Vol. I. No. 4 1912 OCTOBER
a
The Scottish “ Botanical Review
A QUARTERLY MAGAZINE
INCLUDING THE
Transactions of the Botanical Society of Edinburgh
M
Edited by M‘Taccarr Cowan, Jr.
-EDITORIAL COMMITTEE
WILLIAM Barc.iay. CARLETON Rea, B.C.L., M.A. ARTHUR BENNETT, A.L.S. A. Lorrain Smit, F.L.S.
A. W. BortuHwick, D.Sc. . W. G. SmiTH, B.Sc., Ph.D.
H. N. Dixon, M.A., F.L.S. James Stirton, M.D., F.LS. Ropert H. MELDRUM. G. S. West, M.A., F.L.S., A.R.C.S.
EDINBURGH NEILL. é& CO. LTD
BELLEVUE
Price 2s.6d. Annual Subscription, payable in advance, 75. 6d., post free in U.K.
Dy Adie s Wedderburn
in amalgamation with
R. S. RICHARDSON & CO.
CUTLERS, Etc.
52 Georae Si., Edinburgh
*Phone 2489.
Optical ieaaniwen ‘
Spectacles and Eyeglasses Lorgnettes, Reading Glasses Field and Opera Glasses
Instrument Department
Barometers, Barographs Thermometers, Rain Gauges Surveyors’ Instruments
Photographic Department
Cameras and Kodaks Plates, Films, Papers Negatives Developed and Printed
R. S. RICMARDSON & CO,
= = Cutlers and Cycle Agents = = 52 GEORGE STREET, EDINBURGH
Established 1828 (Adjoining the Music Hall) Telephone 2489 Superior SHEFFIELD CUTLERY of every description DRESSING CASES - - MANICURE and SHAVING REQUISITES
PRINCIPAL DEPOT for the Renowned GILLETTE SAFETY RAZOR
The Razor which really Shaves without Stropping or Honing
AUTO-STROP, DURHAM-DUPLEX, CLEMAK AND OTHER SAFETY RAZORS
‘““EASY-OPEN” POCKET KNIVES of many kinds Our ‘“‘RING” KNIFE has attained Great Popularity
CERMAN-SILVER IVORY, STAC, PEARL
1; 2/6, 3/6 from 3/6 each also in ale in STERLING SILVER COLD (HALL-MARKED)
Practical Simplicity, Quality of Material, and Careful Workmanship have resulted in thousands now being in use
SPARBROOK and other CYCLES
ALL ACCESSORIES, including Many Novelties REPAIRS IN ALL DEPARTMENTS UNDER PERSONAL SUPERVISION
The Scottish Botanical Review
None pean LOL | OcTOBER
Morphological Notes. By K. von Goebel, pe-b). (Cami.), IL. D. (Se_Amd.);,
Director of the Botanic Garden, Munich. (With One Plate.)
fog INEEORESCENCES OF THE AMBROSIACE.
THE large family of the Composite, as is well known, is one of those groups whose individual representatives, in spite of all their variation, still show such a close agreement in the structure of the flowers and the inflorescences that one can offhand recognise them as members of one family. Only a few groups deviate to any great extent, and of these one of the most interesting is the Ambrosiacez.
Ecologically they are interesting in the manner in which pollination on the one hand and the distribution of the fruit on the other hand are accomplished among them.
The Composite as a rule exhibit insect-pollination, but the Ambrosiacez have reverted to wind-pollination.
Hardly any greater contrast can be presented than between the resplendent flower-head of a Helzanthus or a Dahlia, with its remarkable arrangements for dehiscence and for trans- ference of the pollen, and the insignificant male and female floral attire of a Xanthium or an Ambrosia. There is a clear indication here that, quite apart from the lack of a corolla conspicuous in its coloration, the structure of the floral organs is in strict correlation with their functions. In the
VOL. I. 193 15
194 THE SCOTTISH BOTANICAL REVIEW
flowers no nectar is formed, there is no ‘‘concrescence’’ (in reality it is only agglutination or sticking together) of the anthers, and the pollen is formed in great quantity, as is the case with other anemophilous flowers. The condition of the exine indicates, however, that originally pollination took place by insects as in other Composite.
It is well known that the pollen in entomophilous plants is provided with a spiny or sticky exine, whereas in anemo- philous plants the exine of the pollen-grains is smooth and not sticky. The Ambrosiacez, so far as I have been able to examine them, still show in the exine the remains of spinose thickenings such as are found in numerous other Composite, but these are so reduced that the pollen is no longer adapted for adhering.
The male flowers still show on the rudiment of the stigma a hairiness which recalls the “stigmatic brush’’ of other Composite. In the female flowers, in which the stamens have dwindled without leaving a trace, there is no longer any indication of this stigmatic brush. Thus the Ambrosiacee, in contrast to other Composite, are retrogressive in structure. On the other hand; it is evident that they have developed new characters not attained by other Composite. This is seen more especially in the character of the noteworthy envelopes with which the fruit is enclosed. The fruiting heads of Xanthium are well enough known to the wool-grower as the detested “burrs” (Kletten), which by means of their bent hooks attach themselves to the woolly coats of animals, and are so dispersed. We shall see that as regards these fruiting heads the other Ambrosiacez have also undergone retrogres- sion in contrast with Xanthzum.
It is not surprising that such noteworthy plants have repeatedly formed subjects for investigation. So far as the developmental history is concerned, and apart from Payer’s? contributions, which in the present instance need only be indirectly considered, there are available only the investiga- tions of Rostowzew,” and these I propose in the following to supplement on some points.
1 Payer, ‘‘ Traité d’Organogénie comparée de la fleur” (Paris, 1857, p. 638). 2T. Rostowzew, ‘‘ Die Entwicklung der Bliiten und des Bliitenstandes bei einigen Arten der Gruppe Ambrosiez ” (‘‘ Bibliotheca botanica,” 20).
MORPHOLOGICAL NOTES 195
Thus one topic will be the male inflorescence, while another will be the ‘‘ fruit’? of Amzbrosza.
A. The Mate Inflorescences.
As is known, the Ambrosiacee are monoecious to this extent, that the male inflorescences occupy the apex of shoots at the base of which are placed the female ones,
The individual flower-heads (‘‘ capitula”) of Ambrosia trt- partita are arranged in large numbers indefinitely (botryose) on an elongated axis, which in turn is terminated by a flower- head.
The lateral capitula have this noteworthy characteristic, that the flowers are not placed as usual on the upper (adaxial) side, but on the under side—that is, the side turned away from the primary axis of the whole infloresence (abaxial). It is natural, at first sight, to ascribe this occurrence to a Zorszon of the flower-stalk. This is indeed the opinion of Rostowzew, who says that the flower-head undergoes a torsion, in that the peduncle grows more rapidly on its upper side than on its lower.
This interpretation in itself does not agree with the developmental history. If one examines the early stages, it is seen that the position of the capitula is “reversed” at a very early stage.
The capitula are differentiated from the embryonal tissue as hemispherical primordia. The cells of the primordia on the adaxial (upper) side pass first into the phase of elonga- tion-growth, with the exception of the terminal part (a, fig. 1), which develops as the first leaf. On the other hand, the lower side remains embryonal. This is utilised for the development of the growing-point of the capitulum (4, fig. 1), except the basal part (nearest the primary axis), which later gives rise to the intercalary meristem in the elongating peduncle of the capitulum.
How shall we interpret this peculiar development? Two different views are obviously possible.
It may be that the first leaf (a, fig. 1) arising from the growing-point of the capitulum is the first leaf of the in- volucre of the capitulum, the individual leaves of which,
196 THE SCOTTISH BOTANICAL REVIEW
united together, form an apparently entire envelope. This is the concept of Rostowzew, which, however, has thus far to be supplemented, that the “torsion of the capitulum ”—if one assumes such a thing—is not a subsequent event, but it existed from the first; in other words, it is “congenital.” Rostowzew does not mention that if this interpretation be assumed, then the lateral capitula of the Ambrosia would present one of the rare cases in which the “bracts” (Deck- blatter) of lateral shoots have aborted completely. This occurrence is known in the flowers of the crucifere, etc., in which one can correlate the abortion of the bracts with ex- cessive crowding originally undergone by the flower-primordia before the elongation of the axis of the inflorescence. In the case of Ambrosia, this would be all the more striking because the female inflorescences possess well-developed bracts, although they are quite as closely crowded together as the male ones. In no instance have I observed in the male capitula even a trace of a subtending bract.
The second possibility is that the first leaf (indicated by a@ in fig. 1) is the bract (Deckblatt) of the capitulum. The manner in which (a) develops from the primordium that gives rise to (a) and (0) is similar to what occurs frequently in flowers and inflorescences. In this instance the bract, so to speak, is late in being formed. It does not develop in advance of its axillary shoot, but from a primordium common to both. The thing that surprises one is that the axillary shoot should arise on the under side of the bract, and not, as usual, on the upper side. But, after all, this is no more wonderful than the “ congenital torsion” already referred to, nor is it quite without precedent amongst other Dicotyledons. The remarkable flowers of Evythrochiton hypophyllanthus are situated on the under side of the leaf ; also the axillary branches on the creeping shoots of some of the terrestrial Utriculariz arise on the side of the leaf furthest away from the growing-point.?
In other respects it may be assumed that the position of the male capitula of A7zbrosta means the same thing as the torsion (entirely brought about by their weight) of the male inflorescences of Corylus, Alnus, Juglans, or the torsion of
1K. Goebel, Utricudarza (‘‘ Annal. du jardin botan. de Buitenzorg,” vii. 1889).
MORPHOLOGICAL NOTES 197
the anther of grasses: by this means the shaking out of the pollen is facilitated in all these anemophilous plants.
Returning now to the morphological question, one might, in arriving at a decision, also take the anatomical facts into account. If (a) (fig. 1) represents the bract of the capitulum, then one might expect that the normal orientation would be shown in the constitution of the vascular bundle, phloem on the lower side, xylem on the upper. Of course, J] do not regard the anatomical conditions as decisive, since, in my opinion, these are determined by the morphological, not the reverse. In the present instance this would mean that, in the event of a relatively limited development and retardation in time on the part of the bract in comparison with the axillary shoot, it appears quite natural that the former (the bract) should be provided with its vascular system from the latter (the shoot). This being so, one expects the xylem to be uppermost, with the phloem underneath.
The conditions actually existing are briefly as follows: The thin, much-flattened peduncle of the capitulum contains two vascular bundles (rarely three); the phloem-groups of these are set towards the narrow margins, and the xylems are turned towards one another and somewhat obliquely downwards (fig. 3). This anatomical structure is interesting because unusual in a shoot-axis.
A certain biassed school of anatomists assumes that shoots are distinguished from leaves by their anatomical structure, particularly in the arrangement of the vascular bundles. The shoot of the capitulum of Ambrosza does not differ in structure from many leaf-stalks, except that in the latter the xylem of the vascular bundle is directed upwards.
There is little doubt that this anatomical structure is the result of reduction; that is, the peduncle of the primitive type possessed more than two vascular bundles. Linked with these bundles are those which ramify throughout the involucral leaves and the flower, but I have not followed these in detail. It may be mentioned, however, that the vascular bundles of the involucral leaves are normally orientated in that their xylem lies towards the growing-point of the capitulum. The orientation is that described above, and for the reasons given it does not seem to me possible to arrive at any definite con-
198 THE SCOTTISH BOTANICAL REVIEW
clusion as to the morphological interpretation of this leaf (a) from the anatomical structure.
It might be advanced in opposition to the view that the leaf (a) is a bract, that later on it does not always stand opposite the peduncle; this might, however, result from displacement. In the younger stages I saw it in the median position occupying the whole breadth of the inflorescence- primordium (fig. 4). As regards the further development of the male capitula, two facts may be pointed out. Firstly, that the external side (that on which the letter (a) is placed) appeared to be much further advanced than the inner side ; this is seen at once in fig. 4. Secondly, that the arrange- ment of the flowers is not “dichasial” sympodial (as one of the recent authors wrongly states), but corresponds essentially with the other Composite. One sees quite clearly the broad growing-point of the capitulum (V., fig. 4), from which the individual flowers arise ; some of the outer ones have bracts even now. The characteristic arrangement of the flowers is determined by the fact that the capitulum as a whole is dorsiventral in structure, with a more advanced development on the outer side.
B. The Female Inflorescences.
As indicated by Rostowzew, these are dichasially arranged (fig. 5). Each consists of a single flower enclosed by an “envelope” (fig. 8). To understand their constitution it will be necessary to first compare the inflorescences of other Ambrosig. Here one finds the following series :—
1. Mixed inflorescences with female marginal florets.
2. Inflorescences with sexes distinct, in so far that in the female only the marginal florets flower, and only the minority of these, while in the male inflorescence the formation of female flowers is entirely suppressed.
3. There is also a diversity in the arrangement of the female and male inflorescences. Whereas the arrange- ment was originally indefinite (botryose), this is re- tained only in the case of the male inflorescences, the female ones showing dichasial arrangement.’
1 With regard to diversity of male and female, compare Goebel, ‘‘ Ueber sexuellen Dimorphismus bei Pflanzen ” (‘‘ Biolog. Centralblatt,” p. 657, 1910).
MORPHOLOGICAL NOTES 199
In Xanthium the male inflorescences are orientated norm- ally ; the structure of a young male inflorescence in longi- tudinal section is shown in fig. 6, |. The female capitulum consists of two flowers enclosed in the many-spined envelope. This envelope originates from the fusion of two bracts (Sa, Sé, fig. 6, III.) in whose axils the female flowers are placed. With reference to the development, the reader is referred to my recent account.t. This is noteworthy in this respect, that the two floral bracts entirely monopolise the growing-point of
the capitulum (except what is required for the flowers arising
in their axils), as is shown in the view from above (fig. 6, IV.), and that the flowers are deeply sunk in the axis of the capitulum.
Comparing this inflorescence with that of Amdrosza, it will be found to have undergone still further reduction. Firstly, we see that the spines or barbed hooks outside the envelope are here reduced to a few small processes (figs. 7 and 8, s?) ; secondly, each envelope contains only one flower. The processes referred to can no longer be of use in the dispersal of the fruits by animals.?, How dispersal is effected can only be ascertained in the native land of the plant. The fruits are relatively light, and float in water for a short time at least, and they may even be rolled to a distance by wind.
It is evident that the envelope of the fruit of Ambrosza corresponds to that of Yanthium. But is it, like the former, a double one, or is it single? That there is some suggestion of a double envelope is evident by the fact that the apex of the envelope (originally laid down as a closed ring ; see fig. 7, right-hand figure) is distinctly two-lobed in the later stages of growth. This indicates that two leaf-primordia take part in the formation of the envelope. Only one of these, however, has an axillary flower-primordium. Obviously a characteristic retrogression has taken place here: the flower monopolises the whole area within the envelope; hence it arises not as a lateral outgrowth on the growing-point of a capitulum, but is terminal. There are, of course, many examples of an organ genetically lateral in origin becoming ultimately terminal. We may cite the spikelets of many
1 Goebel, /.c. (‘‘ Biolog. Centralblatt,” xxx., 1910, p. 722). * They might, of course, become lodged between the claws or in the hoof.
200 THE SCOTTISH BOTANICAL REVIEW
grasses, also the carpels which in many flowers monopolise all the residual part of the growing-point of the flower, and the terminal stamen of WVazas, Callitriche, etc. Ambrosia is, however, a specially well-marked example of this procedure. The development of the female flower need not be described further, except to point out that there is only a mere trace of the corolla, while the stamens and calyx have disappeared without leaving a trace.
Thus we see that Amdbrosza has carried still further in its female inflorescence that reduction already indicated in Xanthium. Even in Xanthium the male organs of the capitulum are completely suppressed and the number of female flowers is reduced totwo. As new structures there are present the hook-like spines on the outside of the concrescent floral-bracts, which, taking the place of the pappus originally present, facilitate dispersal of the fruit. In Ambrosza these spines dwindle to a few rudiments and the number of flowers diminishes to a single one.
In the male inflorescences, however, the number of capitula is probably increased considerably in comparison with the type-form with hermaphrodite flowers. With this may also be correlated, that these male capitula have departed from the prevailing scheme of development, and as seen in their “reversal” have progressed along new lines. Thus with no great effort, and with a basis of facts admissible in any new speculation, we are able to trace, in what seems to me a satisfactory manner, the historical evolution of the structure of the inflorescences of Ambrosza. At the same time, the case dealt with here illustrates once again the phenomenon to which the author has frequently made reference : namely, that our phylogenetic series, so far as we can depict them with any degree of probability, all represent a reduction-series.
The following may be advanced in support of this :—
1. In a descending series we have a definite starting-point (that is, some one of the more completely equipped forms as distinct from the more reduced ones) with which we can compare the less completely equipped members of the series.
2. In many instances the organs in question may still be recognised as rudiments.
MORPHOLOGICAL NOTES 201
3. The descending series arise latest ; hence they are more completely preserved and easier to recognise than the ascending with a history extending much further back, and whose members are as a rule very incompletely preserved.
Descending series of this kind are known to every botanist, since they appear again and again in almost every family. Other facts also indicate that organisms become modified mainly through retrogression and _ simplification: thus “mutations,” for example, are essentially of this nature, since in them there is a loss of some definite characteristic.
Has then the “nisus formatoris” of the ancient philo- sophers itself become antiquated? Not at all; botany at least has remained youthful. To be convinced of this, one need only glance at what is only possible where youthful aspirations exist, namely, the construction of genealogical trees from below upwards. “Alas, alike in their tenure of life, they are mostly ruins, not of the trees, however, but of the ephemeral day-flies !”
MUNICH, Aprz/ 1912.
EXPLANATION OF THE FIGURES.
Fig. 1. Longitudinal section through an inflorescence of Ambrosia tripartita. WV, growing point of the male inflorescence ; the individual capitula (with the exception of the terminal one) are placed laterally on the primary axis. a, the first leaf of a male capitulum of which @ is the growing-point. £/, female flower with its envelope, H.
Fig. 2. Ambrosia tripartita. Longitudinal section through an older male capitulum. V, the growing-point.
Fig. 3. Transverse section through the peduncle of a male capitulum of Ambrosia tripartita. The xylem in each of the two large conductive bundles is shaded.
Fig. 4. Capitulum of Ambrosia trifartita seen from above. Around the growing-point, V, there are seen fifteen embryonal flowers in various stages of development ; the involucre surrounds the whole.
Fig. 5. Ambrosia tripartita. Transverse section through a young female inflorescence-group. In the axil of a bract (Deckblatt), D, is a one-flowered female inflorescence, I, with its envelope, H; this has two
1 E. Baur, ‘‘ Einfiihrung in die experimentelle Vererbungslehre” (Berlin, IQI1), says : ‘‘ The large majority of mutations which have been closely investigated depend simply on the loss of some single Mendelian unit character. I have not found, up till now, any absolutely certain case in which one or more unit characters have arisen de novo.”
202 THE SCOTTISH BOTANICAL REVIEW
prophylls (Vorblatter), V, in the axils of which other inflorescences are present.
Fig. 6, I-III. Xanthium spinosum.
I. Longitudinal section through a young male inflor- escence. BB, male flower with its bract, S.
II. Longitudinal section through a female inflor- escence. .Sa, Sd, the bracts (Deckblatter) of two flowers, Sa,, S4,, which on the side towards the incurved margins of the bracts are proceed- ing to develop the floral organs.
III. Older inflorescence in which each female flower has now the stigma developed, sv. IV. Xanthium strumasta. A young female inflorescence seen from above.
Fig. 7. Ambrosia tripartita. On the left a female inflorescence, seen from the outside. s¢, primordia of the spines which remain rudimentary. H, the envelope (clearly two-partite). 2/, flower-primordium seen through the envelope (which is regarded as transparent). On the right a young inflorescence seen from the outside.
Fig. 8. Ambrosia tripartita.
I. Fruit with its envelope, bisected longitudinally. H, en- velope ; s¢, spines; P, pericarp; S, seed-coat (very thin) ; E, embryo.
II. Fruit with envelope seen from outside.
Notes on some Mosses from the Three Lothians. By James M‘Andrew,
Assoc. of the Botanical Society of Edinburgh.
PERHAPS the following notes may prove interesting to local and Scottish bryologists. They consist principally of new records of British mosses gathered in the Lothians since the “Census Catalogue of British Mosses” was published in 1907. I am indebted to Mr. William Evans, Edinburgh, for about one-half of them; the others were gathered by myself and from time to time reported to Mr. R. H. Meldrum, and will no doubt in due course appear in the next edition of the “Census Catalogue.”
HADDINGTON, v.c. 82. Sphagnum cymbifolium Ehbth. ; S. rigidum Schp.; Andreea petrophila Ehrh.; And. Rothiz W. and M. (Traprain Law, East Linton); Polytrichum
Scottish Botanical Review.)
Fig.8
K. von GOEBEL, ‘‘ Morphological Notes.”
NOTES ON SOME MOSSES FROM THE THREE LOTHIANS 203
urnigerum L. ; P. alpinum L. (Traprain Law) ; P. formosum Hedw. ; Pleuridium subulatum WRabenh.; Rhabdowetsia Jugax B. and S. (Traprain Law); Decranella squarrosa Schp. ; Blindia acuta B. and S. (Traprain Law) ; Grimmia apocarpa Hedw., var. rivularzs WW. and M. (East Linton) ; G. patens B. and S. (Traprain Law); G. decipiens Lindb. (Traprain Law—cum fructu); G. montana B, and S. (Trap- rain Law); G. Stzrtonz Schp. (Garleton Hills, by W. Evans) ; Rhacomitrium protensum Braun (Traprain Law, by W. Evans); R. canescens Brid., var. evicoides B. and S.; Hedwigia imberbts Spruce (Traprain Law) ; Pottza bryotdes Mitt. (Gosford Bay, by Mr. John Hunter); Barbula fallax Hedw., var. brevifolia Schultz (west of Dunbar); Wezsza microstoma C. M. (Gosford Bay); Cinclidotus fontinaloides P. Beauv. (river Tyne); Zygodon Mougeoti B. and S. (Traprain Law); Orthotrichum stramineum Hornsch. ; Lartramia pomiformts Hedw., var. crispa B. and S. (Trap- rain Law); Leptobryum pyriforme Wils. (W. Evans) ; Plagiobryum Zerit Lindb. (Traprain Law); Webera pro- ligera Bryhn (W. Evans); Bryum alpinum Huds., and var. viride Husn. (Traprain Law); 8. argenteum L., var. lanatum B. and S. (Gullane Links) ; Wnzum stellare Reich. (Gullane Links); Pterygophyllum lucens Brid., and Hetero- cladium heteropterum B. and S. (Traprain Law); Brachy- thectum salebrosum B. and S. (Gullane Bay) ; B. plumosum B. and S. (East Linton) ; Plagiothectum pulchellum B. and S. (Traprain Law); Amblystegium serpens B. and S., var. salinum Carr. (Gullane Links); Hypnum elodes Spruce ; H. aduncum Hedw., var. paternum Sanio (all Gullane Links) ; H. Sendtnert Schp. (Gullane Links). Regarding this moss Mrs J. A: Wheldon; F.L.S., Liverpeol,, writes me: ~ Your plant is typical H. Sexdtneri Schp. It is new to Haddington- shire, and as a matter of fact it is the first specimen I have seen from Scotland, although recorded from v.c.’s 86 and 87. I have for years been trying to get a specimen of the inland plant, but without success so far.” It grows in a shallow lagoon on Gullane Links, and covers the whole bottom with a mass of several acres exclusively of this moss. A. fluztans L.; Hf. cupressiforme L., var. filiforme Brid. ; A. Patientie Lindb.
204 THE SCOTTISH BOTANICAL REVIEW
Traprain Law, East Linton, has several very interesting mosses such as AHedwigia imberbis Spruce; Grimmia montana B. and S.; Grimmza decipiens Lindb., all three in great abundance, the latter in fruit; Axdreza Rothit W. and M.; Bryum alpinum Huds. Gullane Links also, like Tents Muir, Sands of Barrie, Dunbarnie Links, etc., have also several rare mosses already recorded as Dztrichum frexicaule Hpe., var. densum B. and S.; Swartzta montana Lindb., and S. zzclinata Ehrh.; Barbula Hornschuchiana Schultz; Tvrichostomum flavo-virens Bruch; Excalypta rhabdocarpa Schweg.; Amblyodon dealbatus P. Beauv. ; Meesia trichoides Spruce; Catascopium nigritum Brid. ; Bryum calophyllum R. Br.; Amblystegium filicnum De Not., var. Whiteheadizt Wheldon ; Hypnum chrysophyllum Brid. ; H. giganteum Schp., Thuidium recognitum Lindb., etc.
EDINBURGH, v.c. 83. This vice-county has been better searched for mosses than the two adjoining counties, and hence the new records for it are fewer. Sphagnum cuspt- datum FEhrh. var. submersum Schp.; S. molle Sull. ; Polytrichum strictum Banks (all from Bavelaw Moss) ; Oligotrichum hercynicum Lam., recently got in Corstorphine Hill wood, is now extinct; Fuss¢dens crassipes Wils. (Colinton Dell); Barbula Hornschuchtana Schultz (waste ground north of Donaldson’s Hospital); PAyscomztrella patens B. and S. (Torduff reservoir, by Mr. W. E. Evans. I got this moss in plenty on the dried-up bottom of a lagoon west of S. Queensferry last year) ; Bryum argenteum L., var. lanatum B. and S.; Brachythecium glareosum B. and S. (Flotterstone Bridge); Hypuum polygamum Schp.; A. aduncum Hedw., var. polycarpon Bland.; H. fiuitans L., var. Jeanbernati Ren., and var. atlanticum Ren. ; H.. exannulatum Giimb., var. pinnatum Boul., £. stenophyllordes Ren., and var. pimnatum Boul., f£. gracilescens Ren.; HF. entermedium Lindb., var. tenellum Roth (=H. pellucidum Wils.) (all in Bavelaw Moss); AH. cupressiforme L., var. tectorum Brid.; H. imponens Hedw. (Bavelaw Moss). I got this also last year near West Linton in Peeblesshire, v.c. 78.
LINLITHGOW, v.c. 84. Sphagnum rigidum Schp., and var. compactum Schp.; S. cymbifolium Ehrh.; S. tenellum
NOTES ON SOME MOSSES FROM THE THREE LOTHIANS 205
Ehrh.; S. fimbriatum Wils.; S. Girgensohnit Russ. (all in Drumshoreland Moss); Pleurtdium subulatum Rabenh. ; P. alternifolium WRabenh. (N.B. railway embankment) ; Cynodontium Bruntont B. and S. (Cocklerue); /7ssidens recurvus Starke; Barbula lurida Lindb.; Barbula Horn- schuchiana Schultz ; Physcomttrella patens B. and S. (all west of S. Queensferry); Sartramia ithyphylla Brid., Leptobryum pyriforme Wils. (Kirkliston distillery) ; Webera annotina Schweg. (Drumshoreland) ; Bryum alpinum Huds. (Cocklerue); Thuzdiwm recognitum Lindb. (west of S. Queensferry); Hypnum riparium L. (Linlithgow Loch) ; HT. stellatum Schreb., var. protensum Rohl; A. exannu- latum Gimb.; H. cordifolium Hedw. (Drumshoreland curling pond); H. Joreum B. and S. (W. Evans).
In the “Census Catalogue of British Mosses” for 1907 there are several mosses which require rediscovery, for their records are old. For instance, the rare Grimmias on Arthur’s Seat have evidently disappeared. Grimmia leucophea Grev., is the last one of the group I have seen on Arthur’s Seat, and I suspect that now it too is extinct. The following among others require refinding :—Sphagnum Austint Sull. (v.c. 83); Bryum Warneum Bland. (v.c. 82) ; Cryphea heteromalla Mohr (v.c. 82); Hypnum eugyrium Schp. (v.c. 83); Grimmia orbicularis Bruch (v.c. 83); G. anodon B. and S. (v.c. 83); G. conferta Funck (v.c. 83) ; G. commutata Hiibn. (v.c. 83); G. ovata Schweg. (v.c.’s 82 and 83); Axtetrichia curtipendula Brid. (v.c. 83), and several others. Tvichostomum mutabtle Bruch.; TJ. inuclinatum Dixon; 7. xztidum Schp., have yet to be gathered in Vic, 82.
Saxifraga Hirculus, L., in Caithness, and its Dis- tribution in the British Isles. By Arthur Bennett, A: io:
Mr. G LILLIE has kindly sent me good flowering specimens of the above species which he found growing ‘‘in a floating bog about ten yards across each way. It was very shaky,
206 THE SCOTTISH BOTANICAL REVIEW
but there was not much danger of one sinking in it as there was considerable growth of grasses, plants, and mosses.” It occurred between Lybster and Loch Rhuard, altitude 430 feet, 58° 22’ N. lat. about 1} miles from the loch. The loch itself afforded Lobelia Dortmanna and Subularia aquatica, rare plants in the county. As the water from the loch and the stream running into it is discharged into the Loop river, thence to the Little river, and finally into the Thurso river, the plant belongs to the north-west watershed, not to the east.
S. Hirculus is not on record north of West Perth and Kincardine, 57° N. lat. ; the extension of range north to Caithness is interesting, though it is a high arctic and northern species.
As a rare species it may be well to summarise its distribu- tion in our Isles.
g1. Kincardine. Wet moor on the farm of Jacksburns, Glenbervie. 21.6.1839.—-Mr. James Rae. This is the station erroneously given in “‘Topl. Botany” as “ Aberdeen, J. Rae.”
87. Perth, W. Madie Moss, above Tillicoultry, c. 2000 feet. Northern side of the Ochils, Clackmannanshire—Mr. W. Thompson.
83. Edinburgh. Ona wet moor between Fala and Stow. —G. J. Blackie. Three miles beyond Blackshiels, Pentland Hills, Midlothian. 11.8.98.—F. C. Crawford sp.
81. Berwick. Moor south of Langton Lees farmhouse, plentiful.—Dr. Johnston, c. 1831 ; sp. Cardiff Museum !.
78. Peebles. Pentland Hills, source of the Medwin, about 1000 feet. 11.9.1836.—Dr. A. Hunter. J. H. Balfour sp., 19.9.1838.
77- Lanark. Boorland Moss, Walston, Sept. 1850.—G. F. Blackie. No altitude given, but the parish ranges from 660 to 1000 feet alt.
69. Westmoreland. Neathheath Syke, alt. 1800 feet, Sept. 1840.—John Bell. Backhouse in Herbarium, York !.
66. Durham. Wet moor, Inishope, Weardale, 2.8.1885.— J. P. Soutter sp.
65. York, N.W. Sedbergh.—J. Handley, ‘‘ Yorkshire Naturalist” (1903), p. 408. Cotherstone Fell, 1847.—D. Oliver sp. The actual station is swamps at the junction of
SAXIFRAGA HIRCULUS, L., IN CAITHNESS 207
the river Balder with the Black Beck. Discovered here by J. Backhouse, 1810; sp. in York Herbarium.
58. Cheshire. Knutsford Moor, where it was associated with Andromeda, Melampyrum pratense, Carex limosa, curta, and stellulata ;1 also with Szum angustifolium, Cicuta, Pota- mogeton polygonifolius, Carex ampullacea, Lastrea spinulosa, L. thelypteris, and Osmunda regalts.
The date of its first record here (and for Britain) is 1724, Dibiekayy, Soyn,” 3rd: ed. ip. 355;' but the’ plant had been gathered some time between then and 1696, as in an old volume of coloured impressions of Cheshire plants? the locality is given, and the names are those of the 2nd ed. of the ‘‘Synopsis.” Specimen sent from here by Mr. Okell of Chester, and figured in ‘“‘Eng. Botany,” t. 1009,° Aug. 1801. Extinct in 1842. The species did not become extinct here altogether through natural causes, as the following extract will show :—
‘« Still exists on Knutsford Moor, but is almost destroyed by the rapacity of some individuals who have dug it up for sale in the most remorseless manner.”—Dr. J. B. Wood, in ““Ehytolosist,”” 1. (1842), p. 282.
In Ireland in the middle and north-east (ze. in six of Mr. Praegers’ divisions), but characterised as very rare.
In Europe it is a species of Arctic Norway to 69° 20’ N. lat., Swedish, Finnish, and Russian Lapland, Iceland, along the Siberian coast to Behring’s Straits. The American Arctic coast to Labrador, south to Saskatchewan. E. and W. Greenland, as var. alpina, Engler Mon. Warming, ‘‘Om Groenlands Vegetation,” 1886-7, does not give any height for this, though citing many species up to 4000 feet. It will bear intense cold, as on the island of Kolegew, where ‘‘the thermometer never rose above 9° R. in July and August 1841” ;° there it is common. It also occurs on Spitzbergen and Bear Island.
I am not sure whether the first Scottish record was the
1 Lord de Tabley, ‘‘ Fl. Cheshire” (1899), p. 142.
2 Perry, ‘* Phyt.,” i. (1843), p. 700.
3 This plate is not quoted in the 3rd ed., iv. (1865), t. 550.
4 Kjellman, ‘‘ Vega Expedition ” (1882), 263, 302.
® Erman, “‘ Arch, Wiss. Kimde v. Russlandes” (1852), x. 313-16; quoted by Fielden and Geldart, ‘‘ Trans. Nor. and Norf. N. Soc.” (1896), p. 169.
208 THE SCOTTISH BOTANICAL REVIEW
Berwick one in Watson’s ‘‘ Outlines,” 1832, or the Blackshiels one in the ‘‘Edin. Phil. Journal,” as I have not access to the latter. It is not given in Dr. Johnston’s ‘‘Flora of Berwick,” ii., 1831.
Along with the Saxifrage there was a form of Cerastium vulgatum, L. (trivzale, Link.), which looked very different from the ordinary form of the species, no doubt induced by the place of growth. Still thinking it might be one of the Swiss forms so found, I sent specimens to Dr. Schinz of Geneva; he referred them to Dr. Keller of Berne. Dr. Keller reports: ‘‘They are only a form of C. c@spitosum, Gilib.1 (=valgatum, Wahb.), but the plant ought to be observed. Like all species of Cerastium, cespitosum shows a great variation in all parts according to the medium in which it lives.’ Dr. Keller writes: ‘‘C. vulgatum, L. (=glomera- tum, Thuill, v¢scosum, Fr.),’’ which opens the door to a war of words. One accepts the decision ; at the same time, the plant is easily distinguished by the eye. Another addition to the county was growing with it— Ranunculus scotzcus, Marshall.
A New Japanese Grateloupia. By E. M. Holmes; F.L.S5)*Rs525889
(With One Plate.)
AMONGST some marine algz collected in Japan by Mr. S. Okubo, and brought to me for identification, I noticed one which I was unable to match either at the Kew Herbarium or at South Kensington. Although bearing some resemblance to Grateloupia filicina, it differs so much in habit and colour that I have decided to describe it as a new species.
Grateloupia subpectinata, n. sp—Fronde compressa, plana, ad 15 cm. longa, et 3 mm. lata, pinnatim ramosa, ramis a basi angustiore, longe subuliformibus, inferioribus longioribus, infra medium latere inferiori ramellis brevibus subpectinatis, latere superiori dentibus paucis preditis, ramis supremis simplicibus, brevibus. Color pulchre roseus.
1 Gilibert, ‘‘ Fl. Lithuanica,” v. (1782), p. 159. 2 Read before the Botanical Society of Edinburgh.
Scottish Botanical Review.
E. M. HOLMES.
A NEW JAPANESE GRATELOUPIA 209
Hab.: Japan, S. Okubo, 1912.
The nearest approach to this species, in the mode of branching, is Grateloupra Pennatula, Kuetzing, a native of Cuba (“ Tab. Phyc.,” vol. xvii., tab. 27, a, 4,), which has similar ramelli, but both the ramuli and ramelli are lanceolate-linear rather than subuliform, and are much shorter in proportion. The rose colour, so far as I know, is never found in forms of Grateloupia filicina, although I have seen many forms referred to this species. The structure, is however, typical of Graée- loupia, and not of loose texture as in the section Glocogenza, to which a rose-coloured species, G. acuminata, from Japan, previously described by me, belongs.
Kenfig Burrows: An Ecological Study. Communicated by M. Y. Orr.’
KeEnFIG Burrows forms the southern extremity of a fringe of blown sand which borders the south-west coast of Glamorgan as far as Swansea, a distance of fifteen miles. The breaks in its continuity are brought about by the rivers Avon and Neath. At Kenfig the sand dunes extend inland for over two miles at the broadest part, and occupy an area of approximately 1500 acres. ‘The general drift of the sand is in an easterly direction.
Apart altogether from the biological problems involved, the area is of great historical interest, for a waste of sand now covers what was at one time a prosperous town. A few scattered ruins on the northern dunes are all that remain to mark the site of the castle and buried city of Kenfig. The invasion of the sand since Roman times appears to have been gradual, but, according to tradition, sand storms of considerable magnitude occurred in the fourteenth century. In 1538 ruin had overtaken the town and castle, and both were abandoned to the advancing sand.
Kenfig is now represented by a little hamlet, situated about half a mile from the castle ruins, on a ridge overlooking the sheet of water known as Kenfig Pool. This water occupies the central portion of the landward margin of the dunes. From its eastern shore the ground slopes gradually upwards to the ridge, the height of which, and of the adjacent fixed dunes, varies from ninety to one hundred feet above sea-level. The pool forms the apex of a trian- gular wedge of fertile land which has not been invaded by the sand to any great extent. No doubt, the pool, owing to its position, forms a natural barrier to the further incursions of the sand. The
' Read before the Botanical Society of Edinburgh. VOL. I. 16
210 THE SCOTTISH BOTANICAL REVIEW
area of this sheet of water is 68 acres, and its greatest depth is 11 feet. The water is fresh and fed by springs on the landward side. It has existed in its present form since 1876, but is of less extent and slightly different outline to the pool of 1814. It was originally a marsh, and its eastern margin is still, in part, character- ised by a marsh vegetation. At that time it was drained bya stream which flowed in a northerly direction and emptied itself into Kenfig river. To-day there is no visible outlet, but it is possible that its waters filter through the sand and ultimately enter the river in that way.
Geology, Climate, and Rainfall.
The blown sand rests on the Keuper marls of the Trias formation, Rocks which project here and there through the sand nearly all con- sist of conglomerate, which is more or less calcareous in composition. The wedge of land which has the pool as its apex is boulder clay resting on Triassic conglomerate, while the southern boundary of the ‘‘white” dunes is of like glacial origin. A broad stretch of alluvium marks the northern limit, and an irregular alluvial tract extends from the margin of the pool to within a short distance of the shore. The climate is mild and humid. Owing to the prevalence of warm south-westerly winds the mean January temperature is about 41° F., and it is probable that the resultant mild winters have a modifying effect upon the vegetation. The corresponding July temperature is 62° F. The average annual rainfall, estimated over a number of years, is a little over 33 inches. ‘T'he wettest months of the year are July to January inclusive. A complete analysis of the soil and sand taken from different stations on the dunes is now being carried out, and a detailed account of soil conditions will be embodied in a future publication. Cattle and horses are pastured on the dunes, and the soil is thus enriched with manure. Molluscan shells are abundant in many of the hollows.
The plant formation which covers this area is a natural one, and presents many interesting biological features. A comprehensive ecological study of its vegetation, on modern lines, is now being undertaken, and it is hoped to extend this investigation so as to include the entire belt of sand dunes from Porthcawl to Swansea. So far, detailed observations have been chiefly confined to the Kenfig district. This communication is, therefore, not intended to be exhaustive, and is merely a brief account of the more salient features of the vegetation.
THE PLANT ASSOCIATIONS,
The three most prominent and well-marked associations in this formation are the following: 1. The association of Ammophila arenaria; 2. the association of Salix repens; 3. the association of Pteris aquilina.
1. The association of Ammophila arenaria,—This association is
KENFIG BURROWS: AN ECOLOGICAL STUDY Zit
characteristic of the “shifting” dunes, with the Marram grass as the dominant species. ‘This species occupies the first seaward line of sand hills, the Agvopyretum juncet (sea couch-grass association) of the Somerset and Lancashire dunes being practically absent in this area. It is worthy of notice that Llymus arenarius, which in Norfolk gives rise to low dunes, is entirely absent from this coast. The higher inland dunes, many of them over fifty feet in height, bear on their crests the characteristic tufts of Marram grass. It descends on the leeward slopes and colonises the sandy hollows, and in many of the latter,its rhizomic habit of growth is particularly obvious. As a “‘sand-binder” it is pre-eminent, and it is interesting to note that in the Charters of Kenfig of 1330 special provision was made for its protection and preservation. Ammophila also occurs in abundance on some of the ‘‘ fixed” dunes.
2. The Salix repens association.—Salix repens occurs on the shifting” dunes as a “‘sand-binder,” producing a well-marked association. In the sandy dune valleys it forms a carpet of low- growing scrub, but in the more exposed stations it collects around it the blown sand and gives rise to “ hummocks” and small dunes. In the damp hollows it forms a fringe round the marshy ground and the dependent species vary accordingly. Saézx represents the second stage in succession on the dunes, as Ammop/ila represents the first. In the more open stations of this association Marram grass is the subdominant species. Salix repens occurs on the Lancashire dunes, but Moss describes it as a comparatively rare plant on the Somerset sand hills.
3. The Preris aguilina association.—The bracken covers acres of the ‘‘fixed” dunes in this area, and its outliers blend with the willow of the preceding association. Its rhizomic habit of growth makes it likewise a successful sand-binder, and it forms the last stage in succession. According to Massart, Per7s is entirely absent from, or very rare, on the Belgian dunes. It has here undoubtedly adapted itself to life on the dunes and grows luxuriantly. The fronds are regularly harvested for cattle-bedding. Although it is such an abundant type on the “grey” dunes near Kenfig pool, it is sparsely represented on the adjoining boulder clay. This may be due, in part, to the fact that the latter is under cultivation, or perhaps its absence may be accounted for by the more or less calcareous nature of the clay; the bracken being regarded by some authorities as a calcifuge.
In these three chief associations the subordinate species vary according to the character of the association. The Marram grass association is essentially an open one, and on the seaward side of the first range of ‘‘mobile” dunes it is an almost pure association. As a result of this open character, competition among the associated species is reduced to a minimum. The Sadzx repens association is of a less open nature. The habit of growth of the Sadx affords protection from blowing sand, and excessive insolation, to the types which it shelters. At the same time, a certain amount of humus is
212 THE SCOTTISH BOTANICAL REVIEW
present, especially in damper stations. On the embryonic dunes formed by this species few associated plants occur, principally on account of the more exposed situation. These hummocks are sub- jected to frequent denudation by the wind, and their bases commonly present a weathered appearance. In the fixed dune association where Preris is the dominant plant, the amount of shade cast by its fronds is relatively greater, and the dependent species are mostly grasses, Agrostis sp., etc. These three dominant species are rhizomic in habit, and are specially adapted to hold their own under apparently unsuitable edaphic conditions.
Extent and Distribution of these Associations.
The Marram grass association extends inland as far as Kenfig Pool, where its outlying stations dovetail with those of the Sadx association. This latter covers a broad area on the alluvium on the seaward side of the pool, and extends laterally on its flanks. It gradually loses its identity in the bracken association of the fixed dunes. Distributed throughout these chief associations are minor associations which are of local occurrence. Audus cesius, the dew- berry, for instance, forms a community of this description. This species occurs in certain situations on the dunes, and represents, with Prer’s and Sadix, the last stages in succession. Sometimes associated with it is a hybrid form of Rwhus which gives rise to hummocks. In addition to these principal associations many sub- associations and plant societies exist. These will be described at a later stage.
The term “plant association” implies a plant community, and it therefore follows that the dominant types, mentioned above, have associated with them species which may be regarded as subdominant, abundant, or occasional, according to the frequency of their occurrence. Some species are apparently always associated with a particular dominant, but on the dunes there are many cosmopolitan types which are not limited in their distribution to any one association. A list of subordinate species occurring in any one plant community does not therefore imply that they are characteristic of that associa- tion alone, or that they do not occur as frequently in any other association. The majority of associated species colonise the sheltered “flats” and dune valleys which wind in all directions among the high dunes. The configuration of these valleys is varied, and some are characterised by a flora quite distinct in composition from that of a neighbouring depression. Some are marsh-like in character, while others are undulating plains of blown sand, with embryonic dunes in various stages of formation. The species which occupy the dry hollows are psammophilous, although some, like Cvzcus arvensis, which frequently occurs, are as characteristic of other formations. On the fixed dunes sward-forming plants and others are associated with Pris and Ammophila, while many species of moss form patches
KENFIG BURROWS: AN ECOLOGICAL STUDY 213
of bright green colour everywhere, and are particularly obvious during the early spring.
The following detailed description of the associations is not intended to be exhaustive. Many problems arising out of the distribution of the dependent species in this formation have yet to be solved, and the listing of associated tvpes is but a step on the way to their complete elucidation. No sharp line can be drawn between two associations, and it is often difficult to determine whether a certain species belongs to one association or to another.
In the Kenfig sand-dune area the Sa/ix repens association is of a transitional type. In its more open stations on the mobile dunes the majority of its subordinate species are those of the Marram grass association. ‘Towards its inner limit, fixation of the sand is complete, and the included species are those of the fixed dunes
Before enumerating the species which are found in the chief associations, it is necessary to call attention to the plants which occupy the foreshore, above high-water mark. These plants are usually included in the sand-dune formation, although, as a rule, they are more of a halophilous nature. ‘This association of strand plants is not well developed on this part of the coast; only a few species occurring here and there. The following are the commoner species : Cakile maritima, Scop.; Arenaria peploides, Linn. ; Sadsola Kali, Linn.
Marram Grass Association.
In the “flats” and sheltered hollows among the “shifting” dunes the following species occur :—
DOMINANT SPECIES.
Ammophila arenaria, Link.
ABUNDANT SPECIES.
Lrodium cacutarium, L’Herit. Luphorbia Parattias, Linn.
Anaphalis margaritacea, B. & Luphorbia portlandica, Linn. Hi: fil. Tris fetidissima, \.inn.
Senecio Jacobea, Linn. Carex arenaria, Linn.
Cnicus arvensis, Hoffm.
FREQUENT OR OCCASIONAL SPECIES.
Erigeron acre, Linn. Cynoglossum officinale, Linn. Taraxacum erythrospermum, Verbascum Thapsus, Linn. Andrz. Verbena officinalis, Linn.
The variety g/andulosum, Bosch., of Erodium cicutarium has been recorded from this district. Axaphalis margaritacea is well established on the dunes, and apparently succeeds best where competition is reduced toa minimum. Cvicus arvensis colonises the sandy ho!lows
214 THE SCOTTISH BOTANICAL REVIEW
towards the inner limit of the mobile dunes. It is also abundant on the fixed dunes, as in Norfolk. Luphorbia portlandica is absent from the Somerset sand hills.
Salix repens Assoctation.
As already mentioned, this association includes within its limits plants of the mobile dunes, as well as those of the fixed dunes. The following species occur :—
DOMINANT SPECIES.
Salix repens, Linn.
SUBDOMINANT SPECIES.
Rubus cestus, Linn. Ammophila arenaria, Linn.
FREQUENT SPECIES.
Viola ericetorum, Schrad. Leontodon (nudicaule), B. & S. Viola Curtisit, Forster. Euphorbia Paratias, Linn. Erodium circutarium, LHeérit. Tris fetidissima, Linn.
Rosa spinosissima, Linn. Carex arenaria, Linn. Erigeron acre, Linn. Phleum arenarium, Linn.
Cuicus arvensis, Hoffm.
Viola Curtisit was recorded from the sand dunes near Aberavon, over sixty years ago. It is not found in Somerset. The damp sandy hollows which occur within the limits of the Sa//x association possess a characteristic vegetation. These depressions lie at a low level, and during the winter months are frequently submerged. A layer of humus is formed in places, and in conjunction with an increased water content produce a plant society of a definite type. The Sa/ix forms a fringe round the margin of these hollows, which are colonised by the following species :—
Samolus Valerandt, Linn. Littorella untflora, Aschers. Erigeron canadense, Linn. Flelleborine longifolia, R. & B. Flydrocotyle vulgaris, Linn. Orchis incarnata, Linn. Anagallis tenella, Murr. Juncus effusus, Linn.
Blackstonia perfoliata, Huds. Eequisetum palustre, Linn. Mentha aquatica, var. hirsuta
(Huds.).
The occurrence of these species in the different hollows depends upon the relative amount of moisture present. Practically pure societies of one particular species are not uncommon.
Kenfig Pool is situated within the limits of the Sa/zx association, and its general features have already been described. On its sandy margin the vegetation met with is mainly that of the damp hollows. A sheltered bay on its landward side is rich in species, and the
KENFIG BURROWS: AN ECOLOGICAL STUDY 215
vegetation here and there is of the marsh type. On the opposite shore, which is exposed to frequent sand-blasts from the adjoining dunes, very few plants occur. Space does not permit of a detailed description of the flora and its distribution, but the following list of commoner species will suffice to indicate its character and composition :—
Ranunculus peltatus, Schrank. Polygonum amphibium, Linn.
Castalia alba, Wood. Rumex Hydrolapathum, Huds. Hydrocotyle vulgaris, Linn. Tris fetidissima, Linn. Menyanthes trifoliata, Linn. Alisma ranunculotdes, Linn. Scutellaria galericulata, Linn. Lleocharis palustris, R. & S. Scutellaria minor, Huds. Carex leporina, Linn. Littorella uniflora, Aschers. Carex Goodenowitt, Gay.
Limosella aquatica, var. tenutfolia, Lej., was recorded as occurring in great quantities on the sandy shores of the pool in 1898, but it has not been observed in this locality since 1908. Trees are practically absent from the mobile dunes. On the northern limit of the fixed dunes sand plantations occur, while the alder grows freely on the banks of Kenfig river, and follows its course for a considerable distance on the alluvium. Stunted, wind-pruned specimens of Sambucus nigra are met with here and there on the “shifting” dunes, usually in somewhat exposed situations. /Zippophaé rhamnoides, which forms a dense scrub on the Norfolk dunes, and is also reported by Moss as frequent on the Somerset sand hills, does not occur.
Vegetation of the Fixed Dunes.
The transition from the associations of the ‘‘ mobile” dunes to those of the “fixed” dunes is gradual. Fixation by Salix, Rubus, and sward-forming plants, like Festuca rubra, begins in the more sheltered hollows, near the inner limit of the shifting dunes. In the more exposed stations the Marram grass still holds its own, and on the dune grassland, where /er7s is absent, it remains a dominant type. Where dune grassland gives place to cultivated land, bush vegetation and trees form a final barrier to the invasion of the sand.
Pteris aquilina Assoctation.
In the more open stations of this association the following species occur, in addition to many of those already mentioned :—
Erophila verna, E. Meyer. Saxifraga tridactylites, Linn. Cerastium semidecandrum, Carduus nutans, Linn. Linn. Sedum acre, Linn. Cerastium tetrandrum, Curt. Lycopsis arvensis, Linn. Stellaria apetala, Ucria. Myosotts collina, Hoffm. Sagina nodosa, Frenzl. Koeleria gracilis, Pers. Vicia angustifolia, Linn. Festuca rubra, Linn. and _ its
different maritime forms.
216 THE SCOTTISH BOTANICAL REVIEW
On those fixed dunes, from which Pers is absent, Ammophila is almost a dominant type, and the association is a closed one. Many of the included plants are those of cultivated land. In addition to some of the species already mentioned as occurring in the bracken association, the following are abundantly represented :—
Geranium molle, Linn. Leontodon nudicaule, B. & S. Galium saxatile, Linn. Rumex Acetosella, Linn. Bellts perennis, Linn. Urtica dioica, Linn.
Cunicus lanceolatus, Willd. Luzula campestris, D. C.
Cnicus arvensis, Hoffm.
On the innermost margin of these fixed dunes U/ex europaeus is occasionally met with. Mosses and lichens are common here, and in the transitional associations. They play an important part in preparing the ground for the growth of flowering plants. Here and there on these fixed dunes limited areas have been enclosed and are now under cultivation. It is impossible at this preliminary stage in the study of the vegetation of this formation to form any opinions on its composition and distribution which will be of lasting value. The particular area which forms the subject of this communication is too restricted in extent, in any case, for generalised deductions. The mere listing of species included in the different associations is but the initial stage in any ecological study. Were these lists complete, much would yet remain to be done. Critical forms must be made the subjects of careful investigation. <A thorough investigation of the dependent species and their habit of life must be undertaken, to determine the relationship existing between them and the dominant type, in the association in which they occur.
The powers of adaptation and adjustment to environment of the individual plants, and many other kindred problems, still await solution.
The Past History of Monocotyledons, with Remarks on their Origin. By A. R. Horwood. (With Two Plates. ) (Continued from p. 180.)
4. THEORIES AS TO THE ORIGIN OF MONOCOTYLEDONS.
There have been many theories as to the origin of monocotyledons. They may be regarded as (i.) systematic, (il.) morphological and embryological in character.
According to the former evidence monocotyledons are generally
THE PAST HISTORY OF MONOCOTYLEDONS 217
regarded as the more primitive and dicotyledons as derived from them.
As an exponent of this view we may select the classification of Engler with some modifications, and follow the generalisations of Dr. Rendle,! whose conclusions must largely be based upon the vast and unequalled collections of dried specimens in the National Herbarium, supplemented by a knowledge of the living forms repre- sented in the Royal Botanic Gardens at Kew.
Dr. A. B Rendle? adopts Engler’s view that Pandanales are the most primitive. The flower of Zyfha recalls the gymnospermic strobiloid flowers. ‘They are held to represent developments from a common ancestor along different lines.
Helobiez are next in order, and /Vazas is the most primitive, with micro- and mega-sporangia, axial in origin. Glumiflorz have flowers typically naked, and ‘‘correlated with this is the suggestion that the group represents a primitive and not a reduced type of monocotyle- dons, which have developed on their own lines.” It is said to ‘suggest a derivation from an earlier, more strictly aquatic group,” and ‘‘that it was the first group to become established upon the drier land surface.”
In regard to Spadicifloree, similarity of seed-structure serves to unite palms and aroids here. Dr. Rendle thinks they may represent a further development of Pandanales.
Lemnacee are a reduced type of Aroidez, whose huge herb type is an adaptation to a hot, moist climate, and an outcome of this is the epiphytic form, whose origin may be traced in Philodendron. Assuming Glumiflorz to be primitive, the higher types follow on from ‘them.
Farinose (including Restiacez, Eriocaulaceee, Commcelinacee, Pontederiacez, Bromeliaceze) are limited in range and _ highly specialised. The Restiaceze suggest a glumiflorous type, adapted to dry conditions which Glumiflorg in many points appear to confirm. The Eriocaulacez and other families are also highly specialised.
The Lihiflore include Juncaceze, which appear to be derived from Glumiflore. Liliaceze are closely related to them. Iridacez, how- ever, appear to exhibit reduction. In these and in the Liliacez and Amaryllidaceze there is a marked development of corms and bulbs, and the plants are adapted to land areas not occupied by a meso- phyte vegetation.
In aloes and yuccas we find an increase in stem by secondary growth to meet xerophytic conditions on a larger scale; the leaves also are larger and more numerous. In Sax both leaf and flower structure are adapted to a climbing habit.
The Scitaminez are derived from some of the Liliifloree. AZmsa is the most primitive, and all are adapted in their herbaceous characters to a moist climate.
1 “** The Classification of Flowering Plants,” 1904, p. 378 e¢ segg. 2 Tbid.
218 THE SCOTTISH BOTANICAL REVIEW
Amongst Microsperme the Burmanniacez exhibit an affinity with Liliifloree.
Thus far we have reviewed the results attained by the study of the systematist. Let us see what morphology and embryology, with some ecological facts, have to tell us.
The opinion expressed by Schimper and Schenk in their text-book of Paleobotany! largely coincides with the decision arrived at by some of those who have based their researches upon the facts of morphology or embryology. They consider that dicotyledons are the older race. They remark upon the late appearance of mono- cotyledons and their rare occurrence as fossils. They consider the stem-structure proves that monocotyledons are the higher group. It is pointed out that the dicotylous type of stem-structure is found in fossil vascular Cryptogams and Gymnosperms. The simple floral structure is thought to point to a group in process of evolution.
Dr. W. C. Worsdell? holds the view that dicotyledons are derived from monocotyledons, that the cotyledon is always terminal, and that the stem-structure is not due to reduction but is primitive. He regards the fruiting stem and petiole as alone able to unfold the true ontogeny of the individual whereby the stages in the race-history may be made out. Dr. Worsdell’s latest view is that monocotyledons and dicotyledons are variants of one form and that there is only ove cotyledon. He has found a similar stem-structure of scattered bundles in about thirty orders of dicotyledons, and considers the dicotylar vascular system derived from the monocotylous. Many other characters also are correlated with it.
In Jungermanniee (f Pl. II. fig. 3, part 1. p. 180) the seta is derived from the two epibasal quadrants, and it is considered that the cotyledon is homologous with it, and terminal. It arises before other organs, bearing out the sporogonial or phyton theory of the plant, but not the lateral appendage view. If their development is similar, then the single cotyledon has dichotomised to form two ; and the plumule is then lateral to both cotyledons, and between the two. And the bifid cotyledon is primarily terminal. “The actual ontogenetically terminal position of the plumules is a secondary adaptation,” and in some plants, e.g. in palms, “it becomes enclosed in the basal sheathing petiole of a single tubular cotyledon, which is terminal to the hypocotyl.”
In the moss the seta is terminal. If we regard the cotyledon as homologous and the monocotylous embyro an index of the history of the leafy angiosperm, we have a succession of shoots arising, the second like the first, and so on, till a terminal apex or growing point is formed upon the axis thus produced by sympodial arrangement. This monopodial axis with apparent lateral appendages is purely illusory, and ‘‘we need to entirely amend our artificial conception
Stet), jo sys. 2 Vide ‘* A Study of the Vascular System in certain Orders of the Ranales,”” ** Ann. Bot.,’” Oct. 1908, p. 651 ef seqq.
THE PAST HISTORY OF MONOCOTYLEDONS 219
of the leaf as a purely lateral appendage to an axis. We are misled all along the line into believing these secondary modifications to be the original types” (Pl. III. fig. 1).
From the embryonic segmentation and the dominant cotyledons the usual view as to the appendicular nature of the leaf is wrong. ‘The plant is built up of a number of individuals (phytons) by ‘‘anaphytosis,” or sympodial arrangement. On this view monocoty- ledons are the older. Angiospermous plants may be placed in one of two categories according to their habit, viz. :—
Grandifoliate plants (monocotylous), stem subsidiary, with bundle- system like that of the leaf, reduced internodes, leaves dominant, closely succeeding, with wide sheathing base ; e.g. palms, water-lilies.
FParvifoliate (dicotylous), stem dominant, bundle-system differing from that of the leaf, elongated internodes, small leaves, unsheathed bases ; ¢.g. elm, wall-flower.
The grandifoliate is the more primitive, and is due to the precocious assertion of the axis, displacing the terminal cotyledon, which is constantly repeated and gives rise to the short internodes.
Dr. Worsdell points out in regard to the fusion or abortion of one cotyledon to account for the deviation of the monocotylous from the dicotylar type, that in no instance has a monocotylous plant been found to develop a bifid cotyledon or two cotyledons. On the other hand, the converse is found where amongst dicotyledons one is found.
This is held to be a reversion. Bifurcation of cotyledons is common, and the polycotyledonary form seems to be the direction evolution is taking.
Thus we come to the novel view recently promulgated by Dr. Worsdell as follows: ‘‘ Hence I hold that the presence of two cotyledons in dicotyledons is merely an illusive appearance. ‘There is only one cotyledon, as in monocotyledons ; this has become so deeply bifurcated in the great majority of cases as to give the appear- ance of two distinct leaves.”
The sympodial arrangement of the stem and leaves is a recapitula- tion of that of the seedling monocotyledon, and as such lends support to their relatively primitive character.
In regard to the ancestry of Angiosperms generally, Dr. Worsdell remarks :—
“] feel more and more inclined to hold the view that Angio- sperms have developed directly from an ancestor belonging to the Bryophyte level, and that they have not come from either Gymno- sperms, Pteridosperms, or Ferns. On the other hand, it is quite possible that they have descended from a fern-like ancestor.”
The tendency of Dr. Worsdell’s view is thus largely in the direction of the point reached by Celakovsky and Bower.
Ontogeny does not always visibly repeat phylogeny. In seedling structure some stages are omitted, and there is no room for scattered bundles. The adult, however, should include all previous stages.
220 THE SCOTTISH BOTANICAL REVIEW
Leaves retain their primitive character longer than stems which carry all the organs.
The stem is parvifoliate in Umbelliferae, the leaves grandifoliate. If the monocotylous type be derived from dicotylar forms, the stem would not remain the same and leaves become grandifohate ; but if dicotylous forms are derived from monocotylous, the stem might become parvifoliate and the leaves remain grandifoliate and stem become parvifoliate. Scattered bundles are found in the stem of Umbelliferee, and it is not truly parvifoliate.
In Ranunculacee the flower is primitive and the habit grandi- foliate. They have evidently not been derived from a woody parvifoliate type ; nor are Nymphzeaceze—said to retain their grandi- foliate habit owing to adaptation to an aquatic habit, for that induces reduction and concentrated bundles, to form a compact mass in the centre of the stem. Indeed, they retain their habit although aquatic. Berberidaceze, Calycanthacezs, Magnoliaceze possess primitive flowers, sheathing leaf-bases, and retain something of the grandi- foliate habit. The bundles are amphivasal where scattered—a character common to both groups of Angiosperms.
Miss Ethel Sargant holds the view that both monocotyledons and dicotyledons are monophyletic. The absence of a cambium is said to be due to reduction. ‘The stem-structure of Liliacez is regarded as primitive, e.g. in Anxemarrhena, with its bisymmetrical structure: the last stage in the fusion of the cotyledons. Other groups of Liliifloree exhibit the same type. Comparison with pseudomono- cotyledons and with Evanthis and Podophyllum, the latter arrested on its way to become a monocotyledon, confirms this, The correla- tion of this feature with the geophilous habit suggests that it is the cause of the fusion of the two cotyledons to form one, which is regarded as a necessary economy by reduction of material expended in assimilating tissue, owing to the short growing season of such plants as Alpine, bulbous, and tuberous plants. In such plants the leaves are crowded, giving rise to concentric or scattered bundles. Linear leaves assist in elongation. Short-lived roots characterise lowland plants habituated to a short growing season. Albuminous seeds are found in dicotyledonous geophytes. ‘Thus Miss Sargant holds the view that the monocotylous forms are reduced owing to a geophytic habit.
Darwin, in his “‘ Movements of Plants,”! says: ‘“‘We may infer that there is some close connection between the reduced size of one or both cotyledons and the formation, by the enlargement of the hypocotyl or of the radicle, of a so-called bulb.”
Pseudomonocotyledons are geophytes as well as many mono- cotyledons, and thus the common habit is taken to be the cause of the single cotyledon.
As to the possession of a cambium, Queva has found this in second- year tubers of Gloriosa superba, from which he regards dicotyledons
1 1880, p. 97.
THE PAST HISTORY OF MONOCOTYLEDONS 221
as the older group. Professor Jeffrey finds cambial activity in monocotyledonous seedlings in their third period when they become ascending axes, and considers they are derived from dicotyledons by adaptation to an amphibious habit.
The single cotyledon is terminal, but, if derived from dicotyledons, is thought to be only apparently terminal, really lateral. In Delphinium nudicaule (see P}. III. figs. 2 and 3) at eight weeks the cotyledon is terminal, but at fourteen weeks the plumule is. In Alisma (Pl. III. fig. 4, A), Zamus communts (tbid., 4, D), and the pseudomonocotyledon Corydalis cava (tbid., 4, B, C) the cotyledon is formed before the plumule and is terminal ; but when the plumule is developed the cotyledon is forced to one side. This is explained as due to the early formation of the plumule, or to the partial union of one margin only, as in Ranunculus ficaria.
The other characters, parallel venation of leaf, short duration of primary root, albuminous seeds, trimerous symmetry—except the last—are regarded as adaptations to mode of life.
Miss Sargant reviews the theory of Professor Henslow. This is based largely on the great number of aquatic monocotyledonous orders. He considers monocotyledons are derived from dicotyledons by suppression of one cotyledon, due to their aquatic habit. But aquatics and geophytes have characters in common. Vascular structure is reduced by an aquatic habit. Parallel venation is found only in aquatic monocotyledons. Tufted roots are found in aquatic monocotyledons and dicotyledons. Aquatic dicotyledons do not tend to become monocotylous nor produce albuminous seeds. The floral structure is not uniform, and may be derived from an ancestor between Ranales and Liliflore. Probably aquatic monocotyledons were not primitive but driven by severe competition on land to the water, where conditions are more uniform. Aquatic conditions tend to modify vegetative organs, but not the flower. This is because it is a physiological phase.
Geophytes can adapt themselves either to an aquatic or a climbing habit. Arboreal monocotyledons are not aquatic, but possess anomalous thickening rings as in Aloe, Dracena, etc. Palms, again, recall the characters of geophilous plants, being sem1i-bulbous.
Of phylogenetic schemes, which embrace the other characters, eg. parallel venation, trimerous floral structure, ephemeral primary root, albuminous seeds, etc., there is Professor Lyon’s theory of the origin of dicotyledons from monocotyledons by fission of one to form two cotyledons, of use to the cotyledon. in forcing itself from the seed. Agardh first proposed the alternative theory, but only applied it to a few monocotyledons.
Professor G. Henslow extended this theory, deriving monocoty- ledons from dicotyledons by suppression of the one cotyledon due to the aquatic habit. This is based to a great extent on the large proportion (33 per cent.) of aquatic orders. Miss Sargant regards monocotyledons as a decadent race driven to an aquatic habit to
222 THE SCOTTISH BOTANICAL REVIEW
escape competition. The arrest of the cotyledon is found to be confined to one aquatic dicotyledon. The others are geophilous. The sheathing leaf-base is common to both groups, and is correlated with suppression of internodes. The absence of a cambium and substitution of concentric rings of growth may be due to the number of broad-based leaves inserted on a short axis in the case of under- ground aquatics, e.g. Wymphea.
In Peperomoia Mr. A. W. Hill found one cotyledon, but there were probably originally two, and one is hypogeal, acting as a sucker; the other looks like and performs the function of a true leaf. He extends this theory to monocotyledons generally. It is geophilous, with stem-structure like A/sma.
Then we have Miss Sargant’s own theory in which fusion of cotyledons is correlated with a geophilous habit. Suppose the primitive Angiosperm were geophilous. The green parts of the seedling would be reduced in early seasons and fusion would result.
Podophyllum affords an example of a plant with united cotyledons and scattered stem bundles which is a geophyte.
The suggestion is thrown out that the glacial period may have produced conditions most favourable to geophytes and afforded scope for monocotyledonous development.
In attempting to reconstruct the character of a race of primitive Angiosperms! Miss Sargant discusses the question of monocotyledons in a new light. The development from Pteridosperms, first as a pro-anthostrobilus, then as a eu-anthostrobilus, up to the primitive Magnolia and Liriodendron, as recently sketched out by Messrs. Arber and Parkin,” is accepted, and she reconsiders the evidence for regarding Angiosperms as monophyletic, and the reconstruction of the pro-Angiosperm. As to the first, the community of descent of monocotyledons and dicotyledons is proved by the many characters they share in common. And it is pointed out that the angiospermic flower is unique. The homologue of the flower, carpel, or endosperm is by no means settled.
The germination of the embryo-sac and formation of endosperm, where the first nuclear division, origin of endosperm from three nuclei, and the uniform nature of the two processes is so characteristic, supports the monophyletic origin. Double fertilisation is by no means uncommon. The history of the development of the endo- sperm is not known. Commenting on Miss Berridge’s suggestion as to the resemblance between the endosperm of Ephedra and that of Angiosperms, Miss Sargant says: ‘No tissue then in Gvetum, nor, so far as we know, in lWedwttschia, can be considered as the direct representative of the angiospermic endosperm” ;* and she
1“ The Reconstruction of a Race of Primitive Angiosperms,” Ann. Bot., 1908, vol. xxil. p. 121 ef seggq.
2**On the Origin of Angiosperms,” Jour. Linn. Soc., 1907, vol. xxxviil. p- 29. See further, Dr. D. H. Scott, ‘‘ The Evolution of Plants,” 1911, Williams & Norgate.
° See, however, Professor Pearson’s recent researches on Welwr7tschia.
THE PAST HISTORY OF MONOCOTYLEDONS 223
thinks “the germination of the embryo-sac and the history of the endosperm isolate monocotyledons and dicotyledons from all other plants.” The flower also is distinct from other ‘“ flowers,” and characteristic.
In the reconstruction of the primitive Angiosperm Miss Sargant relies on the evidence adduced by Arber and Parkin as to the form and character of the primitive flower, with angiospermic foliage, flowers, seeds, and ovules enclosed in an ovary, three nuclei in the pollen-tube, etc. The flower was elaborate in structure, with sepals, stamens, carpels, spirally arranged in acropetal succession, as in Magnolia.
The early types were of the form of a bisexual strobilus as in Magnolia, with d sporophylls below, @ above, protected by a series of sterile bracts forming a_basal perianth. Such a type is found in the Jurassic Lenxnettiites. The immediate ancestor had an antho- strobiloid flower, with perianth leaves, stamens, carpels, arranged acropetally. The strobilus was the primitive form, and Beznettites stands midway between it and A/agno/ia.
Monocotyledons and dicotyledons differ in stem-anatomy and number of cotyledons. How did the primitive Angiosperm differ from or resemble either? As to stem-anatomy, monocotyledons do not possess a cambium, or rarely. G/ortosa, however, exhibits collateral traces and a cambium in second-year tubers. Gymno- sperms exhibit cambial activity, and so did many fossil vascular cryptogams. Dicotylar seedlings early exhibit a cambium. Some monocotyledons, as Yucca, etc., do. Thus evidence points to the primitive Angiosperm possessing a cambium. As to the number of cotyledons, monocotyledons possess one, dicotyledons two. No monocotyledon possesses two, but several dicotyledons possess one. Many groups of Gymnosperms are dicotylar, and the most primitive Araucariez are polycotyledonous. In what respect did the primitive Angiosperm differ from or resemble either recent group? Analogy, as above, favours the primitive nature of the dicotylar type. What do we learn from embryology within the embryo-sac? The whole of the evidence in this connection centres around the position of the cotyledon. The terminal position of the monocotyledonous form with the derivation therefrom by fission of the two is not favoured by Miss Sargant. Can a terminal cotyledon be a true leaf? Opinions differ as to this. If extensions of the axis, they are terminal and not true leaves. The difficulty is thought to be avoided by considering the cotyledon as only apparently terminal, and so lateral.
In Adisma (Pl. IV. figs. 1-6) the cotyledon is terminal at first, then lateral as the plumule displaces it. In Pistia and Sparganium early leaves are terminal. Are they cauline? Or are they due to suppression of the axis? They are primitive forms and aquatic. The stem exists in the mature /7s¢/a, but not in the embryo. The reduction in stem is due to the aquatic habit, and causes terminal leaves. Can it cause the cotyledon to be terminal ? The form of
224 THE SCOTTISH BOTANICAL REVIEW
the embryo and development of embryo-sac are affected by (1) space rotations, (2) mode of food-supply, (3) shape of embryo, and depend on future form of seedling and mode of freeing itself from the seed- tissue. The embryo-sac is long and narrow, and bent upon itself, evidently due to nature of surroundings. The suspensor conveys. food. The cotyledons are absorptive, and endosperm prepares and draws upon the store. Is the function of the cotyledons to absorb. food and pass it on? The embryo exhibits adaptation to present, past, and future environments. Wide embryo-sacs have a lateral cotyledon, and narrow embryo-sacs, as in Adsma, an apparently terminal cotyledon.
If the single cotyledon was lateral, was that of the primitive. Angiosperm lateral? It is possible to imagine a lateral member split into two, and that one member has revolved through 180°. If it was dicotylar, the monocotylous form might be derived by suppression of one or fusion of two members. The cotyledon was single in pseudomonocotyledons, and derived from two presumably. The development is like that of 7Yamus. Sterckx found in Ranunculus ficaria a bilobed venation in the cotyledon which suggested fusion of two cotyledons. Analogy with Gymnosperms favours this, but development of the embryo-sac yields no evidence, its shape being due to environment.
As regards embryology after germination, certain types of mono- cotylous plants have primitive vascular tissue. In dicotyledons the tetrarch type is found as well as the diarch type.
In Vigel/a it is diarch, but there is transition to a tetrarch root. In Althea, which is tetrarch, there is an approach to diarch structure, _ like Liriodendron. The oldest Gymnosperms exhibit tetrarch struc- ture and also diarch structure. In Pteridosperms probably the structure was tetrarch. Thus presumably the primitive forms were cither tetrarch or diarch. In monocotyledons the structure is more variable, but there is a series of extreme types and also. intermediates.
The common origin indicates presumably a primitive type. Such are Liliacee, e.g. Anemarrhena, which is tetrarch. and they are con- nected with others, ¢.g. Iridaceze, Aroidez, whilst it is in fact a radicle of Liliifloree, and hence may be of monocotyledons in general, recapi- tulating ontogenetically the history of the group. There is a strong resemblance between the structure of Azemarrhena and the dicotylar - A/thea, which is near the primitive gymnospermous type, and prob- ably primitive. Hence probably the primitive Angiosperm type had a tetrarch stem-structure. Would this necessarily be correlated with two cotyledons? Dicotylar forms with cotyledons each sym- metrical about the median plane are symmetrical about two vertical planes. There is no symmetry about one plane, where reduction occurs. In monocotylous stems receiving traces from a single lateral there is only symmetry about the median plane. The primitive Anemarrhena, Galtonia, etc., are exceptions. That the tetrarch skeleton symmetrical about two planes is found in these suggests .
THE PAST HISTORY OF MONOCOTYLEDONS 225
that dicotylar forms gave rise to monocotylous by fusion of the two cotyledons. In Ranales, e.g. Zranthis, the root is diarch, and tetrarch structure is found in the hypocotyl. In Podophyllum peltatum the same occurs. Anemarrhena and Althea are recalled in these. In both the cotyledons are united for some distance. Reduction of the tetrarch type has progressed further than in A/thea, of which Anemarrhena is a reduced form, and with it Podophyl/ium and Eranthis agree, showing that the union of cotyledons in a tetrarch dicotyledon may result in a monocotylous type with structure of Anemarrhena.
Professor G. Henslow, in a paper! read before the Linnean Society, brought forward the theory of the origin of endogens from exogens by adaptation to an aquatic habitat due to suppression of one cotyledon. ‘This theory, which is an extension of Agardh’s, is based upon the large proportion of monocotylous aquatic orders in the group, viz. 33 percent. There are, however, some characters which are found in both monocotyledons and dicotyledons, and those which are thought to be confined to aquatic plants aione are also found in geophytes and other groups. Aquatic conditions have certainly helped to reduce the stem-structure and to modify foliage, but are not responsible for the reduction in cotyledons, nor so far as is known, the character of the flowers.
Messrs. E. A. N. Arber and J. Parkin,” in a paper on the “ Origin of Angiosperms,” trace the ancestry of the group. They disagree with Engler’s view that the present-day primitive Angiosperms have unisexual flowers, e.g. Piperales, Pandanales, etc. But the perianth is to be regarded as arising de novo, and to be an organ sud generts.
The piants cited have a sharply defined complicated structure. This theory has proved barren. The strobiloid theory is held to solve the question, the primitive form being amphisporangiate with micro- and megasporophylls and a well-defined perianth. The parts of the flower were numerous, arranged spirally, the female sporo- phylls above the male. Such a type is found in some Magnoliacee, Ranunculacez, Alismaceze. The apetalous unisexual flowers are regarded as derived from these. The flower is an anthostrobilus of which a gymnospermic and an angiospermic form can be distin- guished. But they are modelled on the same plan, the female and male sporophylls occupying the same relative position, and the perianth is differentiated. These authors consider that some important change in the mode of pollination caused the advent of Angiosperms.
Dealing with the ontogeny of Angiosperms in the paper already cited, Bessey defines the difference in the development of the em- bryo in monocotyledons and dicotyledons as follows :—
‘The only histological difference which is measurably constant is
1 «* A Theoretical Origin of Endogens from Exogens by self-adaptation to an Aquatic Habit,” Journ. Linn. Soc., vol. xxix., 1892, p. 485. But see a more recent paper, 74a.
2 Zbtd., ‘‘ Jour. Linn. Soc.,” 1907, p. 29.
VOL. I. y
226 THE SCOTTISH BOTANICAL REVIEW
that the longitudinal division of the embryo takes place defore! the formation of transverse walls in dicotyledons, and afterwards ' in the monocotyledons. To this rule, however, there are numerous exceptions.”
Commenting on the further progress of this division, he says, “‘ It is at least an interesting coincidence that in the young embryo the undivided foliar cells give rise to the single cotyledon, and the epi- basal cell to the pair of cotyledons.”
The following remarks are so @ propos that they are quoted at length :—
‘‘Are there any indications which may help us to answer the question of the origin of these two groups? Have dicotyledons been derived from monocotyledons, monocotyledons from dicotyledons, or both from a common ancestor? It must be admitted that on theoretical grounds it is no more difficult to pass from two cotyledons to one, than from one to two. Indeed, there have been not a few botanists who have suggested the derivation of the monocotyledons from the dicotyledons. When, however, one compares the two embryos there is a slight preponderance in favour of the view that the struc- ture is a little higher in dicotyledons than in monocotyledons. The row of undivided cells in the embryo of the monocotyledon after the third or fourth segmentation is certainly a lower structure than the compact mass of cells constituting the ‘octant stage’ of the dicoty- ledonous embryo. ‘The cotyledons themselves afford a slight sugges- tion as to the relationship of the two groups. It is a well-established principle in embryology that embryonic stages of higher organisms resemble the adult stages of the organisms which are lower in the same genetic line. Applying this principle to the cotyledons, we observe that while they bear some similarity to the leaves of both monocotyledons and dicotyledons, the similarity is a little more marked in the case of the monocotyledons. Compare the mostly sessile, often clasping, usually elongated leaves of monocotyledons with the cotyledons of either class, and contrast these with the mostly petiolated, generally not clasping, and usually broad-bladed leaves of the dicotyledons.”
Bessey also refers to the fact which Sir J. Lubbock (now Lord Avebury) points out, that the earlier leaves of a plant are generally quite different from the later ones. Young plants are the most alike, and they begin to get more unlike as they mature. So that it is often only possible with seedlings to distinguish the subclass, later the family, and then the genus, whilst until the flower is pro- duced the specific characters are hidden.
The deductions he makes from ontogeny are :—
1. All Angiosperms are essentially alike.
2. The two subclasses (monocotyledons and dicotyledons) appear
to be modifications of a common type which diverged from one another at an early period.
1 Present writer’s italics.
THE PAST HISTORY OF MONOCOTYLEDONS 227
3. There is no indication that either subclass was derived from the other.
4. There are some structural indications that the monocoty- ledons must rank lower than the dicotyledons.
5. The vegetative rank of most cotyledons is so nearly the same as to have left no vestiges on the young plant, which is itself vegetative.
6. The groups into which dicotyledons and monocotyledons are divided are “‘ flower subdivisions” of a greatly multiplied rather common vegetative structure. Therefore, we may not expect to find upon the embryo or immature plant any vestigial record of their origin.
In discussing the results derived from morphology, Bessey, in speaking of tissue systems, draws attention to the short life of monocotyledons and the long life (often amounting to hundreds of years) of dicotyledons. But the ephemeral type of the former occurs amongst the latter, which indicates, he suggests, the close relation- ships of the two subclasses.
He points out that the young stems of monocotyledons and dicotyledons differ less than old stems, and remarks that “ the important difference between these two types of stem is that the skeletal tissues continue to form a single solid column in the dicoty- ledons while they do not in the monocotyledons,” and the further fusion of bundles in the former, due to cambial activity, marks them out as a higher group.
From the normal type of stem seen in lilies, naiads, and orchids, there are two departures in the stem with elongated internodes of grasses and sedges, and the shorter internodes of palms and screw- pines. As to their leaves he says :-—
“The leaves of monocotyledons are usually entire, elongated, parallel-veined blades, placed alternately or scattered upon the stem, to which they are attached directly (in sessile leaves) or indirectly (in petioled leaves) by a common broad base which is rarely supplied with stipules.”
When contrasting these with dicotyledonous leaves which are dentate or lobed, usually broad, net-veined, opposite and alternate, attached by a narrow base, commonly supplied with stipules, these differences are said to be “due to differences in development.” The parallel veins of monocotyledonous leaves are due to localisation of growth at the base of the blade or indefinite bands on each side of its axis. The broad basal attachment of the monocotyledonous leaf may be due to the looser disposition of the fibro-vascular bundles in the stems, or perhaps may be owing to the fact that they are not so far advanced as the leaves of dicotyledons, there being an articulation at the base of the latter only. In the monocotyledons the common leaf type is especially modified in the Graminez.
The flower is held to consist of a strobilus of ‘‘ flower-leaves ” consisting of sterile leaves and spore-bearing leaves, the former being derived according to Bower, from the latter. The perianth as a
228 THE SCOTTISH BOTANICAL REVIEW
ring of sterile leaves may be united by symphysis, or may be apetalous. The last condition is no indication of affinity, but is simply a case of reduction.
The pollen leaves (microsporophylls, stamens) lie between the sterile and ovule leaves, and are largely adapted to the seed-producing or pollen-distributing capacity.
The ovules (macrosporophylls, carpels) occupy the highest portion of the strobilus, being usually separate, and the carpels are often separate as in A//sma, etc., forming apocarpia, or united as in lilies, to form a syncarpium, with some portions still free as in the latter, or with styles united all their length as in Commelinacez.
When some other organs are attached to the syncarpia as in the epigynous irids and orchids, ‘‘there has been such a fusion of the originally separate parts of the strobilus as to result in a single compact structure.”
‘The primitive syncarpia of the monocotyledons appears to have contained three carpels as in lilies.” In the fusion some parts are suppressed. In some dicotyledons, e.g. Caryophyllales, etc., ‘ there is a tendency to a reduction in the number of parts with increased fusion of the strobilar leaves.”
“The same law is illustrated in the genetic line, which includes the lilies (Coronariez), pipeworts (Eriocaulacez), sedges (Cyperacez), the lower grasses (Bambusez), and higher grasses (Agrostide and Panicez) ; or possibly still better in the line from lilies to amaryllids (Amaryllidacez), irises (Iridaceze), burmannias (Burmanniacez), and orchids (Orchidacez).”
There are then two modifications of the strobilus by (a) symphysts, fusion of parts; (4) aphanisis, a suppression of parts.
They may affect some or all organs of the strobilus separately or jointly.
The conclusions arrived at from morphology are :—
1. The identity of the cells and tissues of the two subclasses of
Angiosperms indicates their close relationship.
2. The fibro-vascular tissue-system of the dicotyledons indicates that the subclass is higher than the monocotyledons.
3. The roots of dicotyledons indicate that this subclass is higher than monocotyledons, and suggest the possibility of the origin of the former from the latter.
4. The structure of the dicotyledonous stem indicates the highest rank of this subclass.
5. Among monocotyledons the external morphology of the stem indicates the derivation from lily-like plants of the palms and screw-pines by an excessive shortening of the internodes, and of sedges and grasses by a corresponding elongation.
6. The general morphology of the leaves of monocotyledons and dicotyledons, as has already been indicated many times, emphasises the close relationship of the two subclasses, and repeats the suggestion that the former includes plants which must take rank below the dicotyledons.
THE PAST HISTORY OF MONOCOTYLEDONS 229
In dealing with the hypothetical phylogeny of Angiosperms, Bessey refers to the monocotyledons as follows :—
‘‘The modifications which gave us the main lines of monocoty- ledons were first the fusion of the carpels with one another and the production of a syncarpium, and, second, the progressive fusion of
ASTERALES CAMPANALES RUBIALES LAMIBILES PERSONALES (BE l 1} Li! =n > GE ut a I POLE MONIALES g Ols (Beh \- C6 SAPINDALES Ky) PASSIFLORALES < ps nae eh) — : oe —__] pecastraces eal 2 relly — i- : = GER Py a Ee RANIALES = “ 3 3 (C9) CACTALES X__| cricates oe C ) 3 3% 2S re Se aS S € ALES = aa = ¢ ee | (Non iva 3 aa YRTALES HETERO WmEHE = l 2 an primut-n = Se vane ~— PARIETALES URES HYDRALES Pay taLoid) « é (Hydrocharis, ha sth % Ly Seas AD ARYOPHYLLALES _GLUMACE HW nous # - GLUMACEOUS 7 craase= ee Ap, shesy uw if wb ALS CALYCINE S selene we soon aaa ee CESS perinus Typha ,AToids, Lemna ) me 4o wy POLYGALALES Bind eh, EES (Pp syneaspous (petaloid or vst) ,’ <9 A TRANALES a S59 Ranunculaces o Rerbermdaces spocarPoms jer hymphaces epigyrs )
¢
The Phylogeny of Angiosperms. (After Bessey.)
the syncarpium with the other strobilar leaves. These resulted in the phylum, which begins with Apocarpz and passes to Coronariez, Epigynz, and Microsperme. In some Apocarpz and many plants of the type of the Coronariez the perianth has been more or less reduced (by aphanisis), in some cases amounting to complete suppression, as in palms (Calycinz), aroids (Nudiflorz), and sedges and grasses (Glumacez),”
230 THE SCOTTISH BOTANICAL REVIEW
As to their taxonomy, he writes :—
“The Angiosperms are separable into two diverging subclasses— the monocotyledons (Monocotyledonez), and the dicotyledons (Dicotyledoneze), the first ranking structurally lower than the second. ‘The monocotyledons are well divided by Bentham and Hooker into seven series, and these we may accept unchanged, with the single exception that the water-worts (Hydrocharitaceze) should probably be removed from the Microsperme to constitute an additional co-ordinate group. These eight groups, which appear to be deserving of no more than ordinal rank, should then be arranged so as to have the following sequence, namely, Apocarpze, Coronariee, Nudifloree, Calycinze, Glumacez, Hydrales, Epigynze, Microsperme. Here it must be understood that the Nudiflorz, Calycinz, and Glumacez are separate orders radiating from the present order Coronarieze, and that the Hydrales constitute a diverging order from the base of the Epigyne.”
Some researches made by Professor H. H .W. Pearson ! in regard to Welwitschia are of interest in this connection. In studying the endosperm he found all the cells are multinucleate. Later, each cell possesses only one nucleus by fusion of nuclei in young cells. The original nucleus by division has become a thousand. The embryo-sac elongates, and there is a redistribution of nuclei. Two poles are formed: one at the micropylar, the other at the opposite end. In the former the nuclei are not crowded, in the latter they are. Then a division into compartments or segmentation takes place, with 2 to 6 nuclei at the micropylar end, 12 or more elsewhere. When there are more than 6 nuclei they are divided up into cells with single nuclei; but those at the micropylar end are not so affected, as each wall grows up into the prothallial tube. The nuclei and cytoplasm pass into this, and the nuclei become functional gametes. This unusual characteristic has led Professor Pearson to regard the endosperm as representing a new stage, which he calls the trophophyte, which serves to mark its intercalation into the life-history—a terminology now familiar to us from Professor Bower’s theory of the antithetic generation or intercalation of the sporophyte into the life-history of the moss plant. This trophophyte is neither the sporophyte nor gametophyte, but is regarded as phylogenetically related to the endosperm of Angiosperms by a series of reductions and specialised stages. The fact that in Angio- sperms a similar procedure takes place is corroborative of this view. In a more recent paper? Professor Pearson finds that the ovule in Welwitschia is cauline, and it is considered that the female cone and male flower are derived by reduction and specialisation from an amphisporangiate strobilus of a type similar to Benmettites. After division 1024 nuclei are contained in the embryo-sac, and it is repeatedly divided. The endosperm of the primitive Angiosperm
1 “¢Rep, Brit. Assoc.. Dublin,” 1908.
2 “Wurther observations on Welwztschia,” ‘‘ Proc. Royal Soc.,” Nov. 1908.
THE PAST HISTORY OF MONOCOTYLEDONS 231
is thought to have been homologous with that of Welwitschia. Gnetum and Welwitschia are derived from the Angiospermic stock, but before the carpel became the pollen-receiver.
In the Penzacez, a group of dicotyledons, Miss E. L. Stevens ! finds that there is no polarity in the early stages of development of the endosperm, as in most Angiosperms. The embryo-sac contains not 8 but 16 nuclei which form four egg-apparatus. By the fusion of 4 nuclei a definitive nucleus results. By this reductional process the same features met with in We/wztschia are recalled. A very similar process is recognised in Getum by Lotsy in the germina- tion of the megaspore or embryo-sac, and the development of the endosperm.
5. CONCLUSIONS.
Summing up the evidence afforded by the different views held by the writers cited, and by personal observation and experience, it seems to us that systematic researches have failed to appreciate the results of paleeontology and of morphology, and in considering Pandanus, etc., as the oldest group sufficient attention has not been given to the comparative results of floral structure or of morphology.
As to the theories based upon either embryology or morphology, Dr. Worsdell’s view seems to us to be based upon the most stable evidence.
The view that there is only one cotyledon in both groups, indeed, is perfectly reasonable ; and if the cotyledon and the seta of Bryo- phytes are conceded to be homologous, then their respective order in time is also practically settled, for the single cell in the latter gives rise to two, and so on until, just as in Cafsed/a, Pl. II. fig. 3 (part i.), p. 180, we arrive, in due course, at the bifid cotyledon. The fact of the subdivision from an original single cell presupposes the primitive character of the latter, and the derived nature of the double row of cells.
As to the position of the cotyledon, if the above view is accepted the originally terminal character of the cotyledon also follows. The lateral position subsequently, if we adopt the sympodial arrangement, does not affect the question. The lateral appendage view does more harm, it seems to us, in obscuring the sequence of the ontogeny (and so the phylogeny), and the morphological significance of organs than any other theory promulgated.
The reversionary nature of the monocotyledonous type in Ranales is in itself more or less favourable to the earlier age of monocoty- ledons and the derivation of dicotyledons from them.
Miss Sargant’s views are in direct contrast to those of Dr. Worsdell’s. This is readily understood when it is seen that she has based her evidence mainly upon the earlier embryological features of the species studied, too early in the ontogeny for a proper recapitulation to be observed. Dr. Worsdeil, however, takes the most mature
1 ** Proc, Roy. Soc. S. Africa,” 1908,
232 THE SCOTTISH BOTANICAL REVIEW
structures in his investigations, and there he obtains the full history. One is specially grateful to both of these able investigators for thus, in their several fields, enabling us, by their combined researches, to study both early and late stages. However much we may differ in theory from either one or the other, the data upon which they have been based lose none of their value whatsoever. In some respects the plants Miss Sargant studied were anomalous forms, e.g. Pseudo- monocotyledons, and primitive Liliaceze, and thej evidence is thus inconclusive. ‘The lateral appendage view only leads back again to an unnecessary transposition, in time, of the mono- and di-cotylar types.
The interpretation of certain features, e.g. the absence of a cambium, as due to reduction, instead of being held as a primitive character, is a necessary consequence.
There may really be some truth in Professor Lyon’s view that the fission of the cotyledons has to do with the freeing of the cotyledon from the testa.
Professor G. Henslow’s theory that one cotyledon has been suppressed in monocotyledons is based upon the preponderance of aquatic orders in monocotyledons—and thought to be due to their adaptation to an aquatic habitat, a physiological cause, which is not universally applicable.
In so far as it touches the origin of monocotyledons Messrs. Arber and Parkin’s paper is favourable to the view that a primitive Angiosperm gave rise very early to both mono- and di-cotylar types, the divergence being close to the origin of the primitive ancestor.
Bessey’s views seem to us to be so reasonable that, taken in con- junction with Dr. Worsdell’s, they lie nearest the truth.
It is a remarkable fact that the earliest forms of both monocoty- ledons and dicotyledons exhibit a sort of parallelism of development. The first monocotyledons are apocarpous, just as are Ranunculacee, amongst the latter (except Nymphzeaceze, which are epigynous).
Then there is a higher series which becomes hypogynous, from which the Calycifloree early diverge and are perigynous or epigynous.
So in monocotyledons the apocarpous forms (rarely petaloid) become syncarpous, and then spadiceous or glumaceous, or hypo- gynous, and finally epigynous.
The researches of Professor Pearson and Miss E. L. Stevens as to the embryology of We/witschia and Penzacez favour the derivation of Angiosperms from Gymnospermic or Bennettitean stock, but, as yet, throw no light upon the Angiospermic origin nearer the present time, and the differentiation into mono- and di-cotyledons.
Speaking generally, it seems to us that the monocotyledons and dicotyledons have diverged from a common primitive Angiospermous stock. The earlier types of the former appear to belong to Alismacez, leading on to Liliacez ; and the earlier forms of the latter the Ranales, represented by Magnolia and Liriodendron, from which Ranunculus and its allies are later derivatives. This would allow of the retention of some primitive characters in both groups which are apparently explained only by supposing dicotyledons derived from
THE PAST HISTORY OF MONOCOTYLEDONS 233
monocotyledons or vice versa, or from a stock capable of transmitting either.
Primitively we may consider that there was an adaptation from aquatic to terrestrial conditions, which then gave rise to the geophilous habit, whilst other forms in the harder struggle on land retained or sought refuge again in an aquatic habit.
The derivation of Angiosperms from the same synthetic type as Gymnosperms seems clear. The near approach of the unique Bennet- titeze with two cotyledons and copious endosperm would alone suggest this. The derivation of the latter from Pteridosperms is again more or less clear. The fact that two cotyledons is so characteristic a feature of Gymnosperms is again confirmatory of the early differentia- tion of a dicotylous type. The polycotyledonary! forms are also the more ancient, so that there is some evidence from analogy for reduction. In Gymnosperms a suspensor is not always present. Many of the Gymnosperms exhibit other characters, though these may be homoplastic—e.g. parallel-venation and strap-shaped nature of leaves, e.g. in Cordattes.
It should be noted in regard to stem anatomy being a distinctive character, that the arborescent Lycopods sometimes, though not invariably, exhibit cambial activity, whilst herbaceous forms do not.
As to cotyledons the number is extremely variable amongst Gymnosperms within the same group. So that although dicotyle- dons and monocotyledons are remarkably uniform in this respect, yet the character is apparently due to physical selection and is homo- plastic, like the stem anatomy.
Probably Dr. Worsdell’s suggestion that the two are phases of one group is nearer the mark. Amongst fossil Cephalopods the group Nautiloidea is more or less constant in the central or dorsal position in the siphuncle, whereas in Ammonoidea the siphuncle is ventral. In Clymenioids, an Ammonite group, however, it is dorsal.
Triassic Ammonoids, again, exhibit a curious type of sutural development. In Nautiloidea Triassic Pleuronautilids exhibit what may be called an homologous arrangement.
Thus monocotyledons and dicotyledons may be compared with Nautiloidea and Ammonoidea, and although the first two are plants, and the last two animals, they exhibit a sort of parallel mode of development, in respect of the degree and not the kind of difference. The phenomenon is what Hyatt has described as morphic equivalents.
Summing up the evidence in regard to the relative antiquity of the monocotyledons and dicotyledons, and the bearing this has upon the origin of the latter, we find ourselves reduced to the following conclusions :—
1. There is evidence from paleontology that monocotyledons came into existence almost contemporaneously with dicotyledons, not, as once held, long prior to the latter.
' There may be 3 to 18 cotyledons as in Pemus, 3 to 8 in Adzes, 3 to II in Picea, 6 to 11 in Cedrus.
234 THE SCOTTISH BOTANICAL REVIEW
2. All but a few of the families and orders (6) have been recog- nised in a fossil state, and most of these in the Jertiaries.
3. The group appears to have diverged from the primitive Angio- spermic stock, evolved from a line of ancestors connecting Pterido- sperms, Bennettitales, and eventually such dicotyledons as AZagnolia, Lirtodendron, Nymphea, and the monocotylous Alismaceze and Liliacez.
4. There is every appearance of reduction in the floral symmetry, but the characters of the cotyledons, stem, and Jeaves are apparently as primitive as those of the primitive dicotyledons—further than which latter they have not progressed. The uniform aquatic habit would account for a great deal of this in stem and leaves, and even cause some reduction. In other words, monocotyledons are retrogressive and dicotyledons progressive types.
5. The prevalence of aquatic, geophytic, and climbing genera lends support to the view that they are a weaker or degraded race of Angiosperms which have sought refuge in aquatic habits, thus avoid- ing the severer struggle for existence upon land.
6. The view is held that the difference in cotyledons is due partly to the shape of the embryo-sac and supply of endosperm, partly to the mode of life of the plants after germination.
7. The stem structure is due to physiological causes, since the tree type is more or less absent, and where present traces of a cambium often occur.
8. The absence of any recapitulation during the ontogeny of monocotyledons of a supposed previous dicotylar stage is regarded as conclusive evidence that the former are not derived from the latter.
g. It is held that the primitive Angiosperms resembled an Alismaceous or Liliaceous type, on the one hand, and a Ranalian type on the other, and that the monocotyledons and dicotyledons are divergent series from a common ancestor, recalling the common characteristics of the two as the one or the other were called into being by either physical or natural selection. In the one case, dicotyledons, there has been progression and differentiation; in the other, monocotyledons, retrogression and even some reduction from a common ancestor of the primitive Angiospermic type.
b of
be okey x it
PLATE, TL,
Fig. 1. (A) A shoot of Polyalthza, to illustrate sympodial arrangement. Every stem segment is terminated by a leaf. (B) Monocotyledonous embryo, to show similar arrangement. (After Worsdeil, “‘A Study of the Vascular System in certain Orders of Ranales,” Oct. 1908, ‘‘ Ann. Bot.,” p. 653.)
Fig. 2. Delphinium nudicaule, seedling after eight weeks, to show position of leaf and cotyledon.
Fig. 3. Delphinium nudicaule, seedling after fourteen weeks.
Fig. 4. A=Alisma plantago; B, C=Corydalis cava; D=Tamus communis. Mono- and di-cotyledons for comparison to show position of cotyledon.
(Figs. 2, 3, and 4 after Sargant, ‘‘ The Evolution of Monocotyledons.”)
Scottish Botanical Review. } [Vora
A. R. Horwoop. PEATE, Dik:
PLATE IV.
Figs. 1, 2 and 3. Stages in the germination of the seedlings of Alzsma plantago: eight times natural size.
Fig. 4. The same x 4.
Fig. 5. a natural size,
Fig. 6. 5 e
(Figs. 1-6 after Lord Avebury, ‘‘ Seedlings.” Cot, =cotyledon. )
Scottish Botanical Review. |
PLATE IV
A. R. Horwoop.
SHORT NOTES 235
Short Notes.
Saxifraga atzoides, L.—Among plants from Orkney sent by Mr. M. Spence are two specimens of the above Saxifrage, and answering to the description of the f. awrantia of Hartmann, “ Vet. Ak. Handl.,” 1818. The leaves are orange, shading to yellow at the apex. The lower stem leaves are suffused with red, and the fruit is orange-red (only half-ripe). The leaves are quite entire, very thick, with here and there a long patent hair. This form occurs in Norway, with the orainary form in Sweden, and rarely in Russian and Finnish Lapland. Is not the figure in “‘English Botany,” t. 59, quite a rare form? I have not seen such stem leaves on any specimen as there represented, and the description says “‘rarely denticulate.” A. BENNETT.
Utricularia vulgaris L., in Caithness.—Good specimens of the above (though not in flower) have been sent me by Miss I. Lillie and Mr. G. Lillie from Loch Watten on the east coast of Caithness. There are several of the winter buds ; these are strongly setose, with translucent, spinose-like hairs, and the young leaves are spinose-setose. The young bladders are semi-transparent, the older ones also, but with the addition of a yellowish nucleus. This definitely records the species for the county. A. BENNETT.
Cnicus oleraceus Lin. = Cirsium oleraceum Scop.—This plant has occurred this season on a marshy meadow by the side of the Tay, left bank, about a mile below Perth. It forms a small patch com- prising about sixty or seventy flowering shoots and was certainly not there, at least in the flowering stage, till this season. How it came I am unable to conjecture, as it is certainly not a plant likely to be cultivated, and the meadow, though cut, consists of natural herbage only, and is never sown. Mr. Arthur Bennett informs me that it occurred in Lincolnshire from 1832 to 1840 on the Fen banks, and I believe it has been found in Scotland amongst other casuals. The plant was named for me at the Herbarium of the Royal Botanic Garden, Edinburgh. It has yellow flowers. Near to the same place a little patch of Samgutsorba canadensis Lin. has kept its place amongst some alder bushes for more than half a century. Till this year I have never seen any signs of its spreading. But this summer at least three other patches, at about a hundred yards further down and clear of the bushes, have made their appearance and have flowered freely. One patch in the middle of the meadow forms a circle of a good many yards in diameter and comprises a considerable number of plants. Possibly the very hot summer of last year may have more thoroughly ripened the seeds and thus enabled the plant to extend its area.
Juncus tenuis Lin.—In going through Glen Ogle in July this sedge
236 THE SCOTTISH BOTANICAL REVIEW
occurred in great plenty by the roadside about half-way between Lix and the summit of the pass. For about a quarter of a mile it formed a close band along the left side of the road. For about another half mile I traced it in patches and isolated plants. It seemed as if carts loaded with American fodder had been passing along the road dropping seeds at first thickly and then more thinly. Certainly the plant is not native in any of the Perthshire stations in which it has been found. W. Barctay.
Notes from Current Literature.
“Quel est le vrai caractére biologique du Raphanus Raphanistrum, L., et du Sixapis arvensis, L.,” by A. Verhulst (‘Contributions from the U.S. Nat. Herbarium,” vol. xvi. part iii.).
“The North American Species of Mymphaa,” by G. S. Miller, jun., and P. C. Standley (‘Contributions from the U.S. Nat. Herb- arium,” vol. xvi. part iil.).
“Studies in Tropical American Ferns,” by W. R. Maxon (“ Con- tributions from the U.S. Nat. Herbarium,” vol. xvi. part iii.). Particularly valuable in containing a monographic account of the species of Hemitelia, subgenus Cxemidaria, fully illustrated.
“« Spirea Ulmaria, L., and its Bearing on the Problem of Xero- morphy in Marsh Plants,” by R. H. Yapp (“Annals of Botany,” July 1912).
“* Polygala vulgaris, L., var. grandifiora, Bab.,” by Arthur Bennett (‘Journal of Botany,” July 1912).
“A New Variety of Parnassia palustris,” by W. G. Travis and J. A. Wheldon (“ Journal of Botany,” August 1912).
‘Le genre Balsamocitrus et un nouveau genre voisin, .#glopsis,”’ by W. T. Swingle (“ Bull. Soc. Bot. de France,” vol. xi.).
“‘Beauveria, nouveau genre de Verticillizces,” by M. Paul Vuillemin (‘ Bull. Soc. Bot. de France,” Jan. 1912).
‘“ A propos de la position systematique de Adoxa Moschatellina, L.,” by H. Lonay (“Contributions from the U.S. Nat. Herbarium,” vol. xvi. part ili.).
“ Betula pubescens x nana in den Alpen,” by Dr. F. Vierhapper (““Verhandlungen der K. K. Zoo.-bot. Gesellschaft in Wien,” vol. 1xi.).
“A Beehive Fungus, Pericystis alvii, Gen. et Sp. Nov.,” by A. S. Betts (‘‘ Annals of Botany,” July 1912).
NOTES FROM CURRENT LITERATURE 237
“Bacteria and Other Fungi in Relation to the Soil,” by D. Rivas (** Bull. Soc. Bot. de France,” vol. xi.).
‘“‘Nouvelles maladies de plantes cultivées,” by Arséne Puttemans (“Contributions from the U.S. Nat. Herbarium,” vol. xvi. part iii.).
“Ecologie d’une petite panne dans les dunes des environs des Dunkerque (Phanerogames et Cryptogames),” by M. Bouly de Lesdain (‘‘ Bull. Soc. Bot. de France,” vol. xii.).
“ Nouvelle contribution a la Géographie Botanique du Jurassique Belge: Dispersion du Czrctum acaule, Allioni,” by A. Verhulst (‘ Bull. Soc. Royale de Bot. de Belgique,” 1911).
“‘ Vegetationsskizze der Umgebung von Czernowitz,” by Dr. K. Rudolph (‘‘ Annals of Botany,” July 1912).
‘‘Leaf Movements in the Family Oxalidacez,” by E. B. Ulrich (‘Contributions from the Botan. Laboratory of the University of Pennsylvania ”).
‘Ein neuer Typus der Spaltdffnungen bie den Saxifragaceen,” by B. Hryniewiecki (“ Bull. International de l’Académie des Science, Krakaw,” March 1912).
“Azotobacter Studien: I. Morphologie und Cytologie,” by A. Prazmowski (‘‘Contributions from the U.S. Nat. Herbarium,” vol. xvi. part 111.).
Reviews, Book Notices, etc.
CLARE ISLAND SURVEY. Parts XI.and XII.: Musci anD HEPATIC. Canon H. W. Lett, M.A. tg12. Price 6d.
THE investigation of the cryptogamic flora of the Clare Island survey district is one which cannot fail to stimulate survey work elsewhere. If so remote a region, though botanically important, can receive such systematic attention at the hands of busy specialists, it is to be hoped that other areas may in due course be similarly dealt with, including the many unexplored parts of Scotland, Wales, and England.
Canon Lett in his interesting paper describes the district from a bryological point of view, noting the absence of glens, the exposed surfaces, the peaty districts much denuded by peat-cutting, which in Ireland has helped to restrict the distribution of turfophilous plants on a wide scale, though here it supports few mosses or hepatics. They abound, however, in well-sheltered nooks and corners which absorb the abundant rain. Croaghmore affords shelter to leeward
238 THE SCOTTISH BOTANICAL REVIEW
on the N.E. slopes for a rich flora, while on several low hills running N.W. by S.E., with intervening valleys owing to peat-cutting, they are rare. Saxicolous species are also rare. Though the district is now intersected by walls, they have not as yet been covered by mosses, and rupicolous species grow best near Knocknaveen (729 feet). Salt is not responsible for their scarcity, for many appear to be halophytes here. The loughs yielded no good results, sphagna being mainly restricted to Creggan Lough. Arboreal species are absent, except in plantations, and cutting down of forests has been a factor in extinc- tion here, leaving only sphagna as relics. Some arenicolous species occur on the shore. Canon Lett indicates the most favourable spots for bryological observation as at Croaghaun Mountain and Knocka- curram. No work had been done in Clare Island previous to this survey, though Achill Island had been investigated.
Interest attaches to the statistics of the flora given, the total being 221, of which seven hepatics are new to Ireland and two are second records. Notes are given as to the distribution of the flora, and the absence of some is emphasised. The flora of Clare Island is said to owe its origin to dispersal of spores by the wind. Following the list of mosses and also that of hepatics come notes on the rarer species, in which the respective areas of occurrence are indicated by I. and M., indicating Clare Island and the mainland. A useful bibliography is appended.
Part XIII.: Funct. By Car.ieton Rea, B.C.L., M.A., and Sir H. C.. Hawtey, Bart. 1912, Preeias
THE account of the fungi is divided into two sections, Clare Island being described by the second author, the mainland by the first. In so far as the mycology is concerned this region was previously quite unexplored, wo species only being recorded by Adams in 1910, and of 1400 Irish species 100 only were known in Connaught. The species and varieties discovered number 802, including 295 species and 12 varieties new to Ireland, 11 new to Britain; whilst Hawley describes a new genus, Candelospora, genotype C. tlictcola sp. nov. (figured), and Rea a new species, Mygrophorus sgquamulosus (unfigured). The flora of the island differs from that of the mainland, especially in the number of Autobasidiomycetes. The island is bare and wind-swept, the mainland sheltered, fertile, and wooded. It is remarkable that Hypoxylon coccineum, so common on beeches in S. England and elsewhere, is unknown. MHawley’s work consisted of some three weeks’ collecting, resulting in a list of 283 species, with but few coprophilous species and the minute Fungi Imperfecti. The chief woodland is in the N.E. There are two districts: (1) exposed pastures, and (2) cultivated tracts. Several interesting maritime specimens were collected, on Plantago maritima, etc. The absence of woodland determines the relative poverty of Autobasidiomycetes here, though there is an excess of twenty found in
REVIEWS, BOOK NOTICES, ETC. 239
the Faeroes, with the flora of which comparison is made, and where too it is to be remarked that there were few pratal species. In this list 101 are new to Ireland, eight are new to Britain, one new to science. Mr. A. D. Cotton found all the maritime fungi. Notes follow the list, in which no localities are given, though most were found near Westport. Hawley here separates Hyfoxylon pileatum and H. terrt- genum. He found the spores of A/icroglossum atropurpureum \sarst. variable, and suggests Lpicymatia Balani Wint. is better placed under Mycospherella. A South American species, Phomatospora argentina Spegg., first found here, is said to differ but little from the European P. ovalis (Pass.) Sacc. The genus Candelospora is regarded as allied to Microsporium in the penicillate branching well shown in the figure, differing in the single terminal conidia. It is found on dead holly leaves.
Rea was unfortunate in his choice of weather, meeting on the mainland with snow and drought. The best wood he found was Brackloon, where there are oak, beech, pine, sycamore, holly and alder, and much leaf mould. The species of Cortinarius were especially numerous and in good condition. He records 667 species and varieties, 232 new to Ireland, five new to Britain. In this list localities are given, which is a distinct advantage. Corynedla glabrovirens is regarded as allied more closely to Calloriacee than Bulgariacee. Urceolella incarnatina (Quel.) Bond., new to Britain, is not considered to be related to any other British genus. Avthostoma saprophilum E. and E. is new to Europe. The new species //ygro- phorus squamulosus resembles Zricholoma repens in the tomentose margin of the piles, and differs from A. o/ivaceoalbus Fr. in the floccose squamules, characters sufficiently distinct to warrant a new name. Both accounts of the Clare Island fungi are worthy of careful study.
Tue Genus Fumaria IN Britain. By H. W. Pucstey, B.A. Supplement to the “Journal of Botany,” January to July 1912. Pp. 1-76, with one Plate.
Mr. Pucstey here distributes the British plants of this genus into eight species, two sub-species, and fourteen varieties with sub-varieties and one hybrid.
The number of pages here used to describe and treat on these will at once show how full the work is; the only fear one has 1s, will it be the fate of all British genera? If so, one can but pity the student when wading through the series. Even the artificial key on pages 72 and 73 makes one wonder if any person will ever try to name a specimen by it. Certainly, if all this has to be learnt, the oft-repeated remark as to botany, “all hard names,” will be exemplified.
Still, the trend of all botany is to specialise, and it is hard to find fault with good honest work simply because it is long in telling.
Mr. Pugsley has evidently studied the genus very closely and with
240 THE SCOTTISH BOTANICAL REVIEW
much care, and if means could be adopted to shorten the matter for- a flora, it would represent good and painstaking work.
In addition to the former new species (occidentalis and purpurea),} we have now a third described (7: pardoxa), two sub-species, one hybrid (x / Painter’), and several varieties, etc.
Under / paradoxa Mr. Pugsley certainly seems to have scored, as four Continental botanists referred this to quite another section of the genus, and I think in a case like this we may be forgiven for being a little proud of our countryman.
Lastly, the index of 121 names shows how much is included in the work.
PLant LiFE AND EVOLUTION. Professor D. H. CAMPBELL, “American Nature Series,” Holt & Co., New York, 1911. Price $1.60 net.
Mucu has recently been written upon the subject of evolution following upon the celebration, both here and in America, of the jubilee of the publication of Darwin’s “Origin of Species.” In these discussions plants have not played so prominent a part as animals, hence we may welcome this book all the more, coming as it does from one of the American school, reared up in the traditions of Agassiz, Hyatt, Ribot, Cope, Marsh, Beecher, Osborn, and many other valiant supporters of Neolamarckism. In Europe we can point to Hering, Herbert Spencer, Pfeffer, Semper, F. Darwin, and Semon as able exponents of similar views. Moreover, Professor Campbell has done pioneer work on the development and structure of mosses and ferns, apart from other important studies. He may be said, in fact, to occupy that place in the New World which in the Old World we accord to Professor Bower, as doyen of cryptogamic morphology. Both have reached much the same conclusions (vide the “Origin of a Land Flora,” “ Plant Life on Land”), if by some- what different methods, which is perhaps the best criterion of accuracy.
The book, which may be thoroughly recommended to English students, is admittedly written from a Neolamarckian standpoint, but whilst the author discusses in a masterly way all the theories of evolution, he accepts none as explaining the ultimate cause of evolu- tion. Though primarily written for American students, it is safe to say it is of international interest, since the treatment of the subjects, discussed by one who is a specialist in his own particular field, displays so wide and intimate a knowledge of current work and thought in other fields, with so well balanced and critical an estimate of the value and relative bearing or otherwise of each upon the matter in hand, that the book may be placed on the shelf as an important study in origins, especially applicable to the plant world. Whilst it provides all the material for a text-book of morphology or
‘**Jour, of Botany,” 1902, p. 129; 1904, p. 217.
REVIEWS, BOOK NOTICES, ETC. 241
physiology, general ecology and etiology, it is written from a genetic standpoint, so that the meaning of structures or phenomena discussed is at once apparent. Moreover, not only are the latest discoveries in botanical work, recent or fossil botany, referred to, but many of the more important zoological facts are contrasted with them. It will illustrate the scope of the work best perhaps to refer to a few of these. In connection with the origin of life, Winogradsky’s researches on nitrogen bacteria are mentioned. In discussing the lower plants, Bower’s theory of sterilisation finds a place, and the antithetic alternation of generations of pteridophytes and bryophytes is affirmed.
In relation to heredity, F. Darwin’s views on memory are accepted, and, we think, with good reason. Bower’s theory of sterilisation is however, not accepted, an entirely separate origin for the sporophyte in club-mosses and ferns being assumed. Researches amongst the carboniferous and mesozoic floras as to the origin of seed plants by Scott, Seward, and Wieland are given due prominence. By the way, Seward’s view that conifers such as Avaucaria are related to the Paleeozoic lycopods is favoured. The cumulative effects of stimuli are illustrated by Jenning’s work on Infusoria. In determining the value of current theories of the origin of species, the mutation theory of De Vries and Mendel’s laws of heredity are fully discussed, but Lotsy’s views as to the cause of mutations are preferred, the germ- plasm theory, in so far as plants are concerned (since they are more plastic and respond to external stimuli more readily), not being con- sidered to apply. The nature of the Palaeozoic climate is explained on Manson’s view that a mantle of cloud excluded sunlight. Great stress is laid upon Kleb’s experiments as to the effect of stimuli in determining sex and regulating other factors of the environment. All the important results of plant breeders bearing on the questions discussed are surveyed, and Bailey and Burbank are cited here. Winckler’s work on graft hybrids also receives adequate notice.
The book is divided into ten chapters, including an introduction, the factors in evolution; the lower plants ; the origin of land plants (which are derived from green algz); seed plants, leading on from heterospory in pteridophytes from the zygote or resting stage in algee required by dry conditions ; the Angiosperms, where the division into monocotyledons and dicotyledons is regarded as artificial, and their characters considered as adaptive, developed in parallel series ; environment and adaptation, the terrestrial phase being the cause of seed plants, and their possession of fruit is regarded as the cause of their dominance. The chapter on plant distribution is especially interesting and will appeal particularly to American students. The human factor in plant evolution is dealt with from an original out- look, and the great importance of extinction is adequately recognised.
The origin of species is lucidly expounded, and it is justly re- marked that plants differ from animals in this respect, for while the germ-plasm may play a part in the case of the latter, in the case of plants, “to assume that there is a special germ-plasm, which is passed
VOL. I. 18
2A THE SCOTTISH BOTANICAL REVIEW
on from the tiny gametophyte to the non-sexual and long-lived sporophyte, and finally segregated in the spores, and again passed along to the next generation of gametophytes, is, to say the least, improbable.” Here indeed lies the secret of the whole matter.
We miss any reference to sphagnales in the discussion of the origin of the lower plants. The term prothallus is neglected, and pollen spore is used for pollen grain. Owing to subdivision of the matter there is an unavoidable amount of repetition. Generally speaking, there is an absence of Americanisms, but we notice mold, meter, center, color, gray for grey, skepticism, fiber, canyon, favorite, meager, behavior, armor. The dieresis is used in re-established pre-eminently, zoospore. Sperms is substituted for spermatozoa. A few typographical errors occur: ax (p. 290), especialy (p. 229), futher (p. 335), unequaled (p. 147). The terms horsetail and clubmoss in reference to Palzozoic types are used literally; “forbears” is used for ‘‘ancestors” in reference to plants.
Each section leads up to the next admirably. The use of common types to illustrate facts, e.g. cross pollination in the nasturtium and scarlet geranium, is an excellent feature. The personal element is not entirely lacking. Visits to South Africa, where sunbirds were studied, and Krakatau, in 1906, are related.
We believe that this book if, as it is hoped, it is read widely in this country, will do much to stimulate inquiry upon new and right lines, and can thoroughly recommend its adoption as a standard text-book on plant life and problems of evoJution.
BriTisH PLant Gatis. By E. W. Swanton. Methuen & Co.,, London. §8vo, cloth, pp. 251, sixteen coloured and sixteen photographs, with numerous blocks in the text. 7s. 6d. net.
Tuis book should supply a long-felt want. Up to the present time we have had only one good work dealing with British galls, and that was mainly a translation by C. R. Straton of Dr. H. Adler’s German work ‘Uber den Generationswechsel der Eichengallen,” and was limited to the galls occurring on the oak. E. T. Connold subse- quently published some fine photographs of our British galls, but the accompanying text was of little assistance. The present work condenses into a readily accessible form a mass of information on this subject which for the most part is hidden away in various systematic works and scattered papers published by numerous scientific societies. Mr Swanton in his opening pages deals in a lucid manner with the origin of our British plant galls, and devotes a separate chapter to those that are caused by the Hymenoptera, Coleoptera, Lepidoptera, Diptera, Homoptera, Acari, Nematoda, Fungi, and Mycetozoa. In the detailed catalogue of British plant galls which succeeds the opening chapters the galls are arranged in botanical sequence on their hosts in accordance with the classifica- tion adopted by Engler in “ Die Naturalichen Pflanzenfamilien,” and
REVIEWS, BOOK NOTICES, ETC. 243
the specific name accepted by ‘“‘The London Catalogue of British Plants,” roth edition. Eight hundred and eighty British plant galls are enumerated in this catalogue, but we fail to see that this number is justified, as we presume that it includes the same gall when present in the stem, leaf, or flower as a distinct gall, and it certainly includes the same fungus when growing on different hosts, whilst the hard woody excrescences so common on our ash trees caused by the fungus Dadldinia concentrica are omitted from the work. The book is well got up, and the numerous coloured illustrations and photo- graphs should make it a useful guide to the identification of our more common plant galls.
Index
Acacia, New or imperfectly described Species from Western Australia, 96.
Agathosma trichocarpa, n. sp., 162.
Aglaonema, Embryo-Sac of, 100.
Alchemilla acutidens, Scottish records, 183.
Alien Plants, 39.
Alisma Plantago, vars. and forms of, 21.
Alisma ranunculoides, vars. and forms of 2ie
Ambrosiacez, The Inflorescences of,
193.
Anthelia: an Arctic- Alpine Plant Asso- ciation, 81.
Apium tnundatum, 19.
Applied Botany, Some Modern Aspects of, 24.
Aquatic Forms and Species of the British Flora, 17.
Arcangeli, Prof. John, Vectorta regza,
IIS.
Barbula gracilis in Scotland, 46.
Barbula incavata, sp. n., 93.
Barclay, W., Cvzcus oleraceus, Juncus tenuts, 235.
Bennett, Arthur, Aquatic Forms and Species, 17; Carex helvola, 41; Potamogeton prelongus, 47 ; Juncus alpinus, 47 ; Sparganium, 94; Addi- tions to Caithness Flora, 181; Saxz- fraga Flirculus, 205; S. atzordes, 235; Utricularia vulgaris, 235.
Blackwood, G. G., Cormus suecica, 117.
Borthwick, Dr. A. W., Modern Aspects of Applied Botany, 24.
‘* Botanical Exchange Club Report,” IQII (vev.), 51.
“British Plants: their Biology and Ecology ” (vev.), 125.
‘* British Vegetation, Types of” (vev.), 49; ‘‘ Roses, List of British” (vez. ),
4. Bryum elegantulum, sp. n., 92.
Caithness Lichens, 146 ; Recent Addi- tions to Flora of, 181.
Calluna-Mat Association, 183. Campbell, Prof. Douglas H., Embryo- Sac of Aglaonema, 100. Carex helvola, 41; canescens var. fallax, 41; Lachenaliz, 41 ; rariflora, 41. Centunculus minimus in Wigtown- shire, 46.
Ceratophyllum demersum, 19.
**Clare Island Survey, Phanerogamia and Pteridophyta” (vev.), 56.
Cnicus oleraceus in Perthshire, 235.
Cornus suecica in Peeblesshire, 117, 184.
Corstorphine, M., Barbula gracilis, 46.
Corstorphine, R. H., Mzerochloe odor- ata, 183.
Crampton, C. B., Stable and Migratory Plant Associations, 1, 57, 127; Calluna-Mat Association, 183.
Damasonium Alisma and forms, 23. Druce, G. C., Linnezus’ ‘‘ Flora Anglica,” 154.
Ecological Terminology as applied to Marine Algze, 44.
Epilobium nummularifolium in Argyll- shire, 47.
Evans, Wm,, Zostera nana, Cornus suecica, 184.
IME
Fissidens incurvus from Skye, 48.
“* Flora Anglica,” 154.
Fraser, James, Alien Plants, 39; Centunculus minimus, 46.
‘¢Galls, British Plant” (vev.), 242. Gilbert, E. G., Study of Rubi, 184. Goebel, K. von, Ambrosiacez, 193. Grateloupia, A new Japanese, 208. Grimmia rubescens, Sp. T., 9O. Grimmia undulata, sp. N., 91.
Hierochloe odorata in Glen Calla, 183. Holmes, E. M., Agathosma trichocarpa, 162 ; Grateloupia subpectinata, 208.
INDEX
245
Horwood, A. R., Past History of | Ranunculus Flammu/lavar. natans, 18 ;
Monocotyledons, 164, 216. Hydrocotyle vulgaris, 18.
Johnson, N. Miller, Ecological Ter- minology applied to Marine Algz, 44; Petasites albus, 118.
Juncus alpinus, 47.
Juncus bulbosus, 20.
Juncus supinus, 19; var. nodosus, 19 ; var. pygmaeus, 20; var. Kochit, 20; var, subverticellatus, 20; var. fluztans, 20 ; var. comosus, 20.
Juncus tenuts in Peeblesshire, 47 ; in Glen Ogle, 235.
Kenfig Burrows, An Ecological Study, 209.
Leucobryum pumilum in Britain, 48,
9. Lichens, Caithness, 146. Lillie, Rev. D., Caithness Lichens, 146. Linneeus’ ‘‘ Flora Anglica,” 154. Lothians, Mosses of the, 202.
M‘Andrew, James, Sz/ene jimbriata, Piptatherum multiflorum, Eprlobtum nummularifolium, Juncus tenuis, 47; Mosses of the Three Lothians, 202.
Macgregor, M., Calluna-Mat Associa- tion, 184.
Marine Algze, Ecological Terminology as applied to. 44.
Meldrum, R. H., Philonotis rigzda, 117.
Monocotyledons, Past History of, 164,
216. Morphological Notes: Ambrosiacez,
Oo Morrison, Alexander, Species of Acacia from Western Australia, 96. Mosses from the West Highlands, 89. Mosses from the Three Lothians, 202.
Notes from Current Literature, 48, 118, 185, 236.
Orr, M. Y., Kenfig Burrows, 209.
Peplis Portula, 18.
Petasites alous in Fife, 118.
Philonotis rigida in Perthshire, 117. Piptatherum multifiorum in Britain,
47.
Plant Associations, Geological Relations of Stable and Migratory, I, 57, 127; Calluna-Mat, 183; Anthelia, 81.
Potamogeton prelongus in Orkney, 47.
Pyrenocheta [licts, n. sp., 161.
lingua, 18. Reviews, etc., 49, 121, 186, 237. Types of British Vegetation, 49. Botanical Exchange Club Report,
eT List of British Roses, 54. Plant Life on Land, 56. Clare Island Survey: X. Phanero- gamia and Pteridophyta, 56. Watson Botanical Club Report, IQIO-II, 121. British Plants, their Biology and Ecology, 125. Prodromus Flore Britannice, 186. The Shingle Beach as a Plant Habitat, 188. Monograph of the British Desmidi- acez, 190. Clare Island Survey: XIV. Lichens, 190. Flora of Cambridgeshire, 191. Clare Island Survey: XI.-XII. Musci and Hepatice, 237; XIII. Fungi, 238. Genus Fumaria in Britain, 239. Plant Life and Evolution, 240. British Plant Galls, 242. “Roses, List of British ” (vev.), 54. Rubi, Study of, 184.
Sagittaria sagittifolia, 22; var. vallis- nertfolia, 22; heterophylla, 23. Saxtfraga aizotdes in Orkney, 2353 Hitrcudus in Caithness and its Dis- tribution in the British Isles, 205. Scerpus fluztans, 20. Short Notes :— Barbula gractlis in Scotland, 46. Centunculus minimus in Wigtown- shire, 46. Silene fimbriata in Argyllshire, 47. Piptatherum multifiorunin Britain,
47-
Epilobium nummularifolium im Argyllshire, 47.
Juncus tenuzs in Peeblesshire, 47.
Potamogeton prelongus in Orkney, 47-
Juncus alpinus in Kirkcudbright, AT:
Fissidens incurvus in Skye, 48.
Leucobryum pumilum in Britain,
Philonotis rigida in Perthshire, LE
Cornus suectca in Peeblesshire, 117.
Zostera nana in Haddingtonshire, DE Z-
Petasites albus in Fife, 118.
246
Short Notes—continued.
Hierochloe odorata in Glen Calla, 183.
Alchemilla acutidens in Banff and Linlithgow, 183.
Calluna-Mat Association, 183.
Rubi, Study of, 184.
Cornus suecica, 184.
Saxifraga atzoides in Orkney, 235.
Cnicus oleraceus in Perthshire, 235-
Juncus tenuis, 235.
Otricularia vulgaris in Caithness,
235. Silene fimbriata in Argyllshire, 47. Smith, Dr. W. G., Anthelia Associa- tion, 81.
THE SCOTTISH BOTANICAL REVIEW
Sparganium minimum, 23; hyper- boreum, 23; glomeratum, 23; Scot- tish forms of, 94.
Stirton, James, /zsszdens incurvus, Leucobryum pumilum, 48; Mosses from the West Highlands, 89.
Utricularia vulgaris in Caithness, 235.
| Victoria regia, Note on, 115.
‘* Watson Exchange Club Report,” IQIO-II (rvev.), 121.
Wilson, Malcolm, Pyrenocheta Llicts, sp. n., 161.
Zostera nana in Haddingtonshire, 117.
PRINTED BY NEILL AND CO., LTD., EDINBURGH.
THE
is the latest invention of the kind. It can be had at all prices from 10/6, for
Lady or Gentleman.
The ‘“ WOODPECKER” Sunshade
in any colour.
TO BE HAD ONLY FROM THE PATENTEES
JAS. ROBERTSON & SON, Umbrella Makers,
43 Queensferry Street, Wop 30 & 32 Leith Street,!
George Prescott & Go.
(J. H. MURRAY), Specialists 52 QUEEN STREET, GLASGOW; | DUKE STREET, DUBLIN.
Spectacle & Eyeglass Specialists.
ooo
The New Invisible Frameless Spectacles & \ Eyeglasses A Specialty.
100 Lothian Roads, Edinburgh
TELEPHONE—1478 Central. Glasgow—8630 City. Dublin—2279. Hours: 9-6.30. Please note Early ciosing adtecias 1,30. =
V
Telegraphic Address: ‘* LARCH,” EDINBURGH. Telephone No. 2034.
NE nn Awarded 4 Gold and 4 Silver Medals at recent Flower Shows held in Edinburgh.
——S
DAVID W. THOMSON
Nurseryman and Seedsman
113 GEORGE STREET — EDINBURGH. —— Seed Warehouse—l18 GEORGE STREET.
Selected Vegetable and Flower Seeds, Bulbs and Forcing Plants, Retarded Bulbs and Plants, Garden Tools, Manures, &c.
Catalogues Post Free on Application. NURSERIES—Granton Rd. and Boswall Rd.
AN EXTENSIVE AND WELL-GROWN STOCK OF
Forest Trees of all kinds, Ornamental Trees and Shrubs, Rhododendrons and Flowering Shrubs, Game Covert Plants, Fruit Trees, Roses and Climbing Plants, Herbaceous and Alpine Plants,
ALL IN SPLENDID CONDITION FOR REMOVAL. INSPECTION INVITED.
Catalogues Post Free on Application.
Vi
The Scottish Botanical Review
The Scottish Botanical Review
A QUARTERLY MAGAZINE
Including the Transactions of the Botanical Society of Edinburgh
Volk L192
EDINBURGH NE ELE, < CO. LIMERED
BELLEVUE
Contents
First Part—January 1912
THE GEOLOGICAL RELATIONS OF STABLE AND MIGRATORY PLANT FORMATIONS. C. B. Crampton, M.B.,C.M. (70 be continued)
REMARKS ON SOME AQUATIC FORMS AND AQUATIC SPECIES OF THE BRITISH FLORA. Arthur Bennett, A.L.S. .
SOME MODERN ASPECTS OF APPLIED BOTANY. A. W. Borthwick, IDES:
ALIEN PLANTS. James Fraser . CAREX HELVOLA, BLYTT. Arthur Bennett, A.L.S.
ECOLOGICAL TERMINOLOGY AS APPLIED TO MARINE ALG2&. N. Miller Johnson, B.Sc.
SHORT NOTES :— Barbula gracilis as New to Scotland. Margaret Corstorphine Centunculus minimus, L., in Wigtownshire. James Fraser
Silene fimbriata, Sims, in Argyllshire. Piptatherum multi- florum, Beauv., in Britain. Lpzlobiwm nummularifolium, R. Cunn., in Argyllshire. /cus tenuis, Willd., in Peebles- shire. James M‘Andrew -
Potamogeton prelongus, Wulf., in Orkney. Arthur Bennett Juncus alpinus, Vill., in Kirkcudbright. Arthur Bennett . Fissidens incurvus, Starke, from Skye
Leucobryum pumilum (Michx.) in Britain. James Stirton
NOTES FROM CURRENT LITERATURE
REVIEWS, BooK NOTICES, ETC. :—
The Types of British Vegetation. Edited by A. G. Tansley
The Botanical Exchange Club of the British Isles. Report for Ig1o. C.E. Moss : : ‘ . ;
PAGE
46 46
49
51
vi THE SCOTTISH BOTANICAL REVIEW
A List of British Roses (Supplement to Journal of Botany, 1911). Major A. H. Wolley-Dod
Plant Life on Land, considered in some of its a Professor P. O. Bower .
Clare Island Survey. Part X.: paaeeeee and Preidopby By R. Lloyd Praeger
Second Part—April 1912 THE GEOLOGICAL RELATIONS OF STABLE AND MIGRATORY PLANT FORMATIONS, C. B. Crampton, M.B., C.M. (Zo be continued)
ANTHELIA: AN ARCTIC-ALPINE PLANT ASSOCIATION. W. G. Smith, B:Se., Ph.D.
MOSSES FROM THE WESTERN HIGHLANDS. James Stirton, M.D., F.LS.
SCOTTISH FORMS OF SPARGANIUM. Arthur Bennett, A.L.S. .
NEW OR IMPERFECTLY DESCRIBED SPECIES OF ACACIA FROM WESTERN AUSTRALIA. Alex. Morrison
THE EMBRYO-SAC OF AGLAONEMA. Douglas Houghton Campbell
NOTE ON VICTORIA REGIA, LINDL. John Arcangeli
SHORT NOTES :— Philonotis rigida Brid., in Perthshire. R. H. Meldrum Cornus suecica, Linn., in Peeblesshire. G. G. Blackwood Zostera nana, Roth., in Haddingtonshire. William Evans Petasttes albus, Gaertn., in Fife. N. Miller Johnson.
NOTES FROM CURRENT LITERATURE
REVIEWS, BOOK NOTICES, ETC. :—
The Twenty-Seventh Annual Report of the Watson Botanical Exchange Club, 1910-11
British Plants: their Biology and Ecology. F. Bevis and H. J. jeftery ..
Third Part—July 1912 THE GEOLOGICAL RELATIONS OF STABLE AND MIGRATORY PLANT FORMATIONS. C. B. Crampton, M.B.,C.M. (Concluded) CAITHNESS LICHENS. Rev. David Lillie, B.D. LINNAZUS’ “ FLORA ANGLICA.” G,. Claridge Druce, M.A., F.L.S.
PAGE 54 56
56
57
81
89 94
96 100
115
117 117 117 118
118
I2I
. 126
127 146 154
a E—_—_ -_—~—~
CONTENTS
A NEW SPECIES OF PYRENOCHATA. BRS:
Malcolm Wilson, D.Sc.,
AGATHOSMA TRICHOCARPA, N. SP. E. M. Holmes, F.L.S., F.B.S.E.
THE PAST HISTORY OF MONOCOTYLEDONS, WITH REMARKS ON
THEIR ORIGIN. A. R. Horwood.
RECENT ADDITIONS TO THE CAITHNESS FLORA.
A.L.S. .
SHORT NOTES:
(To be continued)
Hierochloe odorata, Wahl. R. H. Corstorphine Alchemilla acutidens, Buser. M‘Taggart Cowan, Jr.
Note on the Calluna-Mat Association of the Mountain Tops of the Northern Highlands. C. B. Crampton and M. Macgregor
British Rubi and environment, etc.
Cornus suectca, Linn. Wm. Evans NOTES FROM CURRENT LITERATURE REVIEWS, BOOK NOTICES, ETC. :—
Prodromus Flore Britannica. F.
Phytologist,” No. 3, vol. xi.)
A Monograph of the British Desmidiacez. W. ere G. S. West
E. G. Gilbert
Arthur Bennett,
N. Williams. Part IX. The Shingle Beach as a Plant Habitat. F. W. Oliver.
. New
Clare Island Survey. Part XIV.: Lichens. Miss Annie
Lorrain Smith : A Short Flora of Cambridgeshire.
A. H. Evans
Fourth Part—October 1912
MORPHOLOGICAL NOTES. I.: The Inflorescences of the Ambrosi- acez. K. von Goebel, Sc.D., LL.D.
NOTES ON SOME MOSSES FROM THE M‘Andrew
THREE LOTHIANS.
James
SAXIFRAGA HIRCULUS, L., IN CAITHNESS, AND ITS DISTRIBUTION IN THE BRITISH ISLES. Arthur Bennett, A.L.S.
A NEw JAPANESE GRATELOUPIA. E. M. Holmes, F.L.S., F.B.S.E.
KENFIG BURROWS: AN ECOLOGICAL
STUDYe. ) Mesye. Orr
THE Past HISTORY OF MONOCOTYLEDONS, WITH REMARKS ON
THEIR ORIGIN. A. R. Horwood.
(Concluded)
186
188 190
190 19I
202
Vili THE SCOTTISH BOTANICAL REVIEW
SHORT NOTES :—
Saxifraga aizotdes, L.,in Orkney. Arthur Bennett . Utricularia vulgaris L., in Caithness. Arthur Bennett
Cnicus oleraceus Lin., Perthshire, and Juncus tenuzs in Glen
Ogle. W. Barclay
NOTES FROM CURRENT LITERATURE
REVIEWS, BOOK NOTICES, ETC. :—
Clare Island Survey. Parts XI. and XII. : Musci and Hepatice.
Canon H. W. Lett., M.A.
Clare Island Survey. Part XIII.: Fungi. Carleton Rea
The Genus Fumaria in Britain. H. W. Pugsley Plant Life and Evolution. D. H. Campbell
British Plant Galls.
E. W. Swanton .
PAGE
235 235
235 236
237 238 239 240 242
ig
Contents
PAGE MORPHOLOGICAL Notes. I.: THE INFLORESCENCES OF THE
AMBROSIACEH. K. von Goebel, Sc.D., LL.D. : 193
NOTES ON SOME MOSSES FROM THE THREE LOTHIANS. James M‘Andrew : 4 : : : 2e2
SAXIFRAGA Hircu.us, L., in CAITHNESS, AND ITS DIsTRI- BUTION IN THE BriTisH IsLes. Arthur Bennett, A.L.S. 205
A NEw JAPANESE GRATELOUPIA. E. M. Holmes, F.L.S., FB».E. . A , : : . 208 KeEnFIG Burrows: AN EcoLocicaL Stupy. M.Y.Orr . 209 THE Past History oF MONOCOTYLEDONS, WITH REMARKS ON THEIR ORIGIN. A. R. Horwood. (Concluded) ane ¥6
SHortT Notes :—
Saxtifraga aizoides, L., in Orkney. Arthur Bennett ieee
Utricularia vulgaris L., in Caithness. Arthur Bennett. 235 Cnicus oleraceus Lin., in Perthshire, and Juncus tenuis in
Glen Ogle. W. Barclay. é aes Fi
-Nores From CurRENT LITERATURE : ; tek.
Reviews, Book NOTICES, ETC. :—
Clare Island Survey. Parts XI. and XII.: Musci and Hepatic. Canon H. W. Lett, M.A. ; ba BF Clare Island Survey. Part XIII.: Fungi. Carleton Rea 238 The Genus Fumaria in Britain. H. W. Pugsley reso Plant Life and Evolution, D.H.Campbell . A aS British Plant Galls. E.W.Swanton . ; ee: eee
THE
SCOTTISH WIDOWS FUND
(ESTABLISHED 1815)
The Greatest Institution for Mutual Life Assurance in the United Kingdom
FUNDS ANNUAL REVENUE £21,000,000 £2,250,000
Many VALUABLE FEATURES attach to the Society’s Policies—e.g. Large Compound Bonuses, which are added from the issue of the Policy. Liberal Surrender Values, Loan Values and Paid up Policies. _ All Options are available after payment of one year’s premium.
Prospectus and Quotations sent free on application SPECIAL PROSPECTUS FOR LADIES AND CHILDREN
HEAD OFFICE—9 ST ANDREW SQUARE, EDINBURGH GLASGOW OFFICE—114 WEST GEORGE STREET LONDON OFFICES—28 CORNHILL, E.C., & 5 WATERLOO PLACE, S.W.
Scottish ‘Botanical Review Reprints
een
THE
GEOLOGICAL RELATIONS
OF
STABLE AND MIGRATORY PLANT .FORMATIONS
C. B. CRAMPTON, M.B., C.M.
Price 1/6 Post Free