seem to warrant. The journey was made at the expenses of the Carlsberg Fund. In addition I undertook to work up the results of my own observations with the lists of Icelandic fungi previously published. The results are now at hand in the present paper. With few exceptions I have myself examined the fungi given in the list either in their localities or in the Herbarium of Icelandic Fungi in the Botanical Museum at Copenhagen. Of the fungi collected by me those growing on dung and some of the Fungi imperfecti have been examined and determined by Magister O. Rostrup, for which I tender him my cordial thanks. I owe special thanks to the editors of The Botany of Iceland for the confidence they reposed in me by entrusting me with this work, and for the grants for its completion which they have procured for me. 30* INTRODUCTLEON Historical Account of Investigations on the Fungi of Iceland. Literature: (1) O.F. Müller: Enumeratio stirpium in Islandia sponte crescen- tium. Nova Acta Ac. Nat. Cur. 1772. (2) Johan Zoéga: Flora Islandica. Tilhang til Eggert Olafssons Rejse igennem Island. Sore 1772. (3) Bjorn Halldörsson: Grasnytiar. Kaupmannahofn 1783. (4) Nicolai Mohr: Forsøg til en Islandsk Naturhistorie, Kigben- havn 1786. (5) Sveinn Pälsson: Dagbog, holden paa hans Rejse til og i Island 1791—93. Skrifter af Naturhistorieselskabet, 3. Bind, 1. Hæfte, pp. 178—179. Kjøbenhavn 1793. (6) W.J. Hooker: Journal of a tour in Iceland in the summer of 1809. Yarmouth 1811. (7) G.S. Mackenzie: Travels in Iceland in 1810, Edinburgh 1811, p- 433. (8) Th. Gliemann: Geographische Beschreibung von Island 1824, p. 171. (9) Thienemann und Günther: Reise im Norden Europa’s vorzüglich in Island in den Jahren 1820 bis 1821, p. 320. Leipzig 1827. (10) Oddur J. Hjaltalin: Islenzk Grasafr&di. Kaupmannahofn 1830. (11) E. Robert in Paul Gaimard: Voyage en Islande et au Groen- lande exécutée pendant les années 1835 et 1836 sur la cor- vette La Recherche, Paris, 1840, 7° fascicule, p. 355. (12) J. Vahl in the above-mentioned work by Paul Gaimard, 7. fasci- cule, p. 379. (13) L. Lindsay: Flora of Iceland, Edinburgh New Philos. Journal, Vol. XIV, 1861. (14) Chr. Gronlund: Islandske Svampe, Botanisk Tidsskrift, 3. Række, 3. Bind, pp. 72—76. Kjobenhavn 1879. (15) E. Rostrup: Islands Svampe, Botanisk Tidsskrift, 14. Bind, pp. 218—229. Kjøbenhavn 1885. (16) C. J. Johanson: Svampar från Island, Ofversigt af Kongl. Veten- skaps-Akademiens Förhandlingar 1884, Nr. 9. Stockholm 1885. FUNGI OF ICELAND 453 (17) E. Rostrup: Islands Svampe, Botanisk Tidsskrift, 25. Bind, pp. 281—335. København 1903. (18) E. Rostrup: Liste over Svampe samlede paa Island 1903—05 af Helgi Jonsson, 0. Davidsson og C.V. Prytz — in manu- script in the Library of the Botanical Garden. Copen- hagen 1905. The figures in brackets are quoted in the following in refe- rences to this literature. The first botanical investigation of Iceland which included the fungi was made by J.G. Kénig in 1765—66 with the object of collecting plants for the Flora Danica His collection of fungi forms the basis of the lists contained in C. F. Müller’s Enumeratio (1) and in Zoéga’s Flora Islandica (2). These lists comprise respec- tively 11 and 12 species which, however, are identical except for 2. In 1783 Bjorn Halldörsson’s Grasnytiar (3) appeared. In this 7 species of fungi are mentioned by their Icelandic names, of which 2, at any rate, are not to be found in the above-mentioned lists. This brings up the number of species to 15. These 15 species reappear without additions in (4), (6), (7), and (8). Thienemann’s and Günther’s investigations (9) of the Icelandic vegetation in 1820 and 1821, and Hjaltalin’s Islenzk Grasafrædi (10) add each one species to the number. Roberts and Vahl’s lists (11) and (12) bring up the number to 19. L. Lindsay’s Flora of Iceland 1861 (13) only gives 13 species, adding no new ones, and 5 of the earlier 6 species are declared by Berkeley (p. 70) to be impossible to determine. Rostrup, however, regards this reduction as partly unfounded (15). — The 19 species of fungi given in these earlier lists are the fol- lowing: — Humaria granulata (Bull.), Geopyxis Ciborium (Vahl), G. cupu- laris (L.), Chlorosplenium aeruginosum (Fl. D.), Lachnea scutellata (L.), Helvella atra König, Clavaria muscoides (L.), Psalliota campestris (L.), Psilocybe ericaea (Pers.), Russula fragilis (Pers.), Boletus scaber Bull., B. laevis Fr., B. bovinus L., B. luteus L., Globaria Bovista (L.), Bovista clavata Fr., Crucibulum vulgare Tul. The lists further contain a couple of Agaricaceae which must be considered doubtful. The same applies to Boletus laevis, B. bovi- See Carl Christensen, Den Danske Botaniks Historie, p. 118. 454 POUL LARSEN nus and B. luteus (see note on this subject in the succeeding main list of Icelandic fungi). In 1876 the Danish botanist Chr. Grønlund made a journey in Iceland and collected, in addition to other plants, 24 species of fungi. A list of these is given in his paper (14). In 1885 E. Rostrup published in Botanisk Tidsskrift (15) the results of a critical comparison of all the lists of Icelandic fungi hitherto issued, together with a number of Micromycetes which he had found on flowering plants in Icelandic herbaria. The number of known species of Icelandic fungi was thus brought up to 89. In the period 1889—1903 our knowledge of Icelandic fungi was considerably extended. Simultaneously with E. Rostrup’s »Is- lands Svampe« 1885, appeared C. J. Johanson’s »Svampar fran Island« (16), containing 57 species, 31 of which were new for Iceland. — In addition a large material was sent to the Botanical Museum at Copenhagen and to E. Rostrup personally, consisting partly of herbaria of Phanerogams, from which Rostrup gathered a rich harvest of Micromycetes, and partly of collections of fungi. The Icelanders, Dr. phil. Helgi Jönsson, Dr. phil. Th. Thorodd- sen, Stefan Stefänsson, and cand. Olafur Davidsson sent con- siderable collections of fungi to Rostrup during this period. This applies especially to Olafur Davidsson, who sent in about 400 species during the period 1885—1903. — Also Danish botanists, e.g. Dr. C. H. Ostenfeld and Arthur Feddersen, brought home collections of fungi from journeys to Iceland. From these collections in conjunction with the results of con- tinued investigations of herbaria of flowering plants from Iceland, E. Rostrup worked up a new list of the fungi of Iceland in 1903 (17), which comprised 543 species, including all species from previously published lists of fungi from Iceland. From the period after 1903 we have still another list — though not a very comprehensive one — in a manuscript from the hand of E. Rostrup in the Botanical Museum of Copenhagen (18). It con- tains some species of fungi, not previously recorded from Iceland, collected and sent in by Helgi Jonsson, 0. Davidsson, and Pro- fessor C. V. Prytz. This brings to an end the considerable work done by E. Rostrup on the fungi of Iceland (1905). The material since then sent in to the Botanical Museum of Copenhagen by Helgi Jönsson has been determined by the myco- logists J. Lind and Professor C. Ferdinandsen. Of Danish bota- FUNGI OF ICELAND 455 nists Svend Andersen has, during several journeys in Iceland, collected a herbarium of flowering plants and vascular cryptogams, which he has kindly lent me for examination in regard to fungi. The mycologist N. Fabritius Buchwald visited Iceland in the summer of 1923 and brought home a collection of 23 Icelandic species of fungi (among which was one new species for Iceland). These he has kindly sent me for examination. On my journey in Iceland in 1922 my general purpose was the investigation of fungi, while my special object was to make a study of the Agaricaceae, the determination and description being made in the field from fresh material. The colours were determined by comparison with colour charts; other macroscopical characters were noted down in the field. Microscopic characters were examined by means of a travelling microscope, and in addition, material of all the species was brought back in alcohol so that the microscopical characters could subsequently be revised. The main list of Icelandic fungi contained in this work is a result partly of my own observations of fungi in Iceland and partly of my study of all the earlier lists of Icelandic fungi and of the material on which they are based. The greater part of this material is in the Botanical Museum of Copenhagen, and I have tested the determination of the listed species by means of it, and, in so far as errors were found, I have corrected them. This brings up the number of known species of fungi in Iceland to 802, including, however, some few species of Agaricaceae which I have not been able to identify with known species, while, on the other hand, I have not had sufficient material to establish them as new species. Icelandic Localities investigated in Search of Fungi. Large parts of the highlands in the interior are covered with ice, and still greater areas have a covering either of unweathered or of only slightly weathered lava, so that these regions are almost devoid of vegetation. It is chiefly the depressions, the erosion valleys, and the lower coast stretches of the fiords which harbour the vegetation necessary for the development of fungi. The collectors, therefore, have mainly confined their investigations to such tracts. Thus the Icelanders Olafur Davidsson and Stefän Stefänsson have almost exclusively examined the fiord and river valleys of N.W. Iceland, while Helgi Jönsson has especially investigated the 456 POUL LARSEN S.W. country, but also a smaller area in the east country. The finds of C. H. Ostenfeld are mainly derived from the north, north-west and west country, and Chr. Grønlund has visited both the east, north and west country. — My own investigations in the summer of 1922 began in the first part of June in S. W. Iceland, viz. in the country round Reykjavik, Hafnarfiöröur and Pingvellir. In the latter part of June I continued with the part round Borgar- fjöröur, especially the birch copses near Borg and Norötünga. But my main area of investigation was N. E. Iceland, the region between the Øfiord Valley and the east coast of Iceland, viz. the Ofiord Valley itself and the Fnjöskadalur running parallel to it, the depression near Myvatn with Laxädalur, Jökulsa a Heidi from Grimstadir to Môôrudalur, Jökulsa à Brü, Lagarfljöt with Iceland’s largest birch copse, and finally the region round Seydisfjördur. As will appear from this survey, the south country is the least explored part of Iceland as regards fungi. The extensive bare sands along the southern coast of the country cannot, however, be expected to add to the number of species, for even though there is some dune vegetation here, a similar vegetation occurs on the extensive range of dunes along Jökulsä a Heidi. The few samples of the vege- tation of sands and dunes derived from Helgi Jönsson’s collec- tion show in the main the same fungi as those occurring on the plants collected by me on dunes in the interior round Grimstadir near Jökulsa ä Heidi. And the homefields of the farms in the south country bear mainly the same vegetation as the homefields in the rest of the country, and must therefore be supposed to harbour much the same fungi. On the whole, such large areas of Iceland have now been investigated that all the different forms of vegetation are repre- sented, and an addition to the number of species is more likely to be made through a more thorough examination of details than by enlarging the area of investigation. The Special Conditions of Environment offered to Fungi in Iceland. Though the fungus flora is greatly dependent on the rest of the vegetation, we cannot infer from this that the more luxuriant the vegetation of a country is, the richer and more abundant its fungus flora will be. At any rate, this does not apply to the larger fungi. There must, therefore, be other factors besides the chlorophyllaceous FUNGI OF ICELAND 457 vegetation which condition the growth of the fungi. As actual woods are entirely absent in Iceland, or only present in the shape of low birch copses in sheltered valleys and on moist valley slopes, it might be expected, from the occurrence and distribution of the larger fungi in Central Europe, that but few of these would be present in Iceland, and that they would chiefly occur in the aforementioned birch copses. This, however, is by no means the case. For though the number of known species of the larger fungi in Iceland is not very great (about 150), the individual species have a wide distribution and are very frequent in some localities, even out- side the birch copses. In river plains, on mountain slopes, in out- lying pastures and homefields, occur, primarily, the larger fungi also to be found outside forests in Central Europe, for instance species of the genera Mycena, Tricholoma, Omphalia, Russuliopsis, Hygro- phorus, Leptonia, Psalliota, Stropharia, Panaeolus, Galera, Naucoria, Inocybe, Lycoperdon, and Bovista. But there also occur species of genera that chiefly or exclusively inhabit woods, such as Cortinarius, Pholiota and Russula. Of these genera Cortinarius is almost exclu- sively an inhabitant of woods in Central Europe; but several species of it are very numerously represented in Iceland in river plains, fiord valleys, and knolly moorland tracts. It would seem, therefore, that these fungi do not prefer our woods on account of their trees and bushes, but on account of the special climate prevalent there, a climate which may be found in Iceland outside the woods, and which is especially characterised by a relatively greater moisture of the atmosphere than that usually present outside woods in Central Europe. The sporophores of certain of these fungi show peculiar adapta- tions to the somewhat altered environment. Thus, in river plains and knolly outlying pastures, among grasses, sedges and mosses, several species of the genera Inocybe and Cortinarius occur in dense clusters. They have short stems and small pilei, whereas the same species in Central Europe, as forest fungi, form scattered sporophores with long stems and larger pilei. The advantage gained in the former case is that the sporophores, on account of their shorter stems, develop in a stratum of the atmosphere in which they are not exposed to desiccation, and the numerous small pilei can develop just as many spores as the fewer but larger ones. Further, veiled forms occur, with the veil so well developed, that until they are closely examined, one is apt to regard them as 458 POUL LARSEN new species. This, for instance, is the case with Naucoria myosotis, the older sporophores of which are provided with a distinct ring, and the younger pilei of which have the gills covered with a dense filmy veil. The same applies to several Cortinarit. The well developed veil is also a striking feature in many species of the genera Jnocybe, Hebeloma, and Galera, though in the latter genus only in species of the group Bryogenae Fr. The cool and moist climate has also considerable influence on the distribution, density, and time of fructification of the Micro- mycetes, both directly and more indirectly, by affecting the host plants. The period of drought so common in Central Europe in June and July, which arrests fructification in most of the sapro- phytes among these fungi, is unknown in Iceland. Discomycetes and Pyrenomycetes fructify all the summer both in the lowlands and in the highland tracts as far as the vegetation extends. — The withered leaves and stems of most herbaceous plants survive through the winter and provide a fertile soil for these fungi. In Central Europe a great many herbaceous plants appear so early that they wither already during the drought in the summer and become a prey to the rich bacterial life of the moist autumn, disappearing without leaving any trace at the beginning of the winter. Not so in Iceland where these plants appear late. Their decay occurs at such an advanced stage of the summer that the cold and snow- covering prevent the breaking down activities of the bacteria and the fungi, and when the snow-covering melts in the succeeding early summer, large quantities of withered leaves and stems are left, on which numerous fungi thrive. These, in conjunction with the bacteria, complete the work of decay. That the Micromycetes com- peting with the bacteria in the dissimilation of the vegetable sub- stances are stronger in this climate than in Central Europe appears from the greater abundance with which these fungi occur on the decaying parts of plants. While the collector in Central Europe must examine withered leaves and stems very carefully in the field if he wants to bring home any spoil at all, a quite inexperienced collector may gather a rich harvest of Micromycetes in Iceland by merely collecting at random any dead parts of plants at any time of the summer. The luxuriant development of this microflora may be in part due to the fact that the phanerogams have a looser structure and feebler strengthening tissue than the same species of plants in more FUNGI OF ICELAND 459 southerly latitudes. For the leaves this has been demonstrated by Dr. F. Borgesen in his paper »Bidrag til Kundskaben om arktiske Planters Bladbygning« in Botanisk Tidsskrift, Vol. 19, Copenhagen 1895, and by Bonnier in »Comptes rendus« 1894, t. CXXIII, p. 1427. — As a circumstance pointing in the same direction I may men- tion that a great many Cyperaceae which are quite valueless as fodder in Central Europe, are highly valued feeding plants in Ice- land both for horses and cows. Icelandic hay is »richer in nourish- ment« than hay in more southern latitudes — in its native land the Icelandic pony can work on a fodder of hay alone, which perhaps shows that the Icelandic plants have a feebler mechanical tissue and therefore are more easily digested and give a greater surplus of energy to the animals.! That the epidermis of these plants is thinner and the cuticle weaker appears plainly enough in the preparation of the perithecia of Pyrenomycetes or pycnidia of Sphaeroidaceae imbedded in their leaves and stems. It is much easier than the same work with leaves and stems of similar plants in Central Europe. The looser structure evidently makes it easier for the hyphae of the fungi to penetrate into the body of the plants. Also the predominant isolateral struc- ture of the leaf (see Borgesen’s above-mentioned paper) renders invasion easier, as there are stomata on either side of the leaf. Immigration of the Fungi into Iceland. While the answers to the questions dealt with above relating to the fungi of Iceland were based on facts or on conclusions drawn from facts, the case is different when we attempt to solve the problem treated in the present section. In the first place our knowledge of the geographical distribu- tion of the species of fungi is rather uncertain. In the second place we do not know the full extent of the means the fungi have of ! Compare the quotation from P. Feilberg at p. 253, vol. I of this work, and the references to the literature. From these it would seem to appear that in Feil- berg’s opinion Icelandic ponies and cows have in the course of many generations adapted themselves to the Icelandic Cyperaceae and »coarser« grasses, and that it may be partly owing to this circumstance that they derive so much nourishment from these plants. But this argument does not cover the facts, for, when in Den- mark, Icelandic ponies are unable to work on hay alone, but must have oats added to their fodder. 460 POUL LARSEN spreading, especially when, as in the present case, the oceans set up barriers to their migrations. And yet, since the fungi of Iceland are in the main identical with those of the surrounding countries (in so far as the vegetation with which the fungi are associated is common to both), this shows that an exchange of fungi must have taken place. It seems very unlikely that the spores of the fungi could have been carried, either by direct spreading or by means of currents in the air, across the great stretches separating Iceland from the nearest countries, in such large quantities that they would be likely to reach localities where conditions of germination were present. It is much more likely that the spreading of the fungi takes place indirectly. Detached fragments of phanerogams containing living parts of fungi may be carried along by the wind during heavy snowstorms and be swept over the polar ice, which generally in the winter bridges over the seas between the lands in arctic regions and also sometimes reaches the coasts of Iceland.! There are, however, other ways by which the fungi may travel. After the settlement of Iceland many culture plants have been intro- duced into Iceland and with them no doubt many fungi. In the following we shall mention some quite recent examples of such an immigration of fungi. During the recently awakened interest in horticulture in Iceland, which even went as far as the planning of coniferous plantations, (a project that had to be given up, however, after several unsuccessful trials), a number of plants were introduced, which have since become infested with species of fungi previously unknown in Iceland. These fungi, therefore, have probably been brought into Iceland with the host plants. This applies to the following species: Lophodermium pinastri....... on Pinus montana Phylosticta Pseudaceri........ - Iris germanica Phomavendolenrar. 22-72" - Alnus glutinosa Aposphaeria glomerata a olivaceum f et ea Sees nia Phomaltingens 22cm eee - Aconitum sp. 1 J, Lind, The Geographical Distribution of some Arctic Micromycetes. Det Kgl. Danske Vidensk. Selsk. Biologiske Meddelelser, VI, 5. Copenhagen 1927. R. Sernander, Den skandinaviska vegetationens spridningsbiologi. Upsala 1901. FUNGI OF ICELAND 461 Plowrightia ribesia | Leptosphaeria Ribis | Phoma ribicola Phomopsis ribesia | Br on Ribes rubrum Phoma Malvacei | him Hendersonia Ribis alpini |" P PSM RUD , 52.124257 - Rubus idaeus Cytospora leucostoma......... - Prunus padus Comarosporium laburnicum | Rabenhorstia rudis .. — Cytisus laburnum Coniothyrium Laburni | Phytophthora ee Paoma solanicola | 5:24 - Solanum tuberosum Fusarium Solani | Sphaerulina intermixta........ - Lonicera sp. I shall mention one more example of the recent immigration of a Boletopsis, which, similarly to that of the above-mentioned fungi, seems to have taken place simultaneously with the introduction of the plant with which its existence is intimately bound up. This is Boletopsis luteus. — In a small plantation in the birch copses near Hallormsstadir in E. Iceland, there is an area with 10—12 year old Pinus montana. Here for the first and only time in Iceland I found Boletopsis luteus. Upon inquiry the forester who had laid out the plantation informed me that none of these pines had been planted, but were all raised from imported seeds! In this case the most natural ex- planation of the occurrence of the fungi would seem to be that the spores were introduced with the seeds. 1 In Bjorn Halldérsson’s Grasnytiar 1783, Boletus (Boletopsis) luteus is stated to be growing in Iceland. From here this statement has found its way into Mohr’s Islandsk Naturhistorie, 1786, and finally, with a reference to these sources, into Rostrup’s lists of Icelandic fungi. None of the numerous other botanists who have subsequently searched for fungi in Iceland have, as far as I know, ever seen any trace of this easily recognisable fungus. As moreover B. luteus forms mycorrhiza with coniferous trees only, these early statements cannot possibly be correct. ENUMERATION OF THE FUNGI OF ICELAND In the following list of fungi now known from Iceland the classification is founded on the system given by Ernst Gäumann in his work: Vergleichende Morphologie der Pilze, Jena 1926. The following abbreviations are used for the names of the collec- tors of fungi most frequently named in the list: D. = Olafur Davidsson. J = Helgi Jønsson. ÆRES Poul Larsen. H.0. = C. H. Ostenfeld. St. — Stefån Stefånsson. When a species has been collected in several localities, these are, as far as possible, arranged according to their distribution in the following succession: East-, North-, North-West-, West- and South-Iceland (comp. J. Boye Petersen, this work, Vol. II, part II, p- 259). The designations in the descriptions of the Agaricacee consisting of a letter and a figure, e. g. g 4, refer to the colour plate accom- panying this paper; it has been painted by Mr. Jakob E. Lange for his paper, Studies in the Agarics of Denmark, Part VI (Dansk Botanisk Arkiv, Bd. 4, Nr. 12, 1926), and reprinted here with the consent of the author. MYXOMYCETES. Clathroptychiaceae. Enteridium Ehrenberg. 1. E. olivaceum Ehrenberg, Jahrbücher für Gewächskunde, heraus- gegeben von Sprengel, Schrader und Link, Bd.1, Heft. 2, p. 55. Hüsafellsskögur (O. D). — On birch wood. FUNGI OF ICELAND 463 Trichiaceae. Trichia Haller. 3. T. contorta (Ditmar) Rostafinski. Lycogala contorta Ditmar: Sturm, Deutschlands Flora III, Pilze, BE p. 9, 1.5. Hofsfjall (0. D.). — On Sibbaldia procumbens. Physaraceae. Physarum Persoon. 3. P. cinereum (Batsch) Persoon. Lycoperdon ciner. Batsch, Elenchus fungorum, p. 155. Mööruvallanes (O. D.). — Substratum unknown. Didymaceae. Lepidoderma De Bary. 4. L. carestianum (Rabenhorst) Rostafinski. Reticularia carest. Rabenhorst, Fungi europ. exsicc., No. 436. Hestahraun in Porvaldsdalur (O. D.) — On stems of a Hieracium. Stemonitaceae. Lamproderma Rostafinski. 5. L. physaroides (Albertini et Schweinitz) Schroeter. Stemonitis phys. Alb. et Schw., Conspectus fungorum, p. 103, t. II, f. 8. Hofsfjall (O. D.). — In the panicle of Deschampsia caespitosa. 6. L. violaceum (Fries) Rostafinski. Stemonitis violacea Fries, Systema mycologicum III, p. 162. Mööruvellir (O. D.) — On straws of Anthoxanthum odoratum. Comatricha Preuss. 7. C. nigra (Persoon) Rostafinski. Stemonitis nigra Persoon: Gmelin, Systema naturae, p. 1467. Pingvellir (P.L.). — On wood of Betula pubescens. 464 POUL LARSEN EUMYLETES: Synchytriaceae. Synchytrium De Bary et Woronin. 8. S. cupulatum Thomas, Botanisches Centralblatt, XXIX, 1887 p. 19. Helgavatn, Mööruvallafjall (St. St). — On leaves of Dryas octo- petala. 9. S. aureum Schroeter, Saccardo, Sylloge fungorum VII, p. 290. Mööruvellir (O. D.) — On leaves of Ranunculus reptans. 10. S. globosum Schroeter, Sacc., Syll. fung. VII, p. 288. Baldurbeimsholt (O. D.) — On leaves of Veronica anagallis. 11. S. groenlandicum Allescher. Pilze aus dem Umanakdistrikt. Bibliotheca botanica, Heft 42, 1897, p. 40. Hlidarhäls (O. D. og St. St). — On Saxifraga hypnoides. Cladochytriaceae. Physoderma Wallroth. 12. P. menyanthis De Bary, Sacc., Syll. fung. VII, p. 318. Os and Laugarvatn (O.D.). — On leaves of Menyanthes tri- foliata. 13. P. Heleocharidis (Fuckel) Schroeter, Sacc., Syll. fung. VII, p. 317. Mööruvellir (O0. D.). — On stems of Heleocharis palustris. 14. P. vagans Schroeter, Sacc., Syll. fung. VII, p. 318. Hof in Hörgärdalur (O. D.). — On leaves and petioles of Comarum palustre and Caltha palustris. 15. P. Hippuridis Rostrup, Gronl. Svampe 1891, p. 631. Hraun in Fljöt (O. D.) — On leaves of Hippuris vulgaris. 16. P. Crepidis Rostrup, Isl. Svampe 1903, p. 286. Hraun in Fljöt (0. D.). — On the upper surface of leaves of Crepis paludosa. Saprolegniaceae. Saprolegnia Nees von Esenbeck. 17. S. ferax (Gruithusen) Nees, Sacc., Syll. fung. VII, p. 269. Mööruvellir [O. D.] Det. E. Rostrup. — On the larvae of butterflies. FUNGI OF ICELAND 465 Peronosporaceae. Phytophthora De Bary. 18. P. infestans (Montagne) De Bary, Saccardo, Syll. VII, p. 237. Experimental station at Eidar [P. L.]; experimental station at Reykja- vik [Buchwald]; garden at Reykjavik [Semundsson]. — On leaves of Solanum tuberosum. Cystopus Léveillé. 19. C. candidus (Persoon) Léveillé, Sacc., Syll. fung. VII, p. 334. Grafarbakki [O. D.]; Vik (H. J.], Muli near Geysir [Feddersen]; Rey- kjavik [Svend Andersen]. — On leaves and stems of Draba incana, Cardamine hirsuta, Capsella bursa pastoris. Plasmopara Schroeter. 20. P. densa (Rabenhorst) Schroeter. Peronospora densa Rabenhorst, Herbar. mycol. edit. 1. No, 1572. Videy [C. H. O.]. — On leaves of Rhinanthus minor. Peronospora Corda. 21. P. Alsinearum Caspary, Saccardo, Syll. fung. VII, p. 246. Hof [O. D.]; Eskifjöröur and Dyrafjöröur [C. H. O.], Vighölsstadir [H.J.). — On Cerastium alpinum and C.trigynum. 32. P. Ficariae Tulasne, Sacc., Syll. fung. VII, p. 251. Hofsfjall [O. D.); Reykjavik [C. H. O.]. — On Ranunculus acer. 23. P. parasitica (Persoon) Tulasne. Botrytis parasitica Fries, Syst. Myc. III, p. 403. Hof, Torfastadir [O.D.). — On Capsella bursa pastoris and Cardamine pratensis. 24. P. Trifoliorum De Bary, Sacc., Syll. fung. VII, p. 252. Hof (0. D.]. — On Trifolium repens. 25. P. Viciae (Berkeley) De Bary, Sacc., Syll. fung. VII, p. 245. Grafabakki [O.D.). — On Vicia cracca. 26. P. grisea (Unger) De Bary, Sacc., Syll. fung. VII, p. 255. Reykjavik [C. H.0.). — On Veronica serpyllifolia. 27. P. alta Fuckel, Sacc., Syll. fung. VII, p. 262. Vogar near Myvatn (St. St]. — On Plantago major. The Botany of Iceland, Vol, II, part IIL 31 466 POUL LARSEN 28. P. calotheca De Bary, Sacc., Syll. fung. VII, p. 245. Hof [O.D.]; Melstadur [Feddersen]. — On Galium verum and G. boreale. Mucoraceae. Mucor Micheli. 29. M. Mucedo Fries, Syst. Mye. III, p. 320. Mööruvellir, Hof, Fagriskögur, Vidvik [O.D.], det. E. Rostrup. — On sour milk and skin. Common on rotting objects (Mohr). 30. M. Mucerdae (Fries) Lind, Danish fungi, p. 71. Mucor racemosus Fresenius, Sacc., Syll. fung. VII, p. 200. Seydisfjöröur, Hlidarfjall near Myvatn [P. L.]. — On ptarmigan drop- pings, cow- and horse-dung. Rhizopus Ehrenberg. 30a. R. nigricans Ehrenberg, Sacc., Syll. fung. VII, p. 112. Hlidarfjall near Myvatn [P.L.] — On ptarmigan droppings. Pilobolus Tode. 31. P. Kleinii van Tieghem, Sacc., Syll. fung. VII, p. 185. Os, Hof [O.D.]. — On horse and sheep-dung. Phycomyces Kunze. 32. P. nitens (Agardh) Kunze, Sacc., Syll. fung. VII, p. 205. Hraun in Fljôt {St. St.], det. E. Rostrup. — In an old cask containing cod liver oil. Entomophthoraceae. Empusa Cohn. 33. E. Muscae Cohn, Sacc., Syll. fung. VII, p. 251. Gäsir; coastal cliff near Gs; Skrida [O. D.], det. E. Rostrup. — On various species of flies. Protomycetaceae. Protomyces Unger. 34. P. pachydermus Thuemen, Sacc., Syll. fung. VII, p. 319. Mööruvellir. [O. D.]. — On stems and leaves of a Taraxacum sp. Taphrinaceae. Taphrina Fries. 35. T. betulina Rostrup, Tidsskrift for Skovbrug, Bind 6, 1883, p. 296. Norötünga [P.L.]. — On Betula pubescens. FUNGI OF ICELAND 467 36. T.nana Johanson, Bihang t. Vetenskaps-Akademiens Förhand- lingar 1885, p. 34, tab. I, fig. 1. Gaunguskard, Hofsfjall, Hüsavik [O.D.]. On Betula nana. 37. T. carnea Johanson, Bihang t. Vetenskaps-Akademiens Förhand- lingar 1885, p. 43, tab. I, fig. 5—6. Pördarstadarskögur, Pördarstadir, Mödruvellir, Hofsfjall [O. D.]; Médru- vellir (St. St.. — Eskifjördur [C.H.O.]; Hallormstadir, Hälsskögur, Nord- tünga, Pingvellir [P.L.. — On Betula pubescens, Betula inter- media and Betula nana. 38. T. bacteriosperma Johansson, Taphrinaceae II, p. 19, f. 11—12. Efstibær (south-western Iceland) [H.J... — On leaves of Betula nana. Gymnoascaceae. Gymnoascus Baranetzky. 39. G. myriosporus Rostrup, Ostgronlands Svampe, Meddel. om Gronl. 18, 1894, p. 12. Dyrafjordur [N. Hartz]. — On cow-dung. Aspergillaceae. Aspergillus Micheli. 40. A. herbariorum (Wiggers) Schroeter, Pilze Schlesiens II, p. 215. Mucor herbariorum Wiggers, Primitiae florae holsaticae, p. 111. In several places [O.D. and St. St.]. — On withered parts of plants. 41. A. repens (De Bary) Schroeter, 1. c. p. 215. Eurotium repens De Bary, Beiträge III, p. 19. Fagriskögur, Hof [O.D.]. — On bones. Penicillium Link. 42. P. erustaceum (Linné) Fries, Syst. Mye. III, p. 407. Mooruvellir (St. St} Det. E. Rostrup. — On jam in a cellar. 43. P. candidum Fries, Syst. Myc. III, p. 409. Kaldalön (St. St... — On withered leaves of birch. Nos. 42 & 43 were only found in the conidium stage. Erysiphaceae. Erysiphe Link. 44. E. communis (Wallroth) Fries, Sum. veg. Scand., p. 406. Hof in Hörgärdalur [0. D.). — On Draba incana. 31* 468 POUL LARSEN 45. E. Cichoracearum De Candolle, Flore francaise II, p. 274. S. W. Iceland [H. J.], Hofsfjall, Hestarhaun in Porvaldsdalur [O.D.). — On Myosotis arvensis and on Hieracium species. 46. E. Graminis De Candolle, Flor. fr. VI, p. 106. Hof in Hörgardalur [O. D]. — On several species of grasses. Sphaerotheca Léveillé. 47. S. humuli (De Candolle) Burrill, Salmon, A monograph of the Erysiphaceae, New York 1900, p. 45. Hof in Hörgardalur (OD — On Draba incana. 48. S. humuli (De Candolle) Burrill var. fuliginea (Schlechtendal) Salmon, A monograph of the Erys., p. 45. Hof in Hörgardalur [O.D... — On Taraxacum vulgare. Podosphaera Kunze. 49. P. myrtillina Kunze, Mycologische Hefte II, p. 111. Hofsfjall [O. D.]. — On Vaccinium uliginosum. Dothioraceae. Dothiora Fries. 50. D. Sorbi (Wahlenberg) Fuckel. Hysterium Sorbi Wahlenberg, Flora lapponica, p. 523. Bildsfell (Feddersen). — On dead branches of Sorbus Aucuparia. Plowrightia Saccardo. 51. P. ribesia (Persoon) Saccardo, Syll. fung. II, p. 635. Sphaeria ribesia Persoon, Usteri, N. Ann. d. Bot. V, p. 24. The experimental stations at Akureyri and Reykjavik and in several gardens in Reykjavik [P.L.]. — Very common on branches of Ribes rubrum. The asci measure 90—100X16—17 u (pars sporifera). The spores measure 22—37X7—10u (22X9, 26X7, 30X10, 29X9; 22X10, 30X10, 37X10, 32X9 u). Pseudosphaeriaceae. Pyrenophora Fries. 52. P. phaeocomes (Rebentisch) Fries, Summa vegetabilium Scandi- naviae, p. 398. Sphaeria phaeocomes Rebentisch, Flora neomarchicae, p. 338. Fornhagagil [O.D.]. — On leaves of Anthoxanthum odoratum. FUNGI OF ICELAND 469 53. P. hispidula (Niessl) Saccardo, Syll. fung. II, p. 287. Pleospora hispidula Niessl, Notizen über Pyrenom., p. 32. In the plantation at Grund [P.L.). — On withered stems and leaf- sheaths of Luzula multiflora. 54. P. Androsaces (Fuckel) Saccardo, Syll. fung. II, p. 19. Pleospora Androsaces Fuckel, Symbolae, Nachtrag II, p. 19. Occurs throughout Iceland, in the lowlands as well as in the fell-fields. [Strömfelt and P.L.]. — On withered stems and leaves of Cerastium alpinum, Draba alpina, Pedicularis flammea, but most fre- quently on Silene acaulis. 55. P. comata (Niessl) Saccardo, Syll. fung. II, p. 286. Pleospora comata Niessl, Beiträge zur Kenntniss der Pilze, 1872, p. 30. Bær in Hrutafjördur (St. St.); Porvaldsdalur, Hallgilstadafjall, Forn- hagagil and Hofsfjall (O. D.) — On Alsine biflora, Cerastium alpi- num, C. vulgatum and Viscaria alpina. 56. P. hispida (Niessl) Saccardo, Syll. fung. II, p, 284. Pingvellir in Almannagjä [P.L.]. — On withered stems of Arabis petraea and Arenaria ciliata. 57. P. chrysospora (Niessl) Saccardo, Syll. fung. II, p. 173. Pleospora chrysospora Niessl, Hedwigia 1880, p. 173. Grows in all parts of the country on a number of herbaceous plants: Equisetum sp., Festuca rubra, Tofieldia borealis, Rumex acetosa, Oxyria digyna, Cerastium arcticum, Alsine biflora, A.hirta, A. stricta, Arenaria ciliata, Viscaria alpina, Carda- mine bellidifolia, Draba incana, Arabis alpina, A. petraea, Thalictrum alpinum, Saxifraga caespitosa, S. hypnoides, S. rivularis, Sedum annuum, Potentilla maculata, Rubus saxa- tilis, Vicia cracca, Plantago maritima, Primula stricta, Rhinan- thus minor, Euphrasia latifolia, Bartsia alpina, Veronica saxatilis, V. alpina, Gentiana nivalis, G. campestris, Erigeron neglectus, Taraxacum vulgare, Hieracium islandica and other Hieracium sp. 58. P. chrysospora (Niessl) Saccardo, var. polaris Karsten, Hedwigia 1884, p. 38. Mountain slopes facing Lagarfljöt near Hallormstadir [P. L.). On withered stems, leaves, and sepals of Saxifraga aizoides. Diameter of perithecia 200 u. Bristles straight or undulate, 80—90 X 4—5u. Asci cylindric-clavate with a short broad stalk, 8-spored, 120— 135 X 32—35 u (p. sporifera). Spores yellowish brown, cylindric-ovate, ends obtuse, 7 transverse septa, 1—3 longitudinal septa, the end cells having 1, the median cells 3. 8 measurements of the spores produced 470 POUL LARSEN the following results: 33 X 15.5, 35 X 15, 4016, 3217, 30 x 14, 36X 17.5, 35 X 17, 28X13 u. 59. P. phaeocomoides Saccardo, Syll. fung. II, p. 280. Grund near Akureyri in a small plantation (P.L... — Rumex acetosa, Vicia cracca, Achillea millefolium. 60. P. abscondita Karsten, Hedwigia 1884, p. 37. In the plantation at Grund [P.L.]. — On Rhinanthus minor. 61. P. coronata (Niessl) Saccardo, Syll. fung. II, p. 283. Pleospora coronata Niessl, Notizen über neue und kritische Pyreno- myceten, p. 16. Mööruvellir, Hof [O. D.]. — On withered stems of Achillea mille- folium. Pleospora Rabenhorst. 62. P. straminis Saccardo, Michelia I, 407, Fungi ital. autogr. del. t. 329. P. straminis, E. Rostrup Isl. Svampe 1903, p. 308. Hestahraun [O. D.]. — On Trisetum spicatum. P. straminis is not, however, present on the straws of Trisetum spicatum, found in the capsule marked Pleospora straminis in the Ice- landic Herbarium at the Botanical Museum of Copenhagen, whereas a number of Pleospora Karstenii are found on these straws, so it is pos- sible that there may be a mistake and that Pleospora straminis Sacc. should, consequently, be expunged from the list of Icelandic fungi. 63. P. Karstenii Berlese et Voglino. Pleospora arctica Karsten, Sacc., Syll. fung. II, p. 171. Hestahraun [O.D.]. — On dead stems of Deschampsia flexuosa and Trisetum spicatum. This species is very closely allied to Pleospora islandica Johanson. 64. P. microspora Niessl, Notiz. üb. Pyrenom., p. 16. Gäsaeyri [O.D.]. — On Elymus arenarius. 65. P. punctiformis Niessl, Notiz. üb. Pyrenom., p. 24. Skagafjöröur [Strömfelt. — On withered petioles of Agrostis canina. 66. P. islandica Johanson, Svampar från Island, p. 170. Hölar in N. Iceland [Strömfelt). In a bog near Hallormstadir and at Hälskögur near Akureyri [P. L.]. — On withered straws and leaves of Poa caesia, Agropyrum caninum and Trisetum spicatum. FUNGI OF ICELAND 471 67. P. pentamera Karsten, Fungi in insulis Spetzbergen, p. 99. Fornhagagil, Hestahraun in Porvaldsdalur [O. D.) Gudlaugsvik [G. Gudmundsson]; Jökulsä A Fjöllum at Grimstadir [P. L.]. — On dead stems and leaves of Poa caesia, Trisetum spicatum, Glyceria sp. and Juncus balticus. 68. P. vagans Niessl, Notiz. üb. Pyrenom., Brünn 1876, p. 14. Möörudalur, Grimstadir, Grund [P.L.), Vifilsstadahli near Hafnar- fjérdur, Pingvallavatn (Feddersen). — On Elymus arenarius and Luzula multiflora. P. vagans Niessl, var. Airae Niessl, 1. c. The plantation at Raudavatn, Reykjavik [P. L.]. — On withered straws of Deschampsia caespitosa. 69. P. gigaspora Karsten, Hedwigia 1884, p. 37. P. gigantasca Rostrup, Isl. Svampe 1903, p. 307. Blown sand areas between Grimstadir and Mödrudalur near Jökulsä ä Fjöllum (P.L.). Without mention of any locality this species was sent from Iceland to E. Rostrup by Daniel Bruun. Further recorded from Sandey in Pingvallavatn [Feddersen]. — On dead stems, leaves, and chaffs of Elymus arenarius. 70. P. discors (Montagne) Cesati et De Notaris, Sacc., Syll. fung. II, p. 230. Hof, Hjedinshôfôi [O.D.]; bog in low fell-fields south of Akureyri [P.L.]. — On Eriophorum Scheuchzerii, Carex incurva and on dry leaves of Carex rigida. 71. P. scirpicola (De Candolle) Karsten, Mycologia fennica II, p. 72. Sphaeria scirpicola De Candolle, Flor. fr. II, p. 809. Môdruvallafloi [O. D... — On withered leaf-sheaths and stems of Scirpus palustris. 72. P. Triglochinis Har. et Briard, Sacc., Syll. fung. II, p. 878. Höfn in Hafnarfjördur (St. St]. — On stems of Triglochin mari- timum. 73. P. Spartii Saccardo et Berlese, in Berlese Monografia dei generi Pleospora, Firenze 1888, p. 86. In a bog south of Akureyri [P.L.]. — On dead stems of Juncus triglumis. 74. P. Junci Passerini et Beltrani, Sacc., Syll. fung. II, p. 273. Vididalur near Jökulsä 4 Fjöllum [P. L.]. — On petals and the upper part of the stem of dead Juncus balticus. 472 POUL LARSEN P. Junci Passerini et Beltrani var. Luzulae (Feltgen). P. spinosella Rehm var. Luzulae Feltgen. In a birch copse at Pingvellir [P. L.]. — On withered stems of Luzula spicata. Asci: 100 X 26—28 u, 8-spored. The spores: 28 X 10 u, 7 transverse septa, one longitudinal septum through all the joints except the end cells. 75. P. Elynae (Rabenhorst) Cesati et De Notaris, Schema di classifi- cazione degli Sferiacei Italici aschigeri (Comment. Soc. crittog. Ital. vol.]), p. 44. Clathrospora Elynae Rabenhorst, Hedwigia I, Taf. XX, fig. 3. Vididalur near Jökulsä 4 Fjöllum, bog in Ofjordsdal [P.L.]; Gäsir and Hof [O. D. — On withered stems of Juncus balticus and J. triglumis. 76. P. deflectens Karsten, Fungi in insulis Spetsbergen, p. 99. The plantation near Grund south of Akureyri [P.L.]. Fagriskögur [O.D.]. — On dead stems of Vicia cracca and Rhodiola rosea. 77. P. alpina Rostrup, Isl. Svampe 1885, p. 7. Kalmanstünga (Gronlund). — On dead stems of Viscaria alpina. 78. P. Drabae Schroeter, Ein Beitrag zur Kenntnis der nordischen Pilze, p. 15. Jahresb. d. schles. Ges. 1881. Vaölaheidi [Strömfelt]; Hofsfjall, Hallgilsstadafjall [O. D.). — On Draba nivalis and Draba hirta. 79. P. vulgaris Niessl, Notiz. üb. Pyrenom., p. 27. Seydisfjöröur [Feddersen], Krossastadagil and Hof [O.D.); in littoral, meadows and Hrafnagjä on Thingvellir at Akureyri [P. L.]. — On Poten- tilla maculata, Oxyria digyna, Thymus serpyllum, Hieracium islandicum and Tofieldia borealis. 80. P. herbarum (Persoon) Rabenhorst, Herb. mycol. Edit. II, p. 547. Sphaeria herbarum Persoon, Synopsis methodica fungorum, p. 79. Of common occurrence throughout the country and found on withered stems, leaves, and fruits of a number of plants, both dicotyledons and monocotyledons: Silene maritima, Cerastium alpinum, C. vulga- tum, Alsine verna, A. biflora, A. rubella, Draba nivalis, Arabis petraea Cardamine bellidifolia, Rumex acetosella, Dryas, Potentilla maculata, Thalictrum alpinum, Linum catharti- cum, Viola tricolor, Saxifraga caespitosa, S. oppositifolia, Statice armeria, Thymus serpyllum, Campanula uniflora, Galium silvestre, Cirsium arvense, Erigeron alpinum, Hiera- cium sp., Tofieldia borealis. Elymus arenarius, Anthoxanthum odoratum, Agrostis sp. Though this species is very widespread in Iceland and occurs on FUNGI OF ICELAND 473 many different host-plants, its density is much less than in Central Europe. In this respect it falls far short of Pyrenophora chrysospora. As is well known, Pleospora herbarum is a very polymorphous species, especially with regard to the dimensions of the perithecia, asci and spores. But the species is variable in other respects, too. On Saxi- fraga corniculata, Primula veris, Pulsatilla vulgaris and Poly- gonatum multiflorum the spores of P. herbarum may have a wide coating of mucus. On Lotus corniculatus, on which plant the peri- thecia may be found on the stem as well as the pods, I have found 4-spored asci on the stem, and at the same time 8-spored asci on the pods. The spores in the 4-spored asci were 48—50X18—20u, whereas the spores in the 8-spored asci measured 30—50X 14—15 u. Typically the upper and lower halves of the spores are asymmetrical, but on thin dead branches of Hippophaés rhamnoides, where P. herbarum also occurs, these halves are symmetrical If these deviations from the type are constant, the species P. herbarum should rightly be divided into several species, but as this has by no means been established, I have included the various Icelandic forms under one species. The most divergent form of P. herbarum which I have seen in Ice- land, is that occurring on Rumex acetosella, which has both spore- ends somewhat acuminate, while the breadth of the spores is small com- pared with their length, the dimensions being 33—36X11—12 u; hence the proportion of length to breadth is 3 in this case, whereas the typical value of this ratio ranges from 2 to 2.5. Leptosphaeria Cesati et De Notaris. 81. L. Equiseti Karsten, Fungi in insulis Spetsbergen, p. 101. Stock- holm 1872. Tröllafoss [Svend Andersen]; Hallormstadir, the plantation at Grund south of Akureyri, Almannagjä near Pingvellir [P.L.. — On withered pieces of the stem of Equisetum variegatum. In the literature two different views of this species prevail. However, Karsten’s description of L. Equiseli in Mycologia Fennica II, Pyrenomy- cetes. p. 101, will perhaps cover both of them. In The Micromycetes of Svalbard, Skrifter om Svalbard og Ishavet, N. 13, Oslo 1928, Pl. II, figs. 15a and 15b, J. Lind has given a figure of the asci and spores of L. Equiseti Karsten, which agrees perfectly with the Leptosphaeria, found on Equisetum variegatum in Iceland. But a different conception of L Equiseti Karsten has been given by Berlese in Icones Fungorum. Pyrenomycetes Vol. I, p. 54. The Leplosphaeria figured here by Berlese shows considerable deviation, in regard to the dimensions both of the asci and the spores, and especially in regard to the form of spore, from Lind’s Svalbard form and from the Icelandic form. On the other hand, the diagnosis given in Berlese’s figure agrees with a Leplosphaeria, which is very common — at any rate in Denmark — on Equiselum hiemale, where it grows on the dead internodes of the stems so common at the apices of the stems in all growths of Equisetum hiemale. It must, however, be supposed that Berlese received the material for his figure of this Leplosphaeria from Karsten, and that Karsten must have in- 474 POUL LARSEN cluded the two forms under the same species. This, however, is hardly correct. It is true that the two forms of Leptosphaeria must probably be placed in the same line of development, but at a greater distance from one another than is usually allowed in systematic mycology for fungi that must be included under the same species. 82. L. Marcyensis (Peck) Saccardo, Syll. fung. II, p. 80. Almannagja [O.D.]. — On stems of Lycopodium selago. 83. L. arundinacea (Sowerby) Saccardo, Syll. fung. II, p. 62. Brattifjallgaröur (St. St.. — On dead stems and leaves of Calama- Svastis sire ta, 84. L. culmifraga (Fries) Cesati et De Notaris, Syll. fung. II, pp. 75 and 77. Myvatn (Grønlund); Karlskäli (Strömfelt); Hraunsvatn [O.D.]; Grim- stadir near Jökulsä ä Fjöllum, Sluttnes in Myvatn, Hälsskögur and Rauda- vatn near Reykjavik [P.L.]. — On dead stems and leaves of Poa nemo- ralis, Poa caesia, Poa alpina, Milium effusum, Deschampsia caespitosa, Elymus arenarius, Luzula spicata, Kobresia scirpina. 85. L. microscopica Karsten, Fungi in insulis Spetsbergen, p. 102. L. culmorum Auerswald and L. typharum (Desmazieres) Karsten. Hofsös and Hälsskögur (Strömfelt); Nyjahraun and Sandanesmäl (St. St.]; Hestahraun [O.D.]; Pingvellir [P. L.] — On Poa alpina, Agro- stis canina, Puccinellia maritima and Armeria vulgaris £ elongata. 86. L. Fuckelii Niessl, Oesterr. botan. Zeitschr. 1882, No. 11. Hof [O. D.]; the plantation at Grund south of Akureyri [P. L.]. — On Calamagrostis stricta and Deschampsia caespitosa. 87. L. culmicola (Fries) Auerswald, Leipziger Bot. Tausch- Verein 1866, p. 4. Sphaeria culmicola Fries, Syst. Myc. II, p. 430. Hofsfjall and Hof [O.D.]; on the island of Slutnes in Myvatn and Grund plantation near Akureyri [P. L.]. — On Poa alpina, Anthoxan- thum odoratum, Deschampsia caespitosa and Milium effusum. 88. L. nigrans (Desmazieres) Cesati et De Notaris, Schema, p. 61. Vaglaskögur (O. D.]. — On leaf-sheaths of Agropyrum caninum. 89. L. Elymi n. sp. The blown sand areas along Jökulsä 4 Fjöllum between Grimstadir and Vididalur [P.L.). — On dead Elymus arenarius, springing from the axis of the inflorescence. The gregarious perithecia seated beneath the periderm are globose with a short verruciform orifice the diameter of which is 180—270 u. FUNGI OF ICELAND 475 Asci clavate, short-stalked, 7-spored, 80—112 x 18—20 u. Spores biseriate or transversal, a pale yellowish brown, 5- or more rarely 6-septate, slightly constricted at the septa, the 3rd cell from the top prominent, straight or slightly curved, 25—32*8.5—10 u. Numerous filiform, interwoven para- Fig. 1. Leptosphaeria Elymi n. sp. a. Rachis of inflorescence with a few chaffs and mouths of perithecia X 3. b. 2 perithecia 20. ec. 2 asci with spores and paraphyses X 750. physes. Allied to Metasphaeria scirpina (Winter) Sacc., but distinguished with coloured spores. 90. L. Apogon Saccardo et Spegazzini, Michelia I, p. 398. Ofjordsdal near Akureyri (P.L... — On dead stems of Juncus triglumis. The scattered perithecia seated beneath the epiderm, depresso-globose with short barely visible verruciform orifice, diameter 0.1— 0.2 mm. 476 POUL LARSEN Asci cylindric-clavate, shortly stipitate, 8-spored, 60—70*12—14 u. Spores biseriate, fusiform, yellowish brown with 3 transverse septa, 2nd cell from the top prominent, not or only slightly constricted at the septa, 20—24X5—6.5 u. 91. L. juncina (Auerswald) Saccardo, Syll. fung. II, p. 66. Sphaeria juncina Auerswald, Rabenhorst Fungi europ. No. 748. Eskifjördur (Strémfelt), — On dead stems and leaves of Juncus biglumis. 92. L. Luzulae Winter, Hedwigia 1872, p. 149. Almannagjä near Pingvellir [P. L.]. — On dead stems and leaves of Luzula arcuata. 93. L. oreophila Saccardo, Michelia I, p. 120. Asbirgi [St. St]. — On dead leaves and stems of Tofieldia borealis. 94. L. Silenes-acaulis De Notaris, Comment. d. societä critt. ital., Vol. II, fasc. III, p. 485. Reykjavik [Gronlund]; Eskifjöröur [Strômfelt}; Mödruvellir [G. Gud- mundsson}: on sandy lava fields near Reykjavik [P. L.|. — On withered leaves of Silene acaulis and Silene maritima. 95. L. Papaveris Rostrup, Isl. Svampe 1903. p. 305. Bola in Blénduhlid [O.D.]. — On dead stems of Papaver radicatum. 96. L. Doliolum (Persoon) Cesati et De Notaris, Schema, p. 61. Sphaeria Doliolum Persoon, Synops. meth. fung., p. 78. On the island of Sluttnes in Myvatn and Vifilsstadahliö near Hafnar- fjordur [P.L.]. — On dead stems of Archangelica officinalis and Rumex acetosa. i 97. L. Dryadis Rostrup, Isl. Svampe 1903, p. 305. Sponsgerdi [O. D.], Sandafjall and Dyrafjérdur [C. H. O.]. — On stems and fruits of Dryas octopetala. 98. L. Ribis Karsten, in Rev. Myc. 1885, p. 106. Nursery garden at Hallormstadir and the experimental station at Reykjavik [P.L.] — On dead branches of Ribes rubrum. Perithecia scattered, beneath the epiderm, diameter 0.1—0.2 mm. Asci cylindrical, stalked, the elongate asci 1308 u, the short ones 90X10 u, 8-spored. Spores uni—biseriate, elongate-ellipsoidal, pale yellowish brown, typically with. 3 transverse septa, but number of the spores gradually get 4 or even 5 transverse septa, a very few 6, some of the secondarily formed transverse septa are oblique, none of the cells are very promi- nent, 17—22X6—7 u. Numerous delicate paraphyses; they are cylindrical, articulated, 4 4 wide. This species is nearly allied to L. hippophaés (Fabre) Rostrup. FUNGI OF ICELAND 477 99. L. ogilviensis (Berkeley et Broome) Cesati et De Notaris, Schema, p- 61. Sphaeria ogilviensis B. et Br., Notic. of Brit. Fungi, No. 462. Hestahraun in Porvaldsdalur [O. D.) — On dead stems of a Hiera- cium sp. 100. L. agnita (Desmazieres) Cesati et De Notaris. Sphaeria agnita Desm.; Annals des sciences natur. III serie, vol. 16, D: 313. Hestahraun in Porvaldsdalur and Fornhagagil [O.D.). — On dead stems of Hieracium sp. and Geranium silvaticum. Metasphaeria Saccardo. 101. M. culmifida (Karsten) Saccardo, Syll. fung. II, p. 174. Vaölaheidi "Strömfelt]. — On dead parts of Carex lagopina. 102. M. macrotheca Rostrup, Gronl. Svampe 1888, p. 561. Vatnsdalsfjall [St. St]. — On dead parts of Carex rigida. 103. M. Junci (Oudemanns) Saccardo, Syll. fung. II, p. 177. Hrafnagjä near Pingvellir [P.L.. — On dead stems of Luzula spicata. The perithecia, seated gregariously beneath the epiderm are globose, though as a rule somewhat flattened, with a diameter of 0.2—0.3 mm and with a short orifice. Asci cylindrical, curved, stalkless or short-stalked, 70X20 u, surrounded by filiform ca. 2 u broad pseudoparaphyses, 8-spored. Spores biseriate, hyaline, fusiform, somewhat curved, ends obtuse, 3 transverse walls, without constrictions, with a mucous envelope, 20—22 X5—6 u. 104. M. Arabidis Johanson, Svampar fran Isl. 1884, p. 169, Figs. 11a and bb, Tab. XXIX. Reistarargil, Prastarhölsärgljufur [O. D.]; Skagafjördur [P. Zophonias- son}; Eskifjördöur [Strömfelt]. — On withered leaves of Arabis alpina and Arabis petraea. 105. M. islandica (Rostrup) P. Larsen. Sphaerulina islandica Rostrup, Isl. Svampe 1885, pp. 218—239. Brynjudalur [Gronlund). — On dead stems of Arabis alpina. 106. M. complanata (Tode) Saccardo, Syll. fung. II, p. 161. Sphaeria complanata Tode, Fungi mecklenburgenses, fig. 88. Storugjä near Myvatn [P.L.. — On dead stems and petioles of Geranium silvaticum. 478 POUL LARSEN 107. M. empetricola Rostrup, Isl. Svampe 1903, p. 306. Hof in Hörgardalur [O. D.]. — On decorticated stems of Empetrum nigrum. 108. M. Empetri (Fuckel) Saccardo, Syll. fung. II, 171. Hestahraun in Porvaldsdalur [O.D.]; Reykjahlid near Myvatn [P. L.). — On withered but still attached leaves of Empetrum nigrum. 109. M. Angelicae Rostrup, Isl. Svampe 1903, p. 306. Grimstadir near M\vatn [O.D.); the island of Sluttnes in Myvatn [P.L.). — On dead stems of Angelica silvestris and Archangelica officinalis. Didymella Saccardo. 110. D. proximella (Karsten) Saccardo, Syll. fung. I, p. 558. Sphaerella proximella Karsten, Mycologia Fennica II, p. 177. Horgardalur [O.D.]. — On dead leaves of Carex capillaris. 111. D. inconspicua Johanson, Svampar fran Isl. 1884, p. 167. Eskifjordur [Strömfelt). — On dead leaves of Saxifraga oppo- sitifolia. Hypocreaceae. Nectria Fries. 112. N. coccinea (Persoon) Fries, Sum. Veg. Scand., p. 368. Sphaeria coccinea Persoon, Synops. meth. fung., p. 49. Hälsskögur [O. D.]. — On birch-wood. 113. N. Peziza (Tode) Fries, Sum. Veg. Scand., p. 388. Sphaeria Peziza Tode, Fungi Mecklenburgenses selecti II, p. 46. Pingvellir [P.L.). — On dead branches of Betula pubescens. 114. N. Coryli Fuckel, Ascm. N. 860, Hedwigia, XXII, p. 54. In Reykjavik in gardens and in the grounds of the experimental station. — On dead branches of Salix phylicifolia. The darkred, spherical, but soon crateriformly depressed perithecia are gathered in clusters which break through the periderm. Asci clavate 70—90*10 u, as a rule with numerous small (5—7X1—1.5 u), cylindrical, curved, clear sporidia; but other asci occur, with 8 2-celled clear asco- spores, lanceolate, with no constriction at the septum, straight or slightly curved 10—14X2.5—3.5 u, often with a cylindrical appendage 5—6X1 u, which is obstricted and gradually forms the above-mentioned sporidia. (Cf. Winter, Gymnoasceen und Pyrenomyceten, p. 114). LUNGI OF ICELAND 479 115. N. cinnabarina (Tode) Fries, Sum. Veg. Scand., p. 388. Sphaeria cinnabarina Tode, Fungi mecklenburgenses selecti II, p. 9. Reykjavik [Buchwald]; Saudafell [Helgi Jonsson]; Hallormstadir and Akureyri [P.L.. — On branches of Ribes rubrum and Sorbus aucuparia. Hypomyces Fries. 116. H. chrysospermus (Bulliard) Tulasne, Annales des sc. nat., Ser. IV, tom. XIII, p. 16. Hüsafellsskögur [O.D.]; Egilsstadir [P.L.].. — On putrescent Bole- tus scaber. Claviceps Tulasne. 117. C. microcephala (Wallroth) Tulasne. Kentrosporium microcephalum Wallroth, Beiträge II, Taf. 3, Fig. 10—16. S.W. Iceland [H. J]. — On Alopecurus pratensis and Poa pra- tensis. 118. C. purpurea (Fries) Tulasne. Sphaeria purpurea Fries, Syst. Myce. II, p. 325. Reykjavik [H.J.1. — On Festuca rubra. Chaetomiaceae. Chaetomium Kunze. 119. C. indicum Corda, Icones IV, p. 38. Sacc, Syll. fung. I, p. 222. Hlidarfjall near M\vatn, N. Iceland [P. L.]. — On ptarmigan droppings. (Det. O. Rostrup). Sordariaceae. Sordaria Cesati et De Notaris. 120. S. leucoplaca (Berkeley et Ravenel) Ellis et Everhart. Sphaeria leucoplaca B. et Rav., Grevillea IV, p. 143. Hlidarfjall north of Myvatn [P. L.]; det. O. Rostrup. — On ptarmigan droppings. N. Iceland: Hof in Hörgardalur [O.D.]. — On cow dung. 121. S. coprophila (Fries) Cesati et De Notaris, Schema, p. 52. Sphaeria coprophila Fries, Syst. Mye. II, p. 342. Geysir (0. D.] — On sheep dung. 122. S. curvula de Bary, Morphologie und Physiologie der Pilze, 1886, p. 209. Hälsskögur (0. D.]; Seydisfjordur, Hlidarfjall, Nordtünga, Borg [P. L.]. — On droppings of ptarmigan, sheep and horses. 480 POUL LARSEN 123. S. dicipiens Winter, Deutsche Sord., p. 28. Seydisfjordur [P. L.]; det. O. Rostrup. — Horse-, sheep- and cow-dung. 124. S. hirta Hansen, Fungi fimicoli danici, Nat. For. Vid. Medd. 1876; p: 336. Seydisfjördur [P. L.]; det. O. Rostrup. — On horse dung. 125. S. minuta Fuckel, Symb. myc., II. Nachtr., p. 44. Hofsfjall [O. D.]. — On horse dung. 126. S. Winterii Karsten, Mycologia Fennica II, p. 251. Hof in Hôrgardalur (0. D.). — On horse dung. Hypocopra Fries. 127. H. discospora (Auerswald) Fuckel, Symb. myc., Nachtr. II, p. 43. On cow dung (Gronlund). — No locality given. 128. H. fimicola (Roberge) Saccardo, Syll. fung. I, p. 240. Gäsaeyri, Hof, Hälsskögur [O. D.]. — On horse dung. H. fimicola (Roberge) Saccardo f. microspora Starbäck. Seydisfjördöur [P.L.], det. ©. Rostrup. — On sheep dung. Spores 13—14X6 u. 129. H. insignis (Hansen) Saccardo, Syll. fung. I, p. 243. Sordaria insignis Hansen, Fungi fimicoli danici, Vid. Medd. fra Nat. For, 1876, p. 334. Hallgilsstadafjall [O. D. — On sheep dung. 130. H. microspora (Plowright) Saccardo, Syll. fung. I, p. 241. Hörgärdalur (0, D.]. — On horse dung. 131. H. minima Saccardo, Syll. fung. I, p. 244. Sordaria minima Saccardo et Speg., Michelia I, p. 373. Hofsfjall in Hörgärdalur [O.D.]. — On horse dung. 132. H. stercoraria (Sowerby) Saccardo. Rostrup Isl. Svampe 1903, p. 299. Hof, Hälsskögur [O. D.]. On horse dung. Delitschia Auerswald. 133. D. moravica Niessl, Notiz. üb. Pyrenom., p. 47. Seydisfjördur [P.L.], det. O. Rostrup. — On droppings of horses and sheep. FUNGI OF ICELAND 481 Sporormia De Notaris. 134. S, minima Auerswald, Hedwigia VII, p. 66. Mööruvellir [O. D.]. — On droppings of birds. 135. S. ambigua Niessl, Notiz. üb. Pyrenom., p. 97. Hofsfjall [O. D.]; Seydisfjördöur [P. L.]; det. O. Rostrup. — On droppings of horses and sheep. and 136. S. intermedia Auerswald, Hedwigia VII, p. 67. Throughout Iceland. — On droppings of horses, cows, sheep, dogs, ptarmigan. 137. S. promiscua Carestia, in Rahenhorst Fungi Eur., No. 1236. Hofsfjall (0. D.]. — On droppings of ptarmigan. 138. S. lageniformis Fuckel. Symb., p. 242. Melar [Grønlund]. — On cow dung. 139. S. Notarisii Carestia, Rabenhorst: Fungi europaei, No. 976. Hlidarfjall near Myvatn [P. L.j, det. O. Rostrup. — On ptarmigan droppings. 140. S. octomera Auerswald, Hedwigia VII. p. 70. Hlidarfjall near Myvatn [P. L.), det. O. Rostrup. — On ptarmigan droppings. 141. S. commutata Niessl, Notiz. üb. Pyrenom., p. 464. Lurkasteinn [O.D.]. — On cow dung. 142. S. corynespora Niessl, Notiz. üb. Pyrenom., p. 166, Seydisfjördur [P.L.], det. O. Rostrup. — On sheep dung. Sphaeriaceae. Coleroa Fries. 143. C. Alchimillae (Greville) Winter, Rabenhorsts Kryptogamen- flora, erster Band, II Abtheilung, p. 199. Hofsfjall, Hraun in Fljöt, Hrafnagjä (O. D.); Markiä Fos (Feddersen). — On Alchimilla vulgaris. Leptospora Fuckel. 144. L. ovina (Persoon) Fuckel. Sphaeria ovina Persoon, Synops. meth. fung., p. ret Hälsskögur [O.D.]. — On dead branches of Betula pu bescens. The Botany of Iceland, Vol. Il. part HI 32 482 POUL LARSEN Lasiosphaeria Cesari et De Notaris. 145. L. sorbina var. radiata, Berlese: Icones Fungorum, Vol. I, tab. 106, fig. 2. Hälsskögur [O.D.). — On decorticated dead wood of Betula pube- SCens: Herpotrichia Fuckel. 146. H. nigra Hartig, Sacc., Syll. fang. IX, p. 858. Godaland [H:J.]. — On needles of Juniperis communis. Bertia De Notaris. 147. B. Lichenicola De Notaris, Rabenhorst: Fungi europaei, No. 950. Reistarärskard [O. D.. — On the thallus of Solorina crocea. Rosellinia Cesati et De Notaris. 148. R. mammiformis (Persoon) Winter, Rabh. Krypt. Flora II, p. 226. Sphaeria mammiformis Persoon, Synops. meth. fung., p. 64. Hälsskögur [O.D.). — On birch-wood. 149. R. subcorticalis Fuckel, Symbolae, p. 150. Pingvellir, Hrafnagjä [P.L.. — On the inner side of the bark of Betula pubescens. Wallrothiella Saccardo. 150. W. minutissima (Crouan) Saccardo? Syll fung. I, p. 455. Hlöö in Hörgärdalur [O.D.]. — On the droppings of dogs. In Isl. Svampe 1903 p. 300 E. Rostrup states the dimensions of the asci as 47X13 and those of the spores as 8—10X5 u, whereas Ellis and Everhart in North American Pyrenomycetes, p. 255 give the dimen- sions as 35—40X3.5 u for the asci and 3.5—4X2.5 u for the spores. These dimensions cannot possibly refer to the same species. Lizonia De Notaris. 151. L. abscondita Johanson, Svampar fran Island, 1884. Eskifjöröur [Strömfelt). — On dead leaves of Dryas octopetala. Zignoella Saccardo. 152. Z. ovoidea (Fries) Saccardo, Michelia I, p. 346. Syn. Sphaeria ovoidea Fries, Systema II, p. 459. In a birch copse at Borg [P.L.]. — On dead putrescent branches of Betula pubescens. FUNGI OF ICELAND 483 Melanomma Fuckel. 153. M. Pulvis pyrius (Persoon) Fuckel, Symbolae, p. 160. Sphaeria Pulvis pyrius Persoon, Synops. meth. fung., p. 86. N. Iceland: Sluttnes in M\vatn [P. L.] and Hälsskögur [O. D. — On dead branches of Salix phylicifolia and on birch-wood. 154. M. Aspegrenii (Fries) Fuckel, in Kunze: Mycolog. Hefte II, p. 40 and Symbolae, p. 159. Pördarstadaskögur [O. D]; Dyrafjördur [N. Hartz]. — On dead branches of Betula pubescens. 155. M. juniperinum (Karsten) Saccardo, Michelia I. p. 80. Sphaeria juniperina Karsten, Mycologia Fennica II, p. 89. Fornhagagil (0. D.]. — Decorticated branch of Juniperus nana. Amphisphaeriaceae. Amphisphaeria Cesati et De Notaris. 156. A. papillata (Schumacher) De Notaris, Syll. fung. I, p. 725. Sphaeria papillata Schumacher. Enumeratio II, p. 161. Begisargil [O. D.]. — On wood of Salix lanata. Strickeria Körber. 157. S. Kochii Körber, Parerga lichenol., 1865, p. 400. Teichospora Rabenhorstii Saccardo, Syll. fung. II, p. 301. Laxä near M\vatn [P. L.]. — On dead branches of Salix phylici- folia. 158. S. obducens (Fries) Winter. Sphaeria obducens Fries, Syst. Myc. II, p. 456. Gäsir (0. D.) — On wood washed up from the sea. 159. S. obducens (Fries) Winter f. betulina n. f. Pingvellir [P.L.). — On decorticated spots in branches of Betula pubescens. The form deviates from S. obducens in two respects: 1) The spores are not constricted in the middle. 2) The asci are shorter and broader, in part with biseriate spores. 160. S. patellarioides (Saccardo). Teichospora patellarioides Saccardo, Michelia I, p. 47. Gäsir [O. D. — On wood washed up by the sea. 32% 484 POUL LARSEN 161. S. Davidssonii (Rostrup). Teichospora Davidssonii Rostrup, Isl. Svampe 1903, p. 309. Hofsfjall [O. D. — On buds of Salix lanata. 162. S. salicina (Persoon) Gäumann, Vergl. Morph. d. Pilze, p. 261. Sôrlastadir [O. D.]. — On leaves of Salix phylicifolia. Lophiostomaceae. Lophiostoma (Fries) Cesati de Notaris. 163. L. Juniperi H. Fabre, Essai sur les Sphériacées de Vaucluse, p, 105, fig. 52. Fornhagagil [O. D.]. — On branches of Juniperus nana. Mycosphaerellaceae. Guignardia Viale et Ravaz. 164. G. graminicola (Rostrup). Laestadia graminicola Rostrup, Gronl. Svampe 1888, p. 548. Hvammsurö [St. St... — On Poa caesia. 165. G. Potentillae (Rostrup) Lindau. Laestadia Potentillae Rostrup, Isl. Svampe 1885, p. 11. Hvammsfjöröur, Seydisfjöröur [A. Feddersen). — On Potentilla maculata. 166. G. Oxyriae (Rostrup). Laestadia Oxyriae Rostrup. Isl. Svampe, 1903, p. 300. Krossastadagil [O. D.]. — On dry stems of Oxyria digyna. 167. G. Veronicae (Rostrup). Laestadia Veronicae Rostrup, l.c., p. 300. Hestahraun in Porvaldsdalur [O.D.]. — On living leaves of Vero- nica alpina. 168. G. lunulata (Rostrup). Laestadia lunulata Rostrup, Bidrag til Kundskaben om Norges Sop- arter, A. Blytt. Ascomyceter fra Dovre, p. 6. Hallormstadir [P. L.). — On stems and leaves of Erigeron alpina. Mycosphaerella Johanson. 169. M. Filicum (Desmaziéres) Starbäck, Sacc., Syll. fung. I, p. 532. Sphaeria Filicum Desmaziéres (in Ann. sc. nat, II Ser., tom. XIII, D 187) FUNGI OF ICELAND 485 The Experimental Station at Reykjavik [P. L.]. — On withered leaves of Dryopteris sp. 170. M. Equiseti (Fuckel) Schroeter, Die Pilze Schlesiens, H. 2, p. 341. Sphaerella Equiseti Fuckel, Symbolae, p. 102, Hofsfjall [O. D.], Grund near Akureyri [P. L.]. — On withered Equi- setum stems. 171. M. lycopodina (Karsten) Schroeter, 1. c., p.340. Sphaerella lycopodina Karsten, Fungi fennici exsicc. No. 569. Skaptärhraun [St. St. — On withered leaves of Lycopodium selago. 172. M. Juncaginearum (Lasch) Schroeter, 1. c., p. 342. Dothidea Juncaginearum Lasch, Phaeosphaerella Junc. Sacc. Syll. fung. XI, p. 312. Pictured in Lind, Danish Fungi, plate III, figs. 33—34. Hof [O. D.]. — On leaves and stems of Triglochin palustris. 173. M. Tassiana (De Notaris) Johanson, Svampar frän Isl., p. 167. Sphaerella Tassiana De Notaris, Sferiac. ital., p.87, taf. XCVIII. Sphaerella pachyasca Rostrup, Gronlands Svampe 1888, p. 552. Very common on Dicotyledons as well as Monocotyledons. 174. M. pusilla (Auerswald) Johanson, 1. c., p. 166. Sphaerella pusilla Auerswald, Mycologia europ.. 5. and 6. part, p. 20, Table VI, fig. 80. Hofsfjall [O. D.]; Fljötsheidi (Grønlund); Hofsés [Strömfelt). — On Phleum pratense and Carex chordorrhiza. 175. M. recutita (Fries) Johanson, l. c., p. 166. Sphaeria recutita Fries, Syst. Myc. II, p. 524. M\vatn (Grønlund), Eskifjördur (Strömfelt), Grund near Akureyri, Hälsskögur [P.L.]. — On withered leaves of Festuca rubra, Hierochloa odorata and Agropyrum caninum. 176. M. lineolata (Roberge et Desmazières) Schroeter, 1. c., p. 339. Sphaeria lineolata Rob. et Desm., Ann. sc. nat. II Ser. tom. XIX, p. 351. Fornhagagil [O.D.]. — On withered leaves of grasses. 177. M. Wichuriana (Schroeter) Johanson, L.c., p. 166. Sphaerella Wichuriana Schroeter, Ein Beitrag zur Kenntnis der nor- dischen Pilze. 58. Jahresber. der schles. Gesellsch., p. 173. Common on leaves of Carex sp.: C.chordorrhiza, C. rupestris C. rigida, C. vulgaris and C. lagopina. 486 POUL LARSEN 178. M. perexigua (Karsten) Johanson, Le, p.166. Sphaerella perexigua Karsten, Mycologia Fennica II, Pyrenomycetes, p. 54. Eskifjöröur and Hofsös [Strömfelt). — On Juncus biglumis and Scirpus caespitosus. 179. M. salicicola (Fuckel) Schroeter, Die Pilze Schlesiens, 2, p. 333. Sphaerella salicicola Fuckel, Symb.. p. 106. Hof in Hörgärdalur [O. D.). — On leaves of Salix herbacea. 180. M. Capronii Saccardo, Syll. fung. I, p. 487. Sphaerella salicicola Cooke, Handbook of Br. Fungi, No. 2744. Hofsfjall [O.D.]. — On leaves of Salix lanata. 181. M. harthensis (Auerswald). Sphaerella harthensis Auerswald, Mycol. europ. Heft V./VL, p. 9. Fig. 37. Hof in Hörgärdalur [O.D.). — On leaves of Betula nana, 182. M. maculiformis (Persoon) Schroeter, l.c., p. 333. Sphaeria maculiformis Persoon, Synopsis, p. 90. Fornhagagil [O. D.], Hüsafell [H. J.], Hrafnagjä [P. L.]. — On leaves of Betula pubescens. 183. M. Polygonorum (Crié) Lind, The Micromycetes of Svalbard, p. 20. Hallgilsstadafjall [O. D.], Viövik [St. St]. — On Polygonum vivi- parum and Rumex Acetosella. 184. M. isariphora (Desmaziéres) Johanson, Le, p. 164. Sphaeria isariphora Desm., Ann. sc. nat., II Ser., tome XIX, p. 358. Sphaerella Stellariae Fuckel, Symb., p. 102. Of common occurrence on many species of the Alsineae: Alsine strieta, Alsine biflora, Alsine verna, Arenaria ciliata, Cera- stium alpinum, Cerastium trigynum. 185. M. tingens (Niessl), Hedwigia 1883, p. 13. Mööruvellir (St. St]. — On Arenaria ciliata. 186. M. densa (Rostrup) Lind, Micromyceter fra Äreskutan, Svensk Bot. Tidsskr. 1928, p. 64. Sphaerella densa Rostrup, Isl. Svampe 1885, p. 225. Reykjavik [Grønlund]. — On Arenaria ciliata. FUNGI OF ICELAND 487 187. M. sibirica (Thümen). Sphaerella sibirica Thümen, Beiträge zur Pilz-Flora Sibir. No. 766. Of common occurrence on Silene acaulis, Silene maritima and Viscaria alpina. 188. M. fusispora (Fuckel), in Oudemans: »Contributions å la flore mycologique de Nowaja Semlja«, Medd. der Konink. Ak. van Wet. 3. Reeks. Deel IL, p. 146—161. Amsterdam 1885, p.151, tab. II, fig. 4. Hofsfjall [O.D.), Heljardalsheidi (Strömfelt). — On stems of Ranun- culus pygmaeus. 189. M. vulgaris (Karsten) Schroeter, Die Pilze Schlesiens, 2, p. 337. Sphaerella vulgaris Karst., Mycologia Fennica II, p. 168. Sluttnes in Myvatn [P.L.). — On withered stems of Ranunculus acer. 190. M. arthopyrenoides (Auerswald). Sphaerella arth. Auerswald, Mycol. europ., Heft V and IV, p.15, fig. 55. Bildudalur, Heydalså (St. St... — On Papaver radicatum. 191. M. Cruciferarum (Fries). Sphaeria Cruc. Fries, Syst. Myc. II, p. 525. Os in Mööruvallasökn, Hörgärdalur [O.D.. — On Cardamine pratensis. 192. M. Parnassiae (Rostrup). Sphaerella Parn. Rostrup, Isl. Svampe 1903, p. 302. Hof in Hörgärdalur [O.D.]. — On stems and sepals of Parnassia palustris. 193. M. melanoplaca (Desmaziéres) Lindau. This species is described at length by F. Petrak in Hedwigia, Band LXV, p. 231. - Hof in Hörgärdalur [O.D.]. — On withered leaves of Potentilla verna. 194. M. ootheca (Saccardo). Sphaerella ootheca Saccardo, Michelia II, p. 160. Mööruvellir (St. St.) and Hallgilsstadafjall [O. D.). — On Dryas octo- petala. 195. M. Dryadis (Auerswald). Sphaerella Dryadis Auerswald, Mycologia europ., Heft V and VI, p. 8. Berufjördur (Grønlund). — On Dryas octopetala. 488 POUL LARSEN 196. M. innumerella (Karsten) Starbäck, Sacc., Syll. fung. I, p. 506. Sphaerella innum. Karsten, Mycologia Fennica II, p. 182. Hestahraun in Porvaldsdalur [O. D.]. — On withered leaves of Sib- baldia procumbens. 197. M. Viciae (Schroeter). Sphaerella Viciae Schroeter, Ein Beitrag zur Kenntnis der nordischen remplit = RS acc syll. tung kp, 6a: Grafarbakki [O. D.]. — On stems of Vicia cracca. 198. M. Vulnerariae (Fuckel) Lind, Danish Fungi, p. 208. Ascochyta vulneraria Fuckel, Sacc., Syll. fung., III, p. 398. Hvaleyri in Hafnarfjérdur [O. D.], Njarövik [H.J... — On leaves of Anthyllis vulneraria. 199. M. sp. Hrafnagjä, Thingvellir [P. L.]. — On withered stems of Geranium silvaticum. Perithecia gregarious, small, c. 80 « in diameter. — Asci cylindrical, 35X4—5 u, 8-spored. — Spores uniseptate, colourless, 8—10X2.5 u, the uppermost cell slightly broader than the lowermost. 200. M. rubella (Niessl) Magnus. Sphaerella rubella Niessl, Hedwigia 1877, p. 118. Fornhagagil [O. D.], Barkarnautur [H. J.J. — On withered stems of Angelica silvestris. 201. M. polyspora Johanson. Svampar fran Island 1884, p. 164. Eskifjöröur (Strömfelt), Mé6druvellir [St. St]. — On dry fruit and peduncles of Loiseleuria procumbens. 202. M. Gentianae (Niessl). Sphaerella Gentianae Niessl, Oesterr. botan. Zeitschr. 1875, p. 128. Os in Mööruvallasökn [O.D.. — On dead stems of Gentiana nivalis. 203. M. Compositarum (Auerswald) Schroeter. Sphaerella Compositarum Auerswald, Mycolog. europ., Heft V./VL, p. 15. Nollsklif and Hestahraun in Porvaldsdalur [O.D.]. — On dead stems and leaves of Cirsium arvense and Gnaphalium norvegicum. FUNGI OF ICELAND 489 204. M, Hieracii (Cooke et Massee). Sphaerella Hieracii Cooke et Massee, Grevillea XV, p. 111. Hestahraun in Porvaldsdalur and Vidimyri [O.D.|. — On various species of Hieracium. 205. M. eriophila (Niessl). Sphaerella eriophila Niessl, Neue Kernpilze in Oesterr. bot. Zeitschr. 1875, p. 86. Hofsfjall [O. D.]. — On dead stems of Erigeron alpinum. 206. M. Taraxaci (Karsten) Lind, Micromycetes from North-Western Greenland, Meddel. om Grønland 71. 1926, p. 174. Sphaerella Taraxaci Karsten, Kgl. Vet. Ak. Förh. 1872, No. 2, p. 106. Hofsfjall [O.D.]. — Taraxacum officinale. Ophiobolus Riess. 207. O. herpotrichus (Fries) Saccardo, Syll. fung. II, p. 352. Sphaeria herpotricha Fries, Syst. Myc., vol. II, p. 504. Lönsleirur and Hofsfjall [O. D.]. — On Carex salina and Deschamp- sia caespitosa. 208. ©. salicinus Rostrup, Isl. Svampe 1885, p. 224. Laugardalur (Grønlund). — Under loose bark on branches of Salix glauca. 209. O. Cesatianus (Montagne) Saccardo, Syll. fung. II, p. 339. Grund Plantation [P.L.. — On dead stems of Achillea mille- folium. Dilophia Saccardo. 210. D. Graminis (Fuckel) Saccardo, Syll. fung. II, p. 357. Fornhagagil, Hofsfjall [O. D.]. — On withered leaves of Deschamp- Sia caespitosa. Tichothecium Flotow. oii. T. pygmaeum Korber, Parerga lichenol., 1865, p. 467. Mööruvellir and Hof in Hörgärdalur (0. D.j, Reynivellir, Reykjavik and Hafnarfjöröur (Grønlund), Sandur in Snæfellsnessyssel [H. J.J. — On Placodium saxicola and Aspicilia gibbosa. 212. T. gemmiferum (Taylor) Körber, I. c., p. 468. Verrucaria gemmifera Taylor, Mackay, Flora bibern. II, p. 95. Reykjavik and Hafnarfjöröur (Gronlund). — On the thallus of several lichens. 490 POUL LARSEN Venturia Cesati De Notaris. 213. V. chlorospora (Cesati) Karsten. Sphaeria chlorospora Cesati, Rabenhorst: Fungi europ. Nr. 48. Common throughout the country. — On leaves of Salix herbacea, S. glauca and’ S. phylicifolia, 214. V. ditricha (Fries) Karsten. Sphaeria ditricha Fries, Systema mycologicum, vol. II, p. 515. Stadarhraun (Feddersen), Hallormstadir [H.J.) and Vifilsstadahlid [P.L.]). — On dead leaves of Betula pubescens. 215. V. caulicola Rostrup, Isl. Svampe 1903, p. 304. Hestahraun in Porvaldsdalur [O. D.]. — On stems of Rumex acetosa. 216. V. islandica Johanson, Svampar fran Isl. 1884, p. 168. Eskifjordur (Strômfelt). — On dead leaves of Dryas octopetala. 217. V. Geranii (Fries) Winter, Rabh. Krypt. Flora, II, p. 434. Dothidea Geranii Fries, Syst. Myc., vol. II, p. 558. The Experimental station at Reykjavik [P.L.]. — On leaves of Ge- ranium silvaticum. 218. V. Myrtilli Cooke, Journ. Bot. 1866, p. 245. Fornhagagil and Hof [O.D.l. — On leaves of Vaccinium uligi- nosum. Sphaerulina Saccardo. 219. S. Potentillae Rostrup, Isl. Svampe 1885, p. 228. Seydisfjöröur (Feddersen). — On withered stems and sepals of Po- tentilla maculata. 220. S. Diapensiae Rostrup, Isl. Svampe 1903, p. 306. Hofsfjall [O. D. — On peduncles, sepals and fruits of Diapensia lapponica. 221. S. intermixta (Berkeley et Broome) Saccardo, Syll. fung. II, p.187. Sphaeria intermixta Berkeley et Broome, Not. on British fungi, No. 639. Reykjavik in a garden [H.J.].— On branches of a Lonicera sp. Pleosphaerulina Passer. 222. P. vitrea (Rostrup) P. Larsen. Pleospora vitrea Rostrup, Gronl. Svampe 1891, p. 620. Mööruvellir [St. St, Hof [O.D.]. — On Alchimilla alpina. FUNGI OF ICELAND 491 This species has nothing else in common with species of Pleospora than the many-celled spores. It belongs to the genus Pleosphaerulina. Cp. the herbarium specimen in Rostrup’s collection of Icelandic Fungi in the Botanical Museum of Copenhagen. Physalospora Niessl. 223. P. montana Saccardo, Michelia II, p. 378. Hallormstadir [P.L.]. — On dead leaves of Trisetum spicatum. 224. P. Festucae (Libert) Saccardo, Michelia I, p. 27. Kollafjardarnes. — On Festuca rubra. 225. P. Potentillae Rostrup, Gronl. Syampe 1888, p. 548. Hof [0.D]. — On Potentilla maculata. Massariaceae. Massarina Saccardo. 226. M. Dryadis Rostrup, Gronl. Svampe 1888, p. 560. Hörgärdalur [O. D.), Egilsstadir in Vopnafjördur (St. St... — On dead leaves of Dryas octopetala. Massaria De Notaris. 227. M. Thalictri (Rostrup) Lind, Micromyceter fraAreskutan,Svensk Botanisk Tidskrift, 1928, p. 67. Lizonia Thalictri Rostrup, Gronl. Svampe 1888. Fig. 2. Reykjahlid near Myvatn [P. L.]. — Massaria Thalieles: On dead stems of Thalictrum alpi- „ Ascus with immature spores X 333. num. b. 2 mature spores X 333 Gnomoniaceae. Gnomonia Cesati et De Notaris. 228. G. campylostyla Auerswald, Mycol. europ., Heft V./VL, p. 25. Gullfoss near Hvitä (Feddersen), Nordttinga [P. L.]. — On dead leaves of Betula nana and B, pubescens. 229. G. setacea (Persoon) Cesati et De Notaris, Schema sferiac. p. 58. Sphaeria setacea Persoon, Usteri, Ann. d. Bot. St. 11, p. 25. 492 POUL LARSEN Nordtunga, Pingvellir and Vifilsstadahlid [P.L... — On dead leaves of Betula pubescens. 230. G. pleurostyla Auerswald, Mycol. europ. Heft V./VI., p. 28. Gullfoss near Hvitä (Feddersen). — On dead leaves of Salix her- bacea. 231. G. vagans (Johanson) Rostrup, Isl. Svampe 1903, p. 303. Gnomoniella vagans Johanson, Svampar fran Isl. 1884, p. 168. Eskifjördur (Strömfelt). — On stalks of leaves and flowers of Dryas octopetala. 232. G. borealis Schroeter, Die Pilze Schlesiens, 2, p. 391. Reykjahlid near Myvatn in Storugjä [P. L.]. — On dead stems of Geranium silvaticum. Clypeosphaeriaceae. Hypospila Fries. 233. H. groenlandica Rostrup, Gronl. Svampe 1888, p. 561. Hrafnagjä on Pingvellir [P. L.]. — On dead leaves of Salix glauca. 234. H. rhytismoides (Babington) Niessl (in Winter, Fungi europ. No. 3261). Laestadia rhyt. Saccardo, Syll. fung. I, p. 424. Vatnsdalsholar [St. St.], Hofsfjall [O. D.], Berufjördur (Grønlund) and Eskifj6rdur (Strömfelt). — On dead leaves of Dryas octopetala. Linospora Fuckel. 235. L. Capreae (De Candolle) Fuckel, Symbol. p. 124. Sphaeria Capreae De Candolle, Flore franc. VI, p. 130. Hofsfjall, Hestahraun in Porvaldsdalur [O.D.}, Herdubreidarlindir (Thoroddsen). — On dead leaves of Salix glauca and S. lanata. 236. L. insularis Johanson, Svampar fran Isl. 1884, p. 171. Eskifj6rdur (Berlin). — On dead leaves af Salix lanata. 237. L. caudata nov. spec. Grund Plantation south of Akureyri [P.L.. — On dead leaves of Salix phylicifolia. Pseudostroma papillary, 0.5—1 mm broad, enclosing 1 perithecium whose elongated orifice protrudes from the stroma, now laterally, now FUNGI OF ICELAND 493 centrally. — Asci cylindrical, short-stalked, 80-100 X 6—7 u, 8-spored. Spores parallel, needle-shaped, 50X1—2 u, provided — sometimes at both ends, but more often only at one end — with a 20—30 u long, straight or curved appendage, 0.5—1 4 broad, in some few spores 2 or 3 such appendages at the same end. Distinguished by the appendages of the spores. Valsaceae. Valsa (Scopoli) Fries. 238. V. betulina Nitschke, Pyrenomycetes germanici, p. 219. Fornhagagil [O.D.], Holm in Selsundslekur (Feddersen). — On dead branches of Betula pubescens. 239. V. polyspora Nitschke, Pyrenom. germ., p. 238. Vifilsstadahlid [P. L.]. — On dead branches of Betula pubescens. Diaporthe Nitschke. 240. D. salicella(Fries) Saccardo, Syll. fung. I, p. 622. Sphaeria salicella Fries, Syst. Myc., vol. II, p. 377. Sluttnes in Myvatn [P.L.. — On dead branches of Salix phylicifolia. 241. D. aristata (Fries) Karsten, Mycologia Fig. 3. Fennica II, p. 112. Linospora caudata n. sp. : : 2 JER L a. 2 spores X 500. Sphaeria aristata Fries, Syst. Myc, II, p. 363. hs Aron weil DALE SEE Hälsskögur and Hof [O. D.], Hallormstadir, Norötünga and Pingvellir [P.L.]. — On living and dead branches of Be- tula nana and Betula pubescens — a facultative parasite. 242. D. muralis Spegazzini, Michelia I, p. 458. Saccardo, Syll. fung. I, p- 655. Asarnir in Galmarströnd [0.D.). — On dead stems of Sedum villosum. Fenestella Tulasne. 243. F. princeps Tulasne, Selecta fungorum carpologia II, p. 207. Fornhagagil [O.D.). — On dead branches of Salix lanata. 244. F. tumida (Persoon) Saccardo, Syll. fung. II, p. 329. Sphaeria tumida Persoon, Synopsis methodica fungorum, p. 41. Hälsskögur [O.D.). — On dead branches of Betula pubescens, 494 POUL LARSEN Melanconidaceae. Cryptospora Tulasne. 245. C. Betulae Tulasne, Sel. fung. carp. II, p. 149. Hüsafellsskögur [O. D.]. — On dead branches of Betula pubescens. Valsaria Cesati et De Notaris. 246. V. Niesslii (Winter) Saccardo, Syll. fung. I, p. 749. Phaeosperma Niesslii Winter, Hedwigia 1874, p.131. Hälsskögur [O.D.). — On the bark of Betula pubescens. Melanconis Tulasne. 247. M. stilbostoma (Fries) Tulasne, Sel. fung. carp. II, p. 119. Sphaeria stilbostoma a Fries, Syst. Myc. II, p. 403. Norötünga [P.L.]. — On dead branches of Betula pubescens. Pseudovalsa Cesati et De Notaris. 248. P. lanciformis (Fries) Cesati et De Notaris. Sphaeria lanciformis Fries, Syst. Myc., vol. II, p. 362. Fornhagagil [O. D.]. — On dead branches of Betula pubescens, Diatrypaceae. Diatrype Fries. 249. D. bullata (Hoffmann) Fries, Summa Veg. Scand. p. 385. Slüttnes in Myvatn [P. L.]. — On dead branches of Salix phylici- folia. Diatrypella Cesati et De Notaris. - 250, D. verrucaeformis (Ehrhart) Nitschke, Pyrenom. germ., p. 76. Sphaeria verrucaeformis Ehrhart, Plant. crypt. exsicc. No. 280 sec. Nitschke. Gilsbakki in Austurdalur [O. D.), Egilsstadir [H. J.]. — On dead branches of Betula pubescens. 251. D. favacea (Fries) Nitschke, Pyrenom. germ., p. 77 Sphaeria favacea Fries; Syst. Myc., vol. II, p. 354. Skrida in Hörgärdalur [O. D.], Egilsstadir [H. J.]. — On dead branches of Betula pubescens. Calosphaeria Tulasne. 252. C. ciliatula (Fries) Karsten. Sphaeria ciliatula Fries, Syst. Myc., vol. II, p. 406. FUNGI OF ICELAND 495 Norötünga and Pingvellir [P.L... — On dead branches of Betula pubescens. 253. C. pusilla (Wahlenberg) Karsten, Mycolog. fennica II, p. 157. Sphaeria pusilla Wahlenberg, Flora Lappon., p. 520. Pingvellir [P. L.]. — On the inner side of pieces of bark of Betula pubescens. Xylariaceae. Hypoxylon Bulliard. 254. H. fuscum (Persoon) Fries, Summa Veg. Scand., p. 384. Sphaeria fusca Persoon, Usteri, Neue Anal. d. Bot. t. II. 5, p. 22 és Hälsskögur [O. D... — On dead branches of Betula pubescens. Dothideaceae. Mazzantia Montagne. 255. M. Galii (Fries) Montagne. Sphaeria Galii Fries, Elenchus fungorum II, p. 105. Almannagjä on Pingvellir [P. L.|. — On dead stems of Galium verum. Dothidella Spegazzini. 257. D. Laminariae Rostrup, Mykologiske Meddelelser V, Botanisk Tidsskrift vol. 19, 1894, p. 213. Common on sea coasts as well as in fiords. — On the stems of Laminaria saccharina, L. digitata and Alaria esculenta. 257. D. betulina (Fries) Saccardo. Xyloma betulinum Fries, Observ. mycol. I, p. 198. Hüsafellsskögur, Hof in Hörgardalur [O. D.], Vallanes [H.J.l. — On dead leaves of Betula pubescens and B. nana. 258. D. thoracella (Fries) Saccardo. Sphaeria thoracella Rutström, Fries, Syst. Myc. II, p. 558. Hraunatindur near Arnarfell (St. St]. — On dead leaves of Rhodiola rosea. | 259. D. Angelicae (Fries) Rostrup. Dothidea Angelicae Fries, Syst. Mye. II, p. 561. Fusicladium Angelicae (Fries) Lind, Danish Fungi, p. 521. Skrida in Hörgärdalur [O. D.), Fornhagagil and Mardarnüpsgil (St. St.). — On Archangelica officinalis and Angelica silvestris. 496 POUL LARSEN Phyllachora Nitschke. 260. P. Graminis (Persoon) Fuckel, Symbol., p. 216. Sphaeria Graminis Persoon, Observat. mycol. I, p. 18. Fornhagagil and Hof [O.D.], Sandfell [H. J.J, Reykjavik (Strömfelt). — On leaves of Agrostis vulgaris and A. canina. 261. P. Poae (Fuckel) Saccardo. Scirrhia Poae Fuckel, Symbolae, p. 221. Barkarnautur [H.J.]. — On dead leaves of Poa caesia. Hypodermataceae. Lophodermium Chevallier. 262. L. pinastri (Schrader) Chevallier, Flore paris. I, p. 430. Hysterium pinastri Schrader, Journ. Bot. II, p. 69, tab. 3, fig. 4. The plantation on Pingvellir [P. L.). — On needles of Pinus mon- tana. 263. L. juniperinum (Fries) De Notaris. Hysterium juniperinum Fries (pinastri D), Syst. Myc. II, p. 588. Fornhagagil [O.D.], Küadalur (Grønlund). — On needles of Juni- perus nana. 264. L. arundinaceum (Schrader) Chevallier, Flore paris. I, p. 435. Hysterium arundinaceum Schrader, Journ. Bot. II, p.68, tab. 3, fig. 3. Fairly common on Graminaceae throughout the country, viz. on Nardus, Anthoxanthum, Elymus, Trisetum spicatum, Calama- grostis stricta, Hierochloé odorata, Festuca ovina, F. rubra Poa alpina, P. caesia, P. nemoralis. L. arundinaceum (Schrader) Chevallier var. alpinum Rehm, Raben- horst Kryptogamenflora III, p. 46. Vididalur [P. L.], — On dead leaves of Elymus arenarius. 265. L. caricinum (Roberge) Duby. Hysterium c. Roberge, No. 71 in Ann. sc. nat. III. Sér., t. 8, p. 180. Mööruvellir (St. St], Hofsfjall [O. D.], Grund near Akureyri and Borg near Borgarnes [P. L.]. — On dead leaves of Carex festiva, C. capil- laris, Elyna Bellardi, Eriophorum augustifolium. 266. L. versicolor (Wahlenberg) Schroeter, Jahrbuch d. schles. Ges. fir vaterl. Cultur, Breslau 1888, p. 266. Grund Plantation near Akureyri [P. L.].. — On dead leaves of Salix phylicifolia. FUNGI OF ICELAND 497 267. L. maculare (Fries) De Notaris. Hysterium maculare Fries, Syst. Myc. II, p. 592. Hofsfjall [O. D.), Haukadalur and Gullfoss near Hvita (Feddersen). — On dead leaves of Vaccinium uliginosum and Salix glauca. 268. L. petiolicolum Fuckel, Symbolae, p. 255. Hestahraun in Porvaldsdalur [O.D... — On petioles of Sibbaldia procumbens. Hysteriaceae. Lophium Fries. 269. L. dolabriforme Wallroth, Sacc., Syll. fung. II, p. 800. Hüsafellsskögur [O. D.]. — On dead branches of Betula pubescens. Microthyriaceae. Myiocopron Speggazzini. 270. M. calamagrostidis E. Rostrup (in mser.). Peritheciis membranaceis, dimidiato-scutatis, superficialibus, sparsis, radiato-striatis, margine eximie fimbriatis, minutissimis, usque ad 0,3 mm diametro, ostiolo latiusculo pertusis. Ascis clavatis, 37—40 u 1, 6—7 u cr., copiose paraphysatis. Sporis distichis, oblongis 8—10 1, 2x cr., guttulatis. Hraun (O. D.]. — On Calamagrostis stricta. Microthyrium Desmazières. 271. M. Rubi Niessl, Kunze: Fungi selecti, No. 379. Almannagjä on Pingvellir (Feddersen), Hälsskögur and Vifilsstadahlid [P.L.). — On dead stems of Rubus saxatilis. Phacidiaceae. Rhytisma Fries. 272. R. salicinum Fries, Vetensk. Akad. Handl. 1819, p. 104. Common throughout the country on dead leaves of Salix: Salix herbacea, S. glauca, S. lanata, S. phylicifolia. 273. R. Bistortae (De Candolle) Rostrup, Gronl. Svampe 1888, p. 542. Xyloma Bistortae De Candolle, Flor. fr. VI, p. 153. Grimsey, Hof, Störi Nupur [0.D.). — On leaves of Polygonum viviparum. The Botany of Iceland, Vol, Il. part IN, 33 498 POUL LARSEN Coccomyces De Notaris. 274. C. quadratus (Schmidt & Kunze) Karsten, Myc. Fenn. I, p. 255. Phacidium quadratus Schmidt & Kunze, Myc. Hefte I, p. 41. Kälfsdalur (St. St... — On dead stems of Vaccinium Myrtillus. Sphaeropeziza Saccardo. 275. S. Arctostaphyli (Karsten) Rehm, Annal. myc. V, p. 231. Phacidium Arctostaphyli Karsten. Trochila phacidioides Karsten, Myc. Fenn. I, p. 249. Mööruvallafjall (St. St], Hofsfjall [O. D. — On dead leaves of Dia- pensia lapponica. Cryptomyces Greville. 276. C. maximus (Fries) Rehm, Rabh Krypt. Flora III, p. 107. Rhytisma maximum, Fries, Syst. Myc. II, p. 566. Kollafjardarnes (G. Gudmundsson). — On twigs and aments of Sa- lix herbacea. Phacidium Fries. 277. P. repandum Fries, Syst. Myc. II, p. 578. Hüsafellsskögur [O. D.|, Hvammur (Pall Gislason). — On living leaves of Galium boreale. Clithris Fries. 278. C. degenerans (Fries) Rehm, Rabh. Krypt. Flora III, p. 104. Hysterium degenerans Fries, Kunze, Mycolog. Hefte II, p. 60. Sporomega degenerans Corda, Iconum fungorum V., pp. 60, 69, 70. Hof [O. D]. — On dead stems of Vaccinium uliginosum. Pseudophacidium Karsten. 279. P. degenerans Karsten, Revisio monographica ascom. Fenn. 1885, pP: 157. Môôruvellir {O. D]. — On dead stems of Vaccinium Myrtillus. Tryblidiaceae. Heterosphaeria Greville. 280. H. Patella (Tode) Greville. Sphaeria penetrans a patella Tode, Fungi Mecklenburgenses II, p. 45. Mafahlid, Vestmannaeyjar, Drangshliô, Streiti [H. J.J. — On dead stems of Angelica silvestris and Archangelica officinalis. FUNGI OF ICELAND 499 Scleroderris Fries. 281. S. aggregata (Lasch) Rehm, Rabh. Krypt. Flora III, p. 212. Sphaeria aggregata Lasch, Bot. Zeit., 1857, p. 428. Grund Plantation south of Akureyri [P.L... — On dead stems of Rhinanthus crista-galli. Stictidaceae. Schizoxylon Persoon. 282. S. Berkeleyanum (Durieu et Léveillé) Fuckel, Symbolae, p. 251. Stictis Berkeleyanum Durieu et Leveille, Flor. alg. tab. 89, fig. 8. Rhaun in Öxnadalur [O D.]. — On dead stems of Rhodiola rosea. Cryptodiscus Corda. 283. C. pallidus (Persoon) Corda. Stictis pallida Persoon, Obs. myc. II, p. 74. Hüsafellsskögur [O. D.]. — On wood of Betula pubescens. Propolis Fries. 284. P. faginea (Schrader) Karsten, Myc. Fenn. I, p. 244. Hysterium fagineum Schrader, Botan. Journ. II, p. 68. Common in all birch copses. — On wood of Betula pubescens. Naevia Fries. 285. N. atrosanguinea (Rostrup) Saccardo. Trochila atros. Rostrup, Isl. Svampe 1885, p. 224. Svinadalur, Hvalfjöröur (Grønlund). — On Carex rigida and Carex vulgaris. 286. N. diminuens (Karsten) Rehm, Rabh. Krypt. Flora III, p. 142. Trochila diminuens Karsten, Myc. Fenn. I, p. 248. Sörlatüngugil, Hofsfjall, Hestahraun [O.D.], Eyjafjérdur (Strömfelt), Almannagjä [P.L.). — On dead leaves of Carex atrata, C. capitata, C. rigida, Luzula arcuata. 287. N. ignobilis (Karsten) Rehm, Rabh. Krypt. Flora III, p. 142. Trochila ignobilis Karsten, Myc. Fenn. I, p. 248. Of common occurrence on the following species. Monocotyledons: Carex atrata, C. rigida, C. rostrata, C. vaginata and Cobresia scirpina. 33" 500 POUL LARSEN 288. N. fuscella (Karsten) Lind, Danish Fungi, p. 136. Trochila fuscella Karsten, Mycologia Fennica I, p. 248. Phacidium fuscellum Karsten, Revisio monographica .... Acta Soc. Fauna et Flora Fennica II, Nr. 6, p. 160. Norötünga, Hvalfjördur, Pingvellir (Grønlund), Vidvik [St. St], Hofs- vatn near Tvidægra (Thoroddsen). — On Carex hyperborea, C. rigida,: G vulgaris; G. pulla. 289. N. pusilla(Libert) Rehm, Rabenhorst Kryptogamenflora III, p. 118. Trochila juneicola Rostrup (sensu Lind). Hof and Hofsfjall [O. D.]. — On Juncus filiformis, J. balticus, Luzula multiflora. Ocellaria Tulasne. 290. O. chrysophaea (Persoon) Quélet, Enchir. fung., Paris 1886, p. 332. Peziza chrysophaea Persoon, Synops. meth. fung., p. 674. Hüsafellsskögur [O.D.!. — On wood of Betula pubescens. Agyriaceae. Agyrium Fries. 291. A. rufum (Persoon) Fries, Syst. Myc. II, p. 232. Stictis rufa Persoon, Obs. mye. II, p. 74. Hüsafellsskögur [O.D.], Pingvellir (Feddersen). — On wood of Be- tula pubescens, Celidiaceae. Celidium Tulasne. 292. C. varians (Davies) Arnold, Flora 1862, p. 312. Lichen varians Davies, Trans. Linn. Soc. II, p. 284. Grimsey [O.D.]. — On Lecanora sordida. Patellariaceae. Durella Tulasne. 293. D. melanochlora (Sommerfelt) Rehm. Patellaria melanochlora (Som.) Karsten, Myce. fenn. I, p. 233. Mooruvellir [O. D.]. — On dry wood. Scutula Tulasne. 294. S. Stereocaulorum (Anzi) Körber, Parerg. lich., p. 26. Lecidea Stereocaulorum Anzi, Manip. lich., p. 26. Vallanes [H.J.]. On the thallus of Stereocaulon sp. FUNGI OF ICELAND 501 Karschia Körber. 295. K. scabrosa (Acharius) Rehm, Rabh. Krypt. Flora III, p. 350. Lecidea scabrosa Acharius, Meth. lichen., p. 48. Skütustadir near Myvatn [O.D.], Eidar in E.-Icel. [H. J.]. In E. Rostrup »Islands Svampe«, Botanisk Tidsskrift, 25. vol, p. 313, where this fungus is mentioned, no host plant is given. Nor have I been able to find Karschia scabrosa in the Collection of Icelandic Fungi at the Botanical Museum of Copenhagen; but as two localities are given and E. Rostrup states that he has seen specimens of the fungus from both localities, there can be no doubt that the statement is correct. Abrothallus De Notaris. 296. A. Parmeliarum (Sommerfelt) Nylander. Lecidea Parmeliarum Sommerfelt, Lich. lapp. suppl., p. 176. Abrothallus Smithii Tulasne, Mém. lich. in Ann. sc. nat. ser. III, tome XVII, Paris 1852, p. 113. Berufjöröur. — On the thallus of Parmelia saxatilis. Patellaria Fries. 297. P. atrata (Hedwig) Fries, Syst. Myc. II, p. 160. Lichen atratus Hedwig, Spec. musc. frond. II, p. 61. Pingvellir (Feddersen). — On wood of Betula pubescens. 298. P. Bagnisiana (Saccardo) Rehm. Lecanidion Bagnisianum Saccardo, Syll. fung. VIII, p. 799. Hüsafellsskögur [O.D.]. — On wood of Betula pubescens. Dermateaceae. Godronia Mougeot. 299. G. Urceolus (Albertini et Schweinitz) Karsten, Revisio monogr., p. 144. Peziza Urceolus Albertini et Schweinitz, Conspectus fungorum in Lusatiae superioris agro Niskiensi crescentium, Leipzig 1805, p. 332. Birch copse near Norötünga [P.L.. — On thin dead branches of Betula pubescens. 300. G. pusiola Karsten, Myc. Fenn. I, p. 214. Hvammur (Grønlund). — On Nardus strictus. Tympanis Tode. 301. T. saligna Tode, Fungi Mecklenburgenses selecti I, p.24, t. IV, £.37. Hälsskögur [O. D.]. — On a branch of Salix phylicifolia. 502 POUL LARSEN 302. T. tumida (Person) Saccardo, Syll. fung. II, p. 329. Sphaeria tumida Persoon, Synops. meth. fung., p. 41. Hälsskögur [O.D.]. — On dead branches of Betula pubescens. Mollisiaceae. Tapesia Persoon. 303. T. fusca (Persoon) Fuckel, Symbolae, p. 302. Peziza fusca Persoon, Observationes mycologicae I, p. 29. Hälsskögur and HIöö [O. D.]. — On branches of Betula nana and EB: pubescens, Mollisia Fries. 304. M. advena Karsten, Fungi in insulis Spetsbergen et Beeren Eiland collecti. Ofv. af Kgl. Vet. Ak. Förh. 1872, No.2, p.95. Stockholm 1872. Gälmaströnd [O.D.|, Biellarhöll [St.St.. — On Eriophorum augusti- folium. 305. M. graminis (Desmazieres) Karsten, Hedwigia 1893, p. 60. Common throughout the country on many different grasses. 306. M. caesia (Fuckel) Saccardo, Syll. fung. VIII, p. 340. Niptera caesia Fuckel, Symbolae, Nachtr. I, p. 47. Vifilsstadahliö [P.L.]. — Ou dead branches of Betula pubescens. 307. M. Schumacheri (Fries) Rehm, Annal. Mye. vol. V, p. 545. Peziza Schumacheri Fries, Syst. Myc. II, p. 98. Hälsskögur [O. D.]. — On wood of Betula pubescens. 308. M. melaleuca (Fries) Saccardo, Syll. fung. VIII, p. 337. Peziza melaleuca Fries, Syst. Myc. II, p. 150. The plantation on Pingvellir [P.L.]. — On dead branches of Sor- bus suecica. 309. M. atrata (Persoon) Karsten, Myc. Fenn. I, p. 200. Peziza atrata Persoon, Synops. meth. fung., p. 669. Helgadalsheidi (Strömfelt), Hraun in Fljöt [O.D., Gulfoss (Fedder- sen), Storugiä near Reykjahlid [P.L.]. — Grows on dead stems of many different plants: Geranium silvaticum, Ranunculus glacialis, R. acer, Bartsia alpina, Hieracium prenanthoides. 310. M. cinerea (Batsch) Karsten, Myc. Fenn. I, p. 189. Peziza cinerea Batsch, Contr. myc. I, p. 196. Common throughout the country on dead stems of many different plants. FUNGI OF ICELAND 503 Niptera Fries. 311. N. ramealis Karsten, Revisio monogr. 1885, p. 152. Hälsskögur [O. D.]. — On dead branches of Betula pubescens. Belonidium Montagne et Durien. 312. B. iuncisedum (Karsten) Rehm, Sacc., Syll. fung. VIII, p. 347. Mollisia junciseda Karsten, Myce. fenn. I, p. 189. Jökulsä near Möörudalur [P. L.], Nygrædur [St. St.). — On dead stems of Juncus balticus. 313. B. rufum Schroeter, Die Pilze Schlesiens 2. H., p. 109. Hallormstadir [P.L.].. — On dead leaves of Trisetum spicatum. 314. B. Laschii Rehm, Rabh. Krypt. Flora III, p. 570. Jökulsä near Vididalur [P. L.]. — On dead stems of Juncus balticus. Fabraea Saccardo. 315. F. Cerastiorum (Wallroth) Rehm, Rabh. Krypt. Flora III, p. 600. Phlyctidium Cerastiorum Wallroth, Flor. erypt. germ. II, p. 465. Fornhagagil [O.D.). — On living leaves and stems of Cerastium vulgatum. 316. F. Ranunculi (Fries) Karsten, Revisio monogr. asc. Fenn. 1885, p. 161. Dothidea Ranunculi Fries, Syst. Myce. II, p. 562. Hestahraun in Porvaldsnalur [O. D.]. — On living leaves of Ranun- culus acer. 317. F. confertissima Karsten, IL. c., p. 162. — Sacc., Syll. fung. VIII, p. 736. Sörlatüngugil [O.D.], Vifilsstadahlid [P.L... — On dead stems and leaves of Geranium silvaticum. Pyrenopeziza Fuckel. 318. P. Rubi (Fries) Rehm, Rabh. Krypt. Flora III, p. 611. Exipula Rubi Fries, Syst. Myc. II, p. 190. The Experimental Station at Reykjavik [P. L.]. — On dead branches of Rubus idaeus. Orbilia Fries. 319. O. coccinella (Sommerfelt) Karsten, Myc. Fenn. I, p. 98. Peziza coccinella Sommerfelt, Suppl. Flor. Lappon., p. 276. 504 POUL LARSEN Pingvellir [P. L.]. — On bark and wood of dead branches of Betula pubescens. 320. O, auricolor Saccardo, Syll. fung. VIII, p. 625. Hrafnagjä on Pingvellir [P. L.]. — On wood of Betula pubescens. Calloria Fries. 321. C. erythrostigmoides Rehm, Rabh. Krypt. Flora III, p. 464. Hallgilsstadafjall [O. D.]. — On dead leaves of Cerastium alpinum. 322. C. minutissima Rostrup, Gronl. Svampe 1888, p. 537. Skrida in Hörgärdalur [O.D.). — On Archangelica officinalis. Helotiaceae. Chlorosplenium Fries. 323. C. aeruginosum (Oeder) De Notaris. Helvella aeruginosnm Oeder, Flora danica, tab. 534, fig. 2; Vahl, Flora danica, tab. 1260, fig. 1. Recorded in Zoéga's »Flora Islandica«. Sclerotinia Fuckel. 324. S. Vahliana Rostrup, Gronl. Svampe 1891, p. 607. Môôruvellir [St. St]; Framnes near Dyrafjérdur (Ostenfeld); Norö- tünga [P. L.]. — On tufts of Carex and Eriophorum on swampy ground. The peasized sclerotia are often seated in the axils of the leaves, covered by the leaf-sheaths. 325. S. Fuckeliana (De Bary) Fuckel, Symbolae, p. 330. Peziza Fuckeliana De Bary, Morph. Phys. der Pilze, p. 30, fig. 12, p. 238. The sclerotia and conidia (Botrylis cinerea) are of extremely com- mon occurrence throughout the country on many different host plants, as: Rumex domesticus, Polygonum aviculare, Viscaria alpina, Sedum villosum, Saxifraga nivalis, Geranium silvaticum, Geum rivale, Alchemilla alpina, Sibbaldia procumbens, Gen- tiana campestris, Pedicularis flammea, Hieracium sp.. Gnapha- lium norvegicum. Dasyscypha Fries. 326. D. diminuta (Roberge et Desmazieres) Saccardo, Syll. fung. VIII, p. 449. Peziza diminuta Roberge et Desmaziéres, Annales sci. nat. 1847, vol.VII, p. 185. Hanastadir (N. Iceland) [O. D.]. — On dead stems of Juncus bal- ticus. FUNGI OF ICELAND 505 327. D. variecolor (Fries) Lind, Danish Fungi, p. 115. Peziza variecolor Fries, Syst. Myc. II, p. 100. Mööruvellir, Hofsfjall [O. D... — On old woodwork. Lachnella Fries. 328. L. corticalis (Persoon) Fries, Sum. Veg. Scand., p. 365. Peziza corticalis Persoon, Tentamen dispositionis methodicae fungo- rum, p. 34. Fornhagagil, Prastarhölsgljüfur [O.D.]. — On dead branches of Sa- lix lanata. 329. L. flammea (Albertini et Schweinitz) Fries, Sum. Veg. Scand., p- 365. Pezixa flammea Albertini et Schweinitz, Conspectus fungorum, p. 319. Hälsskögur, Fornhagagil [O.D.]. Egilsstadir [P.L.]. — On Betula pubescens. Lachnum Retzius. 330. L. patens (Fries) Karsten, Myc. Fenn. [, p. 179. Peziza clandestina / patens Fries, Syst. Myc. II, p. 94. Porvaldsdalur, Hofsfjall [0.D... — On Phleum pratense, Phl. alpinum and Poa nemoralis. 331. L. calycioides Rehm, Rabh. Krypt. Flora III, p. 909. Eyjafjöröur near Akureyri [P.L.. — On dead stems of Juncus trifidus. 332. L. bicolor (Bulliard) Karsten, Myc. Fenn. I, p. 172. Peziza bicolor Bulliard, Histoire des Champignons de la France, p. 242. Pingvellir. Borg [P. L.], Hälsskögur, Hofsfjall [O. D.], Eyjölfsstadir (H. J.). — On wood of Betula pubescens, B. nana. 333. L. virgineum (Batsch) Karsten, Myc. Fenn. I, p. 169. Peziza virginea Batsch, Elenchus fungorum, p. 125. Hüsafellsskégur, Hälsskögur [O. D... — On wood of Betula pube- scens. 334. L. niveum Karsten, Mye. fenn. I, p. 168. Krossastadagil [O.D.). — On dead branches of Salix lanata. Erinella Saccardo. 335. E. callimorpha (Karsten) Rehm, Rabh. Krypt. Flora III, p. 1241. Lachnum callimorphum Karsten, Mycologia fennica I, p. 173. 506 POUL LARSEN Miöfjardarhäls [O.D.], Laugarnes [P. L.]. — On dead leaves of Erio- phorum angustifolium. Helotium Fries. 236. H. rhodoleucum Fries, Sum. Veg. Scand., p. 335. Hof in Hörgärdalur [O. D.], Eskifjördur (Strömfelt). — On dead stems of Equisetum sp. 337. H. eitrinum (Hedwig) Fries, Sum. Veg. Scand., p. 335. Octospora citrina Hedwig, Species muscorum frondosorum II, tab. 8 C. Hüsafellskögur [O.D.)], Bæjarstadur (Buchwald). — On wood of Be- tula pubescens. 338. H. virgultorum (Vahl) Karsten, Myc. Fenn. I, p. 109. Peziza virgultorum Vahl, Flora danica, tab. 1016, f. 2. Hälsskögur, Krossastadagil, Mööruvellir [O. D.]. — On dead branches of Betula pubescens and Salix lanata. 339. H. scutula (Persoon) Karsten, Myce. Fenn. I, p. 110. Peziza scutula Persoon, Mycologia europaea I, p. 284. Hestahraun in Porvaldsdalur [O. D.]. — On dead stems of Gnapha- lium norvegicum. Phialea Fries. 340. P. eyathoidea (Bulliard) Gillet, Discom. franc., p. 106. Peziza cyathoidea Bulliard, Champignons de la France, p. 250, t. 416, f. 3. Mööruvellir, Porvaldsdalur, Grimstadir near M\vatn, Hörgärdalur, Hraunsvatn [O.D.]; The Experimental Station at Reykjavik, Vifilsstada- hliö [P.L... — On dead stems of: Rumex domesticus, Oxyria, Ranunculus acer, Angelica silvestris, Archangelica offici- nalis, Carum carvi, Gnaphalium norvegicum, Silene vulgaris. 341. P. grisella Rehm? Rabh. Krypt. III, p. 737. Lachnella grisella Phillips, Grevillea 18, p. 84. Hestahraun in Porvaldsdalur [O.D.]. — On a decorticated branch. Is is very doubtful whether this fungus really belongs to the above species. It is not included in the Collection of Icelandic Fungi at the Botanical Museum of Copenhagen, nor is the substratum recorded the usual one, since the fungus generally grows on the under side of fern leaves. 342. P. dolosella (Karsten) Saccardo, Syll. fung. VIII, p. 275. Almannagjä (Pingvellir) [P.L.. — On dead stems of Cerastium alpinum. (Asci 60*6—7 u, 8-spored. Spores biseriate, 15—16X3 u.) FUNGI OF ICELAND 507 Stamnaria Fuckel. 343. S. Equiseti (Hoffmann) Saccardo, Syll. fung. VIII, p. 620. Lycoperdon Equiseti Hoffmann, Vegetabilia Cryptogama II, p. 17. Hof in Hörgardalur [O.D.]), Akureyri [P.L... — On dead Equise- tum palustre. Syll. rum, Coryne Tulasne. 344. C. sarcoides (Jacquin) Tulasne, Sel. fung. Carp. III, p. 190. Hälsskögur [O.D.]. — On wood of Betula pubescens. Geoglossaceae. Mitrula Persoon. 345. M. gracilis Karsten, Revisio monogr. asc. Fenn., p.110.—Saccardo, fung. VIII, p. 34. Grundarfjöröur [H. J.). — On mosses. Geoglossum Persoon. 246. G. ophioglossoides (Linné) Saccardo, Syll. fung. VIII, p. 43. Geoglossum glabrum Persoon, Obs. Mye. IL p. 61. Skridudalur (Thoroddsen). — Growing among grasses and mosses. Ascobolaceae. Ascobolus Persoon. 347. A. furfuraceus Persoon, Obs. Myc. I, p. 33. Peziza stercoraria Bulliard. Champ. France, p. 256. Lurkasteinn [O.D.]. — On cow dung. 348. A. glaber Persoon, Obs. Myc. I, p. 34. Blöndanes (Feddersen). — On cow dung. 349 A. immersus Persoon, Tentamen dispositionis methodicae Fungo- p. 35. Hof in Hörgärdalur [O.D.). — On horse dung. Lasiobolus Saccardo. 350. L. equinus (Müller) Karsten, Revisio monogr. asc. Fenn., p. 122. Peziza equina Miller, Flora Danica, t. 779, fig. 3. Hof in Hörgärdalur, Reistarärskard, Hallgilsstadafjall [O. D.j, Reykja- vik {P.L.] — On horse- and sheep dung. 508 POUL LARSEN Ascophanus Boudier. 351. A. subfuscus Boudier, Mémoire sur les Ascobolés, Paris 1869, Rhaun in Fljötum [O. D.]. — On excrements of foxes. 352. A. microsporus (Berkeley et Broome) Hansen, Saccardo, Syll. fung. VIII, p. 532. Ascobolus microsporus B. et Br., Notices of British Fungi, in Annals and Magazine of Natural History 1865, no. 1087, Pl. 16, fig. 28. Reykjavik {P.L.]. — On horse dung. Rhyparobius Boudier. 353. R. erustaceus (Fuckel) Rehm, Rabh. Krypt. Flora III, p. 1103. Ascobolus crustaceus Fuckel, Hedwigia 1866, p. 4. > Lurkasteinn [O. D.]. — On cow dung. 354. R. polysporus Karsten, Myc. Fenn. I, p. 82. Seydisfjöröur [P.L.]. — On sheep dung. 355. R. dubius Boudier, Mémoire sur le Ascobolés, p. 240, PL 10, Paris 1869, fig. 26. Hofsfjall [O. D.|. — On sheep dung. 356. R. hyalinellus (Karsten) Saccardo, Syll. fung. VIII, p. 542. Peziza hyalinella Karsten, Myc. Fenn. I, p. 83. Hofsfjall [O. D]. — On sheep and ptarmigan droppings. 357. R. caninus (Auerswald) Rehm, Rabh. Krypt. Flora III, p. 1102. Ascobolus caninus Auerswald, Hedwigia 1868, p. 52. Porvaldsdalur [O. D.]. — On excrements of foxes. Saccobolus Boudier. 358. S. Kerveni (Crouan) Boudier, 1. c., p. 38, tab. 8, fig. 18. Ascobolus Kerveni Crouan, Annales des scienc. nat. 1885, IV., vol. X, p. 193. Seydisfjordur [P. L.]. — On sheep dung. Pezizaceae. Lachnea Fries. 359. L. scutellata (Linné) Gillet, Discom. franc. Alencon 1889— 1892, p. 75. Peziza scutellata Linné, Flora Suecica, p. 458. FUNGI OF ICELAND 509 Môdruvallanes [O.D.], Glerä near Akureyri, Framnes near Dyra- fjördur [C. H. O.), Egilsstadir [P. L.], Bæjarstadurskôgur (Buchwald). — On damp soil. 360. L. stercorea (Persoon) Gillet, 1. c., p. 76. Peziza stercorea Persoon. Obs. Myc. II, p. 89. Common throughout Iceland [O.D., St. St. H. J., P.L.]. — On horse- and cow-dung. 361. L. hemisphaerica Wiggers, Primitiae florae holsaticae, 1780, p. 107. Egilsstadir [P. L.]. — Among mosses under Betula pubescens. Sphaerospora Saccardo. 362. S.trechispora (Berkeley et Broome) Saccardo, Consp. Discom., p. 4. Peziza trechispora B. et Br., Notice of British Fungi, Annals and Magazine of Natural History XVIII 1846, p. 77. Skagafjördur (Grønlund), Egilsstadir [P. L.}. — On damp soil. 363. $. confusa (Cooke) Saccardo, Syll. fung. VIII, p. 190. Mööruvellir [St. St.]. Plicariella Saccardo. 364. P. modesta (Karsten) Lindau. Crouania modesta Karsten, Revisio monogr. asc. Fenn., p. 118. Glerä near Akureyri [C. H.O.]. — On damp sandy soil. 365. P. Empetri (Rostrup). Phaeopezia Empetri Rostrup, Isl. Svampe 1903, p. 317. Hestahraun in Porvaldsdalur {O.D.]. — On dead leaves of Empe- trum nigrum. Plicaria Fuckel. 366. P. sepiatra (Cooke) Rehm, Rabh. Krypt. Flora III, p. 119. Peziza sepiatra Cooke, Grevillea III, p. 119. Büdir [H.J.). Humaria Fries. 367. H. aquatica (Lamarck et De Candolle) Rehm, Rabh. Krypt. Flora III, p. 954. Mööruvellir (O. D.]. — On a piece of sacking lying in a swamp. 368. H. granulata (Bulliard) Quélet, Enchir. fung., Paris 1886, p. 290. Peziza granulata Bulliard, Histoire des champignons de la France, p. 258. Vallanes [H. J.J. — On manure, 510 POUL LARSEN 369. H. Jungermanniae (Nees) Saccardo. Peziza Jungermanniae Nees, in Fries Syst. Myc., vol. II, p. 144. Mollisia J. (Nees) Rehm, Rabenhorst’s Kryptogamenflora, III., p. 548. Mula (Feddersen). — On Hepaticae. Geopyxis Persoon. 370. G. cupularis (Linné) Saccardo, Syll. fung. VIII, p. 72. Peziza cupularis L., Species plantarum I, p. 1181. Found in Iceland by König. 371. G. Ciborium (Vahl) Saccardo, Syll. fung, VIII, p. 64. Peziza Ciborium Vahl, Flora Danica. Pl. 1078. Dyrafjordur [C. H. 0.]. — On damp soil in a bog. Acetabula Fries. 372. A. leucomelas (Persoon) Boudier, Sacc., Syll. fung. VIII, p. 60. Peziza leucomelas Persoon, Mycologia europaea, p. 219. Laxä near Myvatn [P. L.]. — In a dense clump on damp sandy soil. 373. A. sulcata (Persoon) Fuckel, Symbolae, p. 330. Peziza sulcata Persoon, Synops. meth. fung., p. 643. Akureyri and Pingeyri [C. H.O.], Môôruvellir, Hällsskögur [O.D.]; Grund south of Akureyri [P. L.]. Macropodia Fuckel. 374. M. Corium (Weberbauer).Saccardo, Syll. fung. VIII, p. 159. Peziza Corium Weberbauer, Pilze, t. III, fig. 7. Hof in Hörgärdalur [O. D]. — On sandy soil. Helvellaceae. Helvella Linné. 375. H. atra König, Zoéga, Flora Islandica 1772, p. 20. Mööruvellir [St. St.]. Verpa Swartz. 376. V. digitaliformis Persoon, Myc. Eur., p. 202, t. 7, fig. 1—3. Skütustadir near the south end of Myvatn [P.L.]. — On a knoll in the lava field. FUNGI OF ICELAND 511 Coleosporiaceae. Coleosporium Léveillé. 377. C. Campanulae (Persoon) Leveille. Uredo Campanulae Persoon, Synops. meth. fung., p. 217. Hörgärdalur [O.D.]; Svarfadardalur (J. Jöhannsson); Egilsstadir in Vopnafjöröur [St. St]. — On Campanula rotundifolia. Melampsoraceae. Melampsorella Schroeter. 378. M. Cerastii (Persoon) Winter. Uredo Cerastii Persoon, Synops. meth. fung., p. 219. Porvaldsdalur, Flatatünga, Prastarhölsgil [O.D.]; Hafnardalur (St. St.]; Hraun near Hekla, Hvitäfos (Feddersen); Dyrafjérdur, Pingeyri, Hölmanes, Eskifjöröur, Videy near Reykjavik [C.H.O.]. — On Cerastium alpi- num and C. vulgatum. Melampsora Castagne. 379. M. arctica Rostrup, Gronl. Svampe 1888, p. 535. Common throughout the country, recorded from about 40 different localities. — On Salix herbacea, S. glauca, S. phylicifolia and S. lanata. 380. M. betulina (Persoon) Tulasne. Uredo betulina Persoon, Synops. meth. fung., p. 219. Hallormstadir (P. L. and Buchwald). — On seedlings of Betula pubescens in a nursery garden. 381. M. Lini (Persoon) Tulasne. Uredo Lini Persoon, Synops. meth. fung., p. 216. Fornhagagil, Hof [O. D.); Glerä [C. H. O.); Reykhüs, Eyjafjördur (Ström- felt); Stadarfell [H. J.J. — On Linum cartharticum. 382. M. Pyrolae (Gmelin) Schroeter, Die Pilze Schlesiens 1. H., p- 366. Böggverstadadalur [O.D.); Asbyrgi [St. St... — On Pyrola minor and P. secunda. 383. M. Vacciniorum (Link) Schroeter, |. c., p. 365. Hofsfjall, Reistarärfossar, Hraun in Fljöt, Porvaldsdalur [O.D.). — On Vaccinium uliginosum and V. Myrtillus. 384. M. pustulata (Persoon) Schroeter, L c., p. 364. Uredo pustulata Persoon, Synops. meth. fung., p. 219. 512 POUL LARSEN Skrifla (Grønlund); Uxahver [O.D.]; Reykhüs, Eyjafjöröur (Ström- felt); Sandey in Pingvallavatn (Feddersen). — On Epilobium palu- stre, BE: alpı num. 385. M. Saxifragarum (De Candolle) Schroeter, 1. c., p. 375. Common throughout the country. — On Saxifraga caespitosa, S. hypnoides, S. aizoides, S. oppositifolia. Hyalospora Magnus. 386. H. Polypodii (Persoon) Magnus. Uredo Polypodii Persoon, Synops. meth. fung., p. 217. Skütustadir near Myvatn [O.D.]; Störugjä; Hröfberg near Steingrims- fjördur [St. St.]; Raudavatn (Feddersen). — On Cystopteris fragilis. Cronartiaceae. Chrysomyxa Unger. 387. C. Pyrolae (De Candolle) Rostrup, Mycologische Notiz. Bot. Cen- tralbl. V, 1881, p. 126. — Sacc., Syll. fung. VII, II, p. 761. Aecidium Pyrolae De Candolle, Flor. fr. VI, p. 99. Skutulsfjöröur [C. H. 0.]. — On Pyrola minor. Pucciniaceae. Uromyces Link. 388. U. Dactylidis Otth; E. Rostrup, Plantepatologi, Kobenhavn 1902, p. 275. Hörgärdalur, Hof [O.D.J. — On Poa alpina, P. pratensis and Deschampsia caespitosa. 389. U. Festucae Sydow, Hedwigia 1990, p.117. Saccardo, Syll. fung. XVI, p. 269. S. W. Icel. [H. J... — On Festuca rubra. 390. U. Polygoni (Persoon) Fuckel. Puccinia Polygoni Persoon, Tentamen dispositionis methodicae fungo- rum, 1797. Akureyri (Grønlund); Mööruvellir [O. D.]; Borgarnes, Reykjavik [H.J.]; Hvammsfjördur (Feddersen). — On Polygonum aviculare. 391. U. Alchimillae (Persoon) Léveillé. Uredo Alchimillae Persoon, Synops. meth. fung., p. 215. Common throughout the country. — On Alchimilla vulgaris. FUNGI OF ICELAND LE 392. U. Trifolii (Hedwig f.) Léveillé. Puccinia Trifolii Hedwig f., Fungi ined. (La Marck et De Candolle, Fl. franc. ID t. 18. (With reference to Schroeter: Die Pilze Schlesiens I, p. 301). Fornhagagil, Hof in Hörgärdalur {O. D.). — On Trifolium repens. 393. U. Limonii (De Candolle) Léveillé. Sydow: Monographia Uredi- ~ nearum, vol. II: Uromyces, p. 41. Eskifjordur (Strömfelt). — On Armeria maritima. Puccinia Persoon. 394. P. Anthoxanthi Fuckel, Sydow: Monographia Uredinearum, vol. I, p. 727. Fornhagagil, Hof [O. D]. — On Anthoxanthum odoratum. 395. P. borealis Juel, Hedwigia 1895, p. 16. — Sacc., Syll. fung., XI, p. 199. Hörgärdalur, Mööruvallanes, Hraun in Fljöt, Hof, Geirhildargardar in @xnadal [O. D.]; Hvarf (St. St]. — On Agrostis sp., Calamagrostis stricta, Hierochloé odorata, Anthoxanthum odoratum, Des- champsia caespitosa. 396. P. Poarum Nielsen, Botan. Tidskr., 3. R., 2. Bd., 1877, p. 34. Hof in Hörgärdalur, Möörufellshraun [O. D]. — On Poa praten- sis, P. alpina. 397. P. Caricis (Schumacher) Rebentisch. Uredo Caricis Schum., Nr. 1555, Flora Danica, tab. 317, fig. 2. Hraunsvatn, Akranes [O, D.]; Reykjavik (Berlin). — On Carex atrata, C. Goodenoughii and C. sp. 398. P. uliginosa Juel, Sydow, Monogr. Ured., vol. I, p. 673. Lambardalur in Dyrafjöröur {C. H. O.], S. W. Iceland [H.J... — On Carex sp. Parnassia palustris (Aecidium). 399. P. septentrionalis Juel, Öfversigt af Kongl. Vetenskaps-Akade- miens Förhandlingar 52 (1895), p. 383. Very common throughout the country. — On Polygonum vivi- parum and aecidial stage on Thalictrum alpinum (Aecidium Som- merfeltii). 400. P. Bistortae (Straus) De Candolle, Sydow, Monogr. Ured., vol. I, p. 571. S. W. Iceland [H.J.); Grimsey, Hof [O.D.); Skjoldolfstadir, Gufudals- häls (St. St... — On Polygonum viviparum. 401. P. Oxyriae Fuckel, Sydow: Monogr. Ured., vol. I, p. 567. Gaunguskard [O.D.). — On Oxyria digyna. The Botany of Iceland Vol. II, part III. 34 514 POUL LARSEN 402. P. Blyttiana Lagerheim. Saccardo, Syll. fung. XI, p. 174. teislarärskarö [O. D.). — On Ranunculus acer. 403. P. Cruciferarum Rudolphi, in Linnæa IV, p. 391. — Saccardo, Syll. fung. VII, II, p. 724. Hof in Hörgärdalur [O. D.]. — On Cardamine pratensis. 404. P. Drabae Rudolphi, Sydow, Monogr. Ured., vol. I, p. 512. Oddeyri[C.H.O.]; Fornhagagil, Arnarnes, Gäsaeyri, Hörgärdalur [O. D.] ; Arnarfell, Reykir in Reykjabraut [St. St]; Hrappsey in Breidifjöröur [Gudm. Magnusson]; Melstadur, Pingvellir [Feddersen]; Myvatn, Skrifla [Grønlund]. — On Drabaincana, D. hirta. 405. P. Saxifragae Schlechtendal, Sydow, Monogr. Ured., vol. I, p. 500. Hofsfjall, Skütustadir near Myvatn [O. D.}; Veöramötsteigur [Jön Björns- son]; Eskifjördur [Strömfelt]. — On Saxifraga nivalis, S. stellaris. 406. P. Fergussonii Berkeley et Broome; Sydow, Monogr. Ured., vol. I, p. 444. Fornhagagil, Hof, Hvammur on Galmarströnd [O.D.]); Skælingar [Thoroddsen]. — On Viola palustris. 407. P. Morthieri Körnicke, Sydow, Hedwigia 1877, p. 19. — Saccardo, Syll. fung. VII, II, p. 681. Reykjahliö near Myvatn [P.L.. — On leaves of Geranium sil- vaticum. 408. P. Violae (Schumacher) De Candolle, Sydow, Monogr. Ured., vol. I, p. 439. Uredo Violae Schumacher Nr. 1570, Flora Danica, tab. 1317. Grafarbakki [O.D.]; Reykjavik, Krisuvik [C.H.O.. — On Viola silvatica, V. canina. 409. P. Epilobii De Candolle, Sydow, Monogr. Ured., vol. I, p. 427. Hörgärdalur, Mööruvellir, Reistarärskard, Hraun in Fljöt [O.D.]; Fljötsheidi [Grønlund]; Guöfinnugjä near Yxnihola [Björn Gudmundsson) ; Geldingsä [St. St]; Gaunguskard, Hofskard, Laufäs [Feddersen]; Dyra- fjordur, Lätravik, Adalvik [C.H.O.]; Frödärheidi [H.J... — On Epilo- bium palustre, E. alpinum, E. lactiflorum, E. alsinefolium. 410. P. Halosciadis Sydow, Annales Mycologici 17 (1919), p. 33. Axarey in Breidifjöröur [H.J.]. — On Haloscias scoticum. 411. P. Schneideri Schroeter, Die Pilze Schlesiens I, p. 344. Hjedinshöfdi, Porvaldsdalur [O. D.]; Oddeyri, Dyrafjöröur, Eskifjöröur [C.H.O.]. — On Thymus serpyllum. FUNGI OF ICELAND 515 412. P. Veronicarum De Candolle, Sydow, Monogr. Ured., vol. I, p. 257. Mööruvellir (St. St]; Hofsfjall, Hestahraun in Porvaldsdalur [O. D.]. — On Veronica alpina. 413. P. punctata Link, Sydow, Monogr. Ured., vol. I, p. 213. Puceinia Galii (Persoon) Schw. Mööruvellir [St. St.]; Eskifjördur [Strömfelt]; Seydisfjordur [P.L.]. — On Galium silvestre. 414. P. Leontodontis Jacky, Sydow, Monogr. Ured., vol. I, p. 114. Mööruvellir [G. Gudmundsson]; Hof, Hjedinshôfüi [O. D.]. — On Leon- todon autumnalis. 415. P. variabilis Greville, Sydow, Monogr. Ured., vol. I, p. 163. Common throughout the country. — Om Taraxacum sp. 416. P. silvatica Schroeter, Die Pilze Schlesiens I, p. 328. Grund (S. W. Iceland) [H.J.).. — On Taraxacum croceum. 417. P. Hieracii Martius, Sydow, Monogr. Ured., vol. I, p. 95. Kolkä, Eskifjérdur [Strömfelt]); Hörgärdalur, M\vatn, Porvaldsdalur (O. D.]; Melrakkasljetta, Dyrafjördur [C. H. O.]. — On Hieracium muro- rum, H. alpinum, H. islandicum. Triphragmium Link. 418. T. Ulmariae (Schumacher) Link. Uredo Ulmariae Schumacher, Enum. plant. Selland. No. 1533. Prestsbakkaheidi (St. St]; Birtingahalt [H.J.). — On Filipendula Ulmaria. Of Uredo forms whose teleutospores are not yet known, the following occurs in Iceland: 419. Uredo Airae Lagerheim, Journal de Botanique II, 1888, p. 432. Reykjavik [H.J.. — On Deschampsia caespitosa. Ustilaginaceae. Ustilago Persoon. 420. U. Hordei (Persoon) Kellermann et Swingle. Uredo Hordei Persoon, Synops. meth. fung., p. 224. Ustilago Jensenii Rostrup, Ustilagineae Daniae, 1890, p. 138. Akureyri, Mööruvellir (St. St]. — On Hordeum vulgare. 34* 516 POUL LARSEN 421. U. Bistortarum (De Candolle) Körnicke, Hedwigia 1877, p. 88. — Saccardo, Syll. fung. VII, II, p. 469. Hörgärdalur [O. D.j; Stykkishölmur [H.J.]; Dyrafjöröur, Pingeyri [C. H. O.]. — On leaves of Polygonum viviparum. 422. U. vinosa (Berkeley) Tulasne, Saccardo, Syll. fung., VII, p. 469. Hestahraun in Porvaldsdalur, Hraun in Fljöt [O.D.). Pörsmörk in S. W. Iceland [H.J.]. — In flowers of Oxyria digyna. 423. U. violacea (Persoon) Roussel, Saccardo, Syll. fung., VII, p. 474. Djüpärbakki [St. St]; common at Eskifjöröur, Isafjordur, Dyrafjordur, Reykjavik [C. H. O.]. — On Silene acaulis. Sphacelotheca De Bary. 424. S. Hydropiperis (Schumacher) De Bary. Uredo Hydropiperis Schumacher, Enum. plant. Sell., No. 1580. Grimsey [Thoroddsen]; Saudanes [St. St]; Hof [O. D.]; Lätravik, Adal- vik, Eskifjöröur [C.H.O.]; Stadarhraun, Pingvellir [Feddersen]; Beru- fjördur [Gronlund]; Stjüpmödurhölmi, Büdir, Grund [S. W. Iceland] [H. J.). Of wide distribution in many localities [H.J... — In the inflorescences of Polygonum viviparum. Cintractia Cornu. 425. C. Caricis (Persoon) Magnus, Uredo Caricis Persoon, Synops. meth. fung., p. 225. Common throughout Iceland. — On Carex dioeca, C. stellulata, C. rigida, C. Goodenoughii, C. capellaris, C. panicea, Kobresia Bellardii, Scirpus caespitosus. 426. C. Luzulae (Saccardo) Clinton. Ustilago Luzulae Saccardo, Syll. fung., VII, p. 463 Büdartungugil, Hraun in Fljöt [O. D.]. — On Luzula multiflora. Tolyposporium Woronin. 427. T. Junci (Schroeter) Woronin, Saccardo, Syll. fung., VII, p. 501. Glerä near Akureyri [C. H.O.]; Mööruvellir [O. D.]. — Filling up the whole stem of Juncus balticus. 428. T. Montiae Rostrup, Vejledn. i d. danske Flora, II. Del, 1904, p. 31. Sorosporium Montiae Rostrup, Mykologiske Meddelelser VI. Botanisk Tidsskrift, vol. 20, 1896, p. 128. Dyrafjöröur, Pingeyri [C.H.O.]. — On Montia rivularis. FUNGI OF ICELAND 517 Tilletiaceae. Tilletia Tulasne. 429. T. striiformis (Westendorp) Winter, Saccardo, Syll. fung., vol. VII, p. 485. Mööruvellir [St St]. — On Calamagrostis stricta and Poa pra- tensis. 430. T. arctica Rostrup, Svampe fra Finmarken, Botanisk Tidsskrift, XV, 1886, p.230. Saccardo, Syll. fung. VII, II, p. 486. Cintractia arctica (Rostrup) Lagerheim. Mööruvellir [O. D.]. — On leaves of Carex sp. Entyloma De Bary. 431. E. crastophilum Saccardo, Syll. fung., vol. VII, p. 491. Geirhildargardur in Öxnadal [O. D.]. — On leaves of Deschampsia caespitosa. 432. E. Catabrosae Johanson, Svampar fran Isl. 1884, p. 160. Hölar [Strömfelt]; Kollafjardarnes [G. Gudmundsson]. — On leaves of Catabrosa aquatica. 433. E.irregulare Johanson, Svampar fran Isl. 1884, p. 159. Eyjafjordur, Reykhüs [Strömfelt]; Litla Arskögssandur, Grafarbakki (O. D.]. — On leaves of Poa annua. 434. E. Ranunculi (Bonorden) Schroeter, Saccardo, Syll. fung., vol. VII, p- 488. Hof, Mööruvellir [O. D.]. — On Ranunculus acer. 435. E. Calendulae (Oudemans) De Bary, Saccardo, Syll. fung., vol. VII, p- 492. Gufudalshäls [St. St... — On Hieracium murorum. Urocystis Rabenhorst. 436. U. Fischeri Körnicke, Saccardo, Syll. fung., vol. VII, p. 516. Urocystis Agropyri Schroeter. Lönsleirur [O.D.]. — On leaves of Carex salina. 437. U. sorosporioides Körnicke, Saccardo, Syll. fung., vol. VII, p. 519. Hof in Hörgärdalur [O.D.). — On Thalictrum alpinum. Tremellaceae. Exidia Fries. 438. E. repanda Fries, Syst. Myc. II, p. 225. Pördarstadaskögur, Husafellsskögur [O.D.); Hallormstadir, Lömagnu- pur, Bejarstadur [Buchwald]. — On Betula pubescens. 518 POUL LARSEN 439. E. albida (Hudson) Brefeld, Saccardo, Syll. fung. VI, p. 775. Pingvellir, Vifilsstadahliö [P.L.. — On dead branches of Betula pubescens. Tremella Dillenius. 440. T. lutescens Persoon, Synops. meth. fung., p. 622. Hälsskögur, Hüsafellsskögur [O.D.]. — On bark of Betula pubescens. Dacryomycetaceae. Dacryomyces Nees. 441. D. deliquescens (Bulliard) Duby. Tremella deliquescens Bulliard, t. 455, Fig. 3. Hälsskögur, Hüsafellsskögur [O. D.}; a garden in Reykjavik [Buchwald]. — On wood of Betula pubescens. 442. D. stillatus Nees, Ueberblick des Systems der Pilze und Schwämme, 1847, p. 89, Fig. 90. Gäsir [O. D.]. — On wood washed up by the sea. Exobasidiaceae. Exobasidium Woronin. 443. E. Vaccinii (Fuckel) Woronin, Saccardo, Syll. fung. VI, p. 664. Fusidium Vaceinii Fuckel, Mycologisches, Bot. Zeit., 1861, vol. 19, p. 251. Vallneskinn, Vikürfjall (St. St.}|; Hvarf, Melrakkasljetta near Grjötnes [C.H.O.]; Hörgärdalur, Hestahraun, Hraun in Fljöt [O. D.]; Kolbeinsä, Haukadalsä [H.J.. — On Vaccinium Myrtillus, V. uliginosum. 444. E. Warmingii Rostrup, Gronl. Svampe 1888, p. 530. — Saccardo, Syll. fung. VI, p. 245. Bær (St. St]; Hölmanes [C. H. O.]. — On Saxifraga oppositifolia. Clavariaceae ex parte. Clavaria Vaillant (but only the stichobasidial species). 445. C. cinerea Bulliard, t. 354. — Fries, Syst. Myc., vol. I, p. 468. Hofsfjall, Güfunes [O. D.]; Eyjölfstadir Skögur [P. L]. — In birch copses. 446. C. cristata Persoon, Synops. meth. fung., p. 591. Hof in Hörgärdalur, Hraun in Fljöt [O.D.). FUNGI OF ICELAND 519 Cantharellaceae. Leptotus Karsten. 447. L. lobatus (Persoon) Karsten. Merulius lobatus Persoon, Myce. Eur. II, p. 23. Hofsfjall [O. D.]; Eskifjördur [C. H. O.]; Hallormstadir, Myvatn [P. L.]. — On mosses. and Leptoglossum Karsten. 448. L. glaucum (Batsch) Ricken, Die Blätterpilze, Leipzig 1915, p. 5. Hallormstadir [P. L.]. — On peaty soil. 449. L. muscigenum (Bulliard) Ricken, I. c., p. 5. Hallormstadir [P. L.]. — On the edges of ditches among mosses. Thelephoraceae. Thelephora Ehrhart. 450. T. caryophyllea (Schaeffer) Persoon. Helvella caryophyllea Schaeffer, Fungorum .... icones, t. 325. Found in Iceland by König (Flora Danica, t. 409, f. 2). 451. T. terrestris Ehrhart, Beiträge kryptogam. Botanik, Nr. 179. Prastarhölsskarö [O. D.]; Hallormstadir [P. L.]. — On tufts of Luzula on the ground under birches. Hydnaceae. Hydnum Linné. 452. H. argutum Fries, Syst. Myc. I, p. 424. Hüsafellsskögur [O. D.]. — On dead leaves of Betula pubescens. Corticiaceae. Tomentella Persoon. 453. T. ferruginea Persoon, Obs. Myc., vol. 2, p. 18. Hälsskögur [O.D.). — On Betula pubescens. Corticium Persoon. 454. C. radiosum Fries, Epicrisis systematis mycologici, p. 560. Mööruvellir (St. St]. — On wood. 455. C. salicinum Fries, Epicr., p. 558. Bejarstadur (H. J.J. — On branches of willow. 520 POUL LARSEN 456. C. granulatum (Bonorden) Winter, Rabenhorst’s Kryptogamen- flora I, 1., p. 329. Hypochnus granulatus Bonorden, Handbuch der allg. Myk., p. 169. Hälsskögur [O.D.). — On Betula pubescens. 457. C. incarnatum Fries, Epicr., p. 564. Bildsfell, Pingvellir [Feddersen]; Bzejarstadur [Buchwald]. — On Be- tula pubescens and Sorbus aucuparia. Coniophora De Candolle. 458. C. puteana (Schumacher) Fries, Hym. Eur., p. 657. Thelephora puteana Schum., No. 1989, Flora Danica, tab. 2033, fig. I. Grimsey [O.D.). Stereum Persoon. 459. S. vorticosum Fries, Obs. Myc., vol. 2, p. 275. Hälsskögur [O.D.]. — On Betula pubescens. 460. S. hirsutum (Willdenow) Persoon. Thelephora hirsuta Willdenow, Florae berolinensis prodromus, 1787, pP: 397. Mööruvellir, Hälsskögur, Hüsafellsskögur [0. D]. — On Betula pubescens. 461. S. rugosum Persoon, Myc. Eur., vol. I, No. 30—34. Norötünga [P. L.]; Hallormstadir [Buchwald]. — On Betula pube- scens. 462. S. tuberculosum Fries, Hym. Eur., p. 644. Hälsskögur [O. D.]. — On Betula pubescens. Cyphellaceae. Cyphella Fries. 463. C. villosa (Persoon) Karsten, Mycologia fennica III, p. 325. Fornhagagil [O. D. — On dead stems of Geranium silvaticum. Clavariaceae ex parte. In this section will be found the supposed chiastobasidiale forms of Clavariaceae Fries. Typhula Fries. 464. T. graminum Karsten, Saccardo, Syll. fung. VI, p. 746. FUNGI OF ICELAND 521 Holm in Myvatn [Grønlund]; Hof in Hörgärdalur [O.D.]; Mödru- vellir [St. St]. — Sclerotia have been found on: Agrostis sp. Agro- pyrum violaceum and Carex rigida. Clavaria Vaillant (ex parte). 465. C. fragilis Holmskiold, Beata ruris otia fungis danicis impensa, vol. I, p. 7. Hjedinshöfdi [O.D.]; Egilsstadir-Skögur [P. L.]. — In the latter locality among grass in a glade. 466. C. inaequalis Müller, Flora Danica, t. 837. Hof in Hörgärdalur [O. D.). 467. C. fastigiata Fries, Syst. Myc. I, p. 467. Clavaria muscoides Linné. Mööruvellir (St. St]; Hof in Hörgärdalur, Hraun in Fljöt [O.D.]; Kirkjubzjarklaustur [Buchwald]; Effersey near Reykjavik [Svend Andersen]. Radulaceae. Radulum Fries. 468. R. orbiculare Fries, Elenchus fungorum, I, p. 149. Hälsskögur [O. D.]; Pingvellir [P. L.]. — On dead branches and trunks of Betula pubescens. Phlebia Fries. 469. P. radiata Fries, Syst. Myc. I, p. 427. Vididalur [Grønlund]; Bæjarstadur [Buchwald]. — On wood and bark of Betula pubescens. Meruliaceae. Merulius Haller. 470. M. lacrymans Fries, Syst. Myc. I, p. 328. Mööruvellir (St. St... — On floors and wainscot. 471. M. corium Fries, Elenchus fungorum I, p. 58. Bæjarstadur [Buchwald]. — On dead branches of Betula pubescens. Polyporaceae. Poria Persoon. 472. P. vaporarius Fries, Saccardo, Syll. fung. VI, p. 311, and XVII, p. 131. Mooruvellir (St, St]. — In houses. 522 POUL LARSEN 473. P. medulla panis Fries, Saccardo, Syll. fung. VI, p. 295. Mödruvellir [St. St... — On beams in a cellar. Polyporus Micheli. 474. P. croceus (Persoon) Fries, Syst. Myc. I, p. 364. Hälsskögur [O. D.]. — On Betula pubescens. 475. P. brumalis (Persoon) Fries. Boletus brumalis Persoon, Synops. meth. fung., p. 517. Hälsskögur [St. St]; Voglaskögur [O. D.]; Hallormstadir [P. L.j. — On stumps and fallen branches of birch. Polystictus Fries. 476. P. hirsutus (Wulfen) Fries. Polyporus hirsutus Fries, Syst. Myc. I, p. 367. Egilsstadir [P.L.]. — On fallen branches of Betula pubescens. 477. P. perennis (Linné) Fries. Boletus perennis Linné, Flora Suecica, No. 1245. Lomagnupur (Buchwald). — On the ground in an Empetrum-Cal- luna-heath. Hygrophoraceae. Hygrophorus Fries. 478. Hygrophorus conicus (Scopoli) Fries, Hym. Eur., p. 419. Myvatn (Grønlund); Akureyri, Reykjavik [C. H. O.); Hallormstadir and Skütustadir [P. L.}. — On knolls in outfields and in homefields. Cap conical, margin straight, colour 16 and 17, becoming black. Flesh thin, yellow, becoming black. Stipe cylindrical, yellow, white below, becoming black. Gills broadest anteriorly, nearly free. at first al- most white, then yellow, becoming black. Spores white, elongate-ovate, 9 1A Ooi, 479. H. miniatus Fries, Hym. Eur., p. 418. Egilsstadir (Lagarfljöt) [P.L.]. — Among grass in outfields. Cap 1—2 cm broad, convex, orange-red, covered with fine yellow scales (projecting hyphz with yellow contents). Stipe cylindrical, stuffed, co- loured like the cap, above clad with yellow scales. Gills thick, rather distant, broadly adnate, decurrent tooth, yellow to orange. Spores white, nearly cylindrical, 8—9X5—5S.5 u. 480. H. pratensis (Persoon) Fries, Hym. Eur., p. 413. Hof in Hörgärdalur [O. D]; Seydisfjördur [P. L.]. Cap 3—5 cm broad, flat, gibbose, margin thin, orange-yellow (16). Stipe concolorous but paler, cylindrical, thinner below. Gills thick, distant, concolorous, strongly decurrent. Spores white, ellipsoidal, 6%4 u. FUNGI OF ICELAND 523 481. H. niveus (Scopoli) Fries, Hym. Eur. p. 414. Seydisfjördur [P. L.] — Among grass in a homefield. Cap plano-convex, umbilicately depresssed, white, hygrophanous, when moist pellucidly striate at margin. Stipe hollow, white, dilated above. Gills thin, white, distant, arcuate-decurrent. Spores white, sub- cylindrical, 8X4—5 u. Agaricaceae. Clitocybe Fries. 482. C. gilva (Persoon) Fries, Hym. Eur, p. 95. Agaricus gilvus Persoon, Synops. meth. fung., p. 448. Seydisfjördur [P. L.]; Dyrafjérdur [C. H. O.]. — In grass on mountain slopes among Betula nana and Salix herbacea. Cap 5—8 cm broad, plano-convex, depressed at centre, in damp weather yellowish brown (g 2), in the dry state greyish yellow (k 4), margin in- volute, mealy and sulcate. Flesh pale yellow (k 1 to k 2), stipe cylin- drical, stuffed, at length hollow, 8 cm high, 8—15 mm thick, pale yellow (k 2), even and naked, but enveloped in white hairs at base. Gills narrow, crowded, decurrent, furcate below, creamcoloured (k 1). Spores white, ovoid, 5X3—4 u. 483. C. odora (Bulliard) Fries, Hym. Eur., p. 85. Agaricus odorus Bulliard, 1791, t. 556, fig. 3. Eyjolfstadir (near Grimsä) [P. L.]. — Under birches. Cap 4—6cm broad, plano-convex, fleshy and firm, naked, greyish green (b 1 to b 3). Flesh pallid, smells strongly of anis. Stipe pale greyish green (e 1), somewhat inflated and hollow, at base with strongly decurrent and interwoven hyphe. Gills white or the same colour as the stipe, broad, distant, only decurrent by a tooth. Spores white ellipsoidal, 6X4 u. 484. C. tornata Fries. Agaricus tornatus Fries, Hym. Eur., p. 87. Hallormstadir [P. L.]. — In a birch copse. Cap 3—6 cm broad, convex, occasionally somewhat gibbous, not hygrophanous, white and covered with a white mealy layer, in age with deep cracks in the flesh of cap, becoming alutaceous. Stipe short, of unequal thickness, dilated now at apex, now at base, stuffed, white. Gills narrow, crowded, white, adnate, only decurrent by a tooth. Spores white, small, 4—5X2 u. 485. C. dealbata (Sowerby) Fries, Syst. Myc. I, p. 92. Agaricus dealbatus Sowerby, Coloured Fig. of English Fungi, London 1797—1805, t. 123. Seydisfjöröur [P. L.). — In a homefield. 524 POUL LARSEN Cap 3—5 cm broad, elongated, frequently with somewhat irregular sinuous margin, flesh thin, white to watergrey, silky when dry. Stipe cylindrical, stuffed, 3—4 cm high and 3—5 mm thick, white or greyish, felted at top. Gills crowded, white, broadly adnate, only slightly decur- rent. The flesh smells and tastes of flour. Spores smooth, white, ellip- soidal, 5X3 u., Omphalia (Persoon) Fries. 486. O. hepatica (Batsch) Fries, Hym. Eur., p. 160. Agaricus hepaticus Batsch, Elenchus fungorum, f. 211. Akureyri [P. L.]. — On grass-covered, sandy meadows at Glerä. Cap 1.5—2.5 cm broad with incurved margin, plano-convex, even, without or with a very slight depression in the centre, hygrophanous, reddish brown (j 4), in the old fungus the cap becomes crateriform with a pendent, undulate and somewhat sulcate margin, and turns aluta- ceous in colour (j 1), first in the centre and then at the margin. Stipe cylindrical, hollow, 1.5—3cm high, 2mm thick, pale reddish brown (j 2), naked, the base covered with white hyphæ. Gills distant, rather narrow, at length strongly decurrent, coloured like the stem. - Spores ovoid, smooth, white, 7X4—5 u. Basidia clubshaped with 4 up to 10 u long sterigmata. 487. O. onisca Fries. Agaricus oniscus Fries, Hym. Eur., p. 158. Isafjördur, Pingvellir and Laugarnes near Reykjavik [P. L.]. — On peaty and swampy ground among mosses and sedges. Cap c. 2 cm broad, deeply umbilicate, campanulate, pendulous, mar- gin sulcate-undulate, at length lobate, hygrophanous dark brown (f 4), horn grey when dry. Stipe short, base somewhat tapering, stuffed, at length hollow, greyish brown, mealy, felted at base. Gills grey, rather crowded, decurrent. Spores piriform with oblique apex, smooth, white, 7.8X5 u. 488. O. umbellifera (Linné) Fries, Hym. Eur., p. 160. Agaricus umbelliferus Linné, Flora Suecica, No. 1192. Akureyri [P.L.]; Hof in Hörgärdalur (O.D.]. — Occurs in great abundance among sedges, mosses, and Salix herbacea in the littoral field near Glerä. Cap 5—10 mm broad, margin incurved and sulcate, centre umbili- cate, straw-yellow (k 4). Stipe. cylindrical with slightly dilated base, 2cm high, 1—2 mm thick, stuffed, white, somewhat mealy, base felted. Gills distant, decurrent, rather broad, white. Spores ellipsoidal, white, smooth, 6.5—8X3.5 u. Pleurotus Fries. 489. P. applicatus (Batsch) Fries. Agaricus applicatus Batsch, Elench. fung., Cont. I, p. 171, f. 125. FUNGI OF ICELAND 525 Hrafnagjä near Pingvallavatn [P.L.). — On rotten branches of Be- tula pubescens. Cap 4-5 mm broad, resupinate, crateriform pellicle gelatinous, greyish brown and mealy. There is no stipe, the fungus being attached by an excentric area of the surface of the cap. Gills distant, white or greyish while, anastomosing in an excentrically placed point. Spores white, smooth, broadly ellipsoidal, 5—6X4 u. Russuliopsis Schroeter. 490. R. laccata (Scopoli) Schroeter, var. rosella (Batsch) f. pusilla. Agaricus laccatus Scopoli; Flora carniolica, p. 444. Lagarfljöt, Laxärdalur, Ljésavatnsskard, littoral field near Akureyri, Isafjöröur, meadows near Pverä (Norötünga), Laugarnes near Reykjavik [P. L.], Cap 1—2 cm broad, flesh thin, smooth, palely or darkly incarnate (n 6 to n 7), margin skin-like, undulate-sulcate, centre somewhat depressed. Stipe short and thin, concolorous. Gills distant, rather thick, adnato- decurrent, coloured like the cap. Spores white, verrucose, spherical, 8—9 u in diameter. i Entoloma Fries. 491. E. sericeum (Bulliard) Fries, Hym. Eur., p. 196. Agaricus sericeus Bulliard, t. 413, f. 2. Hallormstadir [P.L.. — On grass-covered spots in and around the birch copses. Cap 3—5 cm broad, campanulate with broadly incurved margin and often with irregular depressions in various parts of the surface, hygro- phanous, pellucidly striate, dark brown in various shades ranging about c 3, grey when dry, with a silky lustre. The flesh has the flavour and smell of flour. Stipe 3—5 cm high, 4—7 mm thick, cylindrical, stuffed, flesh stringy, often twisted. Gills grey, then red, sometimes broadly ad- nate, sometimes deeply emarginate, edge of gills often undulate. Spores incarnate, almost regularly pentagonal, now and then with an elongated apiculus, $—9X7—8 u, a few spores somewhat larger. 492. E. rhodopolium Fries. Agaricus rhodopolius Fries, Syst. Myc. I, p. 197. Birch copse near Eyjölfstadir. Cap 3—5 cm broad, campanulate, margin thin and incurved, hygro- phanous, greyish brown when moist (h 6), white when dry. Stipe 7—9 cm high, 4—6 mm thick, cylindrical, hollow, somewhat cartilaginous, white. Gills rather crowded, broad, adnate, emarginate, with a decurrent tooth, at first white, then roseate. Spores incarnate, almost regularly pentagonal, 7—9 u in diameter. 526 POUL LARSEN Leplonia Fries. 493. L. lampropus Fries. Agaricus lampropus Fries, Syst. Myc. I, p. 203. Vallanes near Lagarfljöt [P. L.]. — On sandy grass-covered spots. Cap 2—3 cm broad, convex or plano-convex, not hygrophanous, margin involute, brown with a bluish tinge (f 3). Stipe cartilaginous, hollow, glabrous, bluish violet (a 2, but more blue). Gills at first greyish white, then greyish red,‘ broad, but loosely attached to the stipe. Spores angular, incarnate, 10—12X8—9 u. 494. L. serrulata (Persoon) Fries, Hym. Eur., p. 203. Agaricus serrulatus Persoon, Synops. meth. fung. I, p. 463. Egilsstadir [P. L.). — In grass-covered, knolly outfields. Cap from barely 1 to 4cm broad, plano-convex, with incurved and involute margin, later expanded, throughout the development with umbili- cate centre, surface shortly adpressed-pubescent, shining, from a deep black-violet (Somewhat darker than a 1) to brown-violet (o 2); the flesh below the cuticle is a pale bluish red. Stipe cylindrical, as much as 4 cm high, 2—3 mm thick, blackish blue at top, paler below, base covered with white hairs. Gills emarginate, pale violet at first (o 4), later incar- nate, edge of gills coarsely dentate and black. Spores oblong, obtusely pentagonal, elongated to an oblique apiculus, incarnate, 10—11*7—8 u. No cystidia, the blackish blue colour of the edge of the gills being due to the coloured contents of the hyphæ. 495. L. sericella (Fries) Quélet. Agaricus sericellus Fries, Syst. Myc. I, p. 196. Vallanes, Egilsstadir [P. L.. — On knolls in outfields and at roadsides. Cap 1—4 cm broad, at first convex, with incurved margin, white with a yellowish centre, with a silky, mealy-fibrous coating, then some- what orange-coloured (16), finely squamulose and depressed at centre. Stipe cylindrical, up to 3mm thick, pellucid, hollow, white at first, then yellowish. Gills distant, adnate and slightly decurrent, white, then pink to incarnate. Spores incarnate, angular, almost isodiametrical, 8—10 7 BSH. Nolanea Fries. 496. N. juncea Fries. Agaricus junceus Fries, Syst. Myc. I, p. 208. Brekka near Lagarfljöt and at Hallormstadir [P. L.]. — In wet bogs among mosses. Cap 1.5—2.5 cm broad, flatly conical, with obtuse or depressed disc, hygrophanous, pellucidly striate, surface rough, minutely pitted and slightly squamulose, dark brown when moist (f 3), grey when dry (i 3). FUNGI OF ICELAND 527 Stipe cylindrical, 6—7 cm long, 2 mm thick, cartilaginous, brown, but covered with greyish white fibres; gills broad, distant, rather thick and rigid, strongly rounded towards the stem, almost free, grey, then incar- nate. Spores very variable in shape, sometimes polygonal, sometimes oblong and irregularly angular, drawn out below into an oblique apiculus, 9—11X8 u. Mycena Fries. 497. M. avenacea Fries, sensu Schroeter, Die Pilze Schlesiens I, p. 638. Agaricus avenaceus Fries, Systema mycologicum I, p. 150. Seydisfjördur [P. L.]. — On and among grassy knolls in outfields. Cap 1—15 cm broad, conic-campanulate, margin pellucido-striate, greyish brown (g 6), darker at centre. Stipe 4—5 cm long, 1—2 mm thick, hollow, tough, shining, pale, finally greyish yellow (k 2). Gills distant, white, brown-rimmed. Spores ellipsoidal, smooth, white, 12X5—6 u. Edge of gills closely beset with flaskshaped cystidia with brown contents. Marasmius Fries. 498. M. Vaillantii (Persoon) Fries, Epier. p. 380. Dvrafjöröur, Pingeyri [C. H. O.) det. E. Rostrup. 499. M. insititius Fries, Epicr. p. 386. Hof in Hörgärdalur [O. D.] det. E. Rostrup. Tricholoma Fries. 500. T. gambosum Fries. Agaricus gambosus Fries, Syst. Myc. I, p. 50. Fnjöskadalskögur [C. H. O.]. 501. T. pubifolium Romell, Hymenomycetes of Lappland, pp. 2 and 3. Hallormstadir, Mödrudalur, Reykjahlid and Skütustadir [P. L.]. Cap 4—7 cm broad, campanulate, obtusely gibbous margin involute, centre palely ochraceous (k 2), the rest white, the whole surface (under the lens) minutely and densely pubescent, which gives the cap a dull appearance. Flesh thick and white, with no special scent or flavour. Stipe 6—7 cm long, 1—2 cm thick, cylindrical with somewhat swollen base, stuffed, white, assumes a brownish tinge when touched, densely mealy at apex, the rest smooth. Gills narrow, crowded, emarginate, white with transverse stripes. Spores ellipsoidal, white or a faint brown, 1-guttulate 9—115—6 u. T. pubifolium deviates from T. gambosum, which it resembles most, by the absence of the mealy odour and flavour and by the much larger spores. 502. T. panaeolum Fries, Epicr., p. 49. Hjardarholt and Laugarnes [P. L.)|. — On grassy spots in heaths and bogs. 528 POUL LARSEN Cap 5—10 cm broad, at first plano-convex, with margin inrolled, predominating colour clay-brown with a reddish brown tinge (h 2), shot with grey stripes, then concave, paler brown (h 3), here and there with round, dark brown spots of moisture, sometimes arranged in a zone inside the margin of the cap. Stipe 4—6 cm long, 1—2 cm thick, spongy inside, firm outside, greyish brown (h 4), here and there covered with greyish white adpressed hairs. Flesh pale with mealy odour and flavour. Gills fairly crowded, emarginate, often with transverse veins and anastomosing. The colour is b8 to b 7, at length with edge of gills brown. Spores shortly ellipsoidal, 5—6X4 u, pale. The spore powder is pale brown. Grows in dense clusters arranged in circles. 503. T. aggregatum Quelet, Flore mycologique de la France et des pays limitrophes. Paris 1888. (?) Laugarnes [C. H. O.], det. E. Rostrup. In the same place I have found T. panaeolum, but not T. aggregatum, I think it is doubtful whether T. aggregatum grows in this locality. 504. T. conglobatum (Vittadini) Saccardo. Bresadola, Fungi Triden- tini, t. 32. Hallormstadir [P. L.]. — In the birch copses. Cap 5—9 cm broad, convex, then irregularly depressed and wavy, tough, cartilaginous, margin incurved and mealy-floccose, occasionally with watergrey spots forming zones, otherwise greyish brown and grey when dry. Stipe white, fibrous-floccose, cylindrical, stuffed, cartilaginous. Gills greyish white, emarginate adnate, tough, edge entire, acute. — Spores spherical, 5 « in diameter, colourless, verrucose-echinulate. Grows in dense clusters. Melanoleuca Conrad et Maublanc. 505. M. cognata (Fries) Conrad et Maublanc, Icon, sel. Fung., Paris 1924, Pl. 271, var. elatior n. v. Agaricus arcuatus* cognatus Fries, Epicr., p. 46. Hallormstadir [P. L.]. — On open grassy spots in birch copses. Cap c.8 cm broad, convex with a low rounded umbo, later crateri- form with or without an umbo, yellow or pale brown along the margin (ranging from k 3 to g 7), darker at the centre, smooth and greasy. Stipe 12cm high, 1—1.5 cm thick, increasing in thickness towards base, the upper part faintly sulcate and mealy, floccose, the lower part covered by white projecting hyphæ, the colour is greyish-brown (f 8); flesh of stem fibrillose finally becoming so soft that the upper part of the stem cannot support the cap, but bends at an acute angle, the cap becoming pendent. Gills c.12 mm broad, crowded, thin, yellow with a red tinge (b 6), deeply emarginate or almost free. Spores colourless, ellipsoidal or acuminate below, minutely verrucose-echinulate, 9X5 u. Cystidia lanceo- late, up to 60X12 u, bearing a lobate hood at apex. The yellow form of Rickens Tricholoma turritum (Fries) seems to be identical with this. FUNGI OF ICELAND 529 Hebeloma Fries. 506. H. crustuliniforme (Bulliard) Fries, Epicr., p. 180. Hallormstadir, Hälsskögur and at Borg [P.L... — Common in the birch copses. Cap 5—7 cm broad, plano-convex, with incurved margin, destitute of veil, pale brown to alutaceous; flesh thick, pale, smelling like radishes. Stipe cylindrical, but often with a somewhat bulbous base, white, floc- culose-squamulose, mealy at the apex. Gills rounded towards the stem, at first pale, then clay-coloured, edge of gills irregularly toothed, in damp weather exuding small drops. Spores elliptic, rough, brown, 10—12X 6—7 u. The cystidia at the edge of the gills hairshaped, or somewhat swollen at apex, sinuate. 507. H. fastibile Fries, Epicr., p. 178. Egilsstadir [P.L.]. — In birch copses. Cap 5—8 cm broad, convex, with rounded obtuse umbo, glutinous, margin inrolled, flocculose, at first almost while, then palely alutaceous at centre. — Stipe cylindrical. bulbous at base, white, covered with a fibrillose layer, at the apex a ringshaped veil. Gills comparatively narrow, thin, emarginate, at first almost white, then pale chocolate, edge of gills white and toothed. — Spores narrowly ellipsoidal, pale brown, with one large drop in the middle, 11—13X5—6 u. Cystidia at the edge of gills hair-shaped sinuate with swollen apex. 508. H. sp. (H. hiemale Bresadola, Icon. Myc. XV, Milano1930, Tab. 715%). Hallormstadir [P. L.]. — In birch copses. Cap 2—4cm broad, plano-convex, slimy, centre brown (h 2), margin at first grey — covered by the veil — then fuscous (h 3). Stipe cylindrical or somewhat dilated at base, 7cm long, 2—4 mm thick, rigid, brittle, hollow, at first white, then brown, longitudinally adpresso-fibrillose, apex mealy, as a rule a distinct ring. — Gills at first pale grey, then brown with dark dots, deeply emarginate, edge of gills minutely frayed. Spores ellipsoidal, smooth, pale, 10—12*5—6 u. Edge of gills closely set with cystidia which are hair-shaped, but often swollen at the base or in the middle, 60X6—7 u. 509. H. mesophaeum Fries, Epier., p. 179. Common on heaths and in birch copses in the areas examined. Cap 4—5 cm broad, at first convex, but soon plane or even de- pressed, slimy, centre dark brown (h 2), margin clay-coloured (e 3), but long covered by a greyish white veil. Stipe cylindrical, often somewhat flexuose, hollow, rusty brown inside, covered on the outside with the remains of the greyish yellow veil and often bearing a lacerated ring. Gills at first fuscous, then clay-coloured (e 3), crowded, emarginate. Spores ellipsoidal, straight or faintly curved, brown, rough, 10*5—6 u. Cystidia at edge of gills hairshaped, but more or less swollen at apex, 55—65 %4—8 u. The Botany of Iceland, Vol, Il. Part HI 35 Qt Co © POUL LARSEN Inocybe Fries. 510. I. descissa Fries, Epicr., p. 174. Hallormstadir [P. L.]. — Among the grass in outfields. Pileus 2—3 cm broad, convex, umbonate, cuticle radiately cracked and split and recurved at margin, the umbo cracked so as to assume a warty appearance, colour light brown (k 4). Stipe cylindrical or slightly dilated at base, pale, mealy at top, the remaining part finely striate-sulcate. Gills almost coloured like the pileus but somewhat lighter, not emarginate, but narrowly adnate. — Spores smooth, brown, oblique, slightly acu- minate at one end, 1- or 2-guttulate, 9—11 X 5—5.5 u. Cystidia both on the surface and at the edge of gills flaskshaped, apex coroniferous, c. 5018 u. Fig. 4. Inocybe descissa. 511. I. geophylla (Sowerby) Fries, Syst. Myc. I, p. Cvstidi 258. Sowerby, t. 124. ystidia and spores X 500. Hallormstadir and Egilsstadir [P. L.]. Cap ce. 2 cm broad, convex and umbonate or coni- cal, surface dry, white, radiately fibrillose. Stipe cylindrical, but as a rule with a small bulb. at base. — Gills at first greyish white, then greyish clay-coloured, strongly rounded towards the stipe and adnate. Spores brown, smooth, ovoid or ellipsoidal, 1- or 2-guttulate, 8.5—9.5*5 u. — Cystidia both on the surface and at the edge of gills sub- cylindrical or somewhat ventricose below with short stalk, apex coronate, 55—60 X12 u. 512. I. hirtella Bresadola, Fungi tridentini I, p. 52. Glerä near Akureyri [P.L.]. — Littoral fields. Cap 1.5—2.5 cm broad, conical, at first pale yellow, then tawny or brown (g 2 to g 6), apex smooth, rest of cap at first minutely squamulose and lacerate, then longitudinally disunited in fibrils. Stipe cylindrical, bulbous, white or faintly yellow, minutely pubescent Fig. 5. flocculose, stuffed. — Gills at first almost white, then Jrocybe geophylla. coloured like the cap, with white frayed edges, nar- Cystidia and rowly adnate. — Spores ovoid or ellipsoidal, finely spores X 500. punctate, brown, 8.8—9.5X5—6 u, 1- or 2-guttulate. Cystidia at edge of gills and on the en short and broadly Mask shaped, apex coronate, 40X15—20 u, in addition short clubshaped cells at the edge of the gills. 513. I. lacera Fries, Syst. Myc. I, p. 257. Egilsstadir, Hallormstadir, Myvatn, Laxärdalur, Reykjadalur, Ljösa- vatnsskaré and Glerä (Akureyri) [P.L... — Among the grass in littoral fields, in sandy river valleys and outfields. FUNGI OF ICELAND at Cap c. 3 cm broad, convex or plano-convex with a very conspicuous umbo, at first crisped-squamulose below the even summit, then splitting deeply down into the flesh, ground colour brown (h 2) or yellowish brown (e 3), but as a rule with a greyish tinge owing to the coating. Stipe cylindrical or somewhat dilated at base, internally brown, fuscous Fig. 6. Inocybe hirtella. Fig. 7. Sterile cells, cystidia and Inocybe lacera. spores X 500. Cystidia and spores X 500. externally, covered with fuscous fibrils and scurf, apex not or only indi- stinctly mealy. — Gills moderately crowded, broad, ventricose, obtusely adnate, colour about k 4. — Spores smooth, brown, irregular in form, mostly shaped like a projectile, 1- or 2-guttulate, 13—16 X 6—7.5 u. — Cystidia at the edge and on the face of the gills flaskshaped with coro- nate apex or fusiform with an even and rounded apex, 48—60*15—22 u. 514. I. abjecta Karsten, Hattsvampar I, p. 456. Hallormstadir. — Among moss on peaty soil with an admixture of sand. Pileus 15—18 mm broad, plano-convex, umbonate, radiately fibrillose, at length splitting at margin, brown (h 3 to g 7), covered with a thin lace- rate-fibrose white layer forming greyish-white hair- like scales at margin. — Stipe cylindrical, 4—5 cm high, 1—2mm thick, somewhat flexuose, firm, stuffed, PP floccose, pale reddish-brown (k 2 to g 6). — Gills Q distant, anteriorly 3 mm broad, tapering towards the © @ stipe, emarginate, margin denticulate, pale reddish- 42) brown (k1 to j1). — Spores brown, smooth, pip- Fig. 8 shaped, 1-guttulate, 8—9.5%5—6 uw. — Cystidia both pe on the face and at the edge of gills flaskshaped Inocybe abjecta with obtuse more or less coronate apex. At edge Sterile cells, Cystidia of gills also shortly clavate cells. and spores, X 500. 515. I. maculata Boudier, Société botanique de France, 1885, p. 282. Lava fields (Rhaun) near the south end of Myvatn, Laxärdalur, Rey- kjadalur, sandy meadows near Ljösavatn, littoral pasture near Akureyri [P. L.]. 35” 532 POUL LARSEN Cap 3—5 cm broad, at first campanulate with incurved margin, then almost plane, yellowish brown (e 3), covered with a thin white layer, subsequently splitting, at centre the cracks penetrate into the white flesh, making this area grey and verrucose. Stipe short (2—3 cm X 4—6 mm), somewhat marginato-bulbose, stuffed, at first white, then coloured like the cap, mealy above, the rest adpresso-fibrous. — Gills emarginate or nearly free, at first pale, then pale olive-brown with paler edge. — Spores brown, smooth, from ovoid to reniform, 1- or 2-guttulate, 9—11.5X5—6.5 u. — Cystidia both 9 ©) % at the edge and surface of the gills, fusiform, apex CS coronate, 44—50X16—24 u. > EE Note. I. maculata Boudier differs from I. brunnea Quélet: 1) The surface of the cap is paler and sub- Fig. 9. squamulose, 2) it has genuine cystidia, 3) broader Inocybe maculata. spores. rstidi d z 2 à : 2 yetidıa and spores 516. I. rimosa (Bulliard) Fries sensu Bataille. a Fries Hym. Eur. p. 232. — Bulliard Champ, t. 388. Akureyri. — Grows amongst grass, moss and Salix herbacea in littoral pastures. Pileus 3—4 cm broad, convex, obtusely gibbous, entirely clothed with silky fibres, at length cracked at the margin which projects beyond the edge of gills and in young pilei is connected with the stipe by a fibril- lose veil. The colour is brown (h 2 to h 3), the flesh white. Stipe c. 3 cm long, 4—5 mm thick, thinner at apex and somewhat dilated at base, stuffed, pale reddish brown, in young pilei with a fugacious ring on a level with the margin of cap. — Gills broadest at the margin of cap, deeply emarginate, at first creamcoloured (e 5), then brown (h 3), edge of gills white and toothed. — Spores brown, smooth, ellipsoidal or ovoid, 11.5—13.5X6.5—7.5 u. — Cystidia both at the edge and on the surface of the gills and on the upper part of the stipe, cylindrical or elongate flaskshaped, apex coronate, 65—75X13—19 u. 517. I. umbonata Quélet, sensu Ricken, Die Blatterpilze, p. 106. Seydisfjöröur [P. L.]. — Among mosses in a bog. Pileus 2—3 cm broad, plano-convex, with conspicuous as a rule acute umbo, radiately sericeo-fibrillose, light brown (h 4), slimy. Stipe 3 cm long, 2—3 mm thick, cylindrical, pierced by a slender canal, coloured like the cap but paler, mealy at apex, otherwise naked, smooth. — Spores brown, smooth, ellipsoidal, 8-10X5 u. — Cystidia both at edge and on face of gills fusiform, apex coronate, 30—35*12—15 u. 518. |. sp. Hallormstadir [P. L.]. — Among mosses and grass in a bog. Pileus 4—5 cm broad, plano-convex, floccosely fibrillose, not crisped- felted and not radiately cracked, tawny but with a fibrous white coating densest in the centre. — Stipe 4cm long, 8—10 mm thick, stuffed or later FUNGI OF ICELAND 533 pierced, with a frayed ring like a Telamonia, above the ring yellow (1 4) and mealy, below ring of the colour k 2, towards the base sulcate and dilated. — Gills broad, emarginate, cinnamon, with yellow frayed edge. — Spores brown, smooth, ellipsoidal, the greater part 8—9X5 u, a few 10—11%X5.5 u and very few 74.5 u. No coronate cystidia, but edge of gills densely beset with vesiculously inflated cells, some of which con- tain a yellow juice. Allied to I. dulcamara, but distinguished by form and colour. 519. I. fastigiata (Schaeffer) Fries, Epicr., p.174. Schaeffer Fung. Icon., t. 26. Egilsstadir [P. L.). Pileus 4—6 cm broad, at first conical, then expanded with a con- spicuous umbo, cuticle radiately fibrillose and rimose except in the centre where it is entire and even, colour of margin 12 to k 2, colour of the umbo k3 to f8. Flesh nearly white. Stipe cylindrical or somewhat attenuated at apex, stuffed, pale, fibrillose-lacerate. Gills rounded towards stipe, narrowly adnate or nearly free, greyish yellow, then olivaceous, edge of gills dentate-fimbriate at length nearly even. — Spores brown, smooth, broadly ellipsoidal or ovate, a few reniform, as a rule 2-guttu- late, 11-12 X 6.5—8 u (a very few up to 15 X 7.8 u.) No coronate cystidia, but numerous thick-walled, clavate or fusiform cells at the edge of the gills. 520. I. calamistrata Fries, Syst. Myc. I, p. 256. Seydisfjördur, Lagarfljötsdalur, Laxärdalur, Akureyri [P.L.. — In littoral fields, sandy meadows, and outfields. Pileus 2—4 cm broad, campanulate, somewhat hygrophanous, densely covered with squarrose scales, when moist the colour of the pileus is f 6, when dry f 8. A similar change takes place in the colour of the flesh, which is a pale greenish blue when moist (a 8), when dry b8. When crushed the flesh colours Q red (n 7). — Stipe cylindrical, 2—4 cm high, 3—4 mm thick, occasionally flexuose, mealy | CN g () above, otherwise densely squamulose and brown, at base strongly blue-green. — Gills broad, deeply emarginate, decurrent Fig. 10. by a tooth, edge of gills fimbriate and Inocybe calamistrata. thick, colour at first pale brown, then Sterile cells and spores, x 500. rusty. — Spores broadly ellipsoidal or ovoid, sligthly curved, smooth, brown, 1- to 3-guttulate, 10—16.5%X6—8 u. No coronate cystidia, but the edge of gills closely beset with clavate, swollen cells. 521. I. dulcamara, f. autumnalis (Albertini et Schweinitz) Fries, Hym. Eur., p. 228. Hallormstadir, M\vatn, Reykjadalur, Ljösavatn and Akureyri [P. L.). — Common in as well as outside birch copses among mosses and grass. 534 POUL LARSEN Pileus 2—4 cm broad, convex, umbonate, tomentose-squamose, with a distinct veil, olivaceous yellow (between h3 and o 5); flesh pale olive yellow. — Stipe cylindrical, at first stuffed, then hollow, felted, mealy above, concolorous, but paler. — Gills ventricose, obtusely adnate, concolorous, at length brown. — Spores ellipsoidal, curved, smooth, pale brown, with or without guttulae, 8—11*5—6 u. No coronate cystidia, but clavate, smooth 0 cells at the edges of gills. 522. I. caesariata Fries, Hym. Eur., p. 234. 0) 0 Hallormstadir, Myvatn [P. L.}. — On knolls in lava Fig. 11 fields, among mosses and in birch copses. Inocybe dulcamara. Pileus 2—3 cm broad, convex, gibbous, slightly Sterile cells and tomentose-fibrillose, flaxen. Margin somewhat incurved, spores X 500. covered with white fibres. Stipe 5—6 cm long, 3—5 mm thick, slightly expanded below, pale flaxen or nearly white, longitudinally fibrous or slightly squarrose, mealy at apex. — Gills slightly emarginate, adnate, with decurrent tooth, at first pale, then concolorous. Edge of gills white and fibrillose. — Spores ellipsoidal, ovoid, 1- or 2-guttulate, smooth, brown, 8—9%5.6 u. No eoronate cystidia, but at the © edge of gills clavate, smooth cells, often with trans- Qe verse septa. © CD 523. I. conica n. sp, © Hallormstadir [P. L.]. — On dry grassy hills. 78 18. ° Pileus regularly conical, 1.5—2 cm long and a... broad, cuticle radiately resolved into fine fibrils so sterilecellsand spores dense that the cap seems smooth, almost as in x 500. I. geophylla, tawny (between h3 and e3) with a silky lustre. — Stipe cylindrical, stuffed, 2—2.5 mm thick, pale reddish-brown above and nearly naked, pale lemon-colour below (1 1). — Gills ascending, very narrowly adnate, pale lemon colour (11), edge white and fimbriate. — Spores ellipsoidal, smooth, brown, 1-guttulate, 9—11.2 X 6—6.5 u. No coronate cystidia, but fusiform smooth cells, 6) swollen at apex, at the edge of the gills. @ 6) Allied to I. geophylla, but no coronate cysti- ? Q) > ©) dia and larger spores. os 524. I. hjulea (Fries) Bresadola, Fungi triden- Ro) mE i 2) RC ME Fig 13. Inocybe conica n. sp. Myvatn, Glerä (Akureyri) [P.L.]. — Among grass in littoral fields and lava fields. Sterile cells and spores, x 500. Pileus 2—3 cm broad, convex, umbonate, cuticle broken up into radiate fibrils, the umbo even and greyish white or fuscous (h 3). — Stipe cylindrical, marginato-bul- bose, stuffed, fibrous, mealy above, in the middle palely incarnate (17), FUNGI OF ICELAND 535 white above and below. — Gills nearly free, at first grey with a reddish tinge (c 7), then brown, edge of gills toothed. — Spores oblong, from rectangular to irregularly angular, without pro- minent prickles or warts, brown, 1- or 2-guttu- ©) late, 8—10X5—6.5 w. — At the edge and on the face of the gills fusiform and coronate cystidia, 50—72 X 16—21 u. 525. I. praetervisa Quélet, Flore myc. Fr., 2 99: Seydisfjördur, Lagarfljötsdalur, Laxärdalur [P. L.]. — In open grassy spots, in littoral pastures = Fig. 14. and in sandy meadows. ie Inocybe hjulca. Pileus 3—6 cm broad, at first conical, then Cystidia and spores, X 500. expanded and umbonate, cuticle radiately rimose and fibrillose, tawny (e 3), when fresh viscid, flesh thin. — Stipe cylin- drical, marginato-bulbose, stuffed, at first white, then flaxen (k 2) in the middle, above floccosely hairy, otherwise naked, longitudinally sulcate-striate. Gills rather crowded, ventricose, emarginate, with denticulate edge, at first grey (g 5 to i 2), then brown. — Spores brown, oblong, angular, verrucose, 8.5—11 *5.5—6.5 u. — At edge and on face of gills fusiform coronate cysti- dia 60—70X15—16 u. 526. I. sp. Egilsstadir [P.L.].. — On knolls in outfields and bogs. Pileus 1.5—2.5 cm broad, at first conico-campa- nulate, then expanded with a conspicuous verru- ciform umbo, radiately adpressedly fibrous, split at the margin, dark reddish brown (g 8), somewhat shining. Stipe cylindrical, slightly bulbous at base, Fig. 15. 3.5—4 cm long, 2—3 mm thick, rigid, firm and Inocybe praetervisa. flexuose, greyish mealy at apex, otherwise nearly Cystidia and spores x 500. naked, only slightly fibrous, reddish brown (h 2). Gills at first grey, then reddish grey-brown, ventri- cose, deeply emarginate, edge almost entire and sharp. — Spores brown, oblong, angular, almost without warts, 8.5—9.5%5.5—6.5 u. — Fusiform coronate cystidia both at the edge and on the face of the gills 50—60 X15—19 u. Allied to I. proximella Karsten, but spores with smaller warts. 527. I. decipiens Bresadola, Fungi tridentini II, p. 13, t. 118. Hallormstadir [P.L.]. — In sandy, grassy spots in birch copses. Pileus 3—4cm broad, convex, conspicuously umbonate, radiately rimose and fibrillose, the umbo even, tawny (k5). — Stipe cylindrical, marginato-bulbose, stuffed, 4—5 cm high, 6—8 mm thick, white growing 536 POUL LARSEN yellowish. Apex mealy, otherwise naked, but slightly sulcate. — Gills obtusely adnate, with denticulate edge, at first greyish white, then fuscous with pale margin. — Spores oblong, tapering towards one end, flexuose- angular, with low verrucose thickenings of the membrane which is tawny, 10—13X6.4—7.5 u. Fusiform, coronate cystidia at edge and on face of gills, 45—60* 14—16 u and also clavate, smooth cells at edge of gills. 528. I. trechispora (Berkeley) Bresadola, Icon. Mycol. XVI, t. 766, 1930. I. scabella Cooke sensu Roger Heim, Le genre Inocybe, Paris 1931, p. 401. Fig. 16. Inocybe decipiens. Cystidia and spores 500. Laxärdalur near Myvatn, Glerä near Akureyri [P. L.]. — On sandy, grassy and mossy flat stretches along the rivers. Pileus 7—10 mm broad and almost as high, conico-campanulate, shortly squarrosely tomentose, reddish brown (j 5), summit occasionally grey; the slightly incurved mar- gin is pale, the almost white 104 © 0; gills being visible below it. — Stipe cylindrical with spherical 9 LF © bulb, 2cm high and 1—1.5 mm thick, white above and slightly F mealy, pale brown in the middle, eS the bulb white; gills ascending, acutely adnate, white edge, at first greyish white, then brown- grey, at length brown. — Spores Fig. 17. irregularly 5- or 6-angular with Inocybe trechispora. low rounded warts, brown, 1-gut- Cystidia and spores, X 500. tulate, 8—9.6X6.5—8 u. — Cysti- dia ‘— both at edge and on face of gills — fusiform with coronate apex, 48—60 X 16,5—19 u. 529. I. grammata Quélet (?), Flore myc. Fr., p. 100. Eyjolfstadir and Hallormstadir [P. L.). — In birch copses: Pileus 4—5 cm broad, flatly conical with rounded summit. cuticle radiately rimose, viscid, fuscous, summit and mar- gin pale grey, shining when dry. — Stipe short and thick, bulbous, in the middle rose-coloured (m 2). Apex farinaceous and sulcate, bulb white. Flesh of cap cream- Fig. 18. coloured, of stipe pale orange (e 6). Gills Inocybe grammata? broad, emarginate, grey, then brown, edge Cystidia and spores x 500. fimbriate. Spores brown, oblong, approach- FUNGI OF ICELAND 537 ing parallelogram form, with few low warts, 9—13X5—6.5 u. — Cystidia — both at edge and on face of gills — broadly fusiform, coronate, 40— 52 X 14—20 u. Differs from I. grammata Quélet in the more fuscous colour of the pileus. Cortinarius Fries. 530. C. (Hydrocybe) tortuosus Fries, Syst. Myc. I, p. 235. Hallormstadir [P. L.). — In birch copses. Cap 2.5—4cm broad, convex, umbonate, hygrophanous, when fresh dark chestnut-colour (c 3), when dry a lighter brown; margin covered with a silky white coating; flesh thin. — Stipe cylindrical, hollow, flexuose and twisted, brittle, lilac violet at apex, covered with a silky white coating, brown inside. — Gills ascending, emarginate adnate, often with a decur- rent tooth, brown with a paler edge, assuming a red tinge when broken. Spores brown, ellipsoidal, punctate, 8—10.5* 5—6 u. 531. C. (Hydrocybe) decipiens (Persoon) Fries, Epicr., p. 312. Agaricus decipiens Persoon, Synops. meth. fung., p. 298. Egilsstadir [P.L.]. — In birch copses. Pileus c. 2 cm broad, at first conico-campanulate, then expanded with a distinct umbo, hygrophanous, with thin flesh or skin-like margin sericeo- fibrous, chestnut brown (e 4), umbo darker (c 3). — Stipe eylindrical, occa- sionally dilated at base, rigid, 6 cm high, 2—3 mm thick, reddish brown internally, externally covered with white silky fibrils, which here and there — especially at the base of stipe — are tinged with rose colour. — Gills thin, crowded, emarginate adnate, with a decurrent tooth, at first pale reddish yellow, then cinnamon. — Spores tawny, ellipsoidal with obtuse ends, sharply and finely punctate, 7.5—9 X 4.5—5 u. 532. C. (Telamonia) incisus (Persoon) Fries, Syst. Mye. I, p. 213. Agaricus incisus Persoon, Synops. meth. fung., p. 310. Hallormstadir, Akureyri [P.L.]. — On knolls in swamps along Hörgä and in birch copses. Pileus 2—4 cm broad, convex, acutely umbonate, hygrophanous, dark brown at centre (f 4), paler along the margin (c 3), cuticle at first even and clothed with crisped grey hair-like scales, then radiately cracked and broken up into fibrils. — Stipe 3—4 cm high, 3—4 mm thick, cylin- drical or dilated at base, coloured like margin of cap, rust-coloured inter- nally, externally covered by a volva ending on a level with margin of cap in a distinct and lacerated ring. — Gills dark cinnamon, emarginate 3—4 mm broad. — Spores einnamon-coloured, broadly ellipsoidal, punctate, 9% 5.6 u. 533. C. (Telamonia) helvelloides Fries, var. islandica n. var. Egilsstadir, Myvatn, Akureyri [P.L.). — In the littoral field along Glerä, in sandy meadows near Laxä and in meadows by Lagarfljöt. 538 POUL LARSEN Pileus 1—2 cm broad, convex, often with undulate-dentate margin, hygrophanous, tawny when moist (k5), when dry more yellow (15), cuticle even, covered with short yellow fibres. Flesh saffron-yellow or rusty red, very thin, taste bitter. Stipe cylindrical or slightly expanded below, pierced by a slender canal above, 2 cm long, 1.5—2.5 mm thick, the lower two-thirds covered with a fibrous torn, tawny sheath, ending in a raised very conspieuous ring, above which the stipe is shining, smooth and purple violet (02 to o 3). — Gills rather broad, plane, emarginate-adnate, rather thick and distant, at first pale purple (n 8), then cinnamon. Basidia obtusely clavate, 6—7 u broad, 4-spored. — Spores cinnamon- coloured, ellipsoidal, punctate, 1-guttulate, 8—9X5—5.2 u, some few spores up to 10X5.2 u. Caps breaking out in clusters or gregarious. Distinguished by the clothing of the pileus, colour of the stem and the small size of the pileus. 534. C. (Telamonia) hemitrichus (Persoon) Fries, Epicr., p. 302. Agaricus hemitrichus Persoon, Synopsis meth. fungorum, p. 296. Hallormstadir [P.L.]. — In birch copses, not common. Pileus 3—5 cm broad, convex, gibbous, hygrophanous, dark brown (between g 8 and f 6), covered with white hair-like scales especially along the margin, veil strongly developed and pendent from the margin. Stipe 3—7 cm long, 4—5 mm thick, cylindrical, hollow. internally brown, exter- nally densely covered with the white floccose velum, often terminating in a ring above. — Gills rounded adnate, crowded, toothed, at first greyish white, then cinnamon. — Spores cinnamon-brown, slightly punctate, ellip- soidal, 8X4—4.5 u. 535. C. (Telamonia) flexipes (Persoon) Fries, Epicr., p. 300. Egilsstadir [P.L.]. — In birch copses. Pileus 1.5—3 cm broad, at first conical, then expanded with verruci- form centre, hygrophanous, at first dark violet, then reddish grey (k 4), the centre long remaining dark, cuticle covered with a white fibrillose layer, dense and fimbrillate along the margin. — Stipe cylindrical, flexuose, stuffed, 4—7 cm high, 3—4 mm thick, at first all violet, then only violet at apex, constantly covered with an often zone-like, fibrillose white layer. — Gills rather distant, emarginate-adnate, at first violet, then reddish grey and finally cinnamon. — Spores nearly smooth, brown, ellip- soidal, 8—9.6 X 4.5—5 u. 536. C. (Telamonia) rigidus (Scopoli) Fries, Epicr., p. 302. Agaricus rigidus Scopoli, Flora Carniolica, p. 456. Hallormstadir [P. L.]. — In birch copses. Pileus 2—3 cm broad, convex, umbonate, brown (h 3), when dry paler brown, margin straightened, at first covered with white fibrils, then naked and glabrous or with the cuticle lacerate-rimose. — Stipe cylin- drical, 5—7 cm high, 2—4 mm thick, filled with a fibrillose tawny mass, rigid, somewhat flexuose, externally concolorous, but partly covered FUNGI OF ICELAND 539 by a white fibrillose velum, as a rule forming a ring. — Gills 2—3 mm broad, adnate in their entire breadth or somewhat emarginate, tawny (1 3), then cinnamon-brown. — Spores brown, punctate, varying in size, but on the whole rather small, 6—8.5<3—4.5 u. 537. C. (Telamonia) gentilis Fries, Epicr., p. 297. Eyolfsstadir [P.L.]. — In birch copses. Pileus 2.5—4 cm broad, conico-campanulate, acutely umbonate, hygro- phanous, tawny (k 3), shining, along margin covered with the remains of the pure yellow or citron-yellow veil, for the rest naked and glabrous, when dry the whole cap is pale yellow. — Stipe cylindrical, hollow, 5—8 cm long, 3—4 mm thick, internally and externally coloured like the cap and covered with a yellow velum forming a ring. — Gills thick, distant, obtusely adnate, at first yellow (1 5), then cinnamon. — Spores broadly ellipsoidal, punctate, brown, 8—8.5*5.5—6 u. 538. C. (Telamonia) biformis Fries, Epicr., p. 299. Egilsstadir [P. L.]. — In birch copses. Pileus 5—7 cm broad, at first convex, then expanded, obtusely umbo- nate, but slightly hygrophanous, brown, covered only along margin with white fibres. Flesh thin except at centre, brownish. — Stipe cylindrical, pale, white velum covering the surface to the oblique ring terminating in a brownish edge. — Gills broad, rather crowded, emarginate, edge of gills undulate-dentate, at first grey then cinnamon. — Spores ellipsoidal, brown, slightly punctate, 8—9 X 4—5 u. Grows in dense clusters round the base of birches. 539. C. (Telamonia) helvolus (Bulliard) Fries, Epicr., p. 296. Reykjahliö (Myvatn) [P.L.]. — In birch copses on lava fields. Pileus 3—6 cm broad, soon flatly expanded and somewhat depressed about the low rounded umbo, hygrophanous, brown, at length radiately broken up into fibres like an Inocybe. — Stipe cylindrical with some- what dilated base, covered by an at first white, then brown velum forming a ring, medullated, at length hollow, internally, and finally externally, brown. — Gills fairly distant, thick, emarginate, cinnamon, — Spores brown, somewhat almond-shaped, sharply punctate, 8—10 X 5—6 u. 540. C. (Telamonia) bulbosus (Sowerby) Fries, Epicr., p. 292. Agaricus bullosus Sowerby, t. 130. Hallormstadir [P.L.). — In birch copses. Pileus 5—7 cm broad, campanulate, with projecting, broad and rounded umbo, margin incurved and fibrous fimbrillate, only slightly hygro- phanous, brown (k6 to k 7), flesh thick, especially at centre. — Stipe 5—7 cm long, bulbous, covered by a white, fibrous velum. Flesh of stipe pale brown or white, but of the bulb saflron-yellow. — Gills broad, adnate, dark brown, then cinnamon. — Spores ellipsoidal, brown, punctate, 8—9 X5—5.5 u. 540 POUL LARSEN 541. C. (Telamonia?) sp. Skütustadir (Myvatn) [P. L.]. — On knolls in lava fields. Pileus 2cm broad and high, conico-campanulate, somewhat hygro- phanous, dark reddish brown (j 3), cuticle at length minutely cracked crosswise and lengthwise, and finely tessellated, margin straightened, covered with white fibres, at length with short cracks, rendering it dentate. — Stipe dilated below, pale brown, and covered with a white, fibrous velum, which does not form a ring. — Gills very broad, emarginate adnate, brown. — Spores brown, echinulate-verrucose, broadly ellipsoidal, 8—9 X 6 y. i Allied to C. stemmatus Fries, but differing especially in the dilated base of the stem. 542. C. (Dermocybe) einnamomeus (Linné) Fries, Epicr., p. 288. Lagarfljöt near Vallanes [P.L.]. — In sandy moor-like meadows. Pileus 3—5 cm broad, plano-convex, dry, tawny (k 5), covered with fine adpressed fibres. — Stipe cylindrical, lemon-yellow (b 7); veil coloured like the stipe. — Gills broad, emarginate, lemon-yellow (b 7), then cinna- mon-brown. — Spores brown, ellipsoidal, slightly verrucose, 8—-9 X4.5—5 u. 543. C. (Dermocybe) anomalus Fries, Epicr., p. 286. Egilsstadir [P. L.]. — In birch copses. Pileus 4—5 cm broad, plano-convex with incurved margin, brown in centre (g 7), pale violet at margin (0 7) and covered with fibrous remains of the veil. — Stipe cylindric-clavate, the base being dilated, covered by a yellowish white fibrous layer, pale violet above (o 7). — Gills at first pale violet (0 7) then cinnamon, emarginate, margin white and dentate. — Spores brown, punctate, subspherical, 8—8.5 X 7 u. 544. C. (Inoloma) Bulliardii (Persoon) — sensu R. Maire. Agricus Bulliardii Persoon, Synops. meth. fung., p. 289. Egilsstadir [P. L.]. — In birch copses. Pileus 5—7 cm broad, campanulate, with a prominent, broad, and rounded umbo, fibrous, dark brownish red (j 3), shining. — Stipe cylin- drical with clavate swollen base, whitish but covered with red (m 1) threads, here and there confluent in red areas, but not forming red bands as in Cortinarius armillatus, flesh of cap and stipe pale orange (k 1). — Gills rather crowded, emarginate adnate, purple brown to yellow rust-brown with whitish dentate edge. — Spores ellipsoidal, brown, punctate, 8—9*5 u. 545. C. (Phlegmacium) porphyropus (Alb. et Schw.) Fries, Epicr., P..271. Eyjolfsstadir [P. L.]. — In birch copses. Pileus 4—7cm broad, plano-convex, sometimes with a low umbo, mar- gin thin, viscid, slimy, covered with innate grey fibres, clay-coloured (g 7). — Stipe cylindrical with somewhat swollen base, at first violet, then FUNGI OF ICELAND 541 yellowish white, filled with a loose pith, then hollow. — Gills fairly crowded, emarginate, at first purple-violet, then cinnamon-coloured. — Both cap, stipe, and gills assume a purple-violet (n 3) tint when bruised. — Spores brown, roughly punctate, ellipsoidal, 10—12 X 6 u. 546. C. (Phlegmacium) latus (Persoon) Quelet. Agaricus latus Persoon, Synops. meth. fung., p. 176. Eyjolfsstadir [P.L.]. — In birch copses. Cap 5—8 cm broad, campanulate, fleshy, firm, viscid, pale ochrace- ous or alutaceous, in the young, fresh state almost white. — Stipe short, c.5cm high, thick, especially below (c. 3 cm), stuffed, firm, white, veil well developed, white. — Gills crowded, adnate, white or greyish-white with a white margin. — Spores obliquely ellipsoidal, one end acuminate, brown, punctate, 13 X 6—6.5 u. 547. C. (Myxacium) collinitus (Persoon) Fries, Epicr., p. 274. Agaricus collinitus Persoon, Synops. meth. fung., p. 281. Hallormstadir and Egilsstadir [P. L.]. Pileus 6—8 cm broad, campanulate, very slimy, shining when dry, yellow-orange (b 5), in the centre brown-orange (k 5). — Stipe cylindri- cal, stuffed, covered by a slimy violet velum, subsequently splitting up into ring-shaped areas, between which the cuticle is brown and floccose- squamulose, height 10—12 cm, thickness 12—16 mm. — Gills broad, emar- ginate, with a decurrent tooth, at first a brownish orange (k 5), then cinnamon-brown with a white margin. — Spores brown, verrucose, obliquely ellipsoidal, 13 X 6—7 u. Amanitopsis Roze. 548. A. vaginata (Bulliard) Roze, var. fulva (Schaeffer). Agaricus fulvus Schaeffer, Fung. Ic., t. 95. Eyjolfsstadir (c. 4 km east of Vallanes near Lagarfljöt) [P. L.]. — In birch copses. Pileus 6—8 cm broad, campanulate, cuticle viscid and naked, orange- yellow (b5 to g 3), margin sulcate. — Stipe elongate-conical, 8-10 cm high, 1—1.5 cm thick, somewhat bulbous, hollow, white, floccose-squamu- lose, no ring, the lower third of the stipe covered by a loose sheath. — Gills white with a yellow tinge, free, edge covered by a mealy-floc- cose layer, consisting as well as the scales on the stipe of spherical cells. 20—40 u in diameter, as a rule prolonged into a short stalk-like apex. The collected specimens were sterile. Note. This species is also given in E. Rostrups »Islands Svampe«, collected by Helgi Jönsson at Stykkishölmur, but as there is no descrip- tion, it is not possible to see whether it is the same form of this poly- morphous species as the present. 542 POUL LARSEN Pholiota Fries. 549. Ph. togularis (Bulliard) Fries, sensu Ricken. Agaricus togularis Bulliard, Hist. champ. t. 595, f. 2. Hallormstadir [P. L.]). — Among grass in open parts of birch copses. Pileus campanulate, 2cm broad, 1.5 mm long, hygrophanous, flesh thin, pellucidly striate, ochraceous (k 3), brown in the centre (k 6), lighter when dry and slightly rugose. — Stipe cylindrical, 7 cm long, 1-2 mm thick, slightly bulbous, hollow, pale and mealy above, rusty and fibrous below. — Gills ascending, crowded, tawny, margin white and dentate. — The veil forms a membranaceous white ring, radiately striate-plicate on the upper side, movable, central. — Spores elongate-ovoid, brown. smooth, germ pore distinct, 12—13 X 6 u. — Edge of gills beset with flask- shaped cystidia, acuminate above. 550. Ph. praecox (Persoon) Fries, Hym. Eur., p. 217. Agaricus praecox Persoon, Synops. meth. fung., p. 420. Hälsskögur in Fnjöskadalur [P.L.). — In birch copses. Pileus convex, obtuse, 4—5 cm broad, at first white, then yellowish- white or cream-coloured, even, at length minutely fringed along the margin. — Stipe cylindrical, 5cm long, 5 mm thick, white with a raised skin-like ring. — Gills at first almost white, then rusty brown, emargi- nate-adnate, with a decurrent tooth. Flesh soft, white, smelling and tasting like flour. — Spores ovoid, brown, smooth, 8—9.5X5—6 u. — Edge of gills beset with scattered, shortly and broadly flask-shaped cystidia, 40—45 X 18—20 u. 551. Ph. mutabilis (Schaeffer) Fries, Syst. Myc. I, p. 245. Agaricus mutabilis Schaeffer, t. 9. Hallormstadir. Rare [P. L.]. — Grows in clusters on stumps in birch copses. Pileus 5—6 cm broad, plano-convex, obtusely gibbous, hygrophanous, brown (h 3), paler when dry, especially at the margin, (b 7). — Stipe cylindrical somewhat flexuose, at length hollow, bearing a skin-like, per- sistent ring, below which it is rusty brown and squamulose, above the ring naked, pale brown and sulcate. — Gills crowded, thin, tough, adnato- decurrent. Flesh thin, pale brown, taste mild, odour none. — Spores ovoid, brown, smooth, 6—7 X 4—4.5 u. — At edge of gills hair-shaped, 4 u broad cystidia. 552. Ph. marginata (Batsch) Fries(?), Hym. Eur., p. 225. Meadows near Vallanes (Lagarflj6t), a bog at Ljösavatn, the shore at Akureyri and Laugarnes near Reykjavik [P. L]. — On peaty, damp soil in bogs and river valleys, but not in birch copses. Pileus 2—5 cm broad, at first campanulate, with a thin incurved margin, then plano-convex, sometimes with a small umbo, hygrophanous, FUNGI OF ICELAND 543 margin pellucidly striate, shining, orange-brown when moist (between f 8 and b 5), paler when dry (b 6). — Stipe cylindrical, hollow, pale brown, covered with adpressed greyish-white fibres below, bearing above a skin-like pale rusty yellow ring adpressed to the stipe. — Gills narrow, crowded, broadly adnate or somewhat emarginate, yellowish brown, edge dentate. — Spores brown, slightly punctate, broadly ellipsoidal, the greater part 10—10.5 X 6—6.5 u, a few up to 12X 6.5 uw. — Cystidia at edge of gills cylindrical to flask-shaped. In reality the fungus only differs from Ph. marginata in the dimen- sions of the spores. Flammula Fries. 553. F. alnicola Fries, Syst. Myc. I, p. 250. Hallormstadir [P. L.]. — Grows in clusters at the foot of birch trunks. Pileus c. 4 cm broad, convex with an involute margin, moist, viscid, yellow (14), at first covered by a thin, white, mealy layer, then naked, margin joined to the stipe by a rather thick, white veil, which subse- quently splits and hangs down from the margin. Flesh pale yellow. — Stipe cylindrical, concolorous above, covered below with rusty brown fibres or scales. — Gills concolorous, emarginate-adnate, tough, edge white and dentate-floccose. — Spores ellipsoidal, smooth, brown 8—9 X 4.5 u. — Edge of gills beset with sterile hyphae swollen at the apex. Naucoria Fries. 554. N. myosotis Fries, Hym. Eur., p. 261. On the edges of turf-pits at Seydisfjöröur and on the edges of ditches in a bog at Laugarnes near Reykjavik [P. L.]. Pileus 3—6 cm broad, at first conico-campanulate, then expanded, more or less conspicuously umbonate, margin in young specimens joined to the stipe by a well-developed, yellowish-white veil; disc olive-brown (f 6), margin paler. — Stipe cylindrical, 7—12 cm long, 4—8 mm thick, frequently attenuated into a rootshaped base, fistulose, tough, yellowish- white above (b 8) with a ring in young specimens, more brownish below, everywhere fibrous and viscid. — Gills broadly adnate, at first yellowish- white (b 8), then dark-brown, margin serrate. — Spores brown, smooth, ellipsoidal or somewhat oblique, 15—17 X 7.5-—8.5 u. — Edge of gills closely beset with cylindrical cells swollen at the base, length: c. 50 1, breadth above: 6—7 u. below: c. 10 u. 555. N. sobria Fries (?), Hym. Eur., p. 263. On naked ground in deep cracks at Glerä (Akureyri) and on the sides of turf-pits at Seydisfjordur [P. L.). Pileus 1—2.5 cm broad, campanulate with incurved margin, then almost plane with slightly raised centre, not hygrophanous, pale brown or alutaceous (k 2), reddish-brown in the centre (h 2), silky, fibrous, or sprinkled with bran on the surface. — Stipe cylindrical, base somewhat 544 POUL LARSEN dilated, hollow, curved, 3—4 cm long, 2—2.5 mm thick, pale above and covered with the floccose remains of the veil, brown below. — Gills crowded, broadly adnate, edge of gills crenulate and fimbrillate, clay-coloured (k 2). — Spores brown, smooth, ellipsoidal, with an oblique apiculus below, 9—10X 5 u. — Edge of gills beset with sterile cylindrical cells, 6—8 u broad. 556. N. sp. Laxärdalur near Myvatn [P.L.]. — Among moss in sandy meadows. Pileus 10—16 mm broad, at first convex, margin incurved with a white fibrous veil, hygrophanous, pellucidly striate at margin, then plane or somewhat depressed, sometimes umbonate, chestnut-coloured when moist (between h1 and h 2), tawny when dry (e 3), the margin of the cap sometimes crenulate and showing remains of the white veil. — The stipe terete, hollow, concolorous, cylindrical or slightly dilated at base and clothed with white hyphæ, densely pubescent above with projecting short hyphæ. — Gills slightly ventricose, rounded adnate, edge denticu- late, darker brown than the face which has the colour g 2. — Spores ovoid, pale yellowish brown, punctate, 8—11%*5.5—6.4 u. — Edge of gills and upper part of stipe beset with 50 u long, conical cystidia, 3—4 u broad above, and c. 10 u broad below, at length with tawny contents. Galera Fries. 557. G. tenera (Schaeffer) Fries. Agaricus tener Schaeffer, Fung. Ic., t. 70, f. 6—8. Seydisfj6rdur, Akureyri [P. L.]. Pileus 1—3 cm broad, conico-campanulate, hygrophanous, margin pellucidly striate, tawny in the fresh and moist state (k 6), paler when dry. Flesh concolorous, thin skin-like, brittle. — Stipe cylindrical, base bulbous, minutely striate-sulcate, hollow, rigid, brittle, pale above, rusty below. — Gills tawny (g 3), ascending, narrow, crowded, adnate. — Spores brown, smooth, ellipsoidal, germ pore distinct, 12— X 6—6.5 u. — Cystidia at edge of gills flask-shaped with a spherical head, 5 u in diameter, with a 2 u long pedicel. 558. G. sp. Hallormstadir, Akureyri [P.L.]. — Littoral fields and farm- yards. Grows directly on cow-dung. Pileus 1—1.5 cm broad, hemispherical, with thin flesh, hygrophanous, margin pellucidly striate, viscid and brown when moist (e 3), somewhat shining and almost white when dry (e 5). — Stipe short (2—2.5 cm long, 1—2 mm thick), slightly swollen at base and as a rule curved, striate above, everywhere mealy and floccose. — Gills at first pale, almost white, then tawny with a red tinge (16), broad at the margin of cap, rounded towards the stipe, narrowly adnate, edge white and fimbrillate. — Spores ellipsoidal, smooth, with a distinct germ pore, yellow, 12—13 » 6—6.5 u. FUNGI OF ICELAND 545 — Cystidia at the edge of gills flask-shaped, with a short, thin stalk below, neck 10 X 4—5 u, head 5—6 x in diameter. Note. Cannot be referred to any species described in the literature, but as the treatment of the Galera species by the different anthors is very uncertain and dissimilar, it is difficult to give any grounds for the establishment of a new species in this genus. 559. G. siliginea Fries, Obs. Myc. II, p. 168. Isafjordur [Gandrup], Akureyri [P. L.]. —. On peaty soil. Pileus 1—2 cm broad, at first vaulted, then expanded with a some- what irregularly undulate and sometimes reflexed margin about a low obtuse umbo; the whole pileus grey. — Gills adnate, moderately crowded, ochre-brown. — Stipe cylindrical, somewhat undulate, pale, slightly dilated at base. — Spores tawny, ellipsoidal, with a germ pore, 10—12*5—5.5 u. — Cystidia flask-shaped with a long neck and spherical head. 560. G. hypnorum (Schrank) Fries, Syst. Myc. I, p. 267. Lambadalur near Dyrafjöröur [C. H. O.], det. E. Rostrup. 561. G. mycenopsis Fries, Obs. Myc. II, p. 38, no. 28. This species is very common and occurs among moss and grass in bogs, swamps, and wet tuffs [P. L.]. Pileus 1—2 cm broad, hemispherical, then expanded but always with a raised centre, skin-like, with thin flesh, hygrophanous, pellucidly striate, when moist, the colour is e 3, in the dry state b 7, the margin in young specimens has a pendent white fibrillose veil. — Stipe subconical, 1—2 mm thick above, 2—3 mm below, 4—6 cm long, covered with a silky white coating, below which it is coloured like the cap. — Gills distant, adnate. Edge of gills rather thick and somewhat fimbrillate. Colour of gills b 6. — Spores ellipsoidal, smooth, yellow, germ pore absent, length very variable, viz. 10—15X6—7 u. Cystidia at edge of gills rather variable in shape, but mostly elongate-flaskshaped with a swollen apex, 45—50 u long, the greatest breadth near the base being c. 10 u, the head up to 8 u in diameter. Crepidotus Fries. [KD NG À A 562. C. citrinus n. sp. ES Se On the island of Slutnes in a Myvatn [P.L.). — Grows on dead branches of Salix phylicifolia lying on damp ground. pg 1 & a Pileus 5—8 mm broad, resu- b pinate, excentrically attached by the upper side of the pileus, citron- Fig. 19. yellow (13), with dense but short Crepidotus citrinus n. sp. hairs on the raised and somewhat a, Group of fungi, nat. size. incurved margin. — Gills crowded, b. Spores X 750. The Botany of Iceland. Vol. II, part IIL. 36 546 POUL LARSEN at first coloured like the cap, then more tawny, edge dentate. — Basidia clavate, 4-spored. — Spores tawny, spherical or broadly ellipsoidal, echinulate, the smallest 5X5 u, the mediumsized 6.5X5—6 u and the largest 7.5X5.5—6 u. — No cystidia. Allied to C. nidulans (Pers.) Quélet, yet easy to distinguish both macro- and microscopically. Psalliota Fries. 563. P. campestris (Linné) sensu J. E. Lange, Dansk Botanisk Arkiv, vol. 4, No.12, p. 9. Vallanes in Lagerfljöt [P. L.). — In manured homefields. Cap at first hemispherical with incurved margin, then expanded, convex with straight margin, flesh thick, reddening faintly when broken, surface silky and white. — Stipe subcylindrical, stuffed, surface like that of the cap, bearing an evanescent ring splitting up into hairs. — Gills free, at first pale, then red, at length dark brown. — Spores somewhat irregularly ovoid, smooth, purple brown, 6.5—8%*4.5—5 u. Note. Several other localities have been recorded by collectors, though it has not been possible to ascertain what they meant by P. campestris, viz. Grimsey [O. D.], heaths by Grjötnes and Akureyri [C. H. O.], Mööruvellir [St. St., Vallanes [Helgi Jönsson). 564. P. Elvensis Berkeley et Broome var. alba n. var. By Laxä south-west of Myvatn [P.L.]. — On mounds of earth round sheepfolds. Pileus 7—14 cm broad, campanulate with incurved margin, white or dingy white, cuticle thick, splitting up into patches ending with de- flexed and upward curving points, flesh thick, white, reddening faintly when bruised, with a yellow tinge below the cuticle. — Stipe subcylin- drical but with the base attenuated, fistulose, filled below with a felty pith; flesh of stipe like that of cap, but citron-yellow in the lower part. Ring raised, skin-like, single. — Gills at first pale, then incarnate (m 3), finally dark reddish brown (c 3), up to 12 mm broad, crowded, rounded towards the stipe, free. — Basidia 4-spored. — Spores spherical or broadly ellipsoidal, the spherical spores are 6 « in diameter, the ellipsoidal ones 7—7.5X6 u. Differing especially in the colour of the pileus. 565. P. arvensis (Schaeffer) sensu Ricken. Agaricus arvensis Schaeffer, Fung. Ic., t.310 and 311. Reykjahliö near Myvatn [P.L.]. — Under scattered birches on lava fields. Pileus 7—10 cm broad, convex, then plano-convex, silkyhaired or squamulose, white to whitish yellow; flesh white, assumes a yellow tinge when bruised. — Stipe cylindrical, bulbous, hollow, white, at length becoming sooty, bearing a double ring, the lower layer radiately rimose. — Gills at first almost white, becoming greyish red and finally almost black, broadest in front, free. Basidia 4-spored. — Spores ellipsoidal, smooth, purple brown, 7—7.5% 4—4.5 u. FUNGI OF ICELAND 547 Stropharia Fries. 566. $. semiglobata (Batsch) Fries, Hym. Eur., p. 287. Agaricus semiglobatus Batsch, Elenchus fungorum, cont. I, 1786, p. 141. Möörudalur, Isafjérdur, Pingvellir [P. L.]. — On cow-dung and horse- dung. Pileus 2—3 cm broad, hemispherical, pale yellow (1 4), slimy. — Stipe cylindrical, 3—7 cm tall, 2 mm thick, concolorous — paler at apex — slimy, witha membranaceous slimy ring. — Gills broad, distant, broadly adnate, grey. then almost black. margin plane. — Spores ovoid, germ pore distinct, at first violet, then brown, 15—17X8—9 u. — Cystidia at edge of gills cylindrically hairshaped with swollen apex. 567. S. coronilla (Bulliard) Fries, Syst. Myc. I, p. 282. Agaricus coronillus Bulliard, Hist. champ., t. 597. Iceland’s Horticultural Experimental Station at Akureyri [P.L.]. — Among grass under birches. Pileus 3—4 cm broad, convex, viscid, yellow (13—14), flesh thick, firm and white. — Stipe cylindrical or somewhat dilated above, white, sulcate above, bearing a white ring, sulcate on the upper face. — Gills broad, somewhat ventricose, rounded towards the stipe, narrowly adnate with a decurrent tooth, at first greyish white, then purple-violet (a 5), edge dentate. — Spores ovoid with a germ pore, brown under the microscope, 9.5—10X 5.5 u. — Cystidia at edge of gills cylindrical with a head-like swelling at the apex. Annellaria Karsten. 568. A. separata (Linné) Karsten, Hattsvampar I, p. 517. Agaricus separatus Linné, Flora Suecica, No. 1220. Môdruvellir (St. St], D¥rafjordur and Pingeyri [C. H. O.], Stadarhraun [Feddersen], Laugarnes [P.L.). — On dung, especially cow-dung. Pileus 3—4 cm broad and high, campanulate, the viscid surface pale greyish yellow when fresh (k 4) in the dry state k1. — Stipe erect, elongate-conical, rigid, pale, with a white raised ring above the middle, sulcate above the ring, below the ring slimy. — Gills ascending, adnate, dark brown with lighter spots, then black with a white margin. — Spore-powder black. Spores blackish brown, lemon-shaped. 15—20 X 9—11 u. Note. On the remains of a manure heap at Laugarnes from 100 to 200 fungi occurred within an area of 6m?. They were unusually large, the cap up to 12cm broad and stipe 20cm long and 1.5cm broad below. Panaeolus Fries. 569. P. papilionaceus (Bulliard) Fries, Epier., p. 236. Agaricus papilionaceus Bulliard, L c., t. 561, f. 2. 36* 548 POUL LARSEN M\vatn, Glerä near Akureyri [P.L.]. — On horse-dung in meadows near Glerä and Myvatn. Pileus c. 3 cm broad, at first hemispherical, then expanded, fleshy, not hygrophanous, greyish-red (d 8), pitted, at length with cracked cuticle. — Stipe concolorous, darker below, farinaceous above. — Gills broad, adnate, black with white spots, margin white-fringed. — Spores black, almond-shaped, 16—17 X 11 u. — Cystidia at the edge of gills at apex clavate, swollen, up to 7.5 u broad. The cystidia differ decidedly from those of P. campanulatus. 570. P. campanulatus (Linné) Fries, Hym. Eur., p. 311. Agaricus panulatus Linné, Flora Suecica 2, No. 1213. Reykjavik (Feddersen and C.H.O.), det. E. Rostrup. 571. P. fimicola Fries, Syst. Myc. I, p. 301. Reykjahlid, Skütustadir, Laxädalur, Reykjadalur, Ljösavatn and Ellida- vatn [P. L.]. — In homefields. Pileus 1—4 cm broad, at first campanulate, then expanded, hygro- phanous, veil none, dark olive-brown (c 3) when moist, light reddish- brown when dry (between g2 and d7), but long retaining a dark marginal zone. — Stipe 4—7 cm long, 2—3 mm thick, fragile, hollow, brown below, pale and farinaceous above. — Gills crowded, ventricose, adnate, variegated, with white margin, at length black. — Spores ellip- soidal or somewhat almond-shaped, dark brown, smooth, 12—13X7—7.5 u. — Cystidia at edge of gills cylindrical, somewhat dilated at base. Psilocybe Fries. 572. P. ericaea (Persoon) Fries. Agaricus ericaeus Persoon, Synops. meth. fung., p. 413. Found at Reykholt by Robert and recorded in E. Rostrup’s Isl. Svampe 1903, p. 296. 573. P. atrorufa (Schaeffer) Fries, Syst. Myc. I, p. 293. Agaricus atrorufus Schaeffer, Fung. Ic., t. 234. Pingvellir and Myvatn [P.L.]. — Among grass in damp homefields. Pileus 1—1.5 cm broad, convex, hygrophanous, not slimy, margin striate; dark reddish-brown (j 5), when moist, pallid when dry (g 4). — Stipe 3—4 cm long, 1—2 mm thick, pale and mealy above, dark brown below, adpresso-fibrillose, cartilaginous, hollow. — Gills brown, broadly adnate and slightly decurrent, crowded. — Spores ellipsoidal, brown, 8X45 u. — Cystidia at the edge of gills spindle-shaped, acute. 574. P. physaloides (Bulliard) Fries, Hym. Eur., p. 300. Agaricus physaloides Bulliard, Hist. champ., t. 366, f. 1. Seydisfjordur [P. L.]. — Outfields and bogs. FUNGI OF ICELAND 549 Pileus 1—2 cm broad, campanulate, umbonate, depressed about the umbo, with thin flesh, reddish-brown (h 2); margin pellucidly striate, — Stipe short (3 cm long, 1—2 mm thick), hollow, flexuose, concolorous below, paler and mealy above, with a thin coating of adpressed hairs. — Gills at first pale, then concolorous, broadly adnate. — Spores ellip- soidal, smooth, brown, 8—10X5—5.5 u. — Cystidia at the edge of gills cylindric. 575. P. bullacea (Bulliard) Fries, Syst. Myc. I, p. 297. Agaricus bullaceus Bulliard, Hist. champ, t. 566, f. 3. Hallormstadir [P. L.). — Among moss in bogs. Pileus up to 2cm broad, hemispherical, hygrophanous, striate, dark with brownish or reddish tinge (c 2)‘, when dry k2 to k 3, with well- developed veil at margin. — Stipe cylindrical, 3cm high, 2 mm thick, hollow, brown, covered with white scurf sometimes forming a distinct ring. — Gills broad, broadly adnate, purple-brown, edge white, dentate. — Spores ovoid with truncate apex, purple-brown, 7X4.5—5 u. — Cystidia at the edge of gills flexuose, hairshaped with swollen base. 576. P. merdaria (Fries) Ricken. Stropharia merdaria Fries, Hym. Eur., p. 286. Isafjöröur and Tjörnin (Reykjavik) [P. L.]. — In homefields. Pileus 1.5—2 cm broad, at first hemispherical, then plano-convex, olive-brown (h 4 to h 8), epidermal layer viscid, margin striate, distinct marginal veil in young specimens. — Stipe 2—4 cm high, 2—3 mm thick, more or less swollen at base, hollow, concolorous, but with a frayed, greyish-white coating, mealy above. — Gills broad, broadly adnate, at first grey then purple brown with a white fringed edge. — Spores smooth, ellipsoidal with a germ pore, purple violet at length brown, 12—14 X8—9 u. — Cystidia at edge of gills conical or flexuose spindle shaped, strongly acuminate. 577. P. elongata (Persoon) Fries. Agaricus elongatus Persoon, Icones et descriptiones fungorum, t. 1, f. 4. Vallanes in Lagarfljöt, Grund near Akureyri [P. L.]. — Among Sphag- num in bogs. Pileus 1—2 cm broad, plano-convex, — umbonate, pale yellowish- white becoming olive yellow (05), centre as a rule pale reddish-brown (h 3), somewhat hygrophanous and with pellucidly striate margin. — Flesh pale, taste bitter. — Stipe cylindrical, flexuose, tough, 6—8 cm high, 1—2 mm thick, pale yellow above, the remains of the veil forming an imperfect ring, reddish brown externally and internally below, shining when dry. — Gills at first nearly white, then purple-grey. broadly adnate or slightly emarginate, edge of gills denticulate under the lens. — Spores ovoid, pale purple, 9—12%5.5—6.5 u (some few spores up to 14%7.5 u). — Cystidia at the edge of gills (really the ends of hyphae from the trama) spindleshaped with slightly swollen apex, 35% 6—8 u, colourless 550 POUL LARSEN The face of the gills bears true cystidia, these are fusiform, 50—10 u, with yellow granular contents. Psathyra Fries. 578. P. spadiceo-grisea (Schaeffer) Fries, Hym. Eur., p. 306. Lagarfljöt, Reykjahlid and Norötünga [P. L.]. — In copses of Betula pubescens and Betula nana. Pileus 3—4 cm broad, convex, + gibbous, with striate-sulcate margin, flesh thin and brittle, hygrophanous, reddish-hrown when moist (j 3), fuscous when dry (k 4). — Stipe shiny white, rigid, flexuose, fragile, hollow, distantly and slightly floccose above. — Gills narrow, crowded, broadly adnate, pale greyish-brown, then black with white frayed edge. — Spores dark-brown, 8—9X5 u, sometimes faintly curved. — Cystidia short, cylindrical, swollen in the middle, 30—40X10 u. 579. P. gossypina (Bulliard) Fries, Syst. Mye. I, p. 310. Agaricus gossypinus Bulliard, 1. c., t. 425. f. 2. Hallormstadir [P.L.]. — On the ground among twigs and branches in birch copses. Pileus 2—4 cm broad, convex, gibbous with pellucidly striate margin, brown (h 2) when moist, grey (h 4) when dry, the remains of the white veil hanging from the margin. — Stipe cylindrical, shining, white, covered with a white frayed coating, hollow, brittle. — Gills ventricose, broadly adnate, crowded, at first grey then dark-brown. — Spores brown, ellip- soidal, 8—9X4—4.5 u. — Cystidia fusiform, drawn out above into a short point. 580. P. bifrons (Berkeley) Fries, Monographia Hym. II, p. 347. Agaricus bifrons Berkeley, English Flora V, p. 114. Hallormstadir [P. L.]. — Under willows in bogs. Pileus up to 3 cm broad, obtusely conico-campanulate, flesh thin or skin-like, rugose and pitted at the margin, which is at first covered by a thin fugaceous veil, hygrophanous, reddish-brown (j 3) when moist, alutaceous (k 1 to j 1) when dry. — Stipe cylindrical-conical, rigid, brittle. hollow, white, mealy and floccose above, covered with projecting hairs at base. — Gills ascending, adnate, pale grey, then dark-brown, but white at the edge. — Spores ellipsoidal, smooth, dark-brown, 13X7 u. — Cy- stidia elongate-conical with obtuse apex, 40—50 u long. Psathyrella Fries. 581. P. prona Fries, Hym. Eur., p. 315. Agaricus pronus Berkeley et Broome, No. 924. Reykjavik [P. L.]. — Roadside by Ellidaa. Pileus 1—1.5 cm broad, hemispherical, flesh thin, margin striate, sericeo-pulverulent, brown (h3) when moist, livid (e2) when dry. — FUNGI OF ICELAND 551 Stipe 4 cm high, 1 mm thick, white, flexuose, hollow, mealy at apex, base often dilated. — Gills grey, then dark with light edges, ventricose, adnate. — Spores black, ellipsoidal, smooth, 13—16X7—8.5 u. — Cystidia hairshaped with swollen base. 582. P. arata Berkeley, Outlines of Br. Fungology, p. 176. Akureyri [C. O. H.), det. E. Rostrup. — On moist sandy soil near Glerä. Rostrup’s name P.atrata is incorrect, perhaps a misprint. Lactariaceae. Lactarius Fries. 583. L. tabidus Fries, Epicr., p. 346. Hallormstadir [P.L.). — Under birches and willows. Milk white, somewhat pungent. Pileus c. 2 cm broad, plano-convex, slightly umbonate, sometimes uneven, rugulose, margin thin, pellucidly striate, when moist reddish brown (j 2), paler when dry. — Stipe cylin- drical, slightly dilated at base, reddish-brown, often slightly mealy. — Gills rather distant, adnate, pale incarnate (e 7). — Spores white, echi- nate, almost spherical 8—9X7—8 u. 584. L. glyciosmus Fries, Epicr., p. 348. Hallormstadir, Eyjafjördur [P. L.). — On the shore at Glerä and in birch copses. Milk white or watery, sparse. — Pileus c. 5 cm broad, plano-convex, more or less depressed in the centre, with an acute or rounded umbo. Margin incurved, violet-grey (a 5), surface f8—g 7. — Stipe cylindrical, pale reddish yellow (k 4), covered with a greyish-white mealy coating. — Gills at first white, then pale reddish yellow (k 1—k 3), broadly adnate or somewhat decurrent, not branched. — Spores faintly yellow, echinate- verrucose, somewhat angular, 8—8.5X7 u. Flesh pale reddish yellow (k 2), smells like cinnamon. 585. L. lilacinus (Lasch) Fries, Hym. Eur., p. 435. Agaricus lilacinus Lasch, Linnaea III, No. 78. Egilsstadir [P.L.]. — In birch copses, meadows and bogs. Milk white, acrid. — Pileus 4—7 cm broad, plano-convex, then de- pressed in the centre about a small umbo, at first slightly tomentose, then rimose and almost squamose, lilac-incarnate (n 7), turning brown- violet (j 3). Flesh of cap tinged with red. — Stipe cylindrical, reddish yellow to ochre (k 3), apex mealy. — Gills coloured like the cap, some- what decurrent. — Spores with a yellowish tinge, subspherical, echinate, 7.5—8.5 u. 586. L. uvidus Fries, Epicr., p. 338. Eyjölfsstadir [P. L.|. — In birch copses. Milk acrid, turns violet like the flesh. — Pileus 3—7 cm broad 552 POUL LARSEN convex, then depressed in the centre, margin involute, naked, slimy, greyish violet (0 3—o 4). — Flesh white, but turning violet when wounded (n 4—o 6). — Stipe slimy, pitted, greyish yellow (k 2), turns violet when wounded. — Gills white to yellowish (k 1), becoming violet on contact, broadly adnate or somewhat decurrent, crowded. — Spores pale, verru- cose, I0%8 I U. 587. L. uvidus Fries var. farinipes n. var. This variety agrees in all essentials with the main species, but differs from it in the stipe never being slimy, but always covered with a grey or greyish red mealy coating. It is far more frequent in Iceland than the main species and occurs in meadows, bogs, and on knolls in moist spots of the mountain pastures. Lagarfljöt (both at Hallormstadir, Vallanes, Eyjélfsstadir and Egils- stadir), Jökülsä 4 Bru [P.L.). 588. L. torminosus (Schaeffer) Fries, Epicr., p. 334. Agaricus torminosus Schaeffer, Fung. Ic., t. 12. Lagarfljöt, Myvatn [P. L.]. — Common in copses of Betula pubescens and Betula nana. Milk white, acrid. — Pileus 6—8 cm broad, convex, then strongly depressed, viscid, tomentose-squarrose, especially along the incurved bearded margin, pale incarnate (e 5), with more brightly coloured (c 8) zones. — Stipe cylindrical, hollow, pale incarnate (e 5). — Gills pale yellow (b 7), crowded, decurrent. — Spores white, subspherical, echinate, 697.927, Russula Fries. 589. R. delica Fries sensu Bresadola, Fungi tridentini, t. 201. Lagarfljöt. — Fairly common in birch copses. Pileus 6—10 cm broad, convex with depressed centre, at length infundibuliform, margin incurved, not sulcate. Pellicle of pileus but slightly developed, at length split into small patches, colour white with a brownish tinge (g 5). — Flesh white, slightly bitter. — Stipe short, becoming thinner, slightly tomentose, concolorous. — Gills white to creamcolour (never shaded with green), crowded, narrow, forked at margin of cap. — Spores white, subspherical, echinulate, 8—10X8 u. Note. The fact that apparently there only occurs in Iceland the form with white or faintly yellowish gills would seem to indicate that Russula chloroides (Krombh.) Br. is a distinct species and should not be referred to Russula delica. 590. R. graminicolor (Secretan) Quelet. Agaricus graminicolor Secretan, Mycographie Suisse I, No. 518. Here and there in the birch copse in the Lagarfljét Valley [P. L.]. Pileus 5—6 cm broad, plano-convex with depressed centre, margin FUNGI OF ICELAND 553 rounded, at length sulcate, pellicle well developed, separable, somewhat slimy, dark-green in the centre (f5), somewhat paler at the margin (i 7). Flesh white, palatable. — Stipe subcylindrical or attenuated at the base, white with low ridges and veins, at length with brown spots. — Gills cream-coloured, emarginate-adnate, edge denticulate. — Spore powder cream-coloured, spores echinulate, oblong, 7—8X6 u. 591. R. lilacea Quélet, Flore myc. de la Fr., p. 348. Common in birch copses everywhere in the Lagarfljöt Valley [P. L.). Pileus 3—5 cm broad, plano-convex, centre depressed, slimy and viscid when moist, dark reddish-violet (from n1 to n3) in the centre, paler towards the margin (n 7), margin at length slightly sulcate. Flesh comparatively thick, white, taste mild. — Stipe cylindrical or dilated below, shaded with red in the middle, sometimes the whole stipe is red (m 4). — Gills emarginate, crowded, at first pure white, then pale, partly forked. — Spore powder almost white. Spores white, broadly ellipsoidal, 7—8X6 u. 592. R. vinosa Quélet, Flore myc. de la Fr., p. 348. In birch copses and among grass both in the valleys and in moun- tain pastures. Common in the west-, north- and east-country [P. L.]. Pileus 4—6 cm broad, plano-convex, at length with depressed centre, slimy, viscid, margin at length sulcate. Dark red in the centre (d 1), margin vinous red (d 4). Flesh white, but red below the pellicle, turning grey and soft, taste mild. — Stipe cylindrical, with a somewhat dilated but acuminate base, white, mealy and sulcate, firm, but becoming grey and soft. — Gills white with a yellowish tinge, becoming grey, equal, branched at the stipe, brittle, adnate. — Spore powder pale. Spores white, echinulate, 8—9X7—8 u. — Cystidia at the edge of the gills lanceolate, apex pointed, contents granular. Note. Though this Russula is very similar to R. depallens (Pers.) Fries, still it differs so much from it in several respects that it must be con- sidered correct to regard it as a distinct species. Among the differences I may point out its geographical distribution, which does not coincide with that of R. depallens. Thus the latter species or form has not been observed in Iceland. 593. R. grisea (Persoon) Bresadola, Iconographia mycologica, Tab. 452. Hallormstadir [P.L.). — In birch copses. Pileus 7—8 cm broad, convex, centre depressed, margin at length sulcate, well developed with a thin pellicle, viscid and slimy when moist, resembling in colour R. cyanoxantha, changing between olive-green, purple, and ochre. Flesh white, but with a lilac tinge below the pellicle, taste mild. — Stipe almost equal, though sometimes dilated at base, white, finely rugose-sulcate. — Gills broadest in front, narrowly adnate, forked at the stipe, at first cream-coloured, then yellow. Spore powder yellow. — Spores pale yellow, echinulate, subspherical, 7—7.5 u in diameter. 554 POUL LARSEN 594. R. ochracea (Albertini et Schweinitz) Fries, Epicr. I, p. 362. Hallormstadir [P. L.]. — In birch copses. Fairly common. Pileus 5—8 cm broad, plano-convex, centre depressed, margin thin, sulcate. Pellicle slimy and viscid (often covered with earth), margin pale ochre (k 2), centre darker, brownish (h 3 to g7). Flesh ochraceous (k 2), taste mild. — Stipe white with a brownish tinge, sulcate above, rather short and thick. — Gills narrowly adnate or somewhat emarginate and then with a decurrent tooth, yellow with a yellowish-red tinge (b 7). — Spore powder yellow. Spores yellow, echinulate, subspherical, very vari- able in size, 7—9 u in diameter. 595. R. decolorans Fries, Epicr., p. 361. Egilsstadir and Seydisfjérdur [P. L.]. — In birch copses. Not common. Pileus c. 8 cm broad, at first subspherical, then plano-convex, margin very long even, at length somewhat sulcate, pellicle slimy; when fresh it has two main colours: blood-red (j 6—j 7) and orange-yellow (b 5), but soon becoming discoloured to a pale alutaceous (k 2) with a reddish tinge left especially at the margin. Flesh of cap hard, pale, becoming fuscous, taste mild. — Stipe short and thick (4—6 cm X 2—4 cm), base swollen, surface conspicuously veined, at first white, then fuscous with rusty brown spots, especially below. Flesh of stipe soft. — Gills at first pale (g 5), then with a reddish-yellow tinge and finally spotted with rusty brown, especially at the edge of gills. — Spore powder yellow. Spores pale yellow, subspherical or oval, echinulate-verrucose, of rather variable size, 9—11 u in diameter, some few even larger. 596. R. nauseosa (Persoon) Fries, Epicrisis, p. 363. Agaricus nauseosus Persoon, Synops. meth. fung., No. 446. Hallormstadir [P. L.|. — In birch copses. Not common. Pileus 3—5 cm broad, plano-convex, at length almost infundibuliform, flesh thin; slimy, margin at first even, finally sulcate-tuberculate, colour dingy purple (n 8), but the centre may be olive (i7) or fuscous (h 4), while the margin is grey to purple and more or less covered with yellow spots. — Flesh soft, brittle, white, smell unpleasant, taste at first mild, then acrid. — Stipe equal, white, spongy-brittle, spotted with brown on contact, at length becoming grey. — Gills at first pale, then yellow, some few forked, rounded towards the stipe. — Spore powder yellow. Spores pale yellow, echinulate, subspherical, 8—9 u in diameter. 597. R. fragilis (Persoon) Fries?, E. Rostrup, Isl. Svampe 1903, p. 296. Holar in N. Iceland (Grønlund), det. E. Rostrup. Note. The present writer considers it doubtful whether the determina- tion of this species is correct. I have not observed it anywhere in the birch copses, though this should be the locality where one might expect to find this species. 1 FUNGI OF ICELAND 555 598. R. Queletii Fries, in Quélet: Les Champ. du Jura, p. 185, € 24; £ 6. Hallormstadir [P.L.]. — On grassy spots in birch copses. Not rare. Pileus 5—7 cm broad, plano-convex, margin thin, at length sulcate, pellicle scarcely viscid, mealy, purple-violet (d 1), centre almost black (c. 3). — Flesh white, but purple beneath the separable pellicle, at first fairly firm, then soft, odour none, taste acrid. — Stipe cylindrical, pale purplish red (m 4), mealy. — Gills pale, becoming greyish white, exuding drops from the edge of gills when fresh. — Spore powder greyish white, spores white, subspherical, echinulate 8—9X7—8 u. Coprinariaceae. Coprinus (Persoon) Fries. 599. C. velox Godey, in Gillets Les champignons de la France, Hyménomycètes, t. 175. Seydisfjöröur, Norötünga [P. L.. — On horsedung and cowdung. Pileus 4mm broad, skin-like, margin sulcate, centre squamulose or scurfy, grey. — Stipe 2 cm long, '/2mm thick, white, base hairy. — Gills grey, thin, reaching the stem. — Spores ellipsoidal, brown, 8—9X5 u. 600. C. ephemerus (Bulliard) Fries, Epicr., p. 252. Agaricus ephemerus Bulliard, Hist. champ., t. 128. Reykjavik and Seydisfjöröur [P. L.]J. — On horsedung and cowdung. Pileus 1—1.5 cm broad, at first ovoid, then expanded with split raised margin, skin-like, covered with scattered short hairs, greyish yellow with a brownish centre. — Stipe 3—5 cm long, 1—1.5 mm thick, hollow, whitish grey, mealy, base hairy. — Spores dark-brown, ellipsoidal, 10— 13X7 u. 601. C. tigrinellus Boudier, Icones mycologicae, t. 139. On stems and leaves of dead and living species of Carex in wet bogs about Pingvallavatn [P. L.). Pileus at first ovoid with somewhat pointed summit, 1 cm high and broad, then expanded with revolute split margin, white, but covered in spots with a dark-grey, mealy layer. — Stipe white, smooth, pellucid, swollen and floccose at base. — Gills at first white, then dark 2—3 mm broad, free. — Spores dark-brown, broadly ellipsoidal, 11—15*7—9 u. 602. C. cordisporus Gibbs, in J. E. Lange, Dansk Bot. Ark., Bind 2, No. 3, 1915, p. 43, pl. I, fig. g. Seydisfjordur and Reykjavik [P.L.). — On horsedung in bogs. Pileus cylindrical, then flat and radiately striate-plicate, skin-like, 6—8 mm broad, pale with a yellow centre, covered by a mealy layer consisting of spherical cells, 20—40 x in diameter. — Stipe 2—3 cm long, 556 POUL LARSEN 1 mm thick, white, smooth, clothed with projecting hairs below. — Gills at first pale, then black, narrow, distant, free. — Spores dark purplish- brown, flattened, heartshaped on a side view, c. 9 u in diameter, viewed from the edge ellipsoidal and 9X6 u. 603. C. ephemeroides (Bulliard) Fries, Epicr., p. 250. Hofsfjall [O. D.|. — On horsedung. The present writer has not observed this species in Iceland, but it is given by E. Rostrup in Isl. Svampe 1903, p. 296. 604. C. fimetarius (Linné) Fries, Epier., p. 245. Agaricus fimetarius Linne, Flora Suecica, No. 1213. Akureyri [P. L.]. — On highly manured littoral field. Pileus at first clavate, then broadly conical with raised sulcate margin, 2—5 cm high and broad, grey, brownish in centre, covered by a floccose-squamulose layer. — Stipe elongate conical with a peronate- floccose base, white, hollow, very fragile. — Gills at first grey, then black, free, soon deliquescent as well as the whole cap. — Spores blackish brown, ellipsoidal, 12—14.5X 7—8 u. 605. C. atramentarius (Bulliard) Fries, Epicr., p. 243. Agaricus atramentarius Bulliard, L c., t. 164. Mäfahliö (Helgi Jönsson). This species is listed among Iceland’s fungi by E. Rostrup, Isl. Svampe 1903, p. 296. Boletaceae. Suillus Micheli. 606. S. castaneus (Bulliard) Karsten. Boletus castaneus Bulliard, 1. c., t. 328. Grjötnes [C. H. O.], det. E. Rostrup. — On a heath. Boletus Dillenius. 607. B. scaber Bulliard, 1. c., t. 489, f. 1. Common in birch copses throughout Iceland [P. L.). 608. B. laevis Fries, Epicr., p. 425. Note. E. Fries states in the Epicrisis that he received this Boletus from Count Raben, who had collected it in Iceland. The species has been diagnosed on the basis of material preserved in alcohol. JB. laevis has never been found again either in Iceland or elsewhere, and since the diagnosis of Fries renders it quite permissible to regard B. laevis as an accidental smoothly stipitate variant of B. scaber, there seems to be no reason to maintain B. laevis as a species. FUNGI OF ICELAND 557 609. B. bovinus Linné, Flora Suecica, No. 1246 (9). Stated by E. Rostrup in Isl. Svampe 1903 p.295 to have been found in Iceland by König. Note. It must he regarded as doubtful whether this pronounced inhabitant of coniferous woods occurred in Iceland at a time when there were no coniferous trees at all in the island. 610. B. piperatus Bulliard, 1. c., t. 451, f. 2. Egilsstadir [P.L.]. — Among moss in birch copses. Pileus 4—5 cm broad, flatly vaulted, viscid, tawny (g 2), flesh thin, yellowish, taste burning. — Tubes tawny (g 2), adnate to the stipe, some- what decurrent; mouths large, edged with the colour 17. — Stipe cylin- drical, stuffed, 5—6cm long, 6—8 mm thick, coloured like the cap, but the base citron-yellow (b 4). — Spores smooth, tawny, narrowly ellip- soidal, 8—9X3.5—4 u. Boletopsis P. Hennings. 611. B. luteus (Linné) P. Hennings. Boletus luteus Linné, Flora suecica, No. 1247. Hallormstadir [P. L.}. — Under several Pinus montana, c. 15-year- old, grown from seed imported from Norway in a plantation, in a birch copse. The finding of B. luteus by Björn Halldörsson, recorded by E. Ro- strup in Botanisk Tidsskrift, Isl Svampe 1903, p. 295, must undoubtedly be due to an error on the part of Björn Halldörsson, since Iceland was then without coniferous trees. Lycoperdaceae. Bovista Persoon. 612. B. nigrescens Persoon. Lycoperdon nigrescens Vittadini, Monographia Lycoperdineorum, p- 176. Grimsey, Spönsgerdi, Hof, Hl6d in Hörgardalur, Arnarnes, Hraun in Fljöt [O.D.); Mödruvellir (St. St]; Silfrastadir, Skagafjöröur [Thoroddsen]; Dyrafjöröur [C. O.H.); Vestmannaeyjar (St. St.}. 613. B. plumbea Persoon. Lycoperdon plumbeum Vittadini, Monographia Lycoperdineorum, p- 174. Störä Brekka [O. D.); D\rafjérdur [C. O. H.]; in farm yards in Skütu- stadir near Myvatn [P. L.). 614. B. clavata Fries, Syst, Mye. III, p. 23. The species was established on the basis of some specimens brought 558 POUL LARSEN home by Thienemann from a journey in Iceland and has never been found again since. Lycoperdon Tournefort. 615. L. bovista Linné, Species plantarum, p. 1653. Mööruvellir [Thoroddsen]; Hofsfjall, Gäsir [O.D.]; Büdir, Vallanes[H.J.). — Stated by Mohr and Robert to be common in Iceland. 616. L. pusillum (Batsch) Persoon. Lloyd, The Genus Lycoperdon in Europe, t. 53, figs. 9-11. Reykjavik and Myvatn [Grønlund]; Hofsfjall in Hörgärdalur, Hl6d. Prastarhélsskarô, Stora Brekka [O.D.]. 617. L. caelatum Bulliard, Sacc., Syll. fung. VII, p. 115. Grimstunga [Grønlund], meadow by Myvatn [P. L.] Nidulariaceae. Crucibulum Tulasne. 618. C. vulgare Tulasne, Sacc., Syll. fung. VII, p. 43. Olufsdalur [H. J.J. Seydisfjöröur [P. L.]. Reykjavik [Buchwald]. — On dead wood. FUN GI: IMPERE HEA Sphaerioidaceae- Hyalosporae. Phyllasticta Persoon. 619. P. Elymi (Rostrup) Allescher, Rabenhorsts Krypt. Flora I, 7., p. 763. Phoma Elymi Rostrup, Botanisk Tidsskrift 1899, p. 276. Grimstadir near Jökulsä 4 Fjöllum [P.L.]. — On awns of Elymus. 620. P. Pseudacori (Brun) Allescher, Rabenhorst’s Krypt. Flora I, 6., p. 160. Garden in Reykjavik [P.L.]. — On leaves of Iris germanica. 621. P. Ranunculorum Saccardo et Spegazzini, Michelia I, p. 150. — Syll. fung. III, p. 37. Storugjä near Myvatn [O. D.]. — On a leaf of Ranunculus acer. 622. P. filipendulina Saccardo et Spegazzini, Michelia I, p. 150. — Syll. fung. III, p. 41. Sponstadir [Feddersen]. — On leaves of Filipendula ulmaria. Phoma (Fries) Desmazières. 623. P. muscorum Rostrup, Isl. Svampe 1903, p. 318. Hestahraun in Porvaldsdalur [O.D.]. — On Tetraplodon bryoides. 624. P. Equiseti Desmaziéres, Sacc., Syll. fung. III, p. 168. Hof [0. D.]. — On Equisetum palustre. 625. P. Lycopodii Rostrup, Isl. Svampe 1903, p. 318. Mööruvellir (St. St... — On Lycopodium annotinum. 626. P. Tofieldiae Rostrup, Isl. Svampe 1885, p. 226. Hof in Hörgärdalur [O.D.]; also gathered in Iceland by J. Morten- sen. — On Tofieldia borealis. 627. P. salicina Westendorp, Sacc., Syll. fung. III, p. 97. Hörgärdalur [O.D.). — Oa twigs of Salix phylicifolia. 560 POUL LARSEN 628. P. endoleuca Saccardo, Syll. fung. III, p. 98. A garden in Reykjavik [Prytz]. — On Alnus glutinosa. 629. P. urticae Schulzer et Saccardo, Syll. fung. III, p. 140. Efsta-Samtün [O.D.l. — On stems of Urtica dioeca. 630. P. acuta Fuckel, Sacc., Syll. fung. III, p. 133. Reykjavik [H.J.]. — On stems of Atriplex patula. 631. P.tingens Cooke et Massee, Grevillea XVII, p. 56. — Sacc., Syll. fung. IX, p. 166. Reykjavik (The Experimental Station) [P. L.], det. O. Rostrup. — On stems of Aconitum sp. 632. P. oleraceum Saccardo, Syll. fung. III, p. 135. The Experimental Station at Reykjavik [P. L.], det. OÖ. Rostrup. — On stems of Erysimum sp. 633. P. Malvacei Brunaud, Flore myc. Saint. et Four. in Bull. Soc. Sc. Nat. de l'Ouest. A garden in Reykjavik [P. L.], det. ©. Rostrup. — On Ribes al- pinum. 634. P. ribicola Saccardo, Syll. fung. III, p. 17. A garden in Reykjavik [Prytz). — On Ribes rubrum. 635. P. Saxifragarum Westendorp, Notes sur quelques cryptogames VI, p. 23. — Sacc., Syll. fung. III, p. 145. Hofsfjall [O. D.]. — On stems of Saxifraga nivalis. 636. P. Alchimillae Rostrup, Isl. Svampe 1903, p. 318. Hof in Hörgärdalur [O.D.]. — On leaves of Alchimilla alpina. 637. P. ruborum Westendorp, Sacc., Syll. fung. III, p. 76. Vifilsstadahlid [P.L.], det. O. Rostrup. — On branches of Rubus saxatilis. 638. P. melaena (Fries) Durand et Montagne, Sacc., Syll. fung. III, p. 315. Grund near Akureyri [P.L.], det. O. Rostrup. — On stems of Vicia cracca. 639. P. complanata (Tode) Desmaziéres, Saccardo, Syll. fung. III, p. 126. Hof [O.D.]; Skrida in Hörgärdalur, Grund in S. W. Iceland (H. J.]. — On stems of Archangelica officinalis, Rhinanthus crista- galli. FUNGI OF ICELAND 561 640. P. Armeriae Jaap, Schriften der Nat. Verein fir Schleswig-Hol- stein, Bd. XIV (1907), Heft I. p. 28. Akureyri [P. L.]. — On stems of Armeria maritima f. elongata. 641. P. solanicola Prillieux et Delacroix, Saccardo, Syll. fung.X, p. 175. Hof [O. D.]; Eydar [P. L.], det. O. Rostrup. — On stems of Sola- num tuberosum. 642. P. Sceptri Karsten, Saccardo, Syll. fung. III, p. 129. Hraun in Fljöt, Hof, Reistarärgil, Torfastadadalur [O.D.. — On Pedicularis sp., Bartsia alpina. 643, P. deusta Fuckel, Symbolae, p. 377. — Saccardo, Syll. fung. III p- 155. Hof [O.D.]. — On capsules and bracts of Rhinanthus crista- galli. ’ 644. P. herbarum Westendorp, Saccardo, Syll. fung. III, p. 133. Common throughout the country. — On Euphrasia latifolia, Bartsia alpina, Thymus serpyllum etc. Phomopsis Saccardo. 645. P. ribesia (Saccardo) Diedicke, Annales Mycologici IX, p. 29. Phoma ribesia Saccardo, Micheliana I, p. 520. A garden in Reykjavik [P. L.], det. ©. Rostrup. — On Ribes rubrum. Aposphaeria Berkeley. 646. A. pulviuscula Saccardo, Syll. fung. III, p. 175. A garden in Akureyri [P.L.], det. O. Rostrup. — On dead branches of Salix phylicifolia. 647. A. glomerata (Corda) Saccardo, Syll. fung. III, p. 175. Coniothyrium glomeratum Corda, Icones IV, p. 39. The Experimental Station in Reykjavik [P.L.|, det. O. Rostrup. — On dead branches of Ulmus montana. 648. A. subtilis (Fries) Saccardo, Syll. fung. III, p. 171. Sphaeronema subt. Fries in Kunze et Schmidt, Mycol. Hefte II, p. 57. A garden in Akureyri [P. L.), det. O. Rostrup. — On dead branches of Sorbus aucuparia. 649. A. arctica (Karsten) Saccardo, Syll. fung. III, p. 176. Phoma arctica Karsten, Hedwigia 1884, p. 19. Krossastadagil (O. D.). — On a decorticated branch in a raven’s nest. The Botany of Iceland, Vol. If, part IIL 87 562 POUL LARSEN 650. A. labens Saccardo, Syll. fung. III, p. 173. Mööruvellir [O.D.]. — On wood. Dendrophoma Saccardo. 651. D. marchica Diedicke, Kryptogamen-Flora der Mark Branden- burg, Bd. IX, p. 198. The Experimental Station at Reykjavik and Vifilsstadahliö [P. L.], det. O. Rostrup. — On Rumex domesticus. Asteroma De Candolle. 652. A. Salicis Roberge, Saccardo, Syll. fung. III, p. 208. Sörlastadarunnar [St. St... — On leaves of Salix phylicifolia. 653. A. Capreae Desmazieres, Saccardo, Syll. fung. III, p. 208. Hälsskögur [O. D.]. — On leaves of Salix phylicifolia. 654. A. alpinum Saccardo, Syll. fung. III, p. 206. Adaldalshraun [O. D.]. — On leaves of Arctostaphylos uva ursi. Vermicularia Fries. 655. V. Liliacearum Westendorp, Saccardo, Syll. fung. III, p. 233. Hofsfjall [O. D]. — On stems of Luzula multiflora. 656. V. trichella Fries in Greville, Scottish cryptogamic Flora, t. 345, et Sum. Veg. Scand., p. 420. Haukadalur {Feddersen]. — On leaves of Salix sp. 657. V. Dematium (Persoon) Fries, Saccardo, Syll. fung. III, p. 225. Vifilsstadahliö [P. L.], det. O. Rostrup. — On dead stems of Rumex acetosa. 658. V. Geranii Westendorp, Exs. No. 1239, Flore cryptogamique des Flandres I, p. 404. Vifilsstadahliö [P. L.], det. O. Rostrup. — On dead stems of Geranium silvaticum. ; Placosphaeria Saccardo. 659. P. Bartsiae C. Massal., Saccardo, Syll. fung. X, p. 235. Bog near Hallormstadir [P.L.], det. O.Rostrup. — On Bartsia alpina. 660. P. Galii Saccardo, Syll. fung. III, p. 245. Almannagjä near Pingvellir [P.L.], det. O. Rostrup. — In the same stroma as Mazzantia Galii on stems of Galium verum. FUNGI OF ICELAND 563 Cytospora Ehrenberg. 661. C. Salicis (Corda) Rabenhorst, Saccardo, Syll. fung. III, p. 261. Pordarstadir [O.D.]. — On branches of Salix phylicifolia. 662. C. betulina Ehrenberg, Sylvae Mycologicae Berolinenses, p. 28. — Saccardo, Syll. fung. III, p. 259. Akureyri [P.L.]. — On branches of Betula pubescens. 663. C. leucostoma (Persoon) Saccardo, Syll. fung. III, p. 254. A garden in Reykjavik [P. L]. — On branches of Prunus padus. 664. C. Massariana Saccardo, Syll. fung. III, p. 253. A garden in Akureyri [P.L.), det. O. Rostrup. — On dead branches of Sorbus aucuparia. 665. C. microspora (Corda) Rabenhorst, Saccardo, Syll. fung. III, p- 253. A garden in Reykjavik [Prytz]. — On branches of Sorbus aucuparia. Rabenhorstia Fries. 666. R. rudis Fries, Saccardo, Syll. fung. III, p. 243. A garden in Akureyri [P.L.], det. O. Rostrup. — On pieces of bark of Cytisus laburnum. Sphaerioidaceae-Phaeosporae. Coniothyrium Corda. 667. C. myriocarpum (Fries) Saccardo, Syll. fung. III, p. 315. Hof (0. D.]. — On wood. 668. C. lignorum Saccardo, Syll. fung. III, p. 315. Cliosporium lignorum Fries, Syst. Mye. III, p. 335. Hof, Hüsafellsskögur, Hälsskögur [O. D.]. — On birch-wood. 669. C. Laburni Richards, Cat. Champ. Marn. 1889, No. 1645. — Saccardo, Syll. fung. X, p. 264. | Garden in Reykjavik [Prytz]. — On Cytisus laburnum. 670. C. olivaceum Bonorden, Saccardo, Syll. fung. III, p. 305. The Experimental Station at Reykjavik [P. L.], det. O. Rostrup. — On branches of Ulmus montana. 671. C. conoideum Saccardo, Syll. fung. III, p. 316. Skrida in Hörgärdalur [O.D.). — On stems of Archangelica offici- nalis. 37* 564 POUL LARSEN Sphaerioidaceae-Hyalodidymae. Ascochyta Libert. 672. A. teretiuscula Saccardo et Roumerque, Saccardo, Syll. fung. III, p. 405. Hrafnagiä [P. L.], det. ©. Rostrup. — On withered bracts of Luzula spicata. 673. A. baccae Rostrup, Gronl. Svampe 1891, p. 625. — Saccardo, Syll. fung. XI, p. 524. Prastarhélsskard [O.D.). — On berries of Empetrum nigrum. 674. A. Diapensiae Rostrup, Öst-Gronlands Svampe 1894, p. 28. — Saccardo, Syll. fung. XI, p. 524. Hofsfjall [O. D.]. — On leaves of Diapensia lapponica. 675. A. Veronicae Rostrup, Isl. Svampe 1903, p. 319. Mööruvellir [O.D.]. — On leaves of Veronica saxatilis. Diplodina Westendorp. 676. D. Eurhododendri Voss, Saccardo, Syll. fung. X, p. 312. Hof [O.D.]. — On berries of Vaccinium uliginosum. Darluca Castagne. 677. D. Filum (Bivon.) Cast, Saccardo, Syll. fung. III, p. 410. Akureyri [Strömfelt]. — Parasitic on a Uredo on Poa pratensis. Sphaerioidaceae-Phaeodidymae. Diplodia Fries. 678. D. Rubi Fries, Sum. Veg. Scand., p. 417. The Experimental Station at Reykjavik [P. L.]. — On dry branches of Rubus Idaeus. Sphaerioidaceae-Hyalophragmiae. Stagonospora Fries. 679. S. Equiseti Fautrey, Saccardo, Syll. fung. X, p. 337. Os in Hörgärdalur [O.D.]; Eyjarfjardardalur near Akureyri [P. L.]. — On Equisetum palustre. 680. S. islandica Rostrup, Isl. Svampe 1903, p. 320. Grimsey [O. D.]. — On leaf sheaths of a grass. 681. S. graminella Saccardo, Syll. fung. III, p. 454. Mööruvellir, Hof, Gäsir [0. D], — On Deschampsia caespitosa and Poa pratensis. On FUNGI OF ICELAND 56 682. S. curvula Bom. et Rous., Saccardo, Syll. fung. X, p. 337. Grimstadir near Jökulsä 4 Fjöllum [P. L.]. — On Elymus arenarius. 683. S. aquatica Saccardo, Syll. fung. III, p. 452. Hornafjardareyjar [St. St]. — On stems of Heleocharis palustris. 684. S. Galii Fautrey, Revue mycologique 1892, p. 177. — Saccardo, Syll. fung. XI, p. 524. Hallormstadir [P. L.], det. ©. Rostrup. — On Galium pumilum. Sphaerioidaceae-Phaeophragmiae. Hendersonia Berkeley. 685. H. Jungermanniae Fries, E. Rostrup, Isl. Svampe 1903, p. 320. Mula [O.D.]. 686. H. silvatica Fautrey, Revue mycologique 1894, p. 160. — Sac- cardo, Syll. fung. XI, p. 532. Sluttnes in Myvatn [P.L.], det. O. Rostrup. — On Poa alpina. 687. H. arundinacea (Desmaziéres) Saccardo, Syll. fung. III, p. 436. Grimstadir near Jökulsä 4 Fjöllum [P. L.]. — On straws of Elymus arenarius. 688. H. Stefanssonii Rostrup, Isl. Svampe 1903, p. 320. Rjettarhol [St. St]. — On leaves of Carex hyperborea. 689. H. Caricis Oudemans, Mater. Flor. myc. de la Neerlande II, »: 19. Hofsfjall [O. D.) — On leaves of Carex atrata. 690. H. salicina Saccardo, Syll. fung. III, p. 425. Tüngä, Foss [Feddersen]. — On willow branches. 691. H. Ribis alpini Fautrey, Revue mycologique 1892, p. 171. — Saccardo, Syll. fung. XI, p. 529. A garden in Reykjavik [P. L.), det. O.Rostrup. — On Ribes alpinum. Sphaerioidaceae-Phaeodictyae. Camarosporium Schulzer. 692. C. laburnicum Saccardo, Syll. fung. X, p. 339. The Experimental Station at Reykjavik [P. L.), det. O. Rostrup. — On Cytisus alpinum. 566 POUL LARSEN Cytosporium Peck. 693. C. betulinum Rostrup, Isl. Svampe 1903, p. 320. Hälsskögur [O.D.]. — On rotten wood of Betula pubescens. 694. C. Davidssonii Rostrup, Isl. Svampe 1903, p. 320. Gäsir [O. D... — On wood. Sphaerioidaceae-Scolecosporae. Septoria Fries. 695. S. graminum Desmazieres, Saccardo, Syll. fung. III, p. 565. Hestahraun in Porvaldsdalur [O. D.]. — On leaves of Poa alpina. 696. S. punctoidea Karsten, Fragmenta mycologica, Hedwigia 1884, p- 38. Hof in Hörgärdalur [O.D.]. — On Cobresia scirpina. 697. S. Caricis Passerini, Saccardo, Syll. fung. III, p. 566. Grimsey, Hallgilsstadafjall [O. D.). — Carex vaginata and Carex nardina. 698. S. Orchidearum Westendorp, Exs. No. 638, Kickx, Flore crypto- gamique des Flandres I, p. 423. — Saccardo, Syll. fung. III, p. 575. Störugjä near Myvatn [O.D.]; Os in Hegranes [Olafsson]. — On Coeloglossum viride. 699. S. salicella Berkeley et Broome, Annals and Magazin of Natural History, No. 746, tab. XV, fig. 7. — Saccardo, Sylloge f. III, p. 585. Bægisärgil [O. D.]; Laugardalur (Grønlund). — On branches of Salix lanata and Salix glauca. 700. S. salicina Peck, Reports New York Museum, p. 87. — Saccardo, Syll. fung. III, p. 502. Godaland [Feddersen]. — On leaves of a Salix sp. 701. S. Capreae Westendorp, Bulletin Academie Royale de Botanique de Belgique, II. Serie, tome XI, No.6. — Saccardo, Syll. fung. III, p. 501. Myvatnsheidi [O. D.]; Svinahraun [Feddersen]. — On buds of Salix lanata. 702. S. betulina Passerini, Saccardo, Syll. fung. III, p. 506. Myvatn [Grønlund]. — On branches of Betula sp. 703. S. cerasticola Rostrup, Isl. Svampe 1903, p. 321. Grimsey [O. D.]. — On leaves of Cerastium alpinum. FUNGI OF ICELAND 567 704. $. Stellariae Roberge et Desmazieres, Saccardo, Syll. fung. III, p. 518. Os in Mööruvallasökn, Reistarärskard [O. D.]. — On leaves of Cera- stium alpinum. 705. S. Alsines Rostrup, Isl. Svampe 1903, p. 321. Hofsfjall [O. D.). — On leaves and stems of Alsine verna. 706. S. Geranii Roberge et Desmaziéres, Annales des Sciences Na- turelles. Botanique 1853, XX, p. 93. — Saccardo, Syll. fung. III, p. 514. Store Gjä near Reykjahliö [P. L.], det. O. Rostrup. — On petioles of Geranium silvaticum. 707. S. semilunaris Johanson, Svampar fran Isl., 1884, p. 173. Grafarös [St. St.]; Eskifjordur [Strömfelt]; Hofsfjall, M\vatnsheidi [O.D.). — On internodes of Rumex acetosa, Parnassia palustris, Gera- nium silvaticum, Dryas octopetala, Plantago maritima and Erigeron sp. 708. S. Viciae Westendorp, Saccardo, Syll. fung. III, p. 509. Lönshölmi !O.D.]. — On leaves of Vicia cracca. 709. S. Galiorum Ellis, Bull. Torrey, bot. club, 1882, p. 74. — Sac- cardo, Syll. fung. III, p. 543. Hraun in Fljöt [O.D.]. — On stems of Galium verum. Rhabdospora Montagne. 710. R. curva (Karsten) Allescher, Rabenhorsts Krypt. Flora I, 6, p- 916. Septoria curva Karsten, Symbolae XXI, p. 103. Grimstadir near Jökulsä 4 Fjöllum [P. L.], det. O. Rostrup. — On dead stems and leaves of Elymus arenarius. 711. R. pleosporoides Saccardo, Syll. fung. III, p. 588. Hestahraun, Hofsfjall, Fornhagagil [O.D.]; Mööruvellir (St. St]; Rey- kjavik [H. J.J. — Rumex domesticus, R. acetosa, R. acetosella, Oxyria digyna, Polygonum viviparum, Geum rivale. 712. R. inaequalis Saccardo, Syll. fung. III, p. 580. Sluttnes in Myvatn [P. L.], det. O. Rostrup. — On bark of Sorbus aucuparia. 713. R. eupyrenoides Saccardo, Grevillea XXI, p. 67, tab. 184, fig. 9. — Syll. fung. XI, p. 549. Mößdruvellir, Hof in Hörgärdalur [O. D}; Svinhagi [Feddersen]. — On stems of Euphrasia latifolia. 568 POUL LARSEN Nectrioidaceae. Zythia Fries. 714. Z.islandica Rostrup (in mscr.). Rhraun in Fljötum [O. D.). Peritheciis superficialibus gregariis, globosis, 0.3 mm diam., vitellinis, glabris. Sporulis sphaeroideis, 4—5 u cr., asperulis, hyalinis. Ad terram turfosam. Leptostromaceae-Hyalosporae. Leptothyrium Kunze et Schmidt. 715. L. vulgare (Fries) Saccardo, Syll. fung. III, p. 633. Isafjöröur [H.J.]. — On stems of Cornus suecica. Piggotia Berkeley et Broome. 716. P. atronitens, Oudemans, Nat. Myc. Neerl. II, p. 21. — Saccardo, Syll. fung. III, p. 637. Sanda near Hestahraun [Feddersen]. -- On branches of Salix sp. Leptostroma Fries. 717. L. caricinum Fries, Syst. Myc. II, p. 598. Melar, Myvatn, Hrütafjöröur [Gronlund]; Jörudalur, Ejafjôrôur [Ström- felt]; Pingmuli [H. J.. — On Carex Goodenoughi, Carex alpina, Carex rigida, Carex lagopina, Carex sp. 718. L. punctiforme Wallroth, Flora Cryptogamica Germaniae No. 1395. — Saccardo, Syll. fung. III, .p. 642. Mööruvellir [O. D]. — On leaves of Salix glauca. 719. L. Potentillae Karsten, Fungi in insulis Spetsbergen 1872, p. 59. — Saccardo, Syll. fung. III, p. 647. Reykjavik [Krabbe]; Skutustadir near M\vatn [O. D.]. — On leaves of Potentilla maculata. 720. L. herbarum (Fries) Link, Saccardo, Syll. fung. III, p. 645. On stems of Carum carvi. Leptostromaceae-Hyalophragmiae. Discosia Libert. 721. D. Artocreas (Tode) Fries, Sum. Veg. Skand., p. 653. Hof, Fornhagagil, Laugardalshölar [O. D]; Pingmüli [H.J.. — On Alchimilla alpina, Geum rivale, Thalictrum alpinum, Betula pubescens, Salix herbacea. FUNGI OF ICELAND 569 Excipulaceae-Hyalosporae. Excipula Fries. 722. E. sphaeroides (Persoon) Fries, Syst. Mye. II, p.191. Hestahraun in Porvaldsdalur [O.D.]. — On leaves of Salix glauca. 723. E. Empetri Fries, Syst. Myc. II, p. 190. Mööruvellir [St. St]; Hof. Prastarhélsgil [O.D... — On leaves of Empetrum nigrum. Dothichiza Libert. 724. D: Sorbi Libert, Saccardo, Syll. fung. III, p. 671. Reykjavik [Prytz]. — On bark of Sorbus aucuparia. Excipulaceae-Hyalophragmiae. Heteropatella Fuckel. 725. H. cercosperma (Rostrup) Lind, Danish Fungi, p. 473. Septoria cercosperma Rostrup, Mykologiske Notitser i Sverige. — Ofvers. Vet. Ak. 1883, No. 4, pp.35—47. Of common occurrence on the stems of many different herbaceous plants, as Gnaphalium norvegi- cum, Hieracium alpinum, Carum carvi, Archangelica offici- nalis, Ranunculus acer, Arabis petraea. Melanconiaceae-Hyalosporae. Gloeosporium Desmazières et Montagne. 726. G. filicinum Rostrup in Thümen Mye. No. 2083. Herpobasidium filic. (R.) Lind, Arkiv f. Botanik, vol. 7, No. 8, pp. 1—9. Husavik [O.D.]. — On Dryopteris pulchella. 727. G. alpinum Saccardo, Syll. fung. III, p. 708. Hüsafell [H.J.]. — On Arctostaphylos uva ursi. Myxosporium Link. 728. M. salicinum Saccardo et Roumerque, Syll. fung. III, p. 724. The Experimental Station and a garden in Reykjavik [P. L.], det. O. Rostrup. — On Salix phylicifolia. 729. M. Aucupariae Allescher, Berichte d. Bayer. Bot. Gesellsch., vol. IV 1896, p. 36. — Saccardo, Syll. fung. XIV, p. 1014. Skipalön (0. D.). — On branches of Sorbus aucuparia. 570 POUL LARSEN Melanconiaceae-Phaeosporae. Melanconium Link. 730. M. elevatum (Fries) Lind, Danish Fungi, p. 483. Didymosporium elev. Fries, Systema mycologicum III, p. 486. Melanconium betulinum Kuntze, Saccardo, Syll. fung. III, p. 756. Pingvellir [Feddersen]. — On branches of birch. 731. M. bicolor Fries, Syst. Myc. III, p. 488. Hüsafellsskögur [O.D.]. — On branches of birch. Melanconiaceae-Hyalodidymae. Marssonina Magnus. 732. M. Potentillae (Desmaziéres) Magnus, Saccardo, Syll. fung. II, P710. Hof, Skrifla (S. W. Iceland) [O. D. — On living leaves of Poten- tilla anserina and Comarum. Melanconiaceae-Hyalophragmiae. Septogloeum Saccardo. 733. $. Fragariae (Briand et Har.) v. Höhnel, Mycologische Frag- mente, Ann. Myc. I, pp. 391—414. Hof [O.D.]. — On leaves of Comarum palustre. Melanconiaceae-Phaeodictyae. Steganosporium Corda. 734. S. traphinum Saccardo, Syll. fung. II, p. 290. The plantation at Grund south of Akureyri [P. L.], det. ©. Rostrup. — On dead branches of Populus tremula. Mucedinaceae-Hyalosporae. Chromosporium Corda. 735. C. croceum (Montagne) Saccardo, Syll. fung. IV, p 7. Mooruvellir [St. St]. — On rotten agarics. 736. C. vitellinum Saccardo, Syll. fung. IV, p. 7. Grimsey, Hof, Fagriskögur [O. D.]; Médruvellir, Vidvik [St. St.]. — On fish-bones, skin, and horse-dung. HI — FUNGI OF ICELAND 5 737. C. lateritium (Berkeley et Broome), Saccardo, Syll. fung. IV, p. 5. Hof [O.D.]. — On a bone. 738. C. album (Corda) Saccardo, Syll. fung. IV, p. 8. Gymnosporium album Corda, Icones fung. I, p. 1, fig. 10. Hofsfjall, Hälsskögur [O. D.]. — On leaves of Oxyria and of birch. Oospora Wallroth. 739. O.nivea (Fuckel) Saccardo, Syll. fung. IV, p. 16. Grimsey, Hof, Fagriskögur [O. D.]. — On the skeleton of a fish, in a sheep-fold and in a haybarn. Syll. 740. QO. rosella Grove, Saccardo, Syll. fung. IV, p. 63. Hof [O. D. — On horse-dung. 741. O. coccinea (Corda) Saccardo, Syll. fung. IV, p. 21. Vallanes [H.J.]. — On wood. Fusidium Link. 742. F. punctiforme Schlecht., Botanische Zeitung 1852, p. 617. Hof [O. D.]. — On living leaves of Epilobium palustre. Trichoderma Persoon. 743. T. viride Persoon, Synops. meth. fung., p. 230. Hof [0.D.]. — On wood in a stable and on cardboard. 744. T. cinnabarinum Wallroth, Saccardo, Syll. fung. IV, p. 61. Mööruvellir (St. St... — On woodwork in a sheep-fold. Sporotrichum Link. 745. S. griseum Link, Observationes mycologicae I, p. 11. — Saccardo, fung. IV, p. 110. Mööruvellir (St. St... — On food in a cellar. Ovularia Saccardo. 746. O. obliqua (Cooke) Oudemans, Saccardo, Syll. fung. IV, p. 145. Mööruvellir, Hraun in Fljöt [O. D.); Hvammur, Kvennabrekka (H. J.); Reykjavik [Gronlund); Drangshlid, Vallanes [H.J.]. — On living leaves of Rumex domesticus. 747. O. rigidula Delacroix, Saccardo, Syll. fung. X, p. 541. Hof [O.D.). — On living leaves of Polygonum aviculare. 572 POUL LARSEN 748. O. decipiens Saccardo, Syll. fung. IV, p. 139. Hölar in Hjaltadalur (St. St.]. — On living leaves of Ranunculus acer. 749. O. alpina Massee, Saccardo, Syll. fung. X, p. 542. Fornhagagil [O.D.]. — On living leaves of Alchimilla alpina. Botrytis Micheli. 750. B. vulgaris Fries, Syst. Myc. III, p. 398. Hestahraun in Porvaldsdalur [O. D. — On Alchimilla alpina. 751. B. cinerea Persoon, Synops. meth. fung., p. 690. Hestahraun in Porvaldsdalur, Fornhagagil, Hof [O.D.]; Krökur in S. Iceland [H.J.]. — On Hieracium murorum, Geranium silvaticum, Polygonum aviculare, Geum rivale, Sibbaldia procumbens. Verticillium Nees. 752. V. lateritium Berkeley, Saccardo, Syll. fung. IV, p. 156. Hof [O.D.]. — On fish-skin. Mucedinaceae-Hyalodidymae. Trichothecium Link. 753. T. roseum Fries, Syst. Myc. III, p. 427. Hlidarfjall near Myvatn [P.L.], det. ©. Rostrup. — On ptarmigan droppings. Arthrobotrys Corda. 754. A. superba Corda, Saccardo, Syll. fung. IV, p. 181. Seydisfjöröur [P. L.], det. ©. Rostrup. — On sheep dung. Bostrychonema 755. B. alpestre Cesati, Saccardo, Syll. fung. IV, p. 185. Mvvatnsheidi [O.D.). — On leaves of Polygonum viviparum. Mucedinaceae-Phragmosporae. Mastigosporium Ries. 756. M. album Ries in Fresenius, Beitr., p. 56, tab. VI. — Saccardo, Syll. fung. IV, p. 220. Dalsmynni (S. W. Iceland) [H. J... — On Agrostis vulgaris and Hierochloa borealis. FUNGI OF ICELAND 513 Monacrosporium Oudemans. 757. M. elegans Oudemans, Niederlandsch Kruidkundig Archief, 2. Ser. IV, 250 (1884), Tab. V, fig. 9. — Saccardo, Syll. fung. IV, p. 493. Hlidarfiall near Myvatn [P.L.], det. O. Rostrup. — On ptarmigan droppings. Ramularia Unger. 758. R. Bistortae Fuckel, Symbolae, p. 361. Hofsfjall, Hestahraun in Porvaldsdalur [O. D.]. — On leaves of Poly- gonum viviparum. 759. R. aequivoca (Cesati) Saccardo, Syll. fung. IV, p. 201. Hof, Rhaun in Fljöt [O. D. — On leaves of Ranunculus acer, R. repens. 760. R. lactea (Desmazières) Saccardo, Syll. fung. IV, p. 201. Hof [O.D.]. — On leaves of Viola canina and V. tricolor. 761. R. Chamaenerii Rostrup, Isl. Svampe 1885, p. 229. — Syll. fung. X, p- 577. Herdubreidarlindir {Thoroddsen). — On leaves of Chamaenerium latifolium. 762. R. punctiformis (Schlecht.) v. Höhnel, Saccardo, Syll. fung. IV, p. 453. A garden in Reykjavik [H.J.. — On Chamaenerium angusti- folium. 763. R. Archangelicae Lindroth, Saccardo, Syll. fung. XVIII, p. 551. Sluttnes in Myvatn [P.L.], det. O. Rostrup. — On Archangelica officinials. 764. R. Bartsiae Johanson, Svampar fran Isl. 1884, p. 173. Eskifjördur [Strömfelt]). — On leaves of Bartsia alpina. 765. R. filaris Fresenius, Saccardo, Syll. fung. IV, p. 210. Hestahraun in Porvaldsdalur [O.D.]. — On leaves of Gnaphalium norvegicum. 766. R. Taraxaci Karsten, Saccardo, Syll. fung. IV, p. 207. Hof [O.D.]. — On leaves of Taraxacum officinale. Dematiaceae-Phaeosporae. Contosporium Link. 767. C. aterrimum (Corda) Saccardo, Syll. fung. IV, p. 240. Gymnosporium a. Corda, Icones fung. II, p. 1, tab. 8, fig. 2. Myvatn [O.D.). — On a decorticated branch. 574 POUL LARSEN 768. C. fusidioides (Corda) Saccardo, Syll. fung. IV, p. 242. Gymnosporium fusidioides Corda, Icones fungorum, p. 1, fig. 16. Mödruvellir [O. D.]. — On timber. 769. C. variabile (Peck) Saccardo, Syll. fung. IV, p. 241. Gymnosporium y. Peck, Reports New York Museum, vol. 33, p. 27. Gäsir [O.D.]. — On wood. 770. C. melanconidium Saccardo, Syll. fung. IV, p. 239. Hälsskögur [O.D.). — On Arcthostaphylos uva ursi. Torula Persoon. 771. T.epizoa Corda var. muriae Kickx, Flore cryptogamique des Flandres II, p. 299. — Saccardo, Syll. fung. IV, p. 261. Reykjavik [H.J.]. — On split cod. Hormiscium Kunze. 772. H. stilbosporum (Corda), Saccardo, Syll. fung. IV, p. 264. Brunastadahölmi [O. D.]. — On Salix sp. 773. H. betulinum Karsten, Symbolae ad mycologiam fennicam XXV, p. 25. — Saccardo, Syll. fung. IV, p. 575. Hof in Hörgärdalur [O.D.]. — On bark of Betula nana. 774. H. altum Ehrenberg, Sylvae Mycologicae Berolinensis, p. 10 et 12. — Saccardo, Syll. fung. IV, p. 263. Hälsskögur [O.D.]. — On Betula pubescens. Periconia Bonorden. 775. P. alternata (Berkeley) Saccardo, Syll. fung. IV, No. 1332. Hof [O. D.]. — On woodwork and cardboard. Arthrinium Kunze. 776. A. bicorne Rostrup, Botanisk Tidsskrift, vol. 15, p. 235. Hofsfjall [O. D.]. — On Juncus balticus and J. trifidus. Goniosporium Link. 777. G. puccinioides (Fries) Link, Saccardo, Syll. fung. IV, p. 280. Arthrinium pucc. Kunze, Fries: Systema mycologicum III, p. 376. Mööruvellir, Hof [O. D.]; Spénsgerdi [St. St.]; Hurdarös [Thoroddsen]; Eskifjördur [Strömfelt]. — On Carex rigida and Cobresia scirpina. FUNGI OF ICELAND 575 Hadrotrichum Fuckel. 778. H. virescens Saccardo et Roumerque, Syll. fung. IV, p. 301. Hof in Hörgärdalur [O.D.]. — On Agrostis alba. Dematiaceae-Phaeodidymae. Fusicladium Bonorden. 779. F. Angelicae (Fries) Lind, Danish Fungi, p. 521. F. depressum (Berkeley et Broome) Saccardo, Syll. fung. IV, p. 346. Mardarnupsgil, Hörgärdalur (St. St]. — On living leaves of Angelica silvestris and Archangelica officinalis. Scolecotrichum Kunze et Schmidt. 780. S. graminis Fuckel, Saccardo, Syll. fung. IV, p. 348. Grimsey, Hof, Mööruvellir, Hestahraun in Porvaldsdalur [O. D.]; Eyja- fjöröur, Vogar near Myvatn [Strömfelt]. — On Glyceria distans, Alope- curus geniculatus, Agropyrum violaceum and Phleum pratense. Cladosporium Link. 781. C. lycoperdinum Cooke in Ravenel Amer. Fungi, No. 595 et in Grevillea 1883, p. 32. — Saccardo, Syll. fung. IV, p. 368. Rhaun in Fljöt [O.D.). — On Bovista nigrescens. 782. C. graminum Corda, Saccardo, Syll. fung. IV, p. 365. Common on grasses: Poa alpina, P. caesia, Festuca ovina, F. rubra, Trisetum subspicatum etc. 783. C. perpusillum Saccardo, Syll. fung., p. 364. Grimsey [O. D.]. — On straws of Elymus arenarius. 784. C. caricicola Corda, Saccardo, Syll. fung. IV, p. 365. The plantation at Grund near Akureyri, a bog near Hallormstadir IP.L.]. — On Carex rigida and Cobresia scirpina. 785. C. entoxylinum Corda, Saccardo, Syll. fung. IV, p. 353. Mööruvellir, Hälsskögur, Hraun in Fljöt [O.D.]. — On wood. 786. C. herbarum (Persoon) Link, Saccardo, Syll fung. IV, p. 350. Throughout the country on dead stems of many different plants, as: Selaginella, Juncus arcticus, Rumex domesticus, Arenaria ciliata, Viscaria alpina, Cardamine bellidifolia, .Saxifraga caespitosa, Matricaria inodora. 576 POUL LARSEN Dematiaceae-Phaeophragmiae. Cercospora Fresenius. 789. C. Paridis Eriksson, Saccardo, Syll. fung. IV, p. 476. C. Paridis Rostrup, Mykologiske Notitser i Overs.Vet. Akad. 1883, No.4. Budir [Gronlund). — On leaves of Paris quadrifolia. Dematiaceae-Phaeodictyae. Coniothecium Corda. 788. C. applanatum Saccardo, Syll. fung. IV, p. 508. Pjorsärdalur [O. D.]. — On wood. 789. C. betulinum Corda, Saccardo, Syll. fung. IV, p. 510. Hlöd, Hälsskögur [O.D.|; Pingvellir (P. L.|. — On wood of Betula nana and B. pubescens. 790. C. effusum Corda, Saccardo, Syll. fung. IV, p. 508. Hälsskögur [O.D.]. — On birch-wood. Stemphylium Walroth. 791. S. atrum (Preuss) Saccardo, Syll. fung., p. 520. — Ulocladium atrum Preuss in Linnaea vol.25 1852, p. 75. Arnarnes [O.D.]. — On drift-wood. Macrosporium Fries. 792. M. commune Rabenhorst, Saccardo, Syll. fung. IV, p. 524. Common on dead parts of many different plants, as: Archange- lica, Rhodiola, Cochlearia, Cerastium, Oxyria, Elymus and several others, Phaeostilbaceae. Isariopsis Fries. 793. 1. pusilla Fresenius, Beitr. t. XI, fig. 18—28. I. albarosella (Desmazieres), Saccardo, Syll. fung. IV, p. 368. Hraun in Fljöt [O.D.]. — On leaves of Stellaria sp. Mucedineae-Amerosporae. Tubercularia Tode. 794. T. vulgaris Tode, Saccardo, Syll fung. IV, p. 638. A garden in Reykjavik [P. L.], det. O. Rostrup. — On Prunus padus. Or ml =] FUNGI OF ICELAND Illosporium Mart. 795. I. corallinum Robert, Saccardo, Syll. fung. IV, p. 657. Hälsskögur [0. D. — On the thallus of Peltigera. Volutella Tode. 796. V. ciliata (Albertini et Schweinitz) Fries, Saccardo, Syll. fung. III, p. 467. Hof [O.D.]; Seydisfjördur [P.L... — On sheep dung and on rotten potatoes. Mucedineae-Phragmosporae. Fusarium Link. 797. F. Kühnii (Fuckel) Saccardo, Syll. fung. IV, p. 714. Hof [O.D.]. — Common on moss protonema. 798. F. Solani (Mart.) Saccardo, Syll. fung. IV, p. 705. Hof [O. D.]. — On rotting potatoes. 799. F. larvarum Fuckel, Saccardo, Syll. fung. IV, p. 709. Gäsir [O.D.]. — On a larva. Tuberculariaceae-Dematieae. Epicoccum Link. 800. E. Davidssonii Rostrup, Isl. Svampe 1903, p. 324. Torfastadahölmi [O.D.). — On leaves of Geranium silvaticum. Myrothecium Tode. 801. M. roridum Tode, Saccardo, Syll. fung. IV, p. 750. Lava fields at Reykjahlid [P. L.), det. O. Rostrup. — On Achillea millefolium. Epiclinium Fries. 802. E. atrum Bonorden, Handbuch der allgemeinen Mykologie II, Stuttgart 1851, p. 96, t. I, fig. 13. — Saccardo, Syll. fung. IV, p. 755. Mööruvellir [O.D.). — On wood. The Botany of Iceland, Vol. II. part Ill. 38 HOST INDEX. Laminaria digitata Dothidella Laminariae Laminaria saccharina Dothidella Laminariae Alaria esculenta Dothidella Laminariae Boletus scaber Hypomyces chrysospermus Bovista nigrescens Cladosporium lycoperdinum Stereocaulon paschale Scutula Stereocaulorum Solorina crocea Bertia lichenicola Peltigera canina Ilosporium corallinum Lecanora sordida Celidium varians Aspicilia gibbosa Tichothecium pygmaeum Parmelia saxatilis Abrothallus Parmeliarum Tetraplodon bryoides Phoma muscorum Cystopteris fragilis Hyalospora Polypodii Dryopteris pulchella Gloeosporium filicinum Dryopteris sp. Mycosphaerella Filicum Equisetum palustre Stamnaria Equiseti Phoma Equiseti Staganospora Equiseti Equisetum variegatum Leptosphaeria Equiseti Equisetum sp. Pyrenophora chrysospora Mycosphaerella Equiseti Helotium rhodoleucum Lycopodium selago Leptosphaeria Marcyensis Mycosphaerella lycopodina Lycopodium annotium Phoma Lycopodii Selaginella spinulosa Cladosporium herbarum Pinus montana Lophodermium Pinastri Juniperus nana Melanomma juniperinum Lophiostoma Juniperi Lophodermium juniperinum Juniperus communis Herpotrichia nigra Triglochin maritima Pleospora Triglochinis Triglochin palustris Mycosphaerella Juncaginearum Anthoxanthum odoratum Lamproderma violaceum Pyrenophora phaeocomes Pleospora herbarum Leptosphaeria culmicola Lophodermium arundinaceum Puccinia Anthoxanthi P. borealis Hierochloé borealis Mycosphaerella recutita Lophodermium arundinaceum FUNGI OF ICELAND 579 Puceinia borealis Trisetum spicalum Mastigosporium album Pleospora straminis Phleum alpinum P. islandica Lachnum patens P. pentamera Physalospora montana Phleum pratense a Belonidium rufum Mycosphaerella pusilla Lachnum patens Trisetum subspicatum Scolecotrichum graminis Pleospora Karstenii Milium effusum Lophodermium arundinaceum Leptosphaeria culmifraga Cladosporium graminum L. eulmicola Catabrosa aquatica Alopecurus pratensis Entyloma Catabrosae Claviceps microcephala Poa annua Alopecurus geniculatus Entyloma irregulare Scolecotrichum graminis Poa alpina Leptosphaeria culmifraga L. microscopica L. culmicola Lophodermium arundinaceum Uromyces Dactylidis Puccinia Poarum Hendersonia silvatica Agrostis canina Pleospora punctiformis Leptosphaeria microscopica Phyllachora graminis Agrostis alba Pleospora herbarum | Hadrotrichum virescens Septoria graminum | Agrostis vulgaris BA | Cladosporium graminum Phyllachora graminis | Poa caesia Puccinia borealis al | Pleospora islandica Typhula graminum P. pentamera Mastigosporium album Leptosphaeria culmifraga Calamagrostis stricta | Guignardia graminicola Leptosphaeria arundinacea Phyllachora Poae L. Fuckelii | Lophodermium arundinaceum Lophodermium arundinaceum | Cladosporium graminum Myiocopron calamagrostidis | Poa nemoralis Puccinia borealis | Leptosphaeria culmifraga Tilletia striiformis | Lophodermium arundinaceum Deschampsia caespitosa | Lachnum patens Lamproderma physaroides | Poa pratensis Pleospora vagans var. Airae | Claviceps microcephala Leptosphaeria culmifraga | Uromyces Dactylidis L. Fuckelii | Puccinia Poarum L. culmicola | Tilletia striiformis Dilophia graminis Staganospora graminella Uromyces Dactylidis Glyceria distans Puccinia borealis Pleospora pentamera Uredo Airae | Scolecotrichum graminis Entyloma crastophilum Stagonospora graminella | Festuca ovina Pyrenophora chrysospora Deschampsia flexuosa | Lophodermium arundinaceum Pleospora Karstenii | Cladosporium graminum 38" 580 Festuca rubra Claviceps purpurea Mycosphaerella recutita Physalospora Festucae Lophodermium arundinaceum Uromyces Festucae Cladosporium graminum Nardus strictus Lophodermium arundinaceum Godronia pusiola Agropyrum violaceum Typhula graminum Scolecotrichum graminis Agropyrum caninum Pleospora islandica Leptosphaeria nigrans Mycosphaerella recutita Elymus arenarius Pleospora microspora P. vagans P. gigaspora P. herbarum Leptosphaeria culmifraga L. Elymi Lophodermium arundinaceum L. arundinaceum var. alpinum Phyllosticta Elymi Staganospora curvula Hendersonia arundinacea Rhabdospora curva Cladosporium perpusillum Macrosporium commune Hordeum vulgare Ustilago Hordei Graminaceae spp. Erysiphe graminis Mycosphaerella lineolata Stagonospora islandica Eriophorum angustifolium Lophodermium caricinum Mollisia advena Erinella callimorpha Eriophorum Scheuchzerii Pleospora discors Sclerotinia Vahliana Scirpus caespitosus Mycosphaerella perexigua Cintractia Caricis POUL LARSEN Heleocharis palustris Physoderma Heleocharidis Pleospora scirpicola Stagonospora aquatica Cobresia scirpina | Leptosphaeria culmifraga Lophodermium caricinum Naevia ignobilis Cintractia Caricis Septoria punctoidea Goniosporium puccinioides Cladosporium caricicola | Carex dioeca Cintractia Caricis Carex nardina Septoria Caricis Carex capitata Naevia diminuens Carex rupestris Mycosphaerella Wichuriana Carex chordorrhiza Mycosphaerella pusilla M. Wichuriana Carex stellulata Cintractia Caricis Carex lagopina Metasphaeria culmifida Mycosphaerella Wichuriana Leptostroma caricinum Carex festiva Lophodermium caricinum Carex salina Ophiobolus herpotrichus Urocystis Fischeri Carex rigida Metasphaeria macrotheca Mycosphaerella Wichuriana Naevia atrosanguinea N. diminuens N. ignobilis N. fuscella Cintractia Caricis Typhula graminum Leptostroma caricinum Goniosporium puccinioides Cladosporium caricicola Carex hyperborea Naevia fuscella Hendersonia Stefanssonii FUNGI OF ICELAND Carex pulla Naevia fuscella Carex Goodenoughii Mycosphaerella Wichuriana Naevia atrosanguinea N. fuscella Puceinia Caricis Cintractia Caricis Leptostroma caricinum Carex alpina Leptostroma caricinum Carex atrata Naevia diminuens N. ignobilis Puccinia Caricis Cintractia Caricis Hendersonia Caricis Carex capillaris Didymella proximella Lophodermium caricinum Cintractia Caricis Carex panicea Cintractia Caricis Carex vaginata Naevia ignobilis Septoria Caricis Carex rostrata Naevia ignobilis Carex sp. Puccinia Caricis P. uliginosa Tilletia arctica Leptostroma caricinum Juncus balticus Pleospora pentamera P. Junci P. Elynae Naevia pusilla Belonidium juncicedum B. Laschii Dasyscypha diminuta Tolyposporium Junci Arthrinium bicorne Juncus arcticus Cladosporium herbarum Juncus filiformis Naevia pusilla 581 Juncus triglumis Pleospora Spartii P. Elynae Leptosphaeria Apogon Juncus biglumis Leptosphaeria juncina Mycosphaerella perexigua Juncus trifidus Lachnum calycioides Arthrinium bicorne Luzula arcuata Leptosphaeria Luzulae Naevia diminuens Luzula multiflora Pyrenophora hispidula Pleospora vagans Naevia pusilla Cintractia Luzulae Vermicularia Liliacearum Luzula spicata Pleospora Junci var. Luzulae Ascochyta teretiuscula Tofieldia borealis Pyrenophora chrysospora Pleospora vulgaris P. herbarum Leptosphaeria oreophila Phoma Tofieldiae Paris quadrifolia Cercospora Paridis Coeloglossum viride Septoria Orchidearum Iris germanica Phyllosticta Pseudacori Salix herbacea Mycosphaerella salicicola Venturia chlorospora Gnomonia pleurostyla Rhytisma salicinum Cryptomyces maximus Melampsora arctica Discosia Artocreas Salix glauca Ophiobolus salicinus Venturia chlorospora Hypospila groenlandica Linospora Capreae 582 POUL LARSEN Lophodermium maculare Rhytisma salicinum Melampsora arctica Septoria salicella Leptostroma punctiforme Excipula sphaeroides Salix phylicifolia Nectria Coryli Strickeria Kochii S. salina Venturia chlorospora Linospora caudata Diaporthe salicella Lophodermium versicolor Rhytisma salicinum Tympanis saligna Melampsora arctica Crepidotus citrinus Phoma salicina Aposphaeria pulviuscula Asteroma Salicis A. Capreae Cytospora Salicis Myxosporium salicinum Salix lanata Amphisphaeria papillata Strickeria Davidssonii Mycosphaerella Capronii Venturia chlorospora Linospora Capreae L. insularis Fenestella princeps Diatrype bullata Rhytisma salicinum Lachnella corticalis Lachnum niveum Helotium virgultorum Melampsora arctica Septoria salicella S. Capreae Salix sp. Vermicularia trichella Hendersonia salicina Septoria salicina Piggotia atronitens Hormiscium stilbosporum Populus tremula Steganosporium traphinum Alnus glutinosa Phoma endoleuca Betula pubescens Enteridium olivaceum Comatricha nigra Taphrina betulina T. carnea Nectria coccinea N. Peziza Leptospora ovina Lasiosphaeria sorbina var. radiata Rossellinia mammiformis R. subcorticalis Zignoella ovoidea Melanomma Pulvis pyrius M. Aspegrenii Strickeria obducens f. betulina Mycosphaerella maculiformis Venturia ditricha Gnomonia campylostyla G. setacea Valsa betulina V. polyspora Diaporthe aristata Fenestella tumida Cryptospora Betulae Valsaria Niesslii Melanconis stilbostoma Pseudovalsa lanciformis Diatrypella verrucaeformis D. favacea Calosphaeria ciliatula C. pusilla Hypoxylon fuscum Dothidella betulina Lophium dolabriforme Cryptodiscus pallidus Propolis faginea Ocellaria chrysophaea Agyrium rufum Patellaria atrata P. Bagnisiana Godronia urceolus Tapesia fusca Mollisia caesia M. Schumacheri Niptera ramealis Orbilia coccinella O. auricolor FUNGI OF ICELAND 583 Lachnella corticalis Lachnum bicolor L. virgineum Helotium citrinum H. virgultorum Coryne sarcoides Melampsora betulina Exidia repanda E. alba Tremella lutescens Dacryomyces deliquescens Hydnum argutum Tomentella ferruginea Corticium incarnatum Stereum vorticosum S. hirsutum S. rugosum S. tuberculosum Radulum orbiculare Phlebia radiata Merulius corium Polyporus croceus Polystictus hirsutus Pleurotus applicatus Cytospora betulina Cytosporium betulinum Discosia Artocreas Melanconium elevatum M. bicolor Hormiscium altum Coniothecium betulinum C. effusum Betula nana Taphrina nana T. carnea T. bacteriosperma Mycosphaerella harthensis Gnomonia campylostyla Diaporthe aristata Dothidella betulina Tapesia fusca Septoria betulina Hormiscium betulinum Coniothecium betulinum Ulmus montana Aposphaeria glomerata Coniothyrium olivaceum Urtica dioeca Phoma Urticae Rumex domesticus Sclerotinia Fuckeliana Phialea cyathoidea Dendrophoma marchica Rhabdospora pleosporoides Ovularia obliqua Cladosporium herbarum Rumex acetosa Pyrenophora chrysospora P. phaeocomoides Venturia caulicola Vermicularia Dematium Septoria semilunaris Rhabdospora pleosporoides Rumex acetosella Pleospora herbarum Mycosphaerella Polygonorum Rhabdospora pleosporoides Oxyria digyna Pyrenophora chrysospora Pleospora vulgaris Guignardia Oxyriae Phialea cyathoidea Puccinia Oxyriae Ustilago vinosa Rhabdospora pleosporoides Chromosporium album Macrosporium commune Polygonum viviparum Mycosphaerella Polygonorum Rhytisma Bistortae Puccinia septentrionalis P. Bistortae Ustilago Bistortarum Sphacelotheca Hydropiperis Rhabdospora pleosporoides Botrychonema alpestre Ramularia Bistortae Polygonum aviculare Sclerotinia Fuckeliana Uromyces Polygoni Ovularia rigidula Botrylis cinerea Atriplex patula Phoma acuta Montia lamprosperma Tolysporium Montiae Cerastium lapponicum Peronospora Alsinearum 584 POUL LARSEN Cerastium arcticum Pyrenophora chrysospora Cerastium alpinum Peronospora Alsinearum Pyrenophora Androsaces P. comata Pleospora herbarum Mycosphaerella isariphora Calloria erythrostigmoides Phialea dolosella Melampsorella Cerastii Septoria cerasticola S. Stellariae Cerastium caespitosum Pyrenophora comata Pleospora herbarum Fabraea Cerastiorum Melampsorella Cerastii Macrosporium commune Alsine verna Pleospora herbarum Mycosphaerella isariphora Septoria Alsines Alsine stricta Pyrenophora chrysospora Mycosphaerella isariphora Alsine biflora Pyrenophora comata P. chrysospora Pleospora herbarum Mycosphaerella isariphora Alsine rubella Pleospora herbarum Honckenya peploides Phoma herbarum Arenaria ciliata Pyrenophora hispida P. chrysospora Mycosphaerella isariphora M. tingens M. densa Cladosporium herbarum Viscaria alpina Pyrenophora comata P. chrysospora Pleospora alpina Mycosphaerella sibirica Sclerotinia Fuckeliana Cladosporium herbarum Silene vulgaris Phialea cyathoidea Silene maritima Pleospora herbarum Leptosphaeria Silenes-acaulis Mycosphaerella sibirica Silene acaulis Pyrenophora Androsaces Leptosphaeria Silenes-acaulis Mycosphaerella sibirica Ustilago violacea Caltha palustris Physoderma vagans Aconitum sp. Phoma tingens Ranunculus glacialis Mycosphaerella Tassiana Mollisia atrata Ranunculus reptans Synchytrium aureum Ranunculus pygmaeus Mycosphaerella fusispora Ranunculus acer Peronospora Ficariae Mycosphaerella vulgaris Fabraea Ranunculi Phialea cyathoidea Puccinia Blyttianae Entyloma Ranunculi Phyllosticta Ranunculorum Heteropatella cercosperma Ovularia decipiens Ramularia aequivoca Ranunculus repens Ramularia aequivoca Thalictrum alpinum Pyrenophora chrysospora Pleospora herbarum Massaria Thalictri Urocystis sorosporioides Discosia Artocreas Papaver radicatam Leptosphaeria Papaveris Mycosphaerella arthopyre- noides Draba alpina Pyrenophora Androsaces FUNGI OF ICELAND 585 Draba incana Cystopus candidus Erysiphe communis Sphaerotheca humuli Pyrenospora chrysospora Mycosphaerella Tassiana Puceinia Drabae Draba rupestris Pleospora Drabae Mollisia cinerea Puccinia Drabae Draba nivalis Pyrenophora chrysospora Pleospora herbarum P. Drabae Mycosphaerella Tassiana Cochlearia officinalis Macrosporium commune Capsella bursa pastoris Cystopus candidus Peronospora parasitica Phoma herbarum Arabis alpina Peronophora chrysospora Metasphaeria Arabidis M. islandica Arabis petraea Pyrenophora hispida P. chrysospora Pleospora herbarum Metasphaeria Arabidis Mycosphaerella Tassiana Heteropatella cercosperma Cardamine pratensis Peronospora parasitica Mycosphaerella Cruciferarum Puccinia Cruciferarum Cardamine hirsuta Cystopus candidus Cardamine bellidifolia Cystopus candidus Pyrenophora chrysospora Pleospora herbarum Cladosporium herbarum Erysimum sp. Phoma oleraceum Rhodiola rosea Pleospora deflectens Mycosphaerella Tassiana Dothidella thoracella Schizoxylon Berkeleyanum Macrosporium commune Sedum villosum Pyrenophora chrysospora Diaporthe muralis Sclerotinia Fuckeliana Sedum annuum Pyrenophora chrysospora Saxifraga oppositifolia Pyrenophora chrysospora Pleospora herbarum Mycosphaerella Tassiana Didymella inconspicua Melampsora Saxifragarum Exobasidium Warmingii Saxifraga stellaris Puccinia Saxifragae Saxifraga nivalis Sclerotinia Fuckeliana Puccinia Saxifragae Phoma Saxifragarum Saxifraga aizoides Pyrenophora chrysospora var. polaris Melampsora Saxifragarum Saxifraga hirculus Mycosphaerella Tassiana Saxifraga rivularis Pyrenophora chrysospora Saxifraga caespilosa Pyrenophora chrysospora Pleospora herbarum Mycosphaerella Tassiana Melampsora Saxifragarum Cladosporium herbarum Saxifraga hypnoides Synchytrium groenlandicum Pyrenospora chrysospora Melampsora Saxifragarum Parnassia palustris Mycosphaerella Parnassiae Puccinia uliginosa Septoria semilunaris Ribes rubrum Plowrigthia ribesia Leptosphaeria Ribis 586 POUL LARSEN Nectria cinnabarina Phoma ribicola Phomopsis ribesia Ribes alpinum Phoma Malvacei Hendersonia Ribis alpini Rubus saxatilis Pyrenophora chrysospora Microthyrium Rubi Phoma ruborum Rubus idaeus Pyrenopeziza Rubi Potentilla Crantzii = P. maculata Pyrenophora chrysospora Pleospora vulgaris P. herbarum Guignardia Potentillae Sphaerulina Potentillae Physalospora Potentillae Leptostroma Potentillae Potentilla verna Mycosphaerella melanoplaca Potentilla anserina Marssonina Potentillae Potentilla palustris Physoderma vagans Mycosphaerella Tassiana Marssonina Potentillae Septogloeum Fragariae Sibbaldia procumbens Trichia contorta Mycosphaerella innumerella Lophodermium petiolicolum Sclerotinia Fuckeliana Botrytis cinerea Geum rivale Sclerotinia Fuckeliana Rhabdospora pleosporoides Discosia Artocreas Botrytis cinerea Dryas octopetala Synchytrium cupulatum Pleospora herbarum Leptosphaeria Dryadis Lizonia abscondita Mycosphaerella ootheca M. Dryadis Venturia islandica Massarina Dryadis Gnomonia vagans Hypospila rhytismoides Septoria semilunaris Filipendula ulmaria Triphragmium Ulmariae Phyllosticta filipendulina | Alchimilla alpina Pleosphaerulina vitrea Sclerotinia Fuckeliana Phoma Alchimillae Discosia Artocreas Ovularia alpina Botrytis vulgaris Alchimilla vulgaris Coleroa Alchimillae Uromyces Alchimillae Phoma herbarum Prunus padus Cytospora leucostoma Tubercularia vulgaris Sorbus aucuparia Dothiora Sorbi Nectria cinnabarina Corticium incarnatum Aposphaeria subtilis Cytospora Massariana C. microspora Rhabdospora inaequalis Dothichiza Sorbi Myxosporium Aucupariae Sorbus suecica Mollisia melaleuca Anthyllis vulneraria Mycosphaerella Vulnerariae Vicia cracca Peronospora Viciae Pyrenophora chrysospora P. phaeocomoides Pleospora deflectens Mycosphaerella Viciae Phoma melaena Septoria Viciae Geranium silvalicum Leptosphaeria agnita Metasphaeria complanata Fabraea confertissima Sclerotinia Fuckeliana FUNGI OF ICELAND Cyphella villosa Septoria semilunaris Epicoccum Davidssonii Linum catharticum Pleospora herbarum Melampsora Lini Viola tricolor Pleospora herbarum Ramularia lactea Phialea cyathoidea Fusicladium Angelicae Archangelica officinalis Leptosphaeria Doliolum Metasphaeria Angelicae Dothidella Angelicae Heterosphaeria Patella Calloria minutissima Phialea cyathoidea Viola canina Puceiniae Violae Ramularia lacteae Coniothyrium conoideum Heteropatella cercosperma Ramularia Archangelicae Viola palustris Puceinia Fergussoni Epilobium lactiflorum Puccinia Epilobii Epilobium alsinefolium Puccinia Epilobii Epilobium palustre Melampsora pustulata Pucciniastrum Epilobii Puccinia Epilobii Fusidium punctiforme Epilobium alpinum Melampsora pustulata Puceinia Epilobii Chamaenerium latifolium Mycosphaerella Tassiana Ramularia Chamaenerii Chamaenerium angustifolium Ramularia punctiformis Hippuris vulgaris Physoderma Hippuridis Cornus suecica Leptothyrium vulgare Carum carvi Phialea cyathoidea Leptostroma herbarum Heteropatella cercosperma Haloscias scoticum Puccinia Halosciadis Angelica silvestris Metasphaeria Angelicae Mycosphaerella rubella Dothidella Angelicae Heterosphaeria Patella Fusicladium Angelicae Macrosporium commune Pyrola secunda Melampsora Pyrolae Pyrola minor Melampsora Pyrolae Chrysomyxa Pyrolae Loiseleuria procumbens Mycosphaerella polyspora Arctostaphylos uva ursi Asteroma alpinum Gloeosporium alpinum 587 Coniosporium melanconideum Vaccinium uliginosum Podosphaera myrtillina Venturia Myrtilli Lophodermium maculare Clithris degenerans Melampsora Vacciniorum Exobasidium Vaccinii Diplodina Eurhododendri Vaccinium Myrtillus Coccomyces quadratus Pseudophacidium degenerans Melampsora Vacciniorum Exobasidium Vaccinii Diapensia lapponica Sphaerulina Diapensiae Sphaeropeziza Arctostaphyli Ascochyta Diapensiae Primula stricta Pyrenophora chrysospora Armeria maritima Pleospora herbarum Leptosphaeria microscopica Uromyces Limonii 588 Solanum tuberosum Phytophthora infestans Phoma solanicola Volutella ciliata Fusarium Solani Veronica serpyllifolia Peronospora grisea Veronica alpina Pyrenophora chrysospora Guignardia Veronicae Puccinia Veronicarum Veronica saxatilis Pyrenophora chrysospora Ascochyta Veronicae Veronica Anagallis Synchytrium globosum Euphrasia latifolia Pyrenophora chrysospora Phoma herbarum Rhabdospora eupyrenoides Bartsia alpina Pyrenophora chrysospora Mollisia atrata Phoma Sceptri P. herbarum Placosphaeria Bartsiae Ramularia Bartsiae Alectorolophus crista galli Plasmopara densa Pyrenophora chrysospora P. abscondita Scleroderris aggregala Phoma complanata Ph. deusta Pedicularis flammea Pyrenophora Androsaces Slerotinia Fuckeliana Phoma Sceptri Plantago major Peronospora alta Plantago maritima Pyrenophora chrysospora Septoria semilunaris Myosotis arvensis Erysiphe Cichoriacearum Thymus serpyllum Pleospora vulgaris P. herbarum POUL LARSEN Mycosphaerella Tassiana Puccinia Schneideri Phoma herbarum Gentiana nivalis Pyrenophora chrysospora Mycosphaerella Gentianae Gentiana campestris Pyrenophora chrysospora Sclerotinia Fuckeliana Gentiana amarella Mycosphaerella Tassiana Menyanthes trifoliata Physoderma Menyanthis Campanula uniflora Pleospora herbarum Campanula rotundifolia Coleosporium Campanulae Galium pumilum Pleospora herbarum Puccinia punctata Stagonospora Galii Galium verum Peronospora calotheca Mazzantia Galii Placosphaeria Galii Septoria Galiorum Galium boreale Peronospora calotheca Phacidium repandum Cirsium arvense Pleospora herbarum Mycosphaerella Compositarum Erigeron alpinus Pyrenophora chrysospora Pleospora herbarum Mycosphaerella eriophila Guignardia lunulata Septoria semilunaris Erigeron neglectus Pyrenophora chrysospora Gnaphalium norvegicum Mycosphaerella Compositarum Sclerotinia Fuckeliana Helotium scutula Phialea cyathoidea Heteropatella cercosperma Ramularia filaris FUNGI OF ICELAND Achillea millefolium Pyrenophora phaeocomoides P. coronata Ophiobolus Cesatianus Matricaria inodora Phoma herbarum Cladosporium herbarum Leontodon autumnalis Puccinia Leontodontis Taraxacum vulgare Protomyces pachydermus Sphaerotheca humuli Pyrenophora chrysospora Mycosphaerella Taraxaci Puccinia variabilis Ramularia Taraxaci Taraxacum croceum Puccinia silvatica Crepis paludosa Physoderma Crepidis 589 Hieracium alpinum Puccinia Hieracii Heteropatella cercosperma Hieracium prenanthoides Mollisia atrata Hieracium murorum Puccinia Hieracii Entyloma Calendulae Botrytis cinerea Hieracium islandica Pyrenophora chrysospora Pleospora islandica P. vulgaris Puccinia Hieracii Hieracium sp. Erysiphe Cichoriacearum Pyrenophora chrysospora Pleospora herbarum Leptosphaeria ogilviensis L. agnita Mycosphaerella Hieracii Sclerotinia Fuckeliana 590 POUL LARSEN APPENDIX. Mr. Aage Lund has sent me a list of fungi from Iceland collected by Mr. L. Harmsen and Mr.St. Steindérsson. As I have received the list at a moment when a great part of the present paper was printed, I give the list here as an appendix. 105. Metasphaeria islandica (Rostr.) P. Larsen. Langarvatnsfjall (Harmsen). 264. Lophodermium arundinaceum [Schrad.) Chev. Reykholt [H.]. — On Agrostis tenuis. 396. Puccinia Poarum Niels. Kristnes [Steindörsson). 404. Puccinia Drabae Rudolphi. Isafjöröur [H.). Hendersonia Viole A. Lund, n. sp. Pycnidiis globosis, gregariis, in macula albida dispositis, primitus epidermide tectis dein erumpen- tibus, 64—84 uw diam. Conidiis oblongis, rectis vel curvulis, ad sepimentis non constrictis, primo 1-sep- Fig. 20 tatis, dein 2-septatis, denique 3-septatis, pallide fuli- Hendersonia Viole, gineis, 20—27,5 u x 3—4 u. In foliis Viole palustris Conidia. X 800. ad Reykjadalur. Aug. 1931 (leg. L. Harmsen). Hendersonia triceptata Da Camara (Saccardo, Sylloge, Vol.12, p.1060), which occurs on Viola alba, has also conidia with 3 transverse septa, but the conidia are much shorter (12—15 yw) than in H. Viole and they are never curved. Sclerotlum rhizodes Auersw. Reykholt [H.]. — On Agrostis tenuis. CORRIGENDA. Page 460, 1. 5 from bottom, for endolenca read endoleuca. — 467, 1.10 from top, for Johansson read Johanson. — 468, 1 from top, for Cichoracearum read Cichoriacearum. — 478, 1.11 from bottom, for 860 read 680. — 496, 8 and 9 from bottom, for Roberge read Robert. 1—3 mnst be omitted (— No 244, page 413). . 8 and 9 from bottom, for Kerveni read Kerverni. . 14 from top, for 1847 read 1817. ] l 1 ] ] — 498, 1. 3 from top, for 41 read 32. 1 ] l 1.13 from top, for Nat. read Mat. LITTERATURE. 1814. Acharius, E., Synopsis methodica Lichenum. Lundae. 1805. Albertini, J. B.de, et Schweinitz, L. D. de, Conspectus fungorum in Lusatiae superioris agro Niskiensi crescentium e methodo Per- sooniana. Lipsiae. 1896. Allescher, A., Berichte d. Bayer. Bot. Gesellsch., vol. IV, p. 36. 1897. — Pilze aus dem Umanakdistrikt. Bibliotheca Botanica, Heft 42, pp. 40-54. Stuttgart. | 1862. Arnold, F.C.G., Flora, p. 312. 1866. Auerswald, Leipziger Bot. 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(Abhandl. d. Naturf. Gesellschaft zu Halle. Vol. XIII. Halle). 1887. — Die Pilze Deutschlands, Oesterreichs und der Schweiz. II. Abtheilung.— Dr.L.Rabenhorst’s Kryptogamen-Flora, vol. I. Leipzig. 1842. Vittadini, C., Monographia Lycoperdineorum. Torino. 1772. Zoéga, Johan, Flora Islandica. Tilhang til Eggert Olafssons Rejse igennem Island. Sorø. INDEX. (SYNONYMS ITALICIZED). Abrothallus Parmeliarum 501. Agaricus physaloides 548. — Smithii 501. — praecox 542. Acetabula leucomelas 510. — pronus 550. — sulcata 510. rhodopolius 525. Agaricus applicatus. 524. | — rigidus 538. — aratus 551. semiglobatus 547. — arcuatus* cognatus 528. — separatus 547. — arvensis 546. sericellus 526. — atramentarius 556. sericeus 525. — atrorufus 548. serrulatus 526. — avenaceus 527. — tener 544. — bifrons 550. togularis 542. — bulbosus 539. torminosus 552. — bullaceus 549. tornatus 523. — Bulliardii 540. — umbelliferus 524. — campanulatus 548. Agyrium rufum 500. — collinitus 541. | Amanitopsis vaginata 541. — coronillus 547. | Amphisphaeria papillata 483. — dealbatus 523. Annellaria separata 547. — decipiens 537. Aposphaeria arctica 561. — elongatus 549. — glomerata 561. — ephemerus 555. ee labens 562. — ericaeus 548. — pulviuscula 561. — fimetarius 556. | subtilis 561. — fulvus 541. ' Arthrinium bicorne 574. — gambosus 527. puccinioides 574. — gilvus 523. | Arthrobotrys superba 572. — gossypinus 550. Ascobolus caninus 508. — graminicolor 552. crustaceus 508. — hemitrichus 538. furfuraceus 507. — hepalicus 524. gaber 507. — junceus 526. Kerverni 508. — laccatus 525. microsporus 508. — lampropus 526. Ascochyta baccae 564. — latus 541. Diapensiae 564. — mutabilis 542. - teretiuseula 564. — nauseosus 554. | — Veronicae 564. — odorus 523. Vulnerariae 488. — oniscus 524. | Ascophanus microsporus 508. — papilionaceus 547. | subfuscus 508. 598 Aspergillus herbariorum 467. — repens 467. Asteroma alpinum 562. — Capreae 562. - Salicis 562. Belonidium juncisedum 503. — Laschii 503. — rufum 503. Bertia lichenicola 482. Boletopsis luteus 557. Boletus bovinus 557. — brumalis 522. — castaneus 556. — laevis 556. — luleus 557. — perennis 522. — piperatus 557. — scaber 556. Bostrychonema alpestre 572. Botrytis cinerea 572. — parasitica 465. — vulgaris 572. Bovista clavata 557. — 'nigrescens 557. — plumbea 557. Calloria erythrostigmoides 504. — minutissima 504. Calosphaeria ciliatula 494. — pusilla 495. Camarosporium laburnicum 595. Celidium varians 500. Cercospora Paridis 576. Chaetomium indicum 479. Chlorosplenium aeruginosum 504. Chromosporium album 571. — croceum 570. — lateritium 571. — vitellinum 570. Chrysomyxa Pyrolae 512. Cintractia arctica 517. — Caricis 516. — Luzulae 516. Cladosporium caricicola 575. — entoxylinum 575. — graminum 575. — herbarum 575. — lycopodinum 575. — perpusillum 575. Clavaria cinerea 518. — cristata 518. — fastigiata 521. INDEX Clavaria fragilis 521. — inaequalis 521. — muscoides 521. Claviceps microcephala 479. — purpurea 479. Cliosporium lignorum 563. Clithris degenerans 498. Clitocybe dealbata 523. — gilva 523. — odora 523. — tornata 523. Coccomyces quadratus 498. Coleroa Alchimillae 481. Coleosporium Campanulae 511. Comatricha nigra 463, Coniophora puteana 520. Coniosporium aterrimum 573. — fusidioides 574. — melanconidium 574. — variabile 574. Coniothecium applanatum 576. — betulinum 576. — effusum 576. Coniothyrium conoideum 563. — glomeratum 561. — Laburni 563. — lignorum 563. — myriocarpum 563. — olivaceum 563. Coprinus atramentarius 556. — cordisporus 555. — ephemeroides 556. — fimetarius 556. — tigrinellus 555. — velox 555. Corticium granulatum 520. — incarnatum 520. — radiosum 519. — salicinum 519. Cortinarius anomalus 640. — biformis 539. — bulbosus 539. — Bulliardii 540. — cinnamomeus 540. — collinitus 541. — decipiens 537. — flexipes 538. — gentilis 539. — helvelloides v. islandica 537. — helvolus 539. — hemitrichus 538. Cortinarius incisus 537. — latus 541. — porphyropus 540. — rigidus 538. — sp. 540. — tortuosus 537. Coryne sarcoides 507. Crepidotus eitrinus 545. Crouania modesta 509. Crucibulum vulgare 558. Cryptodiscus pallidus 499. Cryptomyces maximus 498. Cryptospora Betulae 494. Cyphella villosa 520. Cystopus candidus 465. Cytospora betulina 563. — leucostoma 563. — Massariana 563. — microspora 563. — Salicis 563. Cytosporium betulinum 566. — Davidssonii 566. Dacryomyces deliquescens 518. — stillatus 518. Darluca Filum 564. Dasyscypha diminuta 504. — variecolor 505. Delitschia moravica 505. Dendrophoma marchica 562. Diaporthe aristata 493. — muralis 493. — salicella 493. Diatrype bullata 494. Diatrypella favacea 494. — verrucaeformis 494. Didymella inconspicua 478. — proximella 478. Didymosporium elevatum 570. Dilophia Graminis 489. Diplodia Rubi 564. Diplodina Eurhododendri 564. Discosia Artocreas 568. Dothichiza Sorbi 569. Dothidea Angelicae 495. — Geranii 490. — Ranunculi 503. Dothidella Angelicae 495. — betulina 495. — Laminariae 495. — thoracella 495. Dothiora Sorbi 468. INDEX Durella melanochlora 500. Empusa Muscae 466. Enteridium olivaceum 462. Entoloma rhodopolium 525. — sericeum 525. Entyloma Calendulae 517. — Catabrosae 517. — crastophilum 517. — irregulare 517. — Ranunculi 517. Epiclinium atrum 577. Epicoccum Davidssonii 577. Erinella callimorpha 505. Erysiphe Cichoriacearum 468. — communis 467. — Graminis 468. Eurotium repens 467. Exidia albida 518. — repanda 517. Excipula Empetri 569. — Rubi 503. — sphaeroides 569. Exobasidium Vaceinii 518. — Warmingii 518. Fabraea Cerastiorum 503. — confertissima 503. — Ranunculi 503. Fenestella princeps 493. — tumida 493. Flammula alnicola 543. Fusarium Kühnii 577. — larvarum 577. — Solani 577. Fusicladium Angelicae 575. — depressum 575. Fusidium punctiforme 571. — Vaccinii 518. Galera hypnorum 545. — mycenopsis 545. — siliginea 545. — sp. 544. — tenera 544. Geoglossum glabrum 507. — ophioglossoides 507. Geopyxis Ciborium 510. — cupularis 510. Gloeosporium alpinum 569. filicinum 569. Gnomonia borealis 492. — campylostyla 491. — pleurostyla 492. 599 600 INDEX Gnomonia setacea 491. Hypocopra discospora 480. — vagans 492. | — fimicola 480. Gnomoniella vagans 492. | — — f. microspora 480. Godronia pusiola 501. | — insignis 480. — Urceolus 501. | — microspora 480. Goniosporium puccinioides 574. | — minima 480. Guignardia graminicola 484. | — stercoraria 480. — lunulata 484. Hypomyces chrysospermus 479. — Oxyriae 484. Hypospila groenlandica 492. — Potentillae 484. | — rhytismoides 492. — Veronicae 484. Hypoxylon fuscum 495. Gymnoascus myriosporus 467. Hysterium arundinaceum 496. Gymnosporium album 571. — caricinum 496. — aterrinum 573. — degenerans 488. — fusidioides 574. — fagineum 499. — variabile 574. — juniperinum 496. Hadrotrichum virescens 575. — maculare 497. Hebeloma crustuliniforme 529. — pinastri 496. — fastibile 529. Illosporium corallinum 577. — mesophaeum 529. Inocybe abjecta 531. — Sb See) — caesariata 534, Helotium citrinum 506. — calamistrata 533. — rhodoleucum 506. — conica 534, — scutula 506. — decipiens 535. — virgultorum 506. — descissa 530. Helvella aeruginosa 504. — dulcamara f. autumnalis 533. — atra 510. — fastigiata 533, — caryophyllea 519. — geophylla 530. Hendersonia arundinacea 565. — grammata 536. — Caricis 565. — hirtella 530. — Jungermanniae 565. — hjulca 534. — Ribis alpini 565. == laceralos0: — silvatica 565. — maculata 531. — Stefanssonii 565. — praetervisa 535. Herpobasidium filicinum 569. — rimosa 532. Herpotrichia nigra 482. — sp. 534. Heteropatella cercosperma 569. — sp. 532. Heterosphaeria patella 498. — trechispora 536. Hormiscium altum 574. — umbonata 532. — betulinum 574. Isariopsis pusilla 576. — stilbosporum 574, Karschia scabrosa 501. Humaria aquatica 509. Kentrosporium microcephalum 479. — granulata 509. Lachnea hemisphaerica 509. — Jungermanniae 510. — scutellata 508. Hyalospora Polypodii 512. — stercoraria 509. Hydnum argutum 519. Lachnella corticalis 505. Hygrophorus conicus 522. — flammea 505. — miniatus 522. Lachnum bicolor 505. — niveus 523. — callimorpha 505. — pratensis 522. — calycioides 505. Hypochnus granulatus 520, — niveum 505. Lachnum patens 505. — virgineum 505. Lactarius glyciosmus 551. — lilacinus 551. — tabidus 551. — torminosus 552. — uvidus 551. — uvidus v. farinipes 552. Laestadia graminicola 484. — lunulata 484. — Oxyriae 484. — Potentillae 484. — rhytismoides 492 — Veronicae 484. Lamproderma physaroides 463. — violaceum 463. Lasiobolus equinus 507. Lasiosphaeria sorbina v. radiata 482. Lecidea Parmeliarum 501. — scabrosa 501. — Stereocaulorum 500. Lepidoderma carestianum 463. Leptoglossum glaucum 519. — muscigenum 519. Leptonia lampropus 526. — sericella 526. — serrulata 526. Leptosphaeria agnita 477. apogon 475. arundinacea 474. culmicola 474. culmifraga 474. culmorum 474. Doliolum 476. Dryadis 476° Elymi 474. Equiseti 473. Fuckelii 474. — juncina 476. — Luzulae 476. — Marcyensis 474. — microscopica 474. — nigrans 474. — ogilviensis 477. - oreophila 476. — Papaveris 476. — Ribis 476. — Silenes-acaulis 476. Leptospora ovina 481. Leptostroma caricinum 568, herbarum 568. INDEX Leptostroma Potentillae 568. — punctiforme 568. Leptothyrium vulgare 568. Leptotus lobatus 519. Lichen atratus 501. — varians 500. Linospora Capreae 492. — caudata 492. — insularis 492. Lizonia abscondita 482. — Thalictri 491. Lophiostoma Juniperi 484. Lophium dolabriforme 497. Lophodermium arundinaceum 496. — — v. alpinum 496. caricinum 496. juniperinum 496. maculare 497. petiolicolum 497. pinastri 496. versicolor 496. Lycogala contorta 463. Lycoperdon bovista 558. — caelatum 558. — cinereum 463. — nigrescens 557. — plumbeum 557. — pusillum 558. Macropodia Corium 510. Macrosporium commune 576. Marasmius insititius 527. Vaillantii 527. Marssonina Potentillae 570. Massaria Dryadis 491. - Thalictri 491. Mastigosporium album 572. Mazzantia Galii 495. Melampsora arctica 511. betulina 511. - Lini 511. pustulata 511. Pyrolae 511. Saxifragarum 512. Vacciniorum 511. Melampsorella Cerastii 511. Melanconis stilbostoma 494. Melanconium belulinum 570, bicolor 570, elevatum 570. Melanoleuca cognata v. elatior 528. Melanomma Aspegrenii 483. 601 602 Melanomma juniperinum 483. — Pulvis pyrius 483. Merulius Corium 521. — lacrymans 521. — lobatus 519. Metasphaeria Angelicae 478. — Arabidis 477. — complanata 477. — culmifida 477. — Empetri 478. — empetricola 478. — islandica 477. = Jimi 47/7 — macrotheca 477. Microthyrium Rubi 497. Mitrula gracilis 507. Mollisia advena 502. — atrata 502. — caesia 502. — cinerea 502. — graminis 502. — junciceda 503. — Jungermanniae 510. — melaleuca 502. — Schumacheri 502. Monacrosporium elegans 573. Mucor herbariorum 467. — Mucedo 466. — Mucerdae 466. — racemosus 466. Mycena avenacea 527. Mycosphaerella arthopyrenoides 487. — Capronii 486. — Compositarum 488. — Cruciferarum 487. — densa 486. — Dryadis 487. — Equiseti 485. — eriophila 489. — Filicum 484. — fusispora 487. — Gentianae 488. — harthensis 486. — Hieracii 489. — innumerella 488, — isariphora 486, — Juncaginearum 485. — lineolata 485. — lycopodina 485. — maculiformis 486. — melanoplaca 487. INDEX Mycosphaerella ootheca 487. — Parnassiae 487. — perexigua 486. — Polygonorum 486. — polyspora 488. — pusilla 485. — recutita 485. — rubella 488. — salicicola 486. — sibirica 487. mn Sob 188: — Taraxaci 489. — Tassiana 485. — tingens 486. — Viciae 488, — vulgaris 487. — Vulnerariae 488. — Wichuriana 485. Myrothecium roridum 577. Myxosporium Aucupariae 569, — salicinum 569. Naevia atrosanguinea 499. — diminuens 499, — fuscella 499, — ignobilis 499, — pusilla 499, Naucoria myosotis 543. — sobria 543, — Sp. 544. Nectria einnabarina 479. — coccinea 478, — Coryli 478. — Peziza 478. Niptera caesia 502. — ramealis 503. Nolanea juncea 526. Ocellaria chrysophaea 500. Oclospora citrina 506. Omphalia hepatica 524. — onisca 524. — umbellifera 524. Oospora coccinea 571. — nivea 571. — rosella 571. Ophiobolus Cesatianus 489. — herpotrichus 489, — salicinus 489, Orbilia auricolor 504. — coccinella 503, Ovularia alpina 572. Myiocopron calamagrostidis 497. a INDEX Ovularia decipiens 572. — obliqua 571, — rigidula 571. Panaeolus campanulatus 548. — fimicola 548. | — papilionaceus 547. Patellaria atrata 501. — Bagnisiana 501. | — melanochlora 500. Penicillium candidum 467. — crustaceum 467. Periconia alternata 574. Peronospora Alsinearum 465. — alta 465. — calotheca 466. — Ficariae 465. — grisea 465. — parasitica 465. — Trifoliorum 465. — Viciae 465. Peziza atrata 502. — bicolor 505. — chrysophaea 500. — Ciborium 510. — cinerea 502. — clandestina ß patens 505. — coccinella 503. — Corium 510. | — corticalis 505. — cupularis 510. — cyathoidea 506. — diminuta 504. — equina 507. — flammea 505. — Fuckeliana 504. — fusca 502. — granulata 509. — hyalinella 508. — Jungermanniae 510 — leucomelas 510. — melaleuca 502. — Schumacheri 502. — sculellata 508. — sculula 506. — sepiatra 509. — stercoraria 507. | — stercorea 509. — sulcala 510. — trechispora 509. | — Urceolus 501. — variecolor 505. Peziza virginea 505. — virgultorum 506. Phacidium Arctostaphili 498. — quadratum 498. — repandum 498. Phaeopeziza Empetri 509. Phaeosperma Niesslii 494. Phialea cyathoidea 506. — dolosella 506. — grisella 506. Phlebia radiata 521. Phlyetidium Cerastiorum 503. Pholiota marginata 542. — mutabilis 542. — praecox 542. — togularis 542. Phoma acuta 560. — Alchimillae 560. — arclica 561. — Armeriae 561. — complanata 560. — deusta 561. — Elymi 559. — endoleuca 560. — Equiseti 559. — herbarum 561. — Lycopodii 559. — Malvacei 560. — melaena 560. — muscorum 559. — oleraceum 560. — ribesia 561. — ribicola 560. — Ruborum 560. — salicina 559. — Saxifragarum 560. — Sceptri 561. — solanicola 561. — tingens 560. — Tofieldiae 559. — Urticae 560. Phomopsis ribesia 561. Phycomyces nitens 466. Phyllachora Graminis 496. - Poae 496. Phyllosticta Elymi 559. filipendulina 559. Pseudacori 559. - Ranunculorum 559. Physalospora Festucae 491. - montana 491. 603 604 Physalospora Potentillae 491. Physarum cinereum 463. Physoderma Crepidis 464. — Heleocharidis 464. — Hippuridis 464. — menyanthis 464. - vagans 464. Phytophthora infestans 465. Piggotia atronitens 568. Pilobolus Kleinii 466. Placosphaeria Bartsiae 562. — Galii 562. Plasmopara densa 465. Pleosphaerulina vitrea 490. Pleospora alpina 472. — Androsaces 469. — arctica 470. — chrysospora 469. — comata 469. — coronata 470. — deflectens 472. — discors 471. — Drabae 472. — Elynae 472. — gigantasca 471. — gigaspora 471. — herbarum 472. — hispidula 469. — islandica 470. — Junci 471. — Junci v. Luzulae 472. — Karstenii 470. — microspora 470. — pentamera 471. — punctiformis 470. — scirpicola 471. —Spact 471 — spinosella v. Luzulae 472. — straminis 470. — Triglochinis 471. — vagans 471. — vagans v. Airae 472. — vulgaris. Pleurotus applicatus 524. Plicaria sepiatra 509. Plicariella Empetri 509. — modesta 509. Plowrightia ribesia 468. Podosphaera myrtillina 468. Polyporus brumalis 522. — croceus 522. INDEX Polyporus hirsutus 522. Polystictus hirsutus 522. — perennis 522. Poria medulla panis 522. — vaporarius 521. Propolis faginea 499. Protomyces pachydermus 466. Psalliota arvensis 546. - campestris 546. — Elvensis v. alba 546. Psathyra bifrons 550. — gossypina 550. — spadiceo-grisea 550. Psathyrella arata 551. — prona 550. Pseudophacidium degenerans 498. Pseudovalsa lanciformis 494. Psilocybe atrorufa 548. — bullacea 549. — elongata 549. — ericaea 548. — merdaria 549. — physaloides 548. Puccinia Anthoxanthi 513. — Bistortae 513. — Blyttiana 513. — borealis 513. — Caricis 513. — Cruciferarum 514. — Drabae 514. — Epilobii 514. — Fergussonii 514. — Galii 515. — Halosciadis 514. — Hieracii 515. — Leontodontis 515. — Morthieri 514. — Oxyriae 513. — Poarum 513. — Polygoni 512. — punctata 515. — Saxifragae 514. — Schneideri 514. — septentrionalis 513. — silvatica 515. — Trifoli 513. — uliginosa 513. — variabilis 515. — Veronicarum 515. — Violae 514. Pyrenopeziza Rubi 503. Pyrenophora abscondita 470. — Androsaces 469. — chrysospora 469. — chrysospora v. polaris 469. — comata 469. — coronata 470. — hispida 469. — phaeocomes 468. — phaeocomoides 470. Rabenhorstia rudis 563. Radulum orbiculare 521. Ramularia aequivoca 573. — Archangelicae 573. — Bartsiae 573. — Bistortae 573. — Chamaenerii 573. — filaris 573. — lactea 573. — punctiformis 573. — Taraxaci 573. Reticularia carestianum 463. Rhabdospora curva 567. — eupyrenoides 567. — ineaequalis 567. — pleosporoides 567. Rhizopus nigricans 466. Rhyparobius caninus 508. — crustaceus 508. — dubius 508. — hyalinellus 508. — polysporus 508. Rhytisma Bistortae 497. — maximum 498. — salicinum 497. Rosellinia mammiformis 482. — subcorticalis 482. Russula decolorans 554. — delica 552. — fragilis 554. — graminicolor 552. — grisea 553. — lilacea 553. — mauseosa 554. — ochracea 554. — Queletii 555. — vinosa 553. Russuliopsis laccata v. rosellus 525. Saccobolus Kerverni 508. Saprolegnia ferax 464. Schizoxylon Berkeleyanum 499. Scirrhia Poae 496. INDEX 605 Scleroderris aggregata 499. Sclerotinia Vahliana 504. — Fuckeliana 504. Scolecotrichum graminis 575. Seutula Stereocaulorum 500. Septogloeum Fragariae 570, Septoria Alsines 567. betulina 566. — Capreae 566. — Caricis 566. — cerasticola 566. — curva 567. — Galiorum 567. — Geranii 567. — graminum 566. — Orchidearum 566. — punctoidea 566. — salicella 566. — salicina 566. — semilunaris 567. — Viciae 567. Sordaria coprophila 479. — curvula 479. — decipiens 480. — hirta 480. — insignis 480. — leucoplaca 479. — minima 480. — Winterii 480. Sorosporium Montiae 516. Sphacelotheca Hydropiperis 516. Sphaerella arthopyrenoides 487. — Compositarum 488. — densa 486. - Dryadis 487. Equiseti 485. — eriophila 489. Gentianae 488. harthensis 486. Hieracii 489. - innumerella 488. Iycopodina 485. - oolheca 487. pachyasca 485. — Parnassiae 487) — perexigua 486, pusilla 485. - rubella 488, - salicicola Cooke 486. - salicicola Fuckel 486. sibirica 487, 606 Sphaerella Stellariae 486. — Taraxaci 489 — Tassiana 485. — Viciae 488. — vulgaris 487. — Wichurianae 485, Sphaeria aggregata 499. — agnita 477. — aristata 493. — Capreae 492. — chlorospora 490. — ciliatula 494. — einnabarina 479. — coccinea 478. — coprophila 479 — Cruciferarum 487. — culmicola 474. — ditricha 490. — favacea 494. — Filicum 484, — fusca 495, — Galii 495. — graminis 496. — herbarum 472. — herpotricha 489. — intermixta 490. — isariphora 486. — juniperina 483. — lanciformis 494. — leucoplaca 479. — lineolata 485. — maculiformis 486. — mammiformis 482. — obducens 483. — ogilviensis 477. — ovina 481, — ovoidea 482. — papillata 483. — penetrans & patella 498. = argon TS: — phaeocomes 468. — Pulvus pyrius 483. — purpurea 479. — pusilla 495. — recutita 485, — ribesia 468. — salicella 493. — scirpicola 471. — setacea 491. — stilbosioma 494. — thoracella 495. INDEX Sphaeria tumida 493. Sphaeronema subtilis 561. Sphaeropezia Arctostaphyli 498. Sphaerospora confusa 509. — trechispora 509. Sphaerotheca humuli 468. — humuli v. fuliginea 468. Sphaerulina Diapensiae 490. — intermixta 490. — Potentillae 490. Sporormia ambigua 481. — corynespora 481. — commutata 481. — intermedia 481. —- lageniformis 481. — minima 481. — Notarisii 481. — octomera 481. — promiscua 481. Sporotrichum griseum 571. Stagonospora aquatica 565. — curvula 564. — Equiseti 564. — Galii 565. — graminella 564. — islandica 564. Stamnaria Equiseti 507. Steganosporium traphinum 570. Stemonites nigra 463. — physaroides 463. — violaceum 463. Stemphylium atrum 542. Stereum hirsutum 520. — rugosum 520. — tuberculosum 520. — vorticosum 520. Stictis Berkeleyanum 499. — pallida 499. — rufa 500. Strickeria Davidssonii 484. — Kochii 483. — obducens 483. — obducens f. betulina 483. — patellarioides 483. — salicina 484. Stropharia coronilla 547. — merdaria 549. — semiglobata 547. Suillus castaneus 556. Synchytrium aureum 464. — cupulatum 464. FE Synchytrium globosum 464. — groenlandicum 464. Tapesia fusca 502. Taphrina bacteriosperma 467. — betulina 466. — carnea 467. — nana 467. Teichospora Davidssonii 484. — patellarioides 483. — Rabenhorstii 483. Thelephora caryophyllea 519. — puteana 520. — terrestris 519. Tichothecium gemmiferum 489. — pygmaeum 489. Tilletia arctica 517. — striiformis 517. Tolyposporium Junci 516. — Montiae 516. Tomentella ferruginea 519. Torula epizoa v. muriae 574. Tremella deliquescens 518. — lutescens 518. Trichia contorta 463. Trichoderma cinnabarinum 571. — viride 571. Tricholoma aggregatum 528. — conglobatum 528. — gambosum 527. — panaeolum 527. — pubifolium 527. Trichothecium roseum 572. Triphragmium Ulmariae 515. Trochila atrosanguinea 499. — diminuens 499. — fuscella 500. — ignobilis 499. — juneicola 500. — phacidioides 498. Tubercularia vulgaris 576. Tympanis saligna 501. Typhula graminum 520. Uredo Airae 515. — Alchimillae 512. INDEX 607 Uredo Campanulae 511. — Caricis 513. —.Cerastii 511. — Hordei 515. — Hydropiperis 516. — Polypodii 512. — Violae 514. Urocystis Agropyri 517. — Fischeri 517. — sorosporioides 517. Uromyces Alchimillae 512. — Dactylidis 512. — Festucae 512. — Limonii 513. — Polygoni 512. — Trifolii 513. Ustilago Bistortarum 516. — Caricis 516. — Hordei 515. — Jensenii 515 — Luzulae 516. — vinosa 516. — violacea 516. Valsa betulina 493. — polyspora 493. Valsaria Niesslii 494. Venturia caulicola 490. — chlorospora 490. — ditricha 490. — Geranii 490. — islandica 490. — Myrtilli 490. Vermicularia Dematium 562. — Geranii 562. — Liliacearum 562. — trichella 562. Verpa digitaliformis 510. Verticillium lateritium 572. Volutella ciliata 577. Wallrothiella minutissima 482. Xyloma betulinum 495. — Bistorlae 497. Zignoella ovoidea 482. Zythia islandica 568. Printing finished February 1932. N AH aT re, ~ pan ie Sale das RE SS ls RE REEL EL GSR i | ta Le i si ye Af THE BOTANY OF ICELAND, VOL. II (Pour LARSEN PLATEWI. CHA, CATO, KBHYM, Fu bin ha otal ers. THE BOTANY ICELAND EDITED BY L. KOLDERUP ROSENVINGE PH.D. AND EUG. WARMING (+) PH. D., SC. D. VOL. II WITH 6 PLATES AND 73 FIGURES IN THE TEXT COPENHAGEN LONDON J. FRIMODT HUMPHREY MILFORD met OXFORD UNIVERSITY PRESS 1932 ID BY THE AID OF THE CARLSBERG FUND | » CONTENTS PART I. 1920. Page 5. ERNST Östrup: Fresh-water Diatoms from Iceland. 1918. (With a ME N N a ©, 1 6. OLAF GALLØE: The Lichen Flora and Lichen Vegetation of LIEGEN oe Se eu Tarsus ho 101 PART II. 1928. 7. Jons. BoyE PETERSEN: The Fresh-water Cyanophyceæ of Ice- UTE Sg Gi ae D ht ee eRe Re mE RR à 249 8. Jons. BoyE PETERSEN: The Aérial Algæ of Iceland. 1928.... 325 PART III. 1932. 9. Pout Larsen: Fungi of Iceland. (With one plate). 1931—1932. 449 MN) ANA AN UT THE BOTANY OF ICELAND EDITED BY L. KOLDERUP ROSENVINGE AND EUG. WARMING (;) PRINTED BY H. H. 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