In/ ■W!S.I.,ARD ^,IJ3LV'IlD ID] :VTL 1 A •JJ /6 Digitized by the Internet Archive in 2007 with funding from Microsoft Corporation http://www.archive.org/details/fernalliesofnortOOclutrich THE FERN ALLIES P L AT E S\ iOCyijl M i)N' \StJo;U R^ N/i- R U I H . Eqiiisetiim •••••*• c' « *c» fc t tti c'**c *c* Jiietnale. CCPYRIOH 1, 1905, BY f HELERICK A. STOKES COMrA^ THE FERN ALLIES OF TFlortb Hmerica IRortb ot /IDejico BY WILLARD NELSON CLUTE Author of '"'' A Flora of the Upper Susqneha/ina,''^ '' The Fern Collector s Guide '^ " Our Ferns in their Haunts,^'' etc. WITH MORE THAN ONE HUNDRED AND FIFTY ILLUSTRATIONS BY IDA MARTIN CLUTE ;*, NEW YORK FREDERICK A. STOKES COMPANY PUBLISHERS Copyright, 1905, By Frederick A. Stokes Company. This edition published in September, 1905. ^^°^ »RN«^ CONTENTS. PAGE List of Illustrations . . . . . vii Preface . . xi The Fern Allies . . i Key to the Families of Fern Allies . . 8 The EQUiSETACE^i: Scouring-Rushes and Horsetails 9 Key to the Species of Equisetum . . .16 The Evergreen Equisetums, or Scouring- Rushes . . . , . . . . \j The Deciduous Equisetums, or Horsetails . 41 The Lycopodiace^:, or Club-Mosses . . .69 Key to the Lycopodiums jj The Trailing Lycopodiums . . . .79 The Erect or Decumbent Lycopodiums . . 105 The Psilotace^ .123 The Selaginellace^, or Dwarf Club-Mosses 129 Key to the Selaginellas 135 The True Selaginellas, or Selaginella Ru- PESTRis Group 137 The Creeping Selaginella Group . . .153 The SALViNiACEyii 167 Salvinia .173 The Azollas 179 The Marsiliace^:, or Pepperworts . . .185 Key to the Marsilias 191 The Marsilias ...,.,. 193 298644 vi CONTENTS. The Isoetace^, or Quillworts Key to the Isoetes The Aquatic Quillworts . The Amphibious Quillworts The Terrestrial Quillworts Checklist of the Fern Allies Glossary .... Index to the Common Names Index to the Scientific Names 207 216 217 231 247 255 267 274 276 List of Illustrations, COMMON SCOURING-RUSH. Equisetuin hieinale. (In colours.) . Frontispiece. PAGE SECTION OF SCOURING-RUSH STEM ........ 12 JOINT OF SCOURING-RUSH STEM 13 SPORE-CASES 13 SPORES, ENLARGED 14 CROSS SECTION OF STEM OF COMMON SCOURING-RUSH .... 19 YOUNG STEMS OF COMMON SCOURING RUSH 20 FERTILE STEM OF COMMON SCOURING RUSH. Equisetum hieninle . 22 SHEATH OF GREAT SCOURING-RUSH. Equisetuin robusium ... 26 EQUISETUM FERRISSI, SECTION OF STEM 28 EQUISETUM FERRISSI, TIP OF STEM 3° SMOOTH SCOURING-RUSH. Equisetum la-vigntum .... facing 30 SHEATH OF SMOOTH SCOURING-RUSH 32 CATKIN OF SMOOTH SCOURING-RUSH 32 BRANCHED EQUISETUM. Equisetuin Eunstoni facing 34 SHEATH OF EQUISETUM FUNSTONI 34 CATKIN OF EQUISETUM FUNSTONI • • - 35 SHEATH OF VARIEGATED SCOURING-RUSH 36 VARIEGATED SCOURING RUSH. Equisetuin variegatum , . . facing 36 CATKIN OF VARIEGATED SCOURING-RUSH. 37 SECTION OF VARIEGATED SCOURING-RUSH STEM 38 DWARF SCOURING-RUSH. Equisetum scirpoides facing 38 SHEATH OF DWARF SCOURING-RUSH ........ 39 CATKIN OF DWARF SCOURING-RUSH 40 STERILE FROND OF FIELD HORSETAIL. Equisetuin arvense . . facing 44 FERTILE FROND OF FIELD HORSETAIL facing 44 SECTION OF FIELD HORSETAIL STEM 46 WOOD HORSETAIL. Equisetuin silvatictim. (In colours) . . . facing 46 EQUISETUM ARVENSE DECUMBENS facing 48 EQUISETUM ARVENSE CAMPESTRE facing 48 BUDS AND TUBERS OF FIELD HORSETAIL ' • 49 FERTILE FROND OF IVORY HORSETAIL, Equisetum telmateia . . facing 50 SECTION OF STERILE FROND OF IVORY HORSETAIL .... facing 52 STERILE FROND OF SHADE HORSETAIL. Equisetum pratense . . facing 54 FERTILE FROND OF SHADE HORSETAIL facing 54 STERILE FROND OFWOOD HORSETAIL. Equisetuin silvaticunt . facing 56 FERTILE FROND OF WOOD HORSETAIL facing 56 BUDS AND TUBERS OF WOOD HORSETAIL 57 VIU LIST OF ILLUSTRATIONS. PA WATER HORSETAIL. Egniseium fluviatile /ndng WATER HORSETAIL. Jiquisetuiu Jluviatilc. (In colours) . . . facing SECTION OF WATER HORSETAIL STEM MARSH HORSETAIL. JCqui^etuiii />auisire facing A FORM OF EQUISETUM LITTORALE facing FORMS OF SHORE HORSETAIL facing A MOSS CAPSULE , FRUITING-SPIKE OFLYCOPODIUM SPOROPHYLL OF LVCOPODIUM SPOROPHYLLS OF VARIOUS LYCOPODIUMS COMMON CLUB-MOSS. Lycopodiuiii claiuituin facing LYCOPODIUM CLAVATUM MONOSTACHYON • STIFF CLUB-MOSS. Lycopodinin nnnotinuin facing LYCOPODIUM ANNOTINUM PUNGENS facing BRANCHLET OF LYCOPODIUM COMPLANATUM GROUND-PINE. Lycopodinin contplanatuiii facing BRANCHLET OF LYCOPODIUM COMPLANATUM CHAM/ECYPARISSUS • LYCOPODIUM COMPLANATUM CHAM/ECYPARISSUS .... facing GROUNDFIR. Lycopodinin alpinurn facing BRANCH OF LYCOPODIUM ALPINUM SAVIN-LEAVED CLUBMOSS. Lycopodinni sabincefolium . . . facing BRANCH OF LYCOPODIUM SABIN/EFOLIUM ... ... LYCOPODIUM SITCHENSE facing BRANCH OF LYCOPODIUM SITGHENSE TREE CLUBMOSS. L.ycopodium ohscuruni. (In colours) . . . facing TREE CLUB-MOSS. Lycopodiujn odscuruin facing STAG-HORN CLUB-MOSS. I^ycopodiuni cernuuni facing SHINING CLUB-MOSS. Lycopodinin lucidulunt facing SPORANGIA OF SHINING CLUB-MOSS LYCOPODIUM LUCIDULUM POROPHILUM f^icing BULBLET OF SHINING CLUBMOSS FIR CLUB-MOSS. Lycopodinin selago facing BOG CLUB-MOSS. Lycopodinin inundatuin facing FOX-TAIL CLUB-MOSS. Lycopodinin alopccnroidcs .... facing LYCOPODIUM ALOPECUROIDES ADPRESSUM ...... facing LYCOPODIUM ALOPECUROIDES ADPRESSUM. (In colours) . . . facing CAROLINA CLUB-MOSS. LyCopodium Carolinianuin .... facing SYNANGIA OF PSILOTUM PSILOTUM TRIQUETRUM facing MEGASPORE OF SELAGINELLA RUPESTRIS ROCK SELAGINELLA Sclagincila rnpe^tris. (In colours) . . . facing SPIKE OF SELAGINELLA LEAF OF SELAGINELLA RUPESTRIS LEAVES OF A BIMORPHIC SELAGINELLA ROCK SELAGINELLA. Sciaginclia rupcstris facing SPIKE OF ROCK SELAGINELLA BRANCH OF SELAGINELLA WATSONI . • • SAND BARREN SELAGINELLA. '*>>^".*r'«''^/« 'i^*""'"'"^'* • • • •, • SELAGINELLA BIGELOVII ' • /"""A' GE. 58 60 61 62 64 66 71 73 73 74 82 84 LIST OF ILLUSTRATIONS. SELAGINELLA CINERASCENS .... OREGON SELAGINELLA. Selaghiella Oregnna PRICKLY MOUNTAIN MOSS. Selaginella sfiinosa CREEPING SELAGINELLA. Selaginella afius SPIKE OF CREEPING SELAGINELLA • SELAGINELLA LUDOVICIANA .... SELAGINELLA LUDOVICIANA. (I" colours) SELAGINELLA DOUGLASII • • • " • RESURRECTION MOSS. Selaginella !c/>ido/>hyna BRANCH OF THE RESURRECTION MOSS • RESURRECTION MOSS, WHEN DRY SPOROCARPS OF AZOLLA SALVINIA NATANS CROSS-SECTION OF SALVINIA SPOROCARPS SPOROCARPS OF SALVINIA NATANS • WATER FERN. Azolla Caroliniaita THE HOME OF AZOLLA AZOLLA FILICULOIDES •..••• SPOROCARP AND SPORANGIA OF MARSILIA VEINING IN THE LEAF OFMARSILIA • SPOROCARP OF MARSILIA CROSS-SECTION OF PILULARIA SPOROCARP • MARSILIA QUADRIFOLIA. (In colours) MARSILIA QUADRIFOLIA MARSILIA UNCINATA MARSILIA VESTITA • MARSILIA MACROPODA PILULARIA AMERICANA LEAF OF ISOETES SHOWING SPORANGIUM CROSS-SECTION OF ISOETES LEAF .... MEGASPORES OF ISOETES MICROSPORES OF ISOETES BRAUN'S QUILLWORT. Isoetes echinosporn Brnunii MEGASPORE OF BRAUNS QUILLWORT MEGASPORE OF ISOETES ECHINOSPORA MURICATA MEGASPORE OF ISOETES TRUNCATA MEGASPORE OF ISOETES ECHINOSPORA FLETTII • MEGASPORE OF ISOETES LACUSTRIS MEGASPORE OF TUCKERMAN'S QUILLWORT. Isoetes Titckc MEGASPORE OF BOLANDER'S QUILLWORT. Jsoetes Bolandc. MEGASPORE OF ISOETES HIEROGLYPHICA MEGASPORE OF ISOETES MACOUNI .... ENGELMANN'S QUILLWORT. Isoetes Engebiinnni . MEGASPORE OF ENGELMANN'S QUILLWORT • MEGASPORE OF ISOETES ENGELMANNI CAROLINIANA MEGASPORE OF EATON'S QUILLWORT. Lwetes vnlida MEGASPORE OF DODGE'S QUILLWORT. Isoetes Canndensi MEGASPORE OF RIVER-BANK QUILLWORT. Isoetes ripatiu MEGASPORE OF ISOETES SACCHARATA .... facing facing facing facing facing facing facing GE. 146 143 150 156 160 160 162 162 164 171 176 171 176 facing 213 214 220 220 221 222 222 224 225 22g 229 facing 234 234 235 236 238 239 24c facing facing facing facing facing facing facing LIST OF ILLUSTRATIONS. r/EGASPORE MEGASPORE MEGASPORE MEGASPORE MEGASPORE MEGASPORE MEGASPORE MEGASPORE MEGASPORE MEGASPORE OF ISOETES OF ISOETES OF ISOETES OF ISOETES OF ISOETES OF ISOETES OF ISOETES OF ISOETES OF ISOETES OF ISOETES FOVEOLATA GRAVESII • MELANOSPORA FLACCIDA • HOWELLI • MELANOPODA BUTLERI • NUTTALLII • ORCUTTI • MINIMA I'AGE. 241 243 244 244 246 251 252 253 253 254 PREFACE The Fern Allies, by reason of their curious forms and often great abundance, seldom fail to attract the atten tion of the student of plants, but their identification has always proved more or less of a puzzle to beginners. Like the ferns, they bear neither flowers nor seeds, and at first glance seem to offer few points by which they may be distinguished. The species are usually included in botanical Manuals, but the necessarily brief and tech- nical descriptions have tended to discourage rather than to aid the novice. In reality, however, most of the species are easily identified, and it is one of the purposes of this book to point out how this may be done. No book has ever before been published in which one may find untechnical descriptions of our fern allies, nor one in which all the species have been figured ; in fact a large number are figured for the first time in this book. Such illustrations as have hitherto appeared are scattered in various American and foreign books, often inaccessi- ble, many of which, published long ago, are more or less inaccurate. It has been our aim, not only to illustrate every species, but to represent them correctly. The drawings have been made from typical specimens of the plants, and it is believed that many of the species will now be easily identified by merely comparing them with the illustrations. In the text each species has been carefully described anew from authentic specimens, and all the known facts xii PREFACE. in its life history added. Preceding the acconnt of the species in each genns will be found a chapter on the group as a whole, followed by a Key to the species. In each group of species the best known is placed first, and those that follow are frequently compared with it. Many of these plants have received so little study from botanists that scarcely anything is known about them. In a further study of the life histories of these species the beginner will find a new and inviting field in which he will be a discoverer rather than a gleaner. I shall be glad to receive notes of this kind, and offer to identity any species that may prove troublesome, provided good herbarium specimens are sent me, accompanied by post- age for reply. I cannot undertake to return such speci- mens, however. Among technical works relating to the American species, first place must be given to Underwood's " Our Native Ferns and Their Allies," which includes brief descriptions' of all but the most recently discovered species in North America north of Mexico. Dodge's " Ferns and Fern Allies of New England " contains somewhat more extended accounts of the New England species, with an excellent chapter on the identification of Isoetes and a list of the species arranged according to the time each fruits. Eastman's " New England Ferns and Their Common Allies," in which there are illustra- tions and untechnical descriptions of a few of the com- mon species, completes the list of works devoted exclu- sively to the subject. Of foreign works. Baker's " Hand- book of the Fern Allies," published in 1887, includes short descriptions of all the species in the world that were known at the time of publication. Some mention should also be made of " T/ie Fern Bulletin'' now in its PREFACE. xiii thirteenth volume, which enjoys the unique distinction of being the only publication in the world devoted to the ferns and fern allies. In past volumes it has published much regarding the haunts and habits of the plants, including descriptions of many new species and forms. A series of Fern Floras of the States is now being published, which gives lists of the ferns and fern allies in each State, with distribution and other notes added. In the matter of nomenclature Ihave adopted a some- what conservative treatment, preferring for the most part the names commonly used, since these will be most fre- quently found in other books. When they differ from others recently proposed, the latter are given also, and they have also been included in the Checklist of the species. It does not seem advisable, in a work of this kind, to follow the practice of radical botanists in treat- ing a large number of forms as species. It is possible that some of these forms may be found to have characters of specific importance, but it will be less confusing to the beginner if they are still regarded as forms of the species from which they have been segregated. These newly named forms have had to be recognized, however, and in giving them what I believe to be their rightful places a aumber of new combinations have un- avoidably been made. In no other way has it seemed possible to indicate to beginners the various disguises under which certain plants are likely to be found in com- ing years. In the Checklist I have followed the plan of citing the authority for the species only, believing that the author of a new combination is not entitled to the prominence which a double citation of authorities confers. xiv PREFACE. Much valuable assistance in the preparation of this book has been given me by students of the fern allies. The source of many notes has'been indicated in the text, but I am especially indebted to, and wish here to thank, Mr. S. B. Parish, Mr. A. J. Hill, Mr. C. H. Demetrio, Dr. C. B. Graves, Mr. J. B. Flett, Mr. Julian Reverchon, Prof. R. S. Cocks, Mr. Thomas Howell, Mr. M. L. Fernald, Mr. J. H. Ferriss, Miss E. Cannon, and Miss L. F. Kimball. Mr. Alvah A. Eaton, of the Ames Botani- cal Laboratory, whose studies of these plants have con- tributed so much to our knowledge, has rendered invaluable assistance by the loan of specimens, by send- ing many interesting notes, and by a critical reading of the proof. It is but fair to add, however, that in matters of nomenclature and the limitations of species I have not always followed his suggestions. WiLLARD N. ClUTE. Joliet, 111., February 27, 1905. THE FERN ALLIES J J J ' 9 ' i , ^ THE FERN ALLIES, INCE ferns are members of the vegetable kingdom, all plants are more or less allied to them, but the term Fern Allies, as commonly understood, has a much more restricted meaning. As regarded by botanists, the fern allies are plants belonging to certain families included in one of the great natural groups of the flowerless plants. The fern allies are quite unlike flowering plants in appear- ance and have little more resemblance to their allies, the ferns ; but their structure and manner of fruiting show them to be closely related. Botanists long ago divided the vegetable kingdom into two sub-kingdoms which they nam.ed respectively the Phancrogamia, or Flowering Plants, and the Cryptogaviia, or Flowerless Plants. In this second division 4 THE FERN ALLIES. were placed such diverse plants as the algae, fungi, liver- worts, mosses, and ferns. None of these ever bear flowers or produce seeds, but, aside from this, the various groups differ as much among themselves as the division as a whole differs from the flowering plants. The ferns and fern allies are the most highly developed of these plant families, and in structure are closely re- lated to the simplest flowering plants. They, alone, have true roots and stems with tissues specialized for different functions. The presence of these specialized tissues — the so-called fibro-vascular system — has caused these plants to be called Vascular Cryptogams or Vascu- lar Acrogens to distinguish them from the less-spe- cialized mosses, algae, etc., composing the Cellular Acrogens. Modern botany still accepts these divisions, though the terms used to designate them have changed some- what as they have become adjusted to our present ideas of nomenclature. We now usually speak of flower- ing plants as the Spcnnatophyta, and of the ferns and fern-like plants (the vascular acrogens) as the Pterido- pJiyta. The mosses and liverworts are now the BryopJiyta^ and the rest of the cellular acrogens are spoken of as the TJiallophyta. The fern allies, then, belong to the high- est division of the flowerless plants, have stems in which there are woody tissues and ducts, and, in short, comprise all the PtcridopJiyta except the ferns themselves, as shown by the accompanying table of the orders represented in the North Ameri- can Flora. THE FERN ALLIES. 5 ORDERS AND FAMILIES OF THE NORTH AMERICAN PTERIDOPHYTA. SERIES I. —FERNS. Order i. — Ophioglossales. Family i. — Ophioglossacece. Order 2. — P^ilicales. Family i . — Hymejiophyllacece, Family 2. — Osmimdacece. Family 3. — SchisceacecB. Fainily 4. — Ceratopteridacece. Fa m ily 5 . — Polypodia cece, SERIES II. — FERN ALLIES. Order i. — Salviniales. Family i . — Marsiliacece, Family 2. — Salviniacecs. Order 2. — Equisetales. Family i. — EquisetacecB, Order 3. — Lycopodiales. Family i. — Lycopodiacece. Family 2. — Psilotacece. Family 3. — Selagiiiellacece, Order 4. — Isoetales. Fa m ily i . — Isoeta cecB. Like the ferns, the fern alHes are reproduced by spores, which, germinating^, form prothallia upon which the reproductive organs, the antheridia and archegonia, are borne. From the union of the contents of archegonia and antheridia, new plants are produced. The pro- thallia, however, are often quite unlike the familiar green, heart-shaped prothallia of the fern. Some are colourless, tuber-like, and develop underground instead of upon the surface in the usual way, and in some that develop above ground the prothallia are not heart- shaped and the antheridia and archegonia are on sepa- rate prothallia. The process of fertilization is essentially 6 THE FERN ALLIES. the same in all, — a fusing of the contents of archegonia and antheridia. The ferns are a strongly marked and easily recognized group of plants, but the fern allies have no such uniformity of appearance. Only the botanist, familiar with their manner of fruiting, would think of associating plants of such diverse habits and dissimilar forms. The club-mosses usually have trailing vine-like stems and tiny scale-like leaves ; the selaginellas grow in moss-like tufts; the pepperworts have leaves resembling four- leaved clovers ; the quillworts have very short trunks and grass-like leaves ; while the scouring-rushes, at first glance, seem to have no leaves at all and to be chiefly remarkable for their development of stem. Neverthe- less, all are practically alike in their manner of fruiting and in the structure of the plant body, and are therefore properly classed together. The great diversity of leaf and stem in the fern allies is made necessary by the habitats of the plants. The club-mosses live on dry moors, in rocky wastes, or sandy swamps ; the scouring-rushes in damp shades or standing water. The water-fern is found floating on the surface of- quiet pools; the marsilias root beneath the water and send their leaves to the surface ; while many of the quillworts pass their entire life at the bottom of rivers, lakes, and ponds. As a whole, the fern allies are members of a decadent group, and the lack of close resemblances between the families is doubtless to be explained upon the supposi- tion that many of the intergrading forms have died out. At present there are about seven hundred living species, or approximately one for every six species of ferns. In the remote past they were much greater in both num- THE FERN ALLIES. 7 bers and importance. The prototypes of our lowly club-mosses and scourlng-rushes — the lepidodendrons, sigiilarias, and calamites — often equalled in size the forest trees of the present, and their remains form the greater part of the Coal Measures. It is reported that one of the Scottish coal beds consists almost entirely of the spores and spore-cases of some extinct Lycopoditini. Of our modern genera, Equisetiiin dates from the Triassic Period ; Isoctes, Marsiiia^ and Pihilaria from the Tertiary ; and Lycopodium from as far back as the Devonian Period. With few exceptions the fern allies are not remark- able for either beauty or utility. Some of the club- mosses, under the more familiar names of running pine and trailing evergreen, are annually used in quantity for holiday decorations, and various species of Selaginella are cultivated for their graceful foliage. The spores of the club-mosses form the lycopodium of the pharmacist and have been used in the manufacture of fireworks, while the rough stems of the scou ring-rushes were once valued for polishing and scouring. Key to the Families of the Fern Allies. I. — Sporangia in terminal cones Stems hollow, rush-like . . Equisetacece 11. — Sporangia in the axils of the leaves or leaf- like bracts, often forming terminal spikes Plants apparently stem less . . IsoetacecB Plants with evident stems Spores of two sizes . SelaginellacecB Spores all alike Sporangia in spikes . Lycopodiacece Sporangia in clusters . PsilotacecB III. — Sporangia in berry-like sporocarps Whole plant floating . . . SalviniacecE Plant rooting in mud . . . Marst'h'accce » THE EQUISETACE^: SCOURING-RUSHES AND HORSETAILS. THE EQUISETACE^. OT inappropriately may the Scoiir- ing-Rushes be likened to the cacti, for, like them, their leaves are reduced to mere rudiments, and the stems perform all the ofifices usual to leaves. This, however, is not their only peculiarity. In their general structure they have little re- semblance to other plants. The stems are jointed, hollow except at the joints, and noticeable for their lack of differentiation from the underground portion of the plant. From the farthest subterranean root-stock to the tip of the tallest shoot, the construction is essentially the same. It may be likened to a line of drain-pipe, each section of which fits Into the slightly flaring top of the one below it. These hollow sections are grooved exte- riorly with from three to fifty longitudinal grooves, vary- ing in number with the species. These grooves are known as valleculas and the intervening ridges as carinae. Within the stem walls, and encircling the central hollow, there are usually found two other series of hollows, — one series beneath the valleculae, and therefore called the vallecular canals ; the other beneath the carlnae, and called 12 THE EQUiSETACE/E. the carinal canals. These differ in size and shape with the species, and thus form excellent characters for their identification. At the top of each joint in the stem there is a papery sheath which seems to form a socket into which the next joint above it fits. This sheath is toothed on its upper border, usually with as many teeth as there are ridges in the stem. From various indications it is evident that this sheath represents a circle of confluent but reduced and functionally useless leaves. Inside the sheath (that is, in the axils of the leaves) buds are formed, — a bud for each leaf, — and if these develop into branches they break out throusrh the base of the sheath in reg-ular whorls. In many species these buds always remain dormant unless the tip of the stem is Section of . . . Stem at injured, when a few near the tip may give rise the sheath. to short branches. Externally the stems are often coated with particles of silex in many curious patterns, such as rings, bands, granules, teeth, and rosettes; and, not infrequently, abundant silex particles may be found lining the central hollow. This silicious coating gives a characteristic harshness to the stems of certain species, rendering them useful for polishing woodwork and other articles. The silex is usually most abundant on the carinae, while the stomata — the minute openings for transpiration — are distributed along the valleculae. The rhizome or underground portion of the plant is often of considerable length, and spreads about in the earth from a few inches to several feet beneath the Sur- face. The sheaths at the joints also contain buds, and THE EQUISETACEyE. these, upon developing, become cither secondary root- stocks pushing up toward the surface, or possibly aerial stems rising above it. From the base of these buds slen- der roots are produced. The sections of the rootstocks are covered with a tawny or blackish felt, which, like the root-hairs, doubtless assists in the work of food-absorption. The buds on the stems readily produce roots if covered with moist earth, while rootstocks exposed to the air soon produce stems. Since the plants are liable to be either covered with mud or washed from their places during freshets, it is a wise provi- sion of Nature that stem and rootstock are^ so nearly interchangeable. In certain species the rootstock occasionally develops small round [|l| tubers. These resemble the rootstock in struc- ture and may be assumed to be undeveloped branches of it. Their use is unknown, unless they may serve as a storehouse for surplus plant- food. Under certain circumstances they may possibly give rise to new plants. ,-p,, ... - A Joint of ine spores are always borne at the tips of the the stem. stems in cone-like spikes or catkins. These spikes consist of numerous, usually six-angled, plates attached to the stem by a central stalk, and bearing from five to nine little sacs or spore-cases on their margins. The sacs extend SPORE-CASES. horizontally toward the centre of the cone, and only the angular plates to which they are attached are to be seen before maturity. When ripe the cone lengthens slightly, drawing the plates apart, the spore-cases open on the side next the stalk that bears them and the spores escape. 14 THE EQUlSETACE^e. The spores are tiny globular, single-celled bodies, bright green in colour, and so small that single indi- viduals cannot be distinguished without a lens. Each posse«""s two filiform appendages with enlarged ends, called elaters, w h i c h are at- t a c h e d to the equator of the spore by their middle, coiling spirally around it when moist and spreading out when dry. As the spore - case dries at maturity, the elaters uncoil and assist in SPORES, ENLARGED. iberating the spores ; and when the spores are free, they assist in float- ing them on the air. The elaters of several spores often become entangled, and the spores float away to- gether, an advantageous arrangement, since the prothallia are dioecious and require more than one spore to repro- duce a plant. The spores contain chlorophyll, the green colouring- matter of plants, and lose their power of germinating within a few days after leaving the spore-case. When they lodge in a favourable place, they germinate in ten or twelve hours, and soon produce small green, lobed pro- thallia. It is said that the fresh spores will germinate readily if sown upon the surface of water. Although the spores are apparently all alike, some produce only THE EQUISETACE^. 15 male and others only female prothallia. It is impossi- ble, before germination, to discover which is which, and, since the male prothallium is always the smaller, it is conjectured that the difference in the sex may be due entirely to the amount of nourishment the prothallia are able to obtain, those well nourished becoming female and the others male. It is interesting to know that the cones of fossil species have been found so well preserved as to show that the ancestors of our present plants had spores of two kinds, like the modern selaginellas and isosetes. The scouring-rushes range in height from a few inches to thirty feet, but the largest seldom exceed two inches in diameter, and the majority are rarely thicker than a lead pencil. In all, the rootstock at least is perennial, and in some the aerial stems last for several years. There are about twenty living species, .i^iost of them in temperate regions. During the Carboniferous Age they were most abundant, almost equalling the ferns in num- bers. Though few in species now, they are abundant and widely distributed. North America* contains repre- sentatives of more than half of all the species in the world. The name Eqiiisctinii is from two Latin words mean- ing ** horse " and '' bristle," and was applied to these plants in allusion to the many slender branches of cer- tain species, which render the plants not unlike the tail of ahorse in appearance. In the order Equisetales there is but one living family, the Equisetace^e, and in this family there is but the single genus Eqiiisetum. The fossil species mostly belonged to the family Calamarise. Many of them attained the size of trees. Key to the Species of Equisetum. Series I. — Evergreen species. Stems rough, seldom branched, catkins usually tipped with a hard point Stems tall, stout, about as thick as a lead pencil Sheaths dilated upward Margins incurved, stems rough E, Fimstoiii Margins not incurved, stems smooth E. lanngattim Sheaths not dilated upward Old stems much branched E. i-obnstn7)i Old stems seldom branched Joints short. . E. hieinale Joints longer . E. Ferrisst Stems slender, tufted Six-angled-, thread-like E. scirpoides More than six-angled, larger E. variegatu}7i Series II. — Deciduous species, Rootstock only, perennial. Stems smooth, usually branching, catkin not tipped with a hard point Fertile stems tawny or flesh-coloured when young Not lasting through the summer Plants stout. Western . E. Telmateia Plants slender, mostly Eastern E. arvense Lasting through the summer Branches of sterile stems unbranched E. pratense Branches of sterile stems again branched E. silvaticujn Fertile stems green like the sterile Sheaths appressed . E, fhiviatfU Sheaths looser Spores perfect, abundant E. palusire Spores imperfect, few E. littorale THE EVERGREEN EQUISETUMS, OR SCOURING-RUSHES. THE SCOURING-RUSHES of the most conspicuous differ- ences among the equisetums is found in the duration of the aerial stems. In some species all traces of them above ground disappear soon after the first hard frost, while in others the stems not only endure at least one win- CROSS-SECTioN OF STEM. tcr, but in the second season possess enough vitality to put forth new branches. It is singular, also, that the evergreen species should all resemble one another in external appearance more than they do the species with deciduous stems. To divide the genus upon the single character of jjerennial or deciduous stems would separate the species into two very natural groups. It has been proposed to make these two groups separate genera, though botanists at present usually include the two in the single genus Eqiiisetuju ; the evergreen specie^s, however, are placed in the sub-genus Hippochc^tcB, The Common Scouring- Rus/j. Undoubtedly the best known of the evergreen equise- tums is the common scouring-rush {Eqtiisetnin Jiiemale). Its stiff unbranched stems of dark green, ringed at the 20 THE SCOURING-RUSHES. nodes with bands of black and ash-colour, are sufficient to attract the eye at any time of the year, but they are especially noticeable in winter, when, in the absence of other greenery, they become very conspicuous against a background of snow or withered leaves. It is a very gre- garious species, and is seldom found except in little thickets that are very characteristic. Early in spring the new stems make their appearance, arising from short branches of the underground portion of the plant. In appearance these budding stems suggest a closed telescope, being of full diameter, but with only the sheaths of the joints showing. Development consists in the lengthen- ing of the inter- nodes, just as a telescope may be lengthened by drawing out the tube, though in the case of the plant the sections are not enclosed one within the other, as in the instrument. The full-grown stems are usually stiffly erect and unbranched the first year; but during the second season, if the tip of the stem is injured, a few of the upper nodes may put forth small branches. These, instead of diverging, grow upward, nearly parallel with the main stem. The height of the stem seems limited only by its capacity for growth, though, since each joint Items, is smaller than the one preceding it, there w^ould come a time, theoretically, when no more joints could be produced. The tip of the stem is usually THE SCOURING-RUSHES. 21 winter-killed long before such a condition is reached. Mature stems seldom reach a height of more than four feet, or a diameter at base of half an inch. A series of joints in the stem divide it into many sec- tions, each three or four inches long. At the top of each section, or internode, there is a Icaf-sheath a quarter of an inch or more long, fitting closely around the base of the next internode, and bearing on its summit numer- ous small triangular teeth which end in a long point. These teeth are jointed to the sheath and usually fall away at maturity, being noticeable only in very young stems. Often the tips coalesce in the bud, and, as the stem lengthens, they are carried upward on its summit in a compact mass resembling an old-fashioned candle- extinguisher or a Chinese pagoda. Where the sheath joins the stem, there is a brown or blackish band, and a line of the same colour borders the outer edge. Between these the colour is purplish, green- ish, or ashy white. The width of the black band and the colour between them varies with age and with the indi- vidual. In some specimens the bands always remain nar- row, while in others they may broaden until the entire sheath is suffused with black. This latter is most com- mon in old stems and in sheaths near the base. The marginal band is always the darker of the two, and in young specimens the second band is frequently missing, or is indicated only by a faint brown line. No species show the manner of jointing better than this. After the stem has been pulled apart it may be easily reconstructed on account of the nicety with which the ends of the internodes fit into the sheaths. At the nodes or joints the stem is solid, but cross-sectionS/ of the internodes show a very large central cavity occupying four fifths of THE SCOURING-RUSHES. the stem, besides a series of small oval vallccular canals alternating with a series of still smaller carinal canals in the thin walh. Externally the stem bears from twenty to thirty or more narrow longitudinal grooves, the ridges between them being covered with many minute cross- bands of silex. Occasionally these bands break down in the centre, leaving a double row of silicious tubercles. The amount of silex in the outer coat varies, but usually it so completely covers the epidermis that the vegetable matter can be dissolved out by acids, leaving a com- plete outline of the stem in silex, — a sort of stone or glass skeleton. The scouring-rush fruits in a yellowish, cone- like catkin at the apex of the stem. Occasion- ally, during the second summer, small cones may be produced at the tips of the short branches also. The terminal cone is ovate, about half an inch long, and ends in a short hard point. The principal fruiting-season is in May and June, though the cones, usually small and undeveloped, may be found at any time, and the plant fruits in a desultory way until October. Even in winter the compact little cones have fully-formed spores packed snugly away until a more propitious season. If one of these winter cones be split from tip to base with a sharp knife, and the cut surface be quickly examined with a lens, a most interest- COMMON inor sight will be revealed. From the gaps SCOURING- t' i5 fat RUSH. made in the delicate walls of the spore-cases, EquisetU7)i * hiemaie. ^ Hvcly crowd of spores come tumbling out, jostling one another in their haste and apparently THE SCOURING-RUSHES. 23 urged on by those behind. As each fat little spore reaches the open, it unfolds its elaters like four tiny wings and quickly sails out of the field. As long as the mois- ture in the tissues is evaporating they continue to come. To change the scene, one has only to dip his specimen into water or to breathe upon it. At once every elater is coiled. Even those spores just balanced on tip-toe as it were, ready for flight, decide to remain, and all seem trying to shrink into the smallest space possible. The change is due to the hygroscopic nature of the elaters, which coil in the presence of moisture. This character- istic ensures that the spores shall not set out on their travels until a fair day comes and the sailing is good, and also prevents the elaters from being folded again and the spores dropped until a moist interval, suitable for ger- mination, occurs. The rough and flinty exterior of this species makes it useful for scouring and polishing. It was once of prime importance in domestic affairs, being used for cleaning pots, pans, floors, and other woodwork. Cabinet-makers and others also found many uses for it, but with the advent of scouring-soaps and sandpaper it has gradually fallen into disuse. In our own country, a few Indians on the borders of civilization still use it for polishing the shafts of arrows and similar work. It is said to be occasionally used in the Old World also at the present day. The names of " scouring-rush," '' scrub-grass," '' shave- grass," *' polishing-rush," and " gunbright " all allude to its use in polishing, while the term ''naked horsetail" has reference to the branchless nature of the stems. In some sections the slender jointed stems have suggested the name of ''bamboo." "Joint-rush" and "joint-grass" 2A THE SCOURING-RUSHES. refer to the same appearance. The names '* snake-weed " and *' snake-rush " are probably derived from the fact that these plants often grow near water, — damp thickets and snakes being alvv^ays popularly associated. The author has also heard the stems called ** frogs' fishing- poles." The species has occasionally been called " smoke-weed " or ** mountain-rush," but the reason for the application of these names is not apparent. ** Horse- pipes " refers to the large size of this species. Smaller species are called ** pipes" or ** paddock-pipes," and the larger ones would naturally be called ** horse-pipes," just as we speak of ** horse-radish " '* horse-fiddle," or *' horse- chestnut." *' Winter-rush " alludes to the fact that this is our commonest evergreen species. At the time of its use as a scouring-agent it was imported into England from Holland in large quantities, and in this way gained the name of ** Dutch rush." It is stated that this species is often planted upon the dykes in Holland, its long branching rootstocks serving to prevent the soil from washing away. Children often amuse themselves by placing the fresh stems on the rails of the street-car lines, and listening for the sharp reports caused by the air in the central cavity bursting through the walls of the stems as the car passes over them. The juices of the stem will also cause them to explode when thrown into the fire, and the medicine- men of various Indian tribes still make use of them in this way, in order that their popping may stimulate their patients to renewed vigour. The hollow joints of the stem may be made into a rude sort of Pan-pipe simi- lar to those made from canes by the negroes of the South. According to an old writer it was thought that if cows fed upon this plant their teeth would drop out. It THE SCOURING-RUSHES. 25 may be added that cattle will not eat it if there is any- thing else to be had. The juice of the plant was once thought to be useful in nosebleed and as an application to wounds. The scouring-rush is found throughout North America growing along streams, on the borders of swamps, and in other low grounds. It is able to exist, however, with much less moisture, and is frequently abundant along dry railway embankments and on gravelly banks. There is some variation in plants from different localities, the one here described being the form common to the North- eastern States. Its closely appressed sheaths and many- grooved stems are characters that usually serve to identify it. It is the most abundant of our evergreen species, and is also found in Europe and Asia, extending in a more or less broad belt around the earth in the North Temperate Zone. It appears to be absolutely unharmed by the cold. The water in the central hollow often freezes solid without hurt to the plant. In exposed situations the stems o.n the southern side turn a dingy brown in winter, but become green again on the approach of a milder season. In the Mississippi Valley, and farther west, there is a form called Equisetum Jiiemale internicdiiuii which has transverse bands of silex on the stems, looser, somewhat funnel-shaped green sheaths with a narrow black-and- white margin and deciduous or persistent teeth. It has often been collected for i5"^//z>^/?/;;/ lcevigat2U)i,\\A\\Q\\ it resembles in many ways, especially in the funnel-shaped sheaths, but the internal structure is that of true Jiiemale. Equisetum Icevigatum is also said to have annual stems, but there is still some doubt upon this subject. In some States, notably Nebraska, Equisetum hiemale intermedium is considered of some importance as a forage crop. No 26 THE SCOURING-RUSHES. less than ten named varieties of Equisetiim hiemale have been reported from America. Many of these are mere ecological forms, of interest only to the systematist. Those wishing to study them will find a full account of all in volume XI of the Fern Bulletin. The Great Scouring-Rush. In the Southern and Western States the most abun- dant of the scouring-rushes is probably the great scour- ing-rush {Eqiiisetjc/n robusttmi), which is supposed to intergrade with the common scouring-rush and is by many considered only a variety of it. It is a strong and robust species, but except for its larger size it cannot be distinguished from Eqiiisetiim hiemale in a cursory examination. Mr. A. A. Eaton, who has carefully studied the genus, is con- vinced that this is only a well-marked race Ij of the scouring-rush, but as it has always appeared in text-books as a separate species it will be so treated here. Mr. Eaton's view is probably the correct one, however. Aside from its larger size, the character- istics usually depended upon for separating Equisetiim robustum from Equisetum hiemale are the greater number of grooves in the stem, the three-keeled ridges of the sheaths, and the sinfjle series of cross-bands of silex on Equisetum hiemale is supposed always to have obscurely four-keeled ridges in the sheaths, and two rows of silex tubercles on the carinae, but any of the characteristics of the one may be matched by specimens of the cnher. Large Sheath. Natural Size. the carina:. THE SCOURING-RUSHES. 27 In favourable situations the stems of this species often reach a height of ten feet, and a diameter of half an inch or more at base, forming thickets similar to those of the common scouring-rush. In the warmer parts of its range the new shoots begin to make their appearance in March or earlier, and by the first week in April the fruiting cones may be obtained, though the stems have scarcely reached their maximum height at that period. During the first year the stems seldom branch, but early the next spring a large number of them put forth long wand-like branches from the upper joints. All authori- ties agree that this form rarely branches, but this is clearly a mistake. It produces branches much more freely than does Equisetiini Jiieniale. In addition to the principal stems this species not infrequently produces several slender stems from each rootstock. The sheaths are rather longer than those of Equisetum Jiieniale, and are pinkish ash-colour with rather narrow marginal and basal dark bands, the latter at first promi- nent and lighter in colour. The teeth are dark brown with tawny margins, elongated triangular in shape, with long tapering points, and usually remain in position until the stems are full grown or even longer. Those upon the branches do not fall off during the life of the stems. The fruiting cones are from half an inch to an inch long and terminate in a sharp point as in the other species of this group. The fertile stems produce a single spike at the apex of the stem the first year, and the following season one or more smaller cones may de- velop on the ends of small branches, the terminal cone, of course, being absent. Like the common scouring-rush, the stem of this species is hollow for the greater part of 28 THE SCOURING-RUSHES. its, diameter, and the contained air causes a loud report when it is forced out under pressure. The great scouring-rush is rare east of the Mis- sissippi River except in the South. It has been reported, apparently upon good authority, from scattered stations in New Jersey, Pennsylvania, Maryland, Indiana, Illinois, and Michigan, and is the common form in the States bordering the Gulf. In the West it appears to be plentiful throughout, extending northward into British Columbia. It is said to occur in India also. The stems are as rough as those of the common species, and are still occasionally used for polishing by the Southern negroes. Being so nearly like Ji^iiisetiim Jiieniale \\. shares with it the various common names. The Slender Scouring- Rush. The characters relied upon for the identification of the various Equisctiini species, such as the num- ber of grooves in the stem, the diameter of the stem, length of the joints, etc., make the variations a matter of easy mathematical demonstration. In making some investigations along this line, recently, the author was surprised to find that the extremes of variation in Eqiiisetvm Jiicviale are much less than is commonly supposed. Out of more than 250 stems selected at random, all but twenty-four were between 5/32 and 8/32 of an inch in diam- eter. The length between joints was between two and three inches in all but fifteen of the Equisetum 230 spccimcus mcasurcd, while of 125 speci- Seciion of mcus in which the g^rooves were counted, all Stem, ^ Natural but thirteen had from twenty-four to thirty THE SCOURING-RUSHES. 29 grooves eacli. At the same time, an Eqiiiseinui was found near Joliet, Illinois, that differed so constantly in these characters that it was considered a new species and was named Eqiiisetuin Ferrissi. This species is principally distinguished by its tall, slender, pale-green stems with few grooves, and the exceedingly long sections between joints. More than fifty specimens, selected at random, were measured, and all but four were 4/32 of an inch or less in diameter. The grooves were also fewer in number, only nine stems having more than fourteen grooves. The greatest difference of all, however, was in the length between joints. None of the intern odes were as short as the average in Equisetiiui hiemale, and but fourteen were less than four inches long. The longest measured more than six and a half inches. This form may also be known by the appressed sheaths, which are green when young, but in age become chalky- white with a narrow black basal band encircling them obliquely. The teeth are two thirds the length of the sheaths, slender and deciduous, with a central streak of dark brown bordered by a wider hyaline margiq. After the teeth have fallen, the border of the sheath becomes thickened, incurved, and dark brown in colour. The grooves between the leaves extend below the basal black band. The catkins, like those of the common scouring- rush, are tipped with a sharp point and are borne on a short pedicel. They ripen about the first of June, but many appear to be abortive and are to be found in the globular expansion formed by the topmost whorl of leaves. The slender scouring-rush resembles Eqiiiset2iin Jiiemale intermedium, but may be distinguished from it by the smoother, slenderer stems, by having fewer grooves in 30 THE SCOUKINORUSHES. the stem, and by the appressed sheaths and strongly apiculate catkin. It is not known at present whether this form occurs elsewhere, or whether its existence at Joliet is unique. At the place where it was discovered it forms an exten- sive thicket, but this may have arisen by means of the spreading rootstock. Possibly the first plant was produceci by a variant spore. If so, it is not ikely to be found in other localities, and the question arises whether it is entitled to be called a species, or is more properly considered a form of Equisctuni liiciualc. From the modern view- point of evolution it might be thought an off- shoot, by mutation, of the species mentioned. In form it appears to be more distinct than either Eqiiuctinn Jiieniale robiistiiin or Eqiiisetiim hiemalc STEM ^^.intermedituii; but should it turn out to be un- LARGED. ^^Q,.^hy q{ specific rank it would still rank as a sub-species with the title of Equisetum hiemale Ferrissi. The Smooth Scouring- Rush. Typical specimens of the equisetums are not difficult to identify, but when one has a large series of a single species from different localities to deal with, the task becomes more perplexing than might be supposed, on account of the numerous variations presented ; in fact, it is hinted that all the species in the section HippocJicetc, though distinct enough as to type, may be connected by intergrading forms. One of the most variable of these species is the smooth scouring-rush {Equisetum hcviga- tuin). On the one hand it is linked to the common scouring-rush by the form known as Equisetum Jiiemali SMOOTH SCOURING-RUSH. Equisetum lcr7>igatuni. THE SCOURING-RUSHES. 31 intcrmediuDi, and on the other it intergrades ahnost imperceptibly with the smaller variegated scouring-rush. In outward appearance the smooth scouring-rush is much like Equisetiim hiemale, though usually shorter and slenderer and with less silex in the epidermis. Well-developed specimens may reach the height of four feet, but the average is probably less than twenty inches. The exterior is comparatively smooth and has from ten to thirty grooves. The sheaths are long-, green, and dilated upward like a funnel, this last characteristic being one of its most distinguishing features. There seems to be some question as to whether or not the stems last through the ' winter. All its affinities are with the evergreen species, and it has always been called evergreen in the books, but Mr. Eaton, the latest monographer of the American species, has stated that the stems are annual, and that the species may be distinguished from Equisetiim hiemale by this single peculiarity. Further observations on this point are desirable. The present lack is no doubt due to the fact that the species is rare in the Eastern States, where most of the studies of Eqtiisetiun have been made. The stems of the smooth scouring-rush usually grow in tufts from the summit of the rootstock. They are slender and usually unbranched, though the more robust specimens may develop several ascending branches from near the base, especially if the tip be injured. In this it is the reverse of the common scouring rush, which, if it branches at all, does so near the tip of the stem. In colour the stems are pale green, and a cross-section shows a large central cavity with medium-sized vallecular canals, those under the carinae being either smaller or absent. On the exterior the grooves are somewhat 32 THE SCOURING-RUSHES. rounded with or without cross-bands of silex. The sheaths are coloured like the stem, or occasionally paler, rarely with a black girdle at base. The leaves of the sheaths usually have a central ridge at base, which fades out as the apex is approached. The teeth are long and slen- der, silvery white in colour, with a narrow streak of dark brpwn down the middle. At maturity these teeth usually fall away, leav- ing the brownish bases, bordered with white, as a narrow brown and white margin to the sheath. This species begins to fruit about the first of May, though the catkins may be found as late as midsummer. The late catkins are produced on secondary stems which spring from the base of the earlier ones. The cones are small, ovate or oblong, with the base often en- closed in the uppermost sheath, and the point at apex short or absent. The range of the smooth scouring- rusli, as usually defined, begins in New Jersey and spreads out in fan shape to the Pacific coast, the line of its south- ern limit passing through Louisiana and Texas, while the line on the north crosses Ohio and Wisconsin, and so on to British Columbia. In the East and South it is extremely rare, and there is a suspicion that the Eastern records are based catkinof on forms that are more properly referred to Equi- sc^u°dng- setmn hiemale. The form Equisetum hiemale inter- ^"*^' medium closely resembles it, especially in the shape of the SHEATH OF SMOOTH SCOURING- RUSH. THE SCOURING-RUSHES. 33 sheaths, though in the latter these are shorter and paler, with a black basal girdle. Eqtiisetum IcEvigatum is found only in America, and is doubtless most common in the Middle West, where it is often used for forage. It pre- fers a moist soil, being usually found in sand or clay on the borders of streams. Many facts in its life history are as yet imperfectly known, and the beginner will find this a species worthy of further observation. Five American varieties of no especial importance have been described in the Fern Biillctin. The Branched Rquisetum. Students who consult other works on the fern allies will find listed among the North American species two that are no longer regarded as members of our flora. These are EqjiisetJivi ramosissiimim ixwd Eqiiisetmn Mcxi- caniim. The first was reported from British Columbia more than fifty years ago, but as it has never been rediscovered there, and the reported situation is far out of the plant's known range, it seems almost certain that some other species was mistaken for it. The second species, Equisettini Mcxicamim, has frequently been reported from southern California, but here again the probabilities are that the identification is incorrect. Baker, in his *' Hand-Book of the Fern Allies," considers Equisetiun Mexicaimm to be a form of the tropical Equi- settim giganteiim ; and while it is possible that an occa- sional plant of this species may stray across our south- western border, it is more probable that the California specimens belong to a different species. Since these plants have always been wrongly identified, it becomes necessary to give them a new name to distinguish them. 34 THE SCOURING-RUSHES. Mr. A. A. Eaton has therefore proposed the name of Eqiiisetum Ftinstoni, in honour of General Funston, who in early life made several botanical expeditions into little-known regions, upon one of which he collected this species. The branched scouring-rush is most like Equisetum Icevigattivi, but may be distinguished from it by its rougher stems and by the shape and make-up of the sheaths. In both species the sheaths are coloured like the stems, and both are dilated upward, but in Equisetum Funstoni the margin of the sheath, after the tips have fallen, turns inward, while in Equisetum Icevigatum it does not. The leaves composing the sheaths of Equisetum Funstoni are somewhat separated at the apex. The stems of Equisetum icevigatum are also supposed to be annual, while those of Equisetum Funstoni last through the winter. This difference, however, may be accounted for by the warmer climate of the region inhabited by the latter. Both species Sheath of ^^^ alike in having catkins lacking the apical ^FunsfonT. poi^t, tliougli, curiously enough, they belong to a section in which the possession of such a point is one of the distinguishing features. It has been suggested that Equisetum Funstoni is but a form of the better-known Equisetum icevigatum. Whether this is true or not will necessitate further study of both plants in the field. Should it be proved to be a form of Equi- setum Icevigatum, it would be known as Equisetum Icevigatum Funstoni, since the other was first named. The new stems of the branched scouring-rush make their appearance early in the year, and by the middle of March are in fruit. At maturity they may reach a BRANCHED EQUISETUM l-.qit/sc/um Fuusfoui. THE SCOURING-RUSHES. 35 height of two feet or more, with a diameter of a quarter of an inch. They contain from ten to thirty grooves, the ridges somewhat rounded and usually rough with many cross-bands of silex. The sheaths are twice as long as they are wide, and are tipped with triangular, long-pointed teeth, most of which are torn off by the developing stems, the rest falling at maturity. The teeth are dark brown or black with a pale margin, and the bases, which remain attached to the sheaths, are slightly grooved in the centre. Each leaf has a low ridge extending lengthwise, and the upper margin, where it is separated from the others, is slightly raised. In cross-section more than four fifths of the stem is hollow, and both the carinal and vallecular canals are very small, or, occasionally, wanting. Much remains to be observed regarding the development and duration of the stems of this species. Apparently the erect fruiting stems do not branch, at least not until after fruiting, but the sterile stems produce regular whorls of branches as they develop. There is also a form of the sterile stem, most noticeable in winter, which spreads flat on the ground and sends out a multitude of short, very slender branches from the base, forming dense mats. In this form the stems are about ten-angled, and the teeth are silvery white and persistent. It does not seem to be known whether the fertile and sterile stems last through the win- ter, but, reasoning from the analogy of related species, it may be assumed that they do. The fruiting-catkins are among the largest produced by this group of plants, being about three quarters of an Catkin of Equiseiuvi % 'unstont. 36 THE SCOURING-RUSHES. inch long and a third as broad. They are nearly ovate, with a rounded apex, and the base is either included in the uppermost sheath or raised above it on a short stem. In most specimens there is a cup-shaped sheath of the same colour as the catkin, closely appressed to the lowest whorl of sporophylls. Equisetum Funstoni is a plant of the extreme South- west. It is very abundant in southern California below about 1,500 feet altitude, and prefers moist sand, espe- cially along streams, although it occasionally grows in soil so dry that the stems perish during the summer. In general appearance the species is so much like Equisetum IcBvigatum that it is easily mistaken for it. Four ecologi- cal forms have been named. It is interesting in this connection to note that there are but two other species of Equisetum in the world, named for botanists. The Variegated Scouring-Rush. One familiar with the appearance of the smooth scouring-rush might easily mistake the variegated scouring-rush {^Equisetum variegatuui) for a small form of that species. Superficially they are much alike except in size and the markings of the sheaths, but a close examination will show many other points of difference. Equisetum variega- tum is much the more widely distributed, and in America the habitats of the two do not overlap to any great extent. The stems of this species grow in tufts from the apex of the rootstock, and reach a height of Sheath of from six to twenty inches. They are slender, varYega7iZt. barely an eighth of an inch in diameter, and so VARIEGATED SCOURING-RUSH. Equisetiim ^uiriegaium. THE SCOURING-RUSHES. 37 weak that they often spread about in a half-recumbent position. Externally they are marked with from four to ten broad, rounded, or slightly two-angled ridges with still broader hollows between. A cross-section shows the central hollow to be about one third the total diameter, the vallecular canals to be relatively large and trans- versely oval, while the carinal canals are much smaller. The sheaths are of moderate length, slightly dilated upward, and tipped with elongated, triangular, slender- pointed teeth with white margins which may or may not fall off at maturity. At the base of old stems the sheaths are jet black; higher up they are ash-colour with two black girdles, one at the base and one on the margin; while near the apex and in young stems they may be clear green with only a narrow blackish band on the margin. The leaves are four-ridged, the two middle ridges separated by a rather deep groove, this latter being considered an impor- tant point in identifying the species. The cat- kins are slightly ovate, half an inch or under in length, and tipped with a comparatively large point. After fruiting, the sporophylls often fall from the axis of the cone, which may persist in this condition for some time. The variegated scouring-rush is a lover of the North, and inhabits a zone encircling the earth Eg^'^l^tum from about the 42d parallel of north latitude to ^'^^"^^"'^'"" the Arctic Circle and beyond. In the southern part of its American range it has been reported from all the northern tier of States and from Illinois and Indiana. It has often been reported from the Southwestern States, but it is likely that in such cases EqiiisetiiDi. licvigatum may have been mistaken for it. It grows in 38 THE SCOURING-RUSHES. swamps, on wet rocks, and on the gravelly borders of streams, but, according to Eaton, seldom in sand. In Europe it has been reported as occurring in sandy places near the seashore. In the northern part of its range the stems possibly do not survive the win- ter, but farther south there is evidence that a majority, if not all, are evergreen. The specific name, variegatum, refers to the appearance given to the stem by the black sheaths. Four varieties Cross Section of Stem, have bccu named, of which Alaskamirn, found from the State of Wasliington northward, is the most noteworthy. It is regarded by many as being a connecting link between this species and Eqiiisetuni Jiie- inale, T'he Dwarf Scouring-Rush. After puzzling over the minute differences that are often depended upon for separating the other species of Equisetttni, it is refreshing to turn to one like the dwarf scouring-rush {Equisetiim scirpoides) that is so distinct in form and so characteristic in appearance that even the beginner, finding it for the first time, has no doubt as to its identity. It is the smallest living species of Equisetuvi^ and for this reason is often overlooked in regions where it is fairly common. This species, though growing only in the colder parts of America, is an evergreen, and, like its relative, the common scouring-rush, carries many of its fruit-buds through the winter. Almost as soon as the snow has dis- appeared, the first catkins begin discharging their spores, and the plant continues to fruit through the summer. DWARF SCOURING-RUSH. Equisetum scirpoidcs. THE SCOURING-RUSHES. 39 The greatest number of mature spikes will probably be found about the middle of April, making it one of the earliest fruiting species of Eqtiisetiun. The stems grow in dense tufts, the longest barely reaching a height of ten inches, and are so slender as to be almost threadlike. They are often branched at base, but seldom so above, unless they become prostrate and covered with soil. The fertile stems are nearly erect, but the sterile are flexuous and bend over at the tip. When dried for the herba- rium they often coil into circles or even double circles. The stem is six-angled, but there are only three leaves in the sheath. In all other species of Equisetum the number of leaves in the sheath and the number of angles in the stem are equal, and the apparent anomaly presented by this species is explained by the fact that in addi- tion to the true ridges there is an equal number of false ridges over the vallecular canals. The^"^^^^" three leaves are not joined together, and do not prop- erly form a sheath, in this showing very clearly that the sheaths of the other species are formed of confluent leaves. The teeth are small, slender, black, with pale margins, and are not deciduous. The leaves have one deep central groove and two lighter lateral ones, making them four-keeled. In age, both leaves and sheaths be- come dark brown or black. Unlike all other equisetums, the stems of this species have no central hollow. The vallecular canals are comparatively large, and the carinal, though small, are present. The fruiting-spikes are scarcely larger than pepper- corns and consist of about half a dozen small sporophylls on an axis tipped with a tiny black point. Many of the 40 THE SCOURING-RUSHHS. embryo fruit-spikes seem never to become fully developed. The first spores are ripe at about the time the anemone and spring beauty are blooming. The dwarf scouring - rush is found from Greenland and Alaska south to Pennsylvania, Illinois, Nebraska, Montana, and British Co- lumbia. It is also found in northern Europe and Asia. The stations on the southern limits of its range in America are widely separated, and the plant does not begin to become common until the northern boundary of the United States is reached. A writer in the Fern Bulletin reports it as covering several acres in western Connecticut, and says of its habitat : CATKIN. " It seems to favour moist, thickly wooded hillsides for the place of its ahode, although Mr. Grout found it in a cold boggy meadow. The place where I first saw this plant is a steep hillside thickly grown up to hemlock and white pine. Underneath, the little Taxus, or ground hemlock, grows in abun- dance, and the twisted-stalk, showy orchis, red trillium, and round- leaved violet are its companions." It is also found on wooded banks, decayed logs, and among fine grasses, usually in forest regions. Since it so nearly resembles the grasses and sedges among which it grows, the best time to search for it is early in the year, before the other early vegetation has started up. THE DECIDUOUS EQUISETUMS, OR HORSETAILS. THE HORSETAILS. HE separation of the Equisetaceae into two divisions, called respectively the Scourin^^-Rushes and the Horsetails, is at best but an arbitrary classification. The manner of growth, the structure of the stem, and the method of fruit- ing are the same in all, and they are therefore properly placed in a single genus. There are however, certain very noticeable characters by which even the novice may separate them into the groups mentioned, and in the popular mind they are usually so separated. As treated in this book, the horsetails will be considered as those species of Eqiiisetiim in which the stems die at the approach of winter and the fruiting- cones are without a terminal point. Their sterile stems also usually produce regular whorls of branches, add the fertile often do so. These form the section Eticquisetuni, or Eguisetum proper, of the systematist. The Field Horsetail. The field horsetail {Eqtiisetuin arvense) is without doubt the most abundant species of Eqiiiscttini in the world. Not only is it widely distributed, but wherever it grows it usually occurs in the greatest abundance- Normally a moisture-loving plant, it can adapt itself to 44 THE HORSETAILS. a wide variety of situations, and is often found in dry and sterile places in which few other plants can exist, such as dry roadsides and railway embankments. In the latter situation it thrives exceedingly well, and, though rooted in cinders, covers vast stretches of the surface with a pleasing mat of its yellowish-green sterile stems. All who have ever travelled a dozen miles on a railway in summer have doubtless seen this plant. The appearance of the fertile stems of this species is among the first signs of returning spring. They come almost before the grass has begun to green, often start- ing up in such numbers as to give a strong tinge of their own warm flesh-colour to the sunny slopes on -which they grow. There is something very mushroom-like in the rapidity with which these fleshy stems mature when once they have started to develop, and the likeness is increased by the fact that, like the mushroom, they have no green in their composition. The first stems are usually fully developed and show- ing their spores long before one has discovered that they have started. If one begins the season early enough, however, he may find just beneath the surface of the earth numerous buds in which the fruiting-cones are all complete and waiting for the first warm day to call them forth. Indeed, as early as midsummer of the preceding year these buds inay be found. Just before growth commences they often measure an inch or more in length and half an inch in diameter. At this time the sheaths are also fully developed, and overlap one another like shingles on a roof, thus completely enclosing the catkin. Growth consists in the development of the internodes, and often proceeds at the rate of nearly two inches a day. At maturity they are from a few inches ,:^- ^1 FIELD HORSETAIL. Eqidsctum arvensc. Sterile frond. FIELD HORSETAIL. Equisctiun arvense. Fertile frond. THE HORSETAILS. 45 to a foot or more high, but less than a quarter of an. inch in diameter The earliest stems are to be found in dry sandy places ; those growing in wet or clay soils develop much later. The full-grown fertile stems are most attractive objects, the yellowish sheaths with long, pointed, dark-brown teeth contrasting very prettily with the deep flesh-colour of the internodes. There are usually from six to ten of these sheaths on a stem, each nearly an inch in length and half an inch wide, at the top, flaring upward like a funnel. The upper sheaths are usually largest. In the bud, the bases of these sheaths are deep yellow in colour. The mature cones are yellowish-brown and frequently two inches in length. They are a third of an inch in diameter and much like those of the scouring-rush in appearance, except that they are softer and more catkin- like and lack the hard terminal point. The sporophylls, owing to the way they are placed in the cone, are usually six-sided, but there are often more than six sporangia, and the outer ends of these are plainly indicated by elevations on the outer surface of the sporophylls. The spores are produced in great abundance, and at the proper time the slightest jar will suffice to shake them out in grey-green clouds. By striking a ripe cone upon the back of the hand one may shake out a little heap of spores that under a simple lens may be seen suddenly to boil up, at the same time becoming lighter in colour. This is due to the uncoiling of the elaters as the mois- ture in them evaporates and the spores prepare to drift away on the wind. Soon after the spores have been shed, the fertile stems wither and disappear. At the same time the sterile fronds begin to be noticed, springing from the small 46 THE HORSETAILS. buds at the top of the rootstock near the point where tlie fertile stem arises. Tlie sterile stems are much taller than the fertile, in favourable circumstances reach- ing a height of three feet. Ordinarily they are from ten to fifteen inches high. The sheaths are shorter and nar- rower than those of the fertile stems, but, like them, are dilated upward. They are never so noticeable, being usually pale green in colour and tipped with slender dark-brown teeth. Toward the base of the stem the entire sheath may be dark brown. In the section to which the field horsetail belongs, the structure and number of grooves in the stem and the arrangement of the sheaths play a less important part- in the identification of the species than they do in the HippocJicete. They are, however, not without value for this purpose. In the present species it may be noted that there are eight or more leaves in the sheath of the fertile stem, and about fifteen in that of the sterile one. Since there is usually one leaf for each groove Section of stem. ^^ ^j^^ ^^^^^^^ ^j^^ number of the latter is easily ascertained. The tips of the leaves of this species are not deciduous, and the central hollow of the stem occupies about one third of its diameter. In what may be considered the normal plant, the stem is erect and bears about twenty whorls of slender branches, a whorl at each joint of the stem. Each whorl consists of a dozen or more simple, three-angled, ascend- ing branches six inches or more long, making a bushy frond in which it is not difficult to fancy a likeness to the tail of a horse. Doubtless it was the appearance of this species that earned the common name for the / J^^^^^^!y^W\>>*" :^ M ^M'. i i 1 i ^-' ■ M' P r; • ^ * ^ PLATE II. WOOD HORSETAIL. Equisetian silvaticum. COPYRIGHT, 1905, BY FFECERICK A STOKES COWPANV THE HORSETAILS. 47 group. The branches, as in the evergreen species, are produced from buds in the axils of the leaves in the sheath, and these, as they develop, burst through the base of the sheath instead of growing up out of it. The branches are, of course, jointed like the stems, with sheaths at the joints, and at their junction with the main stem each is surrounded with a dark-coloured sheath of its own which gives an additional girdle of colour to the joints of the main stem. In the ordinary plant a few of the lower nodes do not produce branches, while toward the tip the whorls of branches are successively shorter, forming a blunt-ended frond above which the stem con- tinues for a short distance as a slender prolongation. As might be expected of a plant growing under such diverse conditions of light, warmth, and moisture, there is great variation in the form of the sterile frond. Mr. A. A. Eaton has recorded no less than nine named forms in the Fern Btilletin. None of these seem fixed, and it is likely that all can be changed to the normal form by a change in the soil or surroundings. The erect form which we have taken as typical is mainly found in moist, rich, light soil in half shade. The next most noticeable form is named deciunbcns, and is characterized by the main stem spreading along the ground with only the tip erect. The short branches, however, are all erect, and this makes a peculiar one-sided form easy to recognize. It is common in exposed sterile soil and is usually to be found on railway embankments. In the form called diffusinn there appears to be no central stem, the branches arising from the summit of the rootstock and spreading flat on the earth. This is often found along roadsides, and in other places, in the company of deciim- bens. Pseudosylvatic2iin is a form in which the branches 4S THE HORSETAILS. branch again, as they do in the wood horsetail. In these forms the branches have no central hollow, and many of them are more than three-angled. The fertile fronds seem little inclined to change with the changes of the sterile one. Occasionally, however, small catkins appear on the tips of sterile stems in early summer, forming the variety cauipcstre. This is supposed to be due to a late spring frost cutting down the regular fertile fronds, and thus throwing a fruiting tendency into the sterile stems. The main rootstock of this species is perennial, branching, and creeps extensively a foot or more below the surface of the earth. At short intervals secondary rootstocks are given off, and these go directly to the surface, there giving rise to both fertile and sterile fronds. The rootstocks are in all respects like the stems except that they lack the central hollow. The internodes of the secondary rootstocks are often heavily clothed with short, tawny felt, and at the nodes, as in the main rootstock, the usual sheaths occur. From the base of the buds in the axils of these sheaths the roots are produced. When the buds develop they produce rootstocks, though if exposed to the air they may take on the form and function of stems. They often remain dormant for an indefinite period, but will grow at once if needed in the economy of the plant. The secondary rootstocks often bear at the nodes small rounded tubers as large as peas. These have the same structure as the rootstock, and are probably in the nature of arrested branches. More than a dozen of these tubers have been found on a twelve-inch section of secondary rootstock. It has been conjectured that these tubers act as storehouses of food upon which the plant can draw when the fronds are developing. Equiscttini iwi'ense dectinibens. V ^ Equisetiun arvense campesire. THE HORSETAILS. 49 In Great Britain this species is called " corn horsetail," J C^' J\ /i ^A m 1^ a great many names referring to its appear- ance, among which may be me4itioned " mare's- tail ," " cat's - tail ," " colt's-tail, " "fox -tail," "pine -top," " pine -grass, " " meadow -pine, " and " bottle- brush." " Jointed rush," in allusion to its structure, and " snake-grass," a reference to its habitat, are names it shares with other species of Eqiiisetiun. In old botanical works it is occasionally called " toad-pipes," " paddock- pipes," and " tad-pipes," all of which have been given in reference to its association with frogs and toads, " paddock " being an old word for " frog." The appellation " smoke-rush " is not clear. The field horsetail is found around the world in the northern hemisphere from lati- tude 38° to 83°. It has also been reported from the Canaries and from the Cape of Good Hope. In the United States it does not appear to reach the Gulf States, but it is found sparingly in California. It grows in woods, fields, meadows, swamps, and along streams, and is especially plentiful along railways. When fresh, cattle eat it \^h. ^ s ^ BUDS AND TUBERS OF FIELD HORSETAIL. 50 THE HORSETAILS. with impunit}', though, when cut witli tlie hay it has been found to be quite poisonous to horses. At the first hard frost in autumn, the stems in exposed places perish, but where protected by vegetation they may exist for some time longer. • This species is so widely distributed that the cultiva- tor of the fern allies seldom has to transplant it to his grounds ; but if it be desired to make it grow, nothing is easier. A bit of the root-stock, planted almost any- where, will soon produce one of its characteristic thickets. Once started, it is most tenacious of life, and if buried six feet or more in loose soil will ultimately come to the surface a^rain. 'The Ivory Horsetail. It is a curious coincidence that the commonest species in both groups of Eqtiisetiim should each be related to a second species that very much resembles it except in size. The great scouring-rush is so near like the com- mon one that it may be doubted whether the two are not forms of a single species ; but in the case of the field, horsetail and its gigantic counterpart no such uncertainty exists. The difference in size alone would almost be sufficient to distinguish them, for the sterile fronds of this giant species, the ivory horsetail (i^^/^?>r///w tchnateid), often reach a height of ten feet. Otherwise the two have many points of general resemblance, though none are sufficiently close to cause confusion in identify- ing them. Both are among the earliest of spring plants and are able to grow in a variety of situations, and the fertile fronds are sharply differentiated from the sterile, dying soon after the spores are shed. In view of these IVORY HORSETAIL. Eqit/sc/it/n tdmatcia. Fertile frond. THE HORSETAILS. 51 resemblances it is curious that the range of Eqiiisctitvi tciuiateia in America should be restricted to a narrow strip of country on the Pacific coast, while Eqiiisetum arvciise is spread over nearly the whole continent. The two may thus sometimes grow in the same locality, but no intergrading forms have been found. When they grow in company, Eqiiisetnui arvense appears to be a week or more earlier than Eqiiisetiim telmatcia. The time at which the fertile spikes appear depends somewhat on the locality. In California, according to Campbell, growth continues all winter, and the fertile fronds, developing gradually, spring up and spread their spores whenever they are ripe. In British Columbia the fertile spikes are produced during the first warm days of spring, which occur about the middle of April. In a short time they have reached a height of from ten inches to two feet, with a diameter of an inch or more. The stems are therefore the heavi- est of any species in the North Temperate Zone. They are reddish brown, contain thirty or more shallow grooves, and at the joints are encircled by the large, loose, light-brown sheaths, which, including the long, slender teeth, are nearly two inches in length. The cat- kins are two or three inches long, and three quarters of an inch thick, and consist of twenty or thirty whorls of sporophylls. The sterile fronds appear as the spores are being shed. These are ordinarily about three feet high, though in favourable situations they may attain to more than thrice that height, in such cases being half supported by the shrubbery among which they grow. Often they grow in such masses that it is difficult to pass through them. When the stems appear, the branches are short and closely appressed, but later they spread out some- 52 THE HORSETAILS. what, as In the field horsetail. There are sometimes more than twenty whorls of these branches, and from twenty to forty branches in a whorl. Near the tip the whorls are rather close together ; below, they are farther apart, and the lower third of the stem is naked. The average length of the branches is nearly six inches, but in some instances they are three times as long. The sterile stems are pure white, and the sheaths which closely invest them are pale green, with brown teeth. The common name of this species was given in allusion to the colour of these stems. Although the ivory horsetail grows in regions where the earth is not penetrated very deeply by the frost, in the North, at least, its stems are strictly annual. The rootstock is similar to that of Eqiiisctitm arvcnse, though larger, and at the nodes it also bears numerous tubers which are as large as marbles. These tubers often occur in necklace-like strings, and show very plainly that they are the swollen internodes of the rhizome. Like Equischiiii arvense, this species has numerous vari- eties, mostly of an ecological nature. Late in the year one may find fruiting-cones on the ordinary green stems. In the case of similar cones on the normally sterile fronds of Equisetum arvense^ it has been assumed that they have been caused by an injury to the fertile stems; but in Francis's '' British Ferns " it is stated that the cones on Equisetum telinateia are caused by drought, and that with specimens grown in pots these cones may be produced at will by withholding water at the proper time. Equisetum telmateia is well distributed in the Old World, being found from Ireland and Scotland to Siberia, Persia, and North Africa. In America it is IVORY HORSETAIL. iLqniscium telmateia. Section of Sterile frond. THE HORSETAILS. 53 found at low altitudes along the coast from southern California to British Columbia and Alaska, being abun- dant in the central part of its range and the dominant Eqiiisettim in British Columbia. According to Mr. A. J. Mill, the Indians are said to eat the fertile spikes. In addition to the usual common names, this plant is some- times called the " great water horsetail " and the *' mud horsetail," neither of which is very appropriate, at least in this country, where the plant grows in any soil, includ- ing railway embankments. The spores lose their vitality soon after they are shed, and this may perhaps account for its being less abundant than the field horsetail. The species seems to be rarely cultivated, though it ought to be a most desirable species for decorative planting. The Shade Horsetail. The American collector is likely to see little of the shade horsetail {Eqiiisetiim pratensc), for its centre of distribution is in the far North. Only a few stations for it in the United States are known. It is possible, how- ever, that when students become more familiar with this species it will be found to be more widely distributed. Its rather close resemblance to the field horsetail makes it easily overlooked by the novice. One of the important features in which this species differs from the field horsetail is found in the fertile shoots, which, after the spores have been shed, put forth whorls of branches from the nodes and thereafter behave in all respects like sterile stems. While this is true of the majority, other stems may be found that die as soon as the spores are shed, and the species is therefore usually described as -having three kinds of fronds. The 54 THE HORSETAILS. vegetative impulse seems to exist in different proportions in each one, some having so Httle that they do not sur- vive the spring fruiting. It is interesting to know that the size of the sheaths varies with the kind of stem, being largest in the evanescent fertile stems, of medium size in those fruiting stems that later bear branches, and smallest in the wholly sterile ones. Before the fertile stems have produced branches, they are much like the fertile stems of the field horsetail, except that they are usually shorter, slenderer, paler in colour, and with less flaring sheaths. They have been described as sea green with pale sheaths tipped with long, pointed, white- margined brown teeth. The catkins are about cylin- drical, an inch long, and a quarter as wide, and perish as soon as the spores are shed. The sterile stems are erect, fifteen inches to two feet in height and very slender. They are white or pale green in colour and contain from eight to twenty grooves. Below, the stems are smooth, but toward the apex the ridges are thickly set with tooth-like projections of silex which are frequently large enough to be seen with the unaided eye. The sheaths closely encircle the stem, and are pale green, tipped with white-margined brown teeth similar to those of the fertile stems. In the upper two thirds of the frond, each node gives rise .to a whorl of simple, jointed, three or more -angled branches. These are peculiar for having the joint nearest the stem short and bent sharply downward, while the rest of the branch is spreading or ascending. This character is one that the eye readily appreciates. The shade horsetail is found in the North Temperate and Arctic Zones of both hemispheres. Accordin'g to A. A. Eaton it ranges southward to New Jersey, Michigan, SHADE HORSETAIL. Eqiiisetum pratense. Sterile frond. SHADE HORSETAIL. Eqinsetuvi pratense. Fertile frond. THE HORSETAILS. 55 Minnesota, and alon^^ the Rocky Mountains to Colorado. It has also been reported from Iowa. In Minnesota it is said to be common, but elsewhere in the United States it is very rare. From Alaska to the Hudson Bay region it appears to be plentiful. It is more abun- dant in the Old World than with us, growing in culti- vated fields as well as in waste places, often so plentifully as to be considered a troublesome weed. Eaton observes that it must be common in the rye fields of Germany, since it is nearly always present in the straw in which German glass is packed for export. In appearance and habitat this species stands so nearly midw^ay between the field horsetail and the wood horsetail that the beginner might fancy it a hybrid between them, but students of the equisetums do not hold this view. The three forms of fronds, however, are of interest in showing in a single species the relationship between fertile and sterile shoots. The Wood HorsetaiL In his book, *'The Fern Garden," Shirley Hibbard characterizes the wood horsetail {Equisetmn silvatiaun) as ** the most elegant of all the plants upon the face of the earth." This may seem like extravagant praise to those who have never chanced upon its graceful green spires reared in the shadows of some moist woodland ; but to those who have, it will probably seem not much overdrawn. If not ready to admit its claim to be the most elegant of plants, they will scarcely deny that it is the handsomest of the equisetums and fully the equal of any other plant whose beauty depends entirely upon the outline and cutting of leaf and stem. 56 THE HORSETAILS. As ill all species of liquisctuin in which tlierc is a marked difference between fertile and sterile fronds, the fertile are first to push up, appearing shortly after those of the field horsetail and in their early stages scarcely to be distinguished from them. There is, however, from the beginning, a greenish tinge to the stems, presaging their subsequent vegetative functions, while the sheaths, rather longer for their width than in Eqiiisettini arvcnse, are tipped with long teeth of bright reddish brown. At first the sheaths are dilated upward, but they soon change to urn-shape on account of the swelling buds within. The fruiting cone is about an inch long and one third as wide. It is of the same general colour as the stem, and consists of the usual number of sporophylls borne above the topmost sheath on a pedicel two or three inches long. Before the spores are ripe, whorls of branches have begun to develop from the upper joints. Sometimes even the lowest whorl of sporophylls push out a few short branches. The fruiting parts usually wither as soon as the spores are shed,. while the rest of the stem continues to develop branches and soon is hard to dis. tinguish from the wholly sterile fronds, except that the sheaths are somewhat larger and the apex of the stem not so slender and tapering. The sterile fronds closely follow the fertile, and when fully developed may reach a height of three feet. The stem is slender and has twelve to eighteen grooves, the ridges between being rough with small particles of silex^ but never rough enough to be noticeable. The lower nodes do not produce branches, but above there is a whorl of branches at each node, the lowermost reaching a length of three to six inches, and the others gradually decreas- WOOD HORSETAIL. Eqmsettwi stlvatkinn. Sterile frond. r^ Ip-V-i WOOD HORSETAIL. Equiscium silvaticum. Fertile fronds. THE HORSETAILS. 57 ing in length to the apex of the frond. Occasionally, however, the branches at the apex are nearly as long as those below. The branches of each whorl spread out nearly horizontally, and each is again branched, the longest branchlets being nearest the stem. The effect produced is that of a series of circular green plat- forms diminishing in size upward, with the main stem as a central column. The fine and slender branchlets with drooping tips make the whole frond exceedingly delicate and graceful. This is the only species in the world in which the branches are again regularly branched. In some cases the secondary branches are also branched. The rootstock of the wood horsetail is slenderer than that of Equisetum arvense; otherwise it much resembles it. The sheaths of the secondary rootstocks, however, are better developed, though the buds from which the fertile spikes are produced are smaller. The secondary rootstocks also bear tubers, though not so abundantly as does Eqiiisetimi arvense or Eqiiisetiivi tebnateia. These tubers are usually much larger than those of Equisettiin arvense and are ovate instead of spherical. The wood horsetail is found in America from Virginia, Michigan, Iowa, and Nebraska to the Arctic WOOD HORSETAIL BUDS AND TUBERS. 58 THE HORSETAILS. Circle, but apparently does not occur in the United States west of the Rocky Mountains. It is also found in the northern parts of both Europe and Asia. It delights in rich moist soil, its favourite haunts being deep woodlands and the banks of shaded streams. It is rarely if ever found in fields, though it may persist in pastures and swamps for some time after the sheltering 'trees have been removed. Like the field horsetail, it is sometimes called " bottle-brush " in allusion to its fronds. It has the reputation of fruiting sparingly, and the fruit- ing-spikes are certainly not so abundant as those of other species when the plant grows in deep shade, though in exposed positions they may always be found in season. Plants that extend their bounds by root- stocks or bulbs usually produce few seeds or spores, and our plant seems to be no exception to the rule. Accord- ing to Withering, horses are fond of this species, and in the north of Europe it is said to be sometimes pre- served for winter fodder. The wood horsetail readily adapts itself to a life in the fern garden if given a fat soil and plenty of shade and moisture. It spreads nearly as rapidly as the field horsetail and presents a far more attractive appearance. It may also be grown in the greenhouse. In such situ- ations the rootstocks, being prevented from following their inclination to spread about, send up great num- bers of the graceful, emerald-green fronds that are the delight of all v/ho see them. The Water Horsetail. Of all our American equisetums the water horsetail (Eqiiisetum fluviatilc) is undoubtedly first to start into growth each spring, but, owing to the length of stem it WATE R H 0 RSETA I L . Eqiiisetum fluviatile. THE HORSETAILS. 59 produces before fruiting, it does not put forth its catkins until several other species have shed their spores. As its name implies, this species is usually found in several inches of water, and the rootstock, lying in the unfrozen mud, early feels the vernal impulse and starts the young stems upward soon after the ice has disappeared and while yet the meadow grasses are brown and sere. These developing stems are most striking objects, being ringed at close intervals with many circles of the black saw-like teeth of the sheaths. Sometimes as many as thirty circles of teeth may be found on the stem before it has pushed above the sur- face of the water. Growth, as in the other species, is principally a matter of lengthening internodes. About the last week in May, in the southern part of its range, the stems that are to produce the spores develop a fruiting-catkin an inch or more in length and a third as thick. Fertile fronds are ordinarily not abun- dant, but' it is said that a period of drouth will greatly increase their numbers. As soon as the spores are shed, this catkin withers, but from the sheaths of the stem that bears it slender branches have been developing, and these, lasting through the season, make the stems look so much like the regularly sterile ones that they cannot be distinguished from them at first glance. Since the production of spores is a heavy draft upon the vigour of the stem, the fertile fronds are usually overtopped by the others, which often reach a height of five feet or more. There is no uniformity in the manner of branching, as in most other species, but each stem is likely to vary the pattern somewhat. In general, however, the lowest ten or twelve joints are unbranched, then come several 6o THE HORSETAILS. whorls of simple branches which grow successively shorter upward, ceasing entirely six inches or a foot below the apex, which thus extends above the bushy portion as a slender whip-like prolongation. The lowest branches are often a foot or more in length and seem more in the nature of secondary stems. Usually the branches are much shorter and are disposed in regular horizontal whorls, though often, especially toward the apex of the stem, the symmetry of the whorls is destroyed by the failure of certain branches to develop. It is not uncom- mon, also, for both fertile and sterile stems to be entirely without branches, in which event they might be mis- taken for forms of the common scouring-rush. In branched forms the lowest branches may occasionally put forth a few branchlets, but usually the branches are simple. The stems of this species are smooth and contain from ten to thirty shallow grooves which are not very promi- nent in the living plant, but become more marked in the dried specimens. The sheaths are like the stem in colour, about as broad as long, and closely appressed to it. The teeth, separated from one another by rounded sinuses, are short, sharp, and nearly black in colour. According to A. A. Eaton, the number of grooves in the stem and the number of leaves in the sheath increase upward, so that the upper joints often contain a third more than those below. The stem is hollow for about four fifths of its diameter, none of our other species equalling it in this respect. The carinal canals are apparently always present, but the vallecular are often wanting in growing stems, though very prominent in older ones. The rootstock, which is about as thick as the stem, is also hollow. It is usually not very deep in PLATE III. WATER HORSETAIL. Eqinsetum fluviatile. CCPYRIOHT, 1905, BY FREDERICK A. STOKES COMPANY THE HORSETAILS. 6i SECTION OF STEM. the soil, perhaps because the overlying water makes it unnecessary by keeping out the frost. As the aerial stems rise through the mud, they send out roots from the basal joints, and it is pro- bable that if the entire stem was buried in the mud it would promptly take up the offices of a rootstock. Branches of the rootstock sometimes produce tubers which are de- scribed as '' about the size of a nutmeg, but shaped like a fig." Half a dozen have been found on a single branch. This species has very little silica in its outer coat and is one of the smoothest of the equisetums. It is readily eaten by cattle, and is said to be fed to cows in Sweden to increase the flow of milk. In Lapland, reindeer eat it even when dried, though they will not touch hay, and Linnaeus recommended that it be gathered and preserved with reindeer-moss for winter use. When abundant it is occasionally cut for hay in America. According to Haller, the Romans were accustomed to eat it. Musk- rats are very fond of the young stems and often work much havoc among them just as they are pushing up to the surface of the water. The water horsetail extends from Virginia, Kansas, and Washington to the far North, being not uncommon in the northern United States, though not always present in what appear to be favourable locations for it. While it prefers to grow in several inches of water and is com- monly found in the quiet reaches of shallow, slow- moving streams or on the margins of lakes and ponds, it 62 THE HORSETAILS. is often found in mud or moist sand and gravel at mid- summer, owing to the lessening of the water by drouth. Along certain rivers it forms a continuous border for miles, almost to the complete exclusion of other plants. It occurs also in northern Europe and Asia, belting the earth in a zone nearly a thousand miles wide. It is a polymorphic species and in some of its disguises is hard to identify. Its irregular branching and appressed sheaths are most characteristic features. It is so much like the marsh horsetail and the shore horsetail in appearance that the novice may have trouble in dis- tinguishing between them, but since this is the only one of the trio that is abundant it is safe to give it the benefit of any doubt that may arise. In many books the species is called Equisctiun liniosuiii, hw\. fluviatile is the older name. This difference in age, however, well illustrates the small differences that govern the work of botanists. The name fluviatile stands just before liuiosnui in ** Species Plantarum " and is, therefore, older by the mere length of time it takes for the printer to set a line of type ; and yet this is held sufficient to make the one for ever right and the other for ever wrong. Limostun is now used to characterize the nearly un- branched form. Among its common names are ** mud horsetail," " joint-grass," and " paddock-pipes." The last name is also given to Eqtiisettun arvcnse, but is more appropriately applied to this species, since it is found in the places beloved of '* paddocks," as frogs were commonly called. The Marsh Horsetail. At first glance it is possible to mistake the marsh horsetail [Eqiiisctuin palnstrc) for the water horsetail, MARSH HORSETAIL. Equisetum pahcsire. THE HORSETAILS. 63 but the fact that Equisctuui palustre is rare in the settled parts of America will save the collector from making many mistakes of this kind. Should he by chance collect the rarer species, he will discover, by comparing it with the other, that there are many small though important points of difference. Although the two are so much alike in habitat and structure, the stems of Equisetiim palustre are more deeply grooved and have a smaller central hollow, the sheaths are dilated upward, and the rootstock is solid, all of which are the exact opposites of the conditions that prevail in the water horsetail. The marsh horsetail is a smaller species than Equisetiim fluviatile, seldom reaching a height of two feet, and, though delighting in rich moist soil, is not so frequently found growing in the water. The stem is slender and often branched from the very base, producing regular whorls of short branches. Occasionally the basal branches may be much longer — perhaps two thirds the length of the main stem — and may be borne half erect like secondary stems. Fertile and sterile stems are much alike, except that in the one the main stem is terminated by a catkin, and in the other the apex ends in a slender unbranched tip. The catkins are unusually large for the size of the plant, being an inch or more long and about a third as wide. They are borne above the last whorl of branches on slender pedicels an inch or more long, and, as is the rule among horsetails, perish as soon as the spores have been dispersed. The species begins to fruit early in summer, and a succession of new stems may often prolong the season into autumn, though the greatest number of catkins will be found early in the year. Sometimes 64 THE HORSETAILS. the long basal branches, or a few of those near the tip, may bear small cones of fruit also. The sheaths in both fertile and sterile fronds are longer than broad, greenish in colour, with rather loose black teeth bordered with white margins. They invest the stem quite loosely, being dilated upward. The leaves are convex, grooved in the middle at the apex, and strongly keeled below. The stems have from five to twelve broad, deep grooves, the ridges separating them being narrower, sharply elevated, and rounded on the back. These grooves are fewer in number than in Equisetiim fltiviatile and in fresh specimens are much more prominent. When dried for the herbarium the difference is not so marked. The branches usually contain fewer angles than the stem, and their sheaths are also green and dilated. The central cavity of the stem occupies about one sixth of the diameter, a character which alone is sufficient to distinguish it from Eqitisetiivi fijiviatile. Carinal and vallecular canals are also present. Although so much like the water horsetail, it occasionally pro- duces forms that are very much like varieties of Equisefmn arvensc, and the likeness is heightened by the similarity of the internal structure of the stem. The marsh horsetail has been reported from all the New England States except Rhode Island, and from Illinois and Washington. In none of these States is it abundant or extensively distributed, and in many the record rests upon a single locality. It is more plentiful in British America, extending to Alaska and Hudson Bay. It grows among grasses in damp mead, ows, in moist woodlands, and in open swamps. Dr. C. B. Graves has found it in Connecticut in meadows sub- A Form of Equisetum Wtorale, THE HORSETAILS. 65 ject to frequent overflow. It occasionally forms thick- ets, as the other species do, but appears not to be as gregarious as some. In the colder parts of the Old World the plant is more plentiful, but becomes rare in southern Europe. Mr. A. A. Eaton notes in the Fern Bulletin that the Indians of Alaska make baskets of the rootstocks of some species of Equisetiim and concludes that this is the one used. "The Shore Horsetail. Many botanists are inclined to question the right of the shore horsetail (Equisetum littorale) to be called a distinct species. It presents a most perplexing series of forms and appears never to be twice alike. Now it is tall and abundantly branched, like Equisetum fluviatile ; again it may be prostrate or decumbent, like forms of Eqttisettnn arvense; and at other times may simulate Equisetum silvaticum or Equisetum palustre. The sheaths may be appressed or dilated, the central cavity may occupy one-half or two-thirds the diameter of the stem, and the stem itself may be either branched or simple. Still more remarkable, the spores are abortive and have no elaters, this being the only form of Equisetum having this latter characteristic. All these differences seem best explained by the theory that the forms given the name of Equisetum littorale are really hybrids between some other species, and while the author accepts this theory the form is here treated as a species in order not to confuse the novice, who will find it listed as a species in all other American works. Since the varieties of the shore horsetail most often resemble specimens of Equisetum fluviatile and Equise- 66 THE HORSETAILS. tnm arvense, it has been conjectured that these species are its parents. In both structure and habit it is about halfway between the two, and in some localities a series of intergrading forms could be selected, leading almost imperceptibly from one to the other. The strongest point made against the theory of the hybridizing of these two species is the fact that they do not fruit at the same time, but in reality this may be indirect evi- dence in its favour. Equisetum prothallia may live for some months if unfertilized, giving ample opportunity for crossing between species that do not fruit at the same time, while the infrequency of such an occurence would account for the rarity of the hybrid form. Since in all the Equiseta the sexes are on separate prothalli, it would be a much easier matter to prove or disprove this theory than it would be in the case of ferns where both sexes are on the same prothallium. As commonly described, Equisctwn littorale is three feet or less in height, usually erect, with slender stems containing from six to twenty grooves. In some speci- mens the stems are unbranched, in others branched only in the lower part, and in still others branches occur nearly to the top. In all, the upper nodes are prolonged into a whip-like tip which in fruiting specimens bears a small fruit-cone. Usually the stems with cones are not branched as much as the others. At the base of the stem the sheaths are dark in colour; above, they are green with short, narrow, dark-coloured teeth bordered with white. The sheaths may be appressed near the base of the stem, but beyond they usually widen out The catkins are borne on very slender pedicels and often do not become much larger than pepper-corns, though occasionally they may attain a length of half an inch. I \ /^ FORMS OF SHORE HORSETAIL. Kqiiisehim littorale. THE HORSETAILS. 67 The sporophylls do not draw apart at maturity, as in other species ; but this is of no consequence, since the spores will not germinate. The range of Equisetiun littorale is given as from New Jersey and Pennsylvania to Minnesota and northward. It is only occasionally found, but, where present at all, often occurs in great abundance notwithstanding the abortive spores, since it spreads rapidly by means of its rootstocks. Mr. Eaton notes that along the lower Mer- rimac River the plant is so abundant as to be cut for hay under the name of *' joint-grass." It prefers a drier location than does Equisetum fliwiatile, but both may be found together. According to Mr. Eaton the two species may readily be distinguished in the field by a section of the stem just below the joints. In stems of Equisetum litto- rale the cross-section presents a star-like opening, while that of Equisetum fluviatile is larger and circular. In Equisetum littorale the vallecular canals are always pres- ent, but they are absent in Equisetum fluviatile except in large or old stems. It is easily distinguished from Equi- setum fluviatile, however, by the fact that the sheaths are never so closely appressed to the stem, the grooves of the stem are fewer and deeper, and the central hollow is not so large. The shore horsetail is also found in the Old World, extending from England to France, Austria, Russia, and Scandinavia. THE LYCOPODIACE/E, OR CLUB- MOSSES. A moss Capsule THE LYCOPODIACE^. N the early days of plant study, long before the art of simpling had crys- tallized into the science of botany, people had very hazy ideas regarding the afifinities of plants, and the most diverse were often placed in the same group. The Lycopodiaceae were then thought to be mosses, but the fact that they bear their spores in club-shaped spikes did not escape notice, and they were accordingly called club-mosses to distinguish them from the true mosses, which bear their spores in capsules. Although everyone nowadays knows that the club-mosses are not very closely related to the mosses, the name is so convenient and descriptive that it is likely always to be used in speaking of them. In appearance the club-mosses are as different from thescouring- rushes as one could well imagine. The most noticeable character- istics of the scouring-rushes are the great development of stem and the small functionless leaves, while the club-mosses are remark- 72 THE LYCOPODIACE>e. able for their leaves, which, though small, are so numer- ous as often to make.it easier to infer the presence of a stem than actually to see it. In our species of Lycopodium there is nothing that can be called a rootstock, unless we are inclined to call the main axis a combination of rootstock and stem. In some species this axis is above ground and covered on all sides with the leaves ; in others it is beneath the surface or buried in the debris that covers the forest floor ; and in still others it creeps upon the surface of the earth with roots on the under surface and leaves on the upper. In all, it may send out roots whenever it comes in contact with the earth. It is noticeable, however, that there is only one growing end to this axis, and that the other is more rootlike in appearance. As the stem continues to add to its length at the growing end, it as slowly dies at the other, and thus the plants year by year move slowly forward, and, though rooted in the soil, no individual plant occupies quite the same position for two successive seasons. Indeed, although the life of the plant has continued uninterruptedly, it may be fairly questioned whether after some years it is the same individual. The leaves are not the same, the roots and stem are not the same, and it does not occupy the same place in the woodland. In some species the main axis reaches a length of ten or fifteen feet ; in others, less than half as many inches. It usually takes a course parallel to the surface of the earth and occasionally sends out secondary stems that are exactly like it in growth and function. From all these stems spring the short upright branches that form the noticeable part of the plant. The leaves are small and pointed, with a distinct midrib, which, however, does THE LYCOPODIACE/E. 72, not extend to the apex. They are arranged on the stem and branches in from four to sixteen rows, the number depending upon the species. These numerous short leaves, mostly standing out from the. stem, make many species look exceedingly like mosses, especially when not m fruit ; but even then they may be distinguished from mosses by the fact that their stems contain pro- nounced fibro-vascular bundles, while those of the mosses do not. The lycopodiums are among the latest of the fern allies to fruit. Some in the northern States do not shed their spores until late in October. The spore- cases are always borne at or near the tips of the branches. In one type they are in the axils of unchanged leaves ; in another the leaves are more or less reduced and yellow in colour, forming cone-like spikes which in some species are borne above the foliage leaves on slender stems. The sporangia or spore- cases, one in the axil of each leaf, are one-celled kidney- shaped structures with thin tough walls. The spores are very abundant, and bright yellow in colour. Undevel- oped spore-cases are often found above and below the zone of fruitful sporangia. The prothallium of Lycopodium is still imperfectly known. In the species in which it has been studied it usually consists of a cylindrical mass of pale cells either wholly or partly underground and bearing both male and female elements. These pale prothallia, lacking the green colouring-matter of ordinary plants, cannot secure Sporophyll and Spore-case, A Fruiting- spike. 74 THE LYCOPODIACE^. their food as other plants do, and so have set up a part- nership with a fungus which is always present and aids in the work. The prothallia of certain exotic species liv- ing on trees are slender, much-branched structures and are saprophytic, that is, they live, like the mushrooms, upon the decayed' vegetable matter in their vicinity. Be- cause of this asso- ciated fungus it is a difficult matter t o grow the prothallia of the Lycopodiacese, and that of many species has never been seen. Further observations of these structures are very much to be desired„ It is suggested that the prothallia might be raised by infest- ing them with spores of the fungus. This might possibly be done by watering the spores with water in which the roots of the lycopodiums have been soaking. This theory is being put to a practical test, but the experiments have not progressed far enough to have the results included here. In all flowering plants, and in nearly all others, the SPOROPHYLLS OF LYCOPODIUM. I. L. complanatum. 2. L. alpinum. 3. L. sabinse folium, 4. L. clavatum. 5. L. Sitchense. 6. L cernuum. 7. L. annotinum. 8. L. Carolinianum, 9. L. inundatum. 10. L. obscurum, 11. L. alopec uroides. THE LYCOPODIACE/E. 75 roots, penetratip.g the earth, give off rootlets here and there as conditions require ; but in the Lycopodiums the roots branch dichotomously, dividing into two equal branches which may again divide in the same way. The roots do not seem to have any special point on the stem from which to grow, but develop on any part that touches the soil. There are about a hundred species of Lycopodiiim known at present. The majority are found in the warmer regions of the world, where they often grow on the branches of trees^ many feet from the ground. Other species clamber over the vegetation like the climb- ing ferns. Our species are all low and inconspicuous plants, keeping close to the earth on moors or in swamps, woodlands, and thickets. Some are very hardy, electing to grow in barren rocky wastes on the very edge of the world, as it were. They are often found in the greatest abundance on rough mountain-tops or bordering the roadsides in elevated districts. Some extend northward to the Arctic Circle and beyond. All our species are perennial, and not only are the leaves of most of them evergreen, but many appear to last for several years. The lycopodiums of the present are mere rem- nants of the race. During the Coal Period they were most luxuriant, and the various forms attained the height of trees. Of these the lepidodendrons and sigil- larias are well known, while the roots of other species were once erroneously referred to a genus called Stig- maria. The spore-cases of some of these old lycopo- diums have been so carefully preserved by nature that their structure may still be discerned. It is a curious fact that the ancient species were heterosporous, with two kinds of spores like Isoeies and Selaginclia, while living lycopodiums have spores all alike. 76 THE LYCOPODIACE^. The club-mosses are probably the best known of the fern allies. During the winter holidays, great quanti- ties of certain species are used in festoons, wreaths, and other decorations. The steadily increasing demand for such greenery is pushing several of the more decorative species to the verge of extinction, since they reproduce very slowly. The spores of some species form an import- ant article of commerce, and, under the name of lyco- podium powder, may be found in any drug store. They contain more than half their bulk in oil, and, if sprinkled in the flame of a candle, may be seen to ignite with a flash. They have been extensively used in fireworks under the names of vegetable brimstone and vegetable sulphur. If sprinkled thickly over the surface of a glass of water, one may plunge his finger to the bottom with- out its being wetted. Their chief value to the druggist is for dusting pill-boxes, to keep the pills from sticking together. Various species of Lycopodium have been used in dyeing, and some are emetic, but their medicinal effects are too violent to entitle them to a place among drugs of the present. Most species are also more or less astringent. The word Lycopodium comes from two Latin words meaning "wolf" and *' foot," but the reason for its application to these plants is not apparent unless it is in allusion to the habit they have of growing in wild and inhospitable regions where only the foot of the wolf is likely to tread. Key To The Lycopodiums. I. — Sporangia in the axils of ordinary leaves Leaves flat. Lowland species . . L. hccididiim Leaves curved upward. Mountain species L. sclago n. — Sporangia in cone-like spikes Sterile stems prostrate ; fertile, erect, unbranched Prostrate stems usually branched Z. alopecuroides Prostrate stems short, seldom branched Rooting throughout . L. Caroliniajiuin Rooting at base and tip only . Z. imindatum Fertile and sterile stems erect; rootstock creeping Cones closely sessile Averaging an inch or more long Z. obsctirmn Averaging less than an inch long Z. ajinolimnn Averaging less than half an inch long Z, ceniiciini Cones apparently stalked Branches about four-sided . Z. alpinmn Branches round Leaves bristle-tipped, \ inch long Z. davatiwi Leaves not bristle-tipped, shorter Z. Sitche7tse Branches flattened Cones two to four, peduncle long, stout Z. co7nplanatiini Cones one to three, peduncle short, slender Z. sabmccfolium THE TRAILING LYCOPODIUMS. THE TRAILING LYCOPODIUMS. IKENESSES among the club-mosses are so noticeable that any member of the group is easily recognized. Certain differences in the manner of growth, however, make them separable into two groups, in one of which the species are small and the plant body mostly erect or decumbent, while in the other the plants are larger and the principal stems long and trailing. These latter are the species that figure in our holiday decorations, and as most of them are well known in consequence, and are also common and widely distrib- uted, they will be discussed in this first of two sections devoted to the club mosses. The Commofi Club-Moss. One seldom goes far in the scrubby uplands without coming upon the long, dark-green stems and yellow spikes of the common club-moss {Lycopodiuin clavatuni), which delights to grow close to the earth and half hidden by the surrounding vegetation. In sunny thickets, however, it is often so abundant as completely to carpet the ground for many yards with its interlacing stems, and it is everywhere one of the most abundant species of its genus. 82 THE TRAILING LYCOPODIUMS. The main stem often reaches a length of ten feet or more, though it is usually much shorter. At the grow- ing end it is usually above ground and covered on all sides with the green leaves; at the opposite end it is more or less hidden under an accumulation of dead vege- tation, and the stems and leaves are yellowish. Here and there, throughout its length, single, stout, cord-like roots are given ofT, u^hich extend downward until they enter the soil, where they usually branch once or twice. Frequently this main stem is branched, and these branches, like the axis from which, they spring, main- tain a course parallel with the earth. At short intervals along these stems other branches are produced which extend upward. During the first year they are from one to three inches long and are simple, but at the next growing-season they add more to their length and at the same time put out short side branches. This con- tinues for several years until the older branches are several times branched, with occasional roots springing from the portions nearest the earth. There is thus a regular gradation from the short simple branches at the growing tip of the stem, less than a year old, to the larger much-divided branches at the other extreme which have outlasted several seasons. The leaves are evergreen and persist for several years. They are arranged on stem and branches in about eight longitudinal rows, and so close in the rows as to over- lap. They are about a quarter of an inch long, very narrow, and each ends in a long soft bristle. On account of the angle at which they are set on the stem, the branches appear about half an inch in diameter. The edges of the branch leaves are entire or occasionally toothed ; those on the main stems have larger teeth. COMMON CLUB-MOSS. Lycopodiiim clavatum. THE TRAILING LYCOPODIUMS. 83 The old leaves are dark green in colour, but the new growth is light silvery green and very noticeable in early summer. Owing to a slight constriction at the place where each season's growth begins, it is very easy to ascertain the age of each branch by counting the constrictions. About midsummer the plant begins to put up its fruiting parts. These are simply transformed branches, and often indicate the relationship by producing one or more sterile branchlets instead of the usual cones of spores. The fruiting-spikes are always borne at the tips of branches of the previous year, in the position that sterile branches hold on other branch-tips of equal age. The fruiting peduncles are most abundant on the older parts of the plant, but any branch that is more than a year old may produce them. Sometimes in a distance of a single foot along the main stem there will be a dozen or more peduncles, each with three or four strobiles, or fruit-cones, at the summit. The stalks or peduncles are from three to eight inches in length, the average being about five inches. They are nearly of the same diameter as the stem, but, owing to the absence of leaves, appear much slenderer. They are clothed with appressed bracts like the leaves in out- line, but which are smaller and at maturity are yellowish in colour. The strobiles are from one to three inches long, thicker than the peduncle, and consist of a great number of close-set, little ovate or heart-shaped sporo- phylls with thin ragged edges and soft bristle tips, each covering a yellow kidney-shaped spore-case. The spores are bright yellow and are produced in prodigious quanti- ties. They, are ripe in early autumn. The lycopodium powder of the shops is composed of the spores of this 84 THE TRAILING LYCOPODIUMS. species, the supply coming mostly from Sweden, Russia, and Switzerland. It is obtained by gather- ing the spikes just before the spores are shed, and collecting the powder in papers. Occasionally a form of this species is found in which there is but one strobile on each peduncle. This has been named variety inonostacJiyon. It is usually found in dryish situations, and its form is appar- ently due to a lack of some of the normal plant's requirements. While the variety usually produces but one strobile to each spike, it is possible to find plants with single strobiles near the growing end, and, farther back, peduncles bearing two or more strobiles, This plant is one of those in greatest demand for holiday decorations, and the demand for it has made it rare in many localities. Fortunately, owing to its manner of rooting, the whole plant is seldom pulled up, and the fragments left behind may ultimately produce thrifty plants, so that it is likely to be a long time before it entirely disappears from a locality. This is the club-moss par excellence, as its specific name indicates. In America, however, it is better known as ** ground-pine," *' running-pine," or ''trailing Christmas green." Among Old World names for it may be mentioned ^^T*iLt:r" " fox-tail," " stag-horn," '■ buck-horn," THE TRAILING LYCOPODIUMS. 85 "buck grass," and ''wolf's claw," all of which doubtless have reference to the manner in which the branches grow. In Cornwall it is known as "good-luck." Other names applied to it in various localities are " coral evergreen," " running-moss," " snake-moss," " toad-tail," and " lamb's- tail." The plant has strong astringent properties, and was once used in medicine. In Sweden the stems are woven into doormats and the plant is known as " matte- grass." It seems to have been the custom for holiday parties in the Old World to trim their hats with the stems of the club-moss. The Swedes especially are men- tioned in this connection, and Wordsworth alluded to the custom in the following lines : " Or with that plant which in our dale We call stag's-horn or fox's-tail Their rusty hats they, trim. And thus as happy as the day These shepherds wear the time away." This species is one of the most widely distributed of its genus. It is common in the Arctic and Sub-Arctic regions of both Hemispheres, and has also been reported from tropical America, Brazil, Cape of Good Hope, Mad- agascar, India, Java, New Guinea, the Hawaiian Islands, and eastern Asia. As might be expected, there is con- siderable difference in the appearance of specimens from the extremes of its range, and it is a question whether they are all varieties of one species or a series of closely related species. Many, of course, have been described as separate species. The author has collected specimens in the American tropics, which are almost exactly like our common form except that they are more luxuriant and have longer peduncles. In North America it ranges from the Arctic Circle southward to Oregon, Iowa, 86 THE TRAILING LYCOPODIUMS. Michigan, Pennsylvania, and New Jersey. It also occurs in the mountains of North Carolina. In the southern part of its range it may be expected only in the elevated regions. Further extensions of its range are likely to be made when these have been thoroughly explored. Its habitat may be described as upland woods, but it is found in many exposed places and often grows in old fields and pastures. Its abundance makes it one of the first species likely to be found by the novice. The Stiff Club- Moss. If, while collecting in the haunts of the common club- moss, one should come upon a plant closely resembling that species except that the fruiting-cones are sessile on the ends of the branches, he may feel sure he has dis- covered the St iff club-moss (Zj't'^/^^^zV/ 7// annotimuii). This is seldom so abundant as its better-known relative, but it is by no means rare in the elevated parts of the northern United States and Canada. The species is like Lycopodwui clavatmn in so many habits and superficial features that, with the exception of the manner of fruiting, one description would almost serve for both. The main stem may be said to come nearer our idea of a rootstock, being yellowish for most of its length, less leafy, and somewhat more deeply buried in the debris of the forest floor. In length it ranges from three to six feet or more, and the upright branches are usually simple the first season. The second season they branch or continue to increase in length, finally reaching a height of twelve inches in robust specimens, and often three or four times forked. The branches appear to arise dichotomously, and are more nearly erect than in the common club-moss. STIFF CLU3-M0SS. Lycopodiuin annotinum. THE TRAILING LYCOPODIUMS. 87 The leaves are about a quarter of an inch long, some- what firmer than those of Lycopodiiun clavatiiiii^ and are arranged on stem and branches in from five to eight rows. They are narrowly lanceolate with toothed mar- gins, and end in an acute point without a bristle. At the ends of the branches the tips of the leaves point up- ward, but below this they are more spreading. As the new season's growth springs from the midst of the erect leaves, there are, in consequence, alternating zones on tlie branches in wdiich the leaves are spreading or appressed, each appressed zone marking the ending of one season's growth and the beginning of another. From tliis circumstance the plant is called the " interrupted club-moss" in the Old World. The zones are most notice- able in specimens growing in exposed places. Accord- ing to Moore's " British Ferns," old branches, after fruiting, bend over, take root, and start new rootstocks, but there appears to be need for further observation on this point before the statement is accepted. The chief distinguishing feature of this species is found in the strobiles or fruit-cones. They are half an. inch to an inch or more long, about one fourth as wide, and are borne singly on the tips of the branches with no sign of the peduncle so noticeable in Lycopodiiun clavatuin. They are, as usual, made up of a great many small, closely assembled sporophylls, yellow in colour when ripe, and broadly heart-shaped with an irregular margin and slender tip. Each subtends a kidney-shaped spore- case filled with pale yellow spores which are ripe in late August or September. In the far North, and on mountain tops in milder re- gions, there is a form of this species called wdiYiQiy puiigens. It is characterized by its thicker, shorter, sharper leaves 8S THE TRAILING LYCOPODIUMS. set closer on the branches and nearly appressed to them. The zones marking the beginning of each season's growth are also very clearly marked. It is in all ways a more compact plant than the type, the differences, without doubt, being due to the cold and exposure to which it is subjected. The stiff club-moss is found from Washington to Col- orado, Minnesota, Michigan, and New Jersey to Alaska and Greenland, appearing to be very common in suitable places in British America. It also occurs in the colder parts of the Old World and in the Himalayas. It loves the moist, shady woodlands, and is seldom plentiful in the dry and exposed places in which Lycopodmin clava- tuin thrives. "The Ground-Pine. Although several lycopodiums are more pine-like in appearance, the name of ground-pine is most often applied to the plant known to the botanist as Lycopodium complaitatum. It would require a lively imagination to detect in this species any resemblance to the pine, for the flat branches form little horizontal fans and semi- circles quite unlike pine needles or branches. By what- ever name called, however, it is a distinct and easily recog- nized species, while its abundance, varied habitat, and extended distribution make it well known to collectors. Like the common club-moss, the ground-pine has a long running main stem or rootstock which may reach a length of eight or ten feet. It creeps along close to the earth, or an inch or two below the surface, and at inter- vals sends down its single cord-like roots. The branches are erect, those of the season being from two to five Lycopodiuin annoiiniun pungens. THE TRAILING LYCOPODIUMS. 89 inches long and consisting of a short main branch termi- nating in a bud-like point with a pdir of opposite fan-like lateral branches just below it. These lateral branches fork four or five times near the base, or, occasionally, nearer the tips, the terminal branchlets being from half an inch to two inches long and spreading out horizon- tally in flat semi-circles. Occasionally there is a single lateral branch near the base of the main stem. The following year the bud-like point carries the main branch upward a few inches more, and there produces another pair of similar forking lateral branches. This process may be repeated for several years in succession, resulting in main stems a foot in height. The lower lateral branchlets also lengthen more or less in subsequent sea- sons by additions to the tips, the new growth being very noticeable at midsummer by reason of its lighter colour. These lateral branches may also send up short branches like the main one the second season, such branches aris- ing from the point where the branchlets are given off. The branchlets of our common plant are flattened in a plane parallel to the earth, and have a very distinct upper and lower side, or, in other words, they are dorsi- ventral. The upper surface is also darker green. In the matter of leaves this species differs greatly from most of our native club-mosses. First of all, owing to the dorsi-ventral branchlets, there are two kinds of leaves arranged in four rows. .yrFiS'orBranchLt. Extending lengthwise of the branchlets on the under side is a row of very short pointed leaves ; in a similar row on the upper or dorsal side is a series of 90 THE TRAILING LYCOPODIUMS. larger leaves with tips closely appressed ; while on each edge of the branchlets, and most noticeable from above, is another row of the large leaves with slender spreading tips. The largest of these leaves are often not an eighth of an inch long, but their bases, being broad and decur- rent, form a tiny lateral wing to the branchlets. The leaves on the main stem usually have narrower bases. The fruit-spikes are an inch or more long and are borne on slender yellowish peduncles three or four inches in length. These are produced from near the tips of the main branches, two or three peduncles from each branch, and from their position are apparently transformed lateral brandies. At the apex each peduncle forks, and each fork immediately forks again, thus giving rise to four cones of fruit. Occasionally there are one or two more fruit-cones, but four is the usual number. The peduncles are sparsely clothed with slender, nearly appressed scales, and the cones consist of large numbers of white-margined, heart-shaped scales with broad bases and slender tips, each covering a kidney-shaped spore- case in its axil. The spores are very numerous and are ripe about August or September. Like those of Lycopodmm clavatum, they are gathered in quantity and have a com- mercial value. In most club-mosses, after a branch has once borne fruit, it commonly does not fruit again, but in this species it is not unusual for new branchlets and new fruit-spikes to be produced for two or perhaps more successive seasons. This species was named complanatum by Linnaeus, and until recently our well-known plant has been called by that name. It would seem, however, that the branch- lets in the Linnaean specimens were less inclined to spread horizontally, and from this circumstance Mr. M. GROUND-PINE. Lycopodhim coinphmatmn^ THE TRAILING LYCOPODIUMS. L. Fenuild thinks our plant should have a different name. He has recently proposed to call it V2^x\^'iy flabel- lifonne. There seems to be good reason for thinking that the Linnaean plant is represented in our far North* or, rather, that our plant with spreading fan-shaped branches tends to bear these branches erect as one pro- ceeds northward. Growing with the common ground-pine, and seldom distinguished from it by the novice, may often be found specimens in which the branchlets are more erect and in which the under row of leaves scarcely differs in size from the upper and lateral rows. This has usually been regard ed as a fairly distinct variety or species named chavicEcy- parisstis. In contradistinction to the type, the main stem is quite like a rootstock, being pale, slender, and buried several inches in the earth. The foliage is often lighter in colour, and the branchlets also more inclined to lengthen at the tips the second season than in Lycopodiiun coniplanatuDi^ and while they are not spreading they are more or less flattened, as in the other. The fruiting parts are exactly like those of Lycopodiiun coniplanatiun but are said to ripen their spores two or three weeks earlier. This latter feature, however, seems to depend entirely upon the soil and surroundings of the plant. CJiamcEcy- parissiis is rarely if ever found growing alone, and the invariable proximity of specimens of Lycopodiiun coniplanatiun suggests that it is only a strong and well-marked form, due, perhaps, to the main stem being accidentally covered with earth. Intergrad- Lyco/>odiujn coiii- planattiin cluDiia'- cyparissus. Upper and under surface of Branchlet. 92 THE TRAILING LYCOPODIUMS. ing forms often occur. Since this form has always been known in American publications as Lycopodiiim com- planatiLin chanicecyparissus, it is called by this name here to avoid confusing the beginner. An older name for it has been recently unearthed, and if one is inclined to call it a separate species it should be named Lycopodiiim tristacJiyon. Tliose who consider it a variety or form sliould call it Lycopodiiim complanatum tristachyon. The difficulty experienced in raising lycopodiums from spores prevents the application of a f^^irly decisive test of the distinctness of these two forms. If it could be shown that from th^ spores of one form tlie other may also be produced, we would be warranted in thinking them forms of the one species. Lycopodiiim complanatum^ like the common club-moss, is occasionally found with fruiting-peduncles bearing a single strobile each. This form has been described as the variety Wibbei. It may be expected in localities where the type abounds, usually in the more sterile and uncongenial surroundings. This species is used in great quantities for decorations. It is said that the trade in Christmas greens began in New Jersey with this plant more than half a century ago. The State is still prominent in the business, though the demand long ago became so great that other sources of supply had to be found. At present the supply is drawn from the States about the headwaters of the Mississippi, more than two hundred tons being gathered each year from a single State. The price realized is about $75 a ton. In consequence of the annual raids made upon it, the plant is rapidly becoming rare, but small patches of it are still to be found in most localities, while in some remote regions it still carpets Lycopodiu]n complanatiim chamcccyparissus. THE TRAILING LYCOPODIUMS. 93 the ground to the exclusion of all else. Because of its use in decorations it is probably oftener seen than any other species. Among its common names are " trailing Christmas green," ** running-pine," ** ground-cedar," and ** festoon ground-pine." It shares the name of " creeping jenny," with the common club-moss, and is also known as '* hog- bed " and "liberty." Occasionally it is called ''princess pine," but this name belongs by right to one of the heathworts. The ground-pine is found in the North Temperate Zone of both Hemispheres and has been reported from Madeira, the Azores, Madagascar, Java, Sumatra, New Guinea, and other tropical islands. It is also found in the Andes. Some of the forms from tropical coun- tries are very different in appearance from ours and will doubtless some day be considered distinct species. In North America the plant ranges from the mountains of Georgia to Labrador, Iowa, Washington, and Alaska. In the United States the greater part if not all of the plants belong to the variety flab e Hi for me. As Canada is reached it fades gradually into the type. The range of the variety chamcEcyparissus is usually given as from Maine to Georgia and Minnesota, but it will probably be found to be coextensive with that of the type when it is better known. The plant loves moist, shady woodlands, but may also be found in thickets and pastures, and along roadsides, often in dry situations, especially in upland regions. The Ground-Fir. In the northern parts of our continent there grows a species of Ly cop odium that much resembles Lycopodiiim 94 THE TRAILING LYCOPODIUMS. coinplanatiini in general appearance, and which is as- sumed by some to be connected with it by the form called Lycopodiuin coniplanatuin chaina^cyparissiis. While it is possible that cJiaincecyparisstis may represent part of tlie line along which its evolution proceeded, it is cer- tainly a distinct species now. Botanists know it by the name of Lycopodiuin alpimim, and the general public speak of it as the ground-fir. The ground-fir resembles its congeners in having a long and creeping main stem, close to the earth, from which at short intervals it sends up short, erect branches that fork repeatedly, forming dense, flat-topped clusters. As in tlie other species, the branchlets add to their length the second and perhaps subsequent seasons, the new growth usually again forking. The leaves are about an eighth of an inch long, broadly lanceolate, pointed, and decurrent. They are dark green in colour, thick, rounded on the outer surface, and closely appressed to the branches, along which they are arranged in four rows. Owing to this arrangement of the leaves, the branchlets appear four-sided. The fruiting parts are raised above the flat-topped clusters of branchlets on very short peduncles which are manifestly continuations of the main branches, and which resemble the branchlets ex- cept that they are less leafy and the leaves are somewhat narrower. The peduncles usually fork once near the spikes, and the leaves gradually merge into the short-pointed, toothed, and broadly heart-shaped sporophylls of the spike. Branch of The spikes are from half an inch to an inch long, Lycopodiuin ^ aij>inu7n. cylindrical, and become yellow-brown with re- flexed sporophylls when aged. The peduncle appears GROUND FIR. Lycopodium alpimim. THE TRAILING LYCOPODIUMS. 95 to remain green. Among the majority of botanists it is customary to call this peduncle a branchlet, and this species is therefore described as having sessile spikes, but these spikes are not sessile in the sense that those of Lycopodiuvt amiotimiin are. . In the other species it is evident that the peduncles are transformed branches, and since the branchlets that bear the spikes in this species differ in a few slight particulars from those that bear only foliage leaves, it is as reasonable to call them peduncles as branches. In the Old World this species is sometimes known as " heath cypress." It was once used in dyeing woollen goods a pale yellow, the process being simply to boil the goods in water with the plant and some leaves of the bog whortleberry. Lycopodiiini alpimnn as now understood ranges from British Columbia to the Arctic Circle, being common in Alaska and Greenland. It is also found in the North Temperate Zone of the Old World, extending southward into the more elevated portions of Germany, Switzer- land, and Spain. It delights in the open spots in moun- tainous country, but in the colder parts of its range may be found on grassy moors near sea-level. The Savin- Leaved Club-Moss. The several forms or species of Lycopodiiun growing in the northern part of North America have given botanists no end of trouble in working out their proper relation- ships. They are all more or less like Lycopodiuni coin- planattim, and it was once the custom of students to refer them all to this species, just as the novice would be inclined to do at present. It was less than ten years 96 THE TRAILING LYCOPODIUMS. ago that the tendency to call Lycopodium coinplanaium chaimecyparissus a distinct species began, and a still shorter interval has elapsed since Mr. Fernald pointed out the differences between the real Lycopodium com- planatum and our common form. Lycopodium alpinum^ while much like these in general appearance, has always had some standing in botanical circles as a distinct species, though even in several editions of " Our Native Ferns" Professor Underwood has suggested the possi- bility of its being another form of Lycopodium com- planatuin. In the same way the savin-leaved club-moss {^Lycopodium sabince folium) has often been thought to be a form of Lycopodium alpinum. All these, however, are now believed by many to be separate species. There is no doubt that they are all closely allied to Lycopodium complanaUim, — they might properly be called the Lycopodium complanatum group ; but with a series of each before him even the novice would have no trouble in distinguishing between them. Whether the differ- ences they present are of specific value depends upon the view-point of the student. The forms were all named long ago, and are not therefore new segregates, but the tendency in the past has been to ignore them as species. The savin-leaved club-moss may be distinguished from its nearest of kin, Lycopodium alpinum^ by the fact that, while the leaves are in four rows as in that species, the branchlets do not usually appear to be so much flat- tened. This is probably due to the fact that the leaves of Lycopodium sabincBfolium are slightly longer and slenderer, and not so closely appressed to the stem. The whole plant is slenderer than Lycopodiuui alpinum, but it has the same trailing habit and manner of growth. SAVIN. LEAVED CLUB-MOSS. Lycopodiim sabincBfolium, THE TRAILING LYCOPODIUMS. 97 The most striking difference between these two species, however, is found in the fruiting portions. In Lycopodiuui alpinum they are raised somewhat above the foliage on thick branch-like stalks with appressed leaves, but in the present form they are borne on slender peduncles two or three inches long, which bear only scattered, slender, spreading leaves. In Lycopodium alpimun there may be some doubts as to whether there is any peduncle at all to the catkins ; but no doubt whatever exists regard- ing their occurrence in Lycopodium sabince* foliinn. The spikes are an inch or less in length, slender, and the whorls of leaves on the peduncles below the spike have the odd trick of producing sporangia. When the spores are ripe the sporophylls are usually re- flexed as in Lycopodium alpinum. The cat- kins are usually borne singly, but there are Branch of ., , - T '1 Lycopodiiim occasionally two or three together. Like sabtnce/oiiu7n. Lycopodium complanatum, the old branches produce new branchlets and new catkins for at least two years in suc- cession. The savin-leaved club-moss is named for its resem- blance to the juniper {Juniperus sabind). Its range is given as from Prince Edward Island, northern New England, and Ontario, northward. In geographical position it lies between Lycopodium coinplanatui?i and Lycopodium alpinum, and the three may not improbably represent three strongly marked races of the same species. It is of interest to note that while Lycopodium alpinum ranges around the globe in high latitudes, Lycopodium sabincefolium is not found in the Old World, although there is a variety much like it in Japan called Lycopodium Nikoense, 98 THE TRAILING LYCOPODIUMS. Lycopodium Sitchense. Half a century ago Ruprecht described a species of club-moss from the northern part of North America, to which he gave the name of Lycopodium Sitchense. Until recently little attention has been paid to this plant, because it has always been considered a variety of Lycopodium sabince folium. It differs from that species as at present considered in having shorter main stems, and shorter, slenderer branches and branchlets which form flat-topped tufts of green after the manner of Lycopodium alpinum. The branches are not dorsi-ventrally flattened, and according to Underwood the leaves are arranged on the stem in five rows. Lycopodium Sitchense is the smallest and most delicate of all our trailing species. The main stems are often less than a foot long and creep on the surface or just beneath it. Its leaves are very slender, about an eighth of an inch long ,and thickly set on the branches, from which they stand out in a way that faintly suggests the leaves of Lycopodium obscurum. As in all the other trail- ing lycopodiums, the main branches con- tinue to add new branchlets for several years. The catkins are from half an inch to an inch long and an eighth of an inch in diameter, and are borne on slender pedun- cles or are occasionally sessile on the ends of the branches. Most descriptions of this species record the peduncle as less than half an inch long; but specimens collected in the Province of Quebec by M. L. Fernald have peduncles nearly two inches long, and this feature seems to be not Lycopodium Sitchense, THE TRAILING LYCOPODIUMS. 99 uncommon. When peduncles occur, they are sparingly clothed with slender bracts that are nearly like the leaves in shape and size. In many cases but a single cone is borne on the peduncle, but in the majority the peduncle forks near the summit, each fork ending in a cone. At maturity the sporophylls appear to be reflexed. Lycopodijiin SitcJicnsc is found in the United States in Maine, New York, Idaho, and Washington, and extends northward to Labrador and Alaska. It has not been half a dozen years since its claims to specific distinction have been seriously considered, and therefore compara- tively little is known about it. It will doubtless be found to be more abundant in the northern tier of States than it has thus far been found to be. Owing to its northern habitat it is likely to occur upon mountain tops only in the southern parts of its range. T'he "Tree Club-Moss. It is not the tree-like proportions of the tree club-moss {Lycopodium obscuriun) that have suggested its common name, but rather its habit of growth and general appear- ance. The upright stems are so much like miniature pine trees that any one finding the plant for the first time is likely to identify it by associating its appearance with the idea suggested by the common name. The tree-like aspect of this species is heightened by the fact that the main stem is deeply underground, and the branches arising at some distance from one another seem to be different plants instead of several branches of one individual. Of all our lycopodiums, this species has a main stem that is most like a rootstock, being slender, loo THE TRAILING LYCOPODIUMS. pale in colour, sparsely clothed with yellowish scale-like leaves, and sending out roots abundantly. It creeps extensively, but seldom becomes as long as the stems of those species that are wholly above ground. The principal branches rise from two to five inches above the earth before producing branchlets, and are covered with many rows of curved, slender leaves each about an eighth of an inch long, but decurrent upon the branches in such a way as to appear much longer. Each main branch produces from five to eight alternate lateral branches, the lowest of which are largest and again branched two or three times before the final branchlets are produced. The branchlets are from half an inch to two inches long, thickly set with slender, almost linear, pointed leaves arranged in four rows. Like the other common lycopodiums this species con- tinues to add to the length of the branches for several years, during which the main branches continue to rise and put forth other lateral branches. The first year these latter are simple or slightly forked at the tips, and the next year the new growth springs from these tips, some producing one and some two branches. During the winter the leaves become a light yellow-green in colour, and the new growth, being dark green with silvery tips, is very noticeable. Branchlets as well as branches are crowded, half erect, and in old specimens form compact tree-like forms nearly a foot high. The spikes of fruit are borne singly on the tips of the old branches, often as many as fifteen spikes on a single main branch, though the number is usually much less. The spikes are cylindrical, from half an inch to two inches or more in length, and an eighth of an inch in diameter. The sporophylls or scales of the spike are PLATE IV. TREE CLUB- MOSS. Lycopodium ohscurum. CCPYRIGHT, 1905, BY FREDERICK A STOKES COMPANY THE TRAILING LYCOPODIUMS. loi broadly heart- shaped, with a slender tip, and closely overlap. Occasionally the spikes are prolonged into leafy branches above, showing unmistakably the rela- tionship of spikes of fruit to the ordinar}^ branches. The spores are ripe about September, though many ripen later. Lycopodiiini obsairtun ranges from Newfoundland to North Carolina, Tennessee, Minnesota, and Montana. It is found in southern Canada and extends northward along the Pacific to Alaska. It prefers moist, shady woods, and is one of the common species of the Eastern States. None of our other species resemble it very closely, which makes it a plant easy to identify. This is another of the species used for holiday decora- tions and is known as " bunch evergreen " or *' crowfoot." "The Stag-Horn Club-Moss. Nearly all the club-mosses in our flora are lovers of the north, and become rare as soon as warmer regions are reached. This probably accounts for the fact that the great State of California has not a single species of Lycopodiiini within its borders. The Gulf States fare somewhat better, though their species are not of north- ern origin, but instead are northward extensions of tropical species. The rarest of the tropical club-mosses within our boundaries is the stag-horn club-moss {Lycopodium cer- nuuni), which barely reaches the southern parts of Missis- sippi, Alabama, and Georgia, but is more frequent in Florida. In general habit it is like the tree club-moss except that the rootstock or main stem is seldom subter- I02 THE TRAILING LYCOPODIUMS. ranean. The aerial branches with us reach a height of fifteen inches to two feet and are erect or ascending. At short intervals they give off whorls of spreading lateral branches that are five or six inches long and branch again repeatedly. There are thus formed several nearly level circles of green about the main branches after the manner of the wood horsetail. Should the main branches become decumbent at base, the lateral branches, near the earth, may lengthen and become secondary rootstocks. The main stems and branches bear large numbers of spreading leaves an eighth of an inch or more long, but so slender that the stems never seem to be heavily clothed. The branchlets bear great numbers of similar, though shorter, spreading leaves, which give the plant a soft and airy appearance. The catkins are very small, often no more than an eighth of an inch long, and are borne at the ends of the branchlets, from which they droop slightly. The sporophylls are ovate, tapering to a slender point, with finely ciliate margins. The plants are very fruitful, and the tall stems, with their circular whorls of branches covered thickly with the small cones, make a very attrac- tive picture. Lycopodiuin cermiiun is pre-eminently a tropical species. It is found around the world in warm latitudes, and ex- tends to Japan, Cape Colony, and New Zealand. As might be supposed, the specimens from the United States are undersized plants. In favourable situations it often grows to the height of six feet or more, half supported by the vegetation in its vicinity. The cones may also reach a length of nearly an inch. In our region the plant may be looked for on moist, half-shaded banks, but in the tropics it occasionally grows in drier situations. TREE CLUB-MOSS. Lycopodiuni odscitrtun. STAG.HORN CLUB-MOSS. Lycopodium cernuum. THE TRAILING LYCOPODIUMS. 103 It is probable that it will yet be found Louisiana, Texas and California. The name of stag-horn club-moss,'., stag-horn moss, has doubtless been given this species in allusion to the branches, which have considerable resemblance to the antlers of the deer. The plant does well in cultivation and is common in conservatories. THE ERECT OR DECUMBENT LYCOPODIUMS. THE ERECT OR DECUMBENT LYCOPODIUMS. RITERS on the fern allies usually place the lycopocliums of the world in four distinct sub-genera, but the plants are all so much alike that no botanist ever thinks of considering any of these divisions as separate genera. The species to be presently 'treated come from three of these sub -genera, and so do not form a natural group ; but since all of them lack the long trailing stems of the other species it will be con- venient to consider them together. The Shining Club-Moss. On deeply shaded hillsides, where the soil is rich and moist, one may often discover the dark-green and glossy stems of the shining club- moss {Ly cop 0 din 111 liicidiiliini). To such localities the plant clings per- sistently in spite of the faUing leaves and shifting particles of soil that constantly tend to bury it. Year after year its growing tips struggle io8 DECUMBENT LYCOPODIUMS. upward, and as regularly the parts at the other extreme disappear beneath an accumulation of debris. It is ex- ceedingly rare to find a specimen that is not thus half buried, and in which many of the basal leaves are not yellow and dead in consequence. The stems of this species are constructed on a plan somewhat different from that of the trailing species. There is neither rootstock nor main stem in the usual sense, but instead, the whole plant may be likened to one of the primary branches of Lycopodiiun clavatuin. When the young plant begins growth, there is at first a single short stem. At length this forks at the apex into two equal branches, and these, after lengthening from one to several inches, fork like the original stem, this process continuing yearly during the life of the plant. The stems do not fork every year, but may continue for several seasons simply adding to their length. Growth proceeds very slowly, often not more than an inch a year. The stems attempt to grow erect, but after some years the weight causes the stem to become decumbent at base, and it then begins to decay. In the meantime, at inter- vals along the old stem, strong roots have been sent down into the soil, and when this decay has reached the first fork there are thus formed two separate plants where there was but one originally. Subsequently these two become four, and so on, a single plant ultimately giving rise to a whole colony. The living plants are often five or six times forked, but the majority fork only two or three times. The leaves are about a quarter of an inch long, narrowly lanceolate or oblanceolate and sharp-pointed, the outer third of each leaf bearing a few scattered teeth on the margins. They are thickly set on all sides of the SHINING CLUB-MOSS. Lycopodhnn hicididum. DECUMBENT LYCOPODIUMS. 109 stem and stand out nearly at right angles to it, except those at the tips of the stems, which are erect. The new and spreading growth, springing from the midst of the erect leaves, marks the stem with regular zones of spreading and appressed leaves, by which the age of the plant may be told. On old parts of the stem, the leaves are usually reflexed. The leaves, though short, are the largest borne by any North American species, and are further distinguished by their very firm texture and dark-green colour. The spores are borne in kidney-shaped sporangia, one of which is found in the axil of each of the ordinary spreading leaves near the tips of the stems. This in appearance is a wide departure from the usual way of fruiting, but when one considers that the difference is simply that in fruiting the leaves are not changed in shape and colour, a fundamental resem- blance is easily seen. One other difference marks the fruiting of this species, — the ends of the fruiting-branches continue to grow, and the new leaves of one year become the spore-bearing leaves of the following season. Thus each stem has in time several zones of sporangia. In some cases there are at least six of these zones. The spor- angia are bright yellow, and quite noticeable among the green leaves, but the spores do not appear to be very abundant. The empty spore-cases often remain upon the stems for years. In addition to the ordinary means of reproduction by spores and the less common multiplication by the division of the stem, this species produces numerous small bulblets that are capable of forming new plants. no DECUMBENT LYCOPODIUMS. A Bulblet. These are found above or below the zones of sporangia and issue from the same part of the leaf that the sporangia do. Each bulblet is borne on a six-bracted stalk barely a quarter of an inch long, much as the seed- pod is borne in flowering plants. The bulblets are about as long as their stalks and appear as two cotyledon-like scales. Stalk and bulblet have been likened to small plump dustpans. They may be found in their prime about midsummer, and by early autumn they have dropped from their stalks and begun to form new plants. They may be easily found by searching beneath the old plants. The stalks upon which the bulblets are borne usually continue for a ^ Single Spore-case. long time on the plants and may often be found in herbarium specimens. This species is sometimes called the '' hemlock club- moss," from the resemblance of its shiny leaves to those of the hemlock tree {Tsuga Canadensis). It is also called ** swamp evergreen," in allusion to the moist places in which it loves to dwell. It is extremely tenacious of life. Specimens have been known to continue growth for a year or more when placed in a vase of water in the house. Most of the club-mosses are very difficult to transplant, but this species takes readily to cultivation. A variety of club-moss has recently been described by Professors Lloyd and Underwood, that differs from this species only in being shorter and thicker and with slightly narrower leaves. It grows in the same manner as does the better-known plant, produces the same kind Lycopodiiini porophilum. DECUMBENT LYCOPODIUMS. m of bulblets, and appears upon examination to be merely a depauperate form of Lycopodiiun liicidiilum. This view of the matter is fully borne out by the habitat of the plant, for it is described as growing only on sandstone rocks. It is only to be expected that this moisture-lov- ing species, germinating upon a dry sandstone rock, would fail to come to its full luxuriance if it lived at all. It has been described as Lycopodiiun porophiluni, but seems scarcely worthy of even subspecific rank. It would more properly be called Lycopodiiun lucidiiliiin porophiliun. Its range is given as from Wisconsin to Indiana, Ken. tucky, and Alabama, always on sandstone rocks. The discoverer of the Kentucky station for this plant. Miss Sadie F. Price, author of " The Fern Collector's Hand Book and Herbarium," has furnished the author with specimens of this form and with the drawing which faces page no. She writes that she collected it for a dwarf form of Lycopodiiun luciduliun and that when growing it looks like an unthrifty specimen of that species. Lycopodiiun luciduliun ranges from Newfoundland to South Carolina, Alabama, Iowa, and Minnesota. Mr. J. B. Flett has recently discovered specimens in Washing- ton that have been referred to this species, but owing to the fact that the leaves are thinner, with bluntish tips and fewer teeth, it has been named forma occidcntale. Lycopodiiun luciduliun is also reported from Japan, China, and the Himalayas. It does not seem to be known in Europe, though the so-called v?ix\^\.y patens of Lycopodiiun selago almost exactly matches our plant. Its favourite haunt is a cool springy bank in the dense shade of coniferous trees, though it may also be found 112 DECUMBENT LYCOPODIUMS. in drier situations. It rarely forms large patches, but is seldom absent from suitable localities throufrhout its The Fir Club-Moss. The fir club-moss {Lycopodium selago) is very much like the shining club-moss in general appearance ; but the collector will not often mistake typical specimens, for the reason that they rarely grow in company. In the United States, the fir club-moss is a plant of high mountain summits, and is not plentiful until British America is reached. It is a shorter plant than Lycopo- diiim liiciduhim and seldom reaches a height of more than six inches. The stem forks several times, produc- ing close, flat-topped tufts of branches that are usually erect, but in old or thrifty stems may become decum- bent. Each year the branches add to their length, though, owing to the short seasons in its haunts, the annual additions are not very great. The leaves are a little more than an eighth of an inch long, crowded, narrowly lanceolate with a rather broad base, and are arranged upon the branches in about eight rows. They are somewhat concave on the upper side and curve upward toward the apex of the stem. In typical plants the edges of the leaves are entire and the apex is sharp- pointed. The sporangia are borne in the axils of the leaves as in Lycopodiiim lucidiihim, but although they are no smaller than in that species they are not as conspicuous, owing to the upward-curving leaves. They are also less numer- ous. The sporangia are not found on stems less than one season old, and, since they persist for some time, FIR CLUB- MOSS. Lye op odium sclago. DECUMBENT LYCOPODIUMS. 113 several zones of sporangia may be found on a single stem. This species also produces gemmae or bulblets in profusion, and propagation by that means is probably more common than by spores. Until recently no doubts were entertained as to the specific distinctness of Lycopodiiim luciduluni and Lycopo- diiim selago, but it has recently been asserted that as one passes downward from the mountain haunts of Lycopodiiim selago he may find forms of it that gradually merge into Lycopodiuiii lucidtiluni. It is therefore sug- gested that Lycopodiiim selago is only a mountain form of our common species. It is also noticeable that in Europe, where Lycopodiiim selago is common and Lycopo- diiim lucidiilum unknown, there is a variety with spread- ing, toothed leaves that appears to be very close to, if not identical with, our Lycopodiiim liicidiiliim. Some botanists are inclined to lay stress upon the fact that in Lycopodiiim lucidiilum the zones of leaves are alternately appressed or spreading, while in Lycopodiiim selago they are all appressed or at least ascending; but it can easily be shown that the alternating zones of Lycopodiiim lucidiilum are due to longer periods of growth, the spreading leaves being produced at the height of the season. If only a few leaves were produced each year, they would undoubtedly be ascending. Should further studies prove the truth of the theory that the plants called L^ycopodiiim lucidiilum and Lycopodiiim selago are but extreme typjss of one species, a rearrangement of names will be necessary. Lycopodiiim selago, having been named first, would retain its name, while the other would become Lycopodium selago luciduluni. This species was once valued for its medicinal quali- ties. It was occasionally used as an emetic and cathar- 114 DECUMBENT LYCOPODIUMS. tic, but it is too powerful to be safe. According to Moore's " British Ferns " it was also used in the form of an ointment as a counter-irritant. A decoction of the stems is said to be used in Sweden to destroy vermin on cattle. Like other species, this plant has been used for dyeing and for fixing the colour of woollen goods. In Ireland it is known as "Virgin Mary's furze," and in Cornwall as " good-luck." According to M. W. Gorman the natives of Alaska use the stems to produce a kind of intoxication. In the United States, Lycopodium sclago is found from North Carolina to Maine, Michigan, and Washington, but only in the higher mountains. It extends to Alaska and Greenland, being most plentiful and growing nearly at sea-level in these northern countries. It is abundant in northern Europe and Asia, and has been reported from Australia, New Zealand, and Antarctic America. Many forms of it are reported from the tropics, but these are probably distinct species. The Bog Club- Moss. The club-mosses with which the average collector is most familiar delight in moist spots in woodland, on mountain side, or on moor, but the bog club-moss {Lycopodium inundatiun) is so fond of moisture that it frequently grows in beds of sphagnum close to the trembling boggy margins of our small Jakes and ponds, its habitat alone being often sufficient to identify it. The stems of this species present still another depar- ture from the more familiar club-moss form. They are slender and threadlike, from two to eight inches long, and are rooted near the base, beyond which they usually BOG CLUB-MOSS. Lycopodium imindatiun, (Twice natural size.) DECUMBENT LYCOPODIUMS. 115 rise clear of the earth, bending over in the form of an arch to root again at the tip. The plant is therefore as truly a walking club-moss as Cainptosoriis rhizopJiyllus is a walking fern. In the smaller specimens the stems commonly do not branch, but in the larger ones two or three short branches may be produced, each of which roots at the tip like the main stem. Indeed, this is their only means of continuing existence, for at the end of the growing season the older parts of the plant die, leaving these vigorous, bud-like tips, filled with plant-food, as so many points from which new stems may be produced the following year. The leaves are from an eighth to a quarter of an inch long, linear, entire, with broad bases and pointed tips, and are closely crowded on all parts of the stem, though owing to its horizontal position those on the under side turn upward, so that all appear to grow from the upper side. The fruiting parts are at the tips of separate stems which are much like the main stems except that they are stiffly erect. They are quite short, usually under five inches high, and spring from the older parts of the main stem. They are clothed with leaves similar to those on the other parts of the plant, but less spread- ing, and there is usually but one fruit-stem to a plant. The cone of fruit is from a quarter of an inch to two inches long and about twice the diameter of the stem. There is no sharp line marking the separation between stem-leaves and sporoph}lls, one almost imperceptibly merging into the other. Typical sporophylls are broad and rounded at base, toothed above, and suddenly narrowed to a long slender tip ; but, near the base of the spike, sporangia are borne by the ordinary linear stem- leaves. The sporangia approach globose in shape, and ii6 DECUMBENT LYCOPODIUMS. though but one is borne in the axil of each sporo- phyll they are numerous enough to make the spike the heaviest part of the plant. The spores are ripe in late autumn. A larger form of this plant, with slender branching stems and slightly longer leaves, has been named the variety Bigelovii. According to Baker's *' Fern Allies " the fertile stems of this are sometimes a foot long, with a spike six inches in length. It is the author's opinion, however, that a form of the closely related Lycopodiiun alopeairoidcs has been wrongly identified as this form. He has seen no specimens of the so-called variety Bigelovii that were not more properly placed elsewhere. In localities where the bog club-moss is undisturbed, the plants frequently form *' fairy rings " like those formed by various fungi. The rings are due to the creeping habit of the plant, which tends to carry the tips slowly outward from the centre, which is left vacant by the dying of the older parts. Where the progress is unob- structed, the circles continue to enlarge for many years. The bog club-moss is a northern plant, being plentiful in Labrador and Alaska, and extending southward to New Jersey, Pennsylvania, Illinois, and Washington. It is also a common species in the north of Europe. It is seldom found except in swampy ground, and is con- sidered rather rare in the United States. After the Carolina club-moss it is our smallest species. It is possi- ble to find fruiting specimens less than two inches long. The Fox-Tail Club-Moss. Just as the bog club-moss begins to be rare southward, another species appears which resembles it so closely /f'^-^/'-Hr FOX-TAIL CLUB-MOSS. Lycopodhun alopeciiroides. One -third natural size. Lycopodium alopecuroides adpressum. DECUMBENT LYCOPODIUMS. 117 that the novice might be excused if he should think it a gigantic specimen of the northern plant. This new spe- cies is the fox-tail club-moss (^Lycopodiiini alopeciLroides\ a plant which reaches its best development in the South- ern States, but which in the northern part of its range is still so robust that the single characteristic of size is nearly enough to distinguish it. The sterile stems of Lycopodiiun alopeciiroides are from ten inches to two feet long. In small specimens they may arch as do those of Lycopodiiun immdatuiii, but in the larger plants they are likely to be simply trailing. The main stems are about an eighth of an inch in diame- ter and give off several lateral branches, the more vig- orous of which may branch again. The stems root most abundantly near the tips, but may also produce slender roots wherever they come in contact with the soil. The leaves are a quarter of an inch or more in length and are produced, thickly on all sides of the stem, but those from the under surface grow upward and appear as if produced from the sides. They are narrowly linear, spreading, with the tips pointed, and the margins bear- ing an occasional slender tooth. The fruiting stems are erect, a foot or more high, and are clothed with appressed or spreading leaves like those of the sterile parts. The spore-bearing area is from one to four inches long, and about one third thicker than the stem ^which bears it. The sporophylls are much like the ordinary leaves, but longer and with more teeth. The spores ripen very late in the year, often not until the end of October in the north. Unlike Lycopodium inundatum, a single plant often produces several fer- tile stems, as well as certain additional upright stems that are ma;nifestly in the nature of fertile stems, but iiS DECUMBENT LYCOPODIUMS. which never come to fruition. These hitter are borne on the branches or on the newer parts of the main stem, and are doubtless produced too kite in the season to be fruit ful. In exposed places throughout its range there is found growing with the type a form that by some has been considered a species and named Lycopodium adpressum. It differs from the type in being somewhat smaller, with shorter, thicker, less spreading leaves, and with slender fruiting-stems clothed with appressed leaves in shape like those of the sterile stems. The fruit- spikes are from one to four inches long, and about twice the diameter of the stems that support them, the sporo- phylls being rather broader at base than in the type. Owing to the appressed leaves, the fruiting parts are more distinct and cone-like than those of the type. The spores are produced in great abundance. Sev- eral fertile stems are usually produced on each plant, and the upright sterile stems noticeable in the typical Lycopodiuin alopecuroides are also plentiful. All the char- acteristics in which this form differs from typical plants are such as might be produced by an unusual amount of light and heat, and the exposed situations in which the plants grow seem fully to account for this appearance. Under these circumstances it seems better to call this a sub-species and to name it Lycopodiuin alopecuroides adpressum. Although this form has always been known by the name oi adpressum, whether treated as a species or as a variety, it has recently been proposed to change it to CJiapmani, because the name adpressum was earlier ap- plied to another plant. If considered as a variety, our plant would now be called Lycopodium alopecuroides Chapmani. A curious form of adpressum was found on Staten ^■"1 ^ I ^B ■i T 3r ^ PLATE V. LYCOPODIUM ALOPECUROIDES ADPRESSUM. CCPirRnHT, ;905, BY FREtEBICK A. STCKES CCV DECUMBENT LYCOPODIUMS. 119 Island, New York, by W. II. McDonald, who named it polyclavatum. It is like ordinary adprcssum with the exception that the fertile stems each bear from two to six short branches, some of wdiich produce fruit cones while others are sterile. Still another form of Lycopodiiuji alopeairoidcs is occa- sionally considered a distinct species and called Lyco- podiiun pinnatum. It is a slender plant, growing in wet places, and derives its specific name from the sup- position that its stems are pinnately branched. It is certain, however, that while the stems may appear pinnate they are not really so, and that this is simply a more branched form of the species. Aside from this character the stem is long and slender, and the leaves are inclined to stand out at right angles to the stem, this being due to the w^atery habitat the form affects. Lycopodiiun alopecuroides is essentially a tropical plant and within our limits is confined rather closely to the Atlantic and Gulf coasts. In South America it is said to extend to Monte Video. The typical form extends northward to Long Island, where it was first discovered by the author near Babylon. The form pinnatum is a lux- uriant phase of the plant found only in watery situations in the Gulf States. Lycopodiiun alopecuroides adpressiun extends to the coast of Massachusetts and is the common- est form from New Jersey to Virginia. The plant is a lover of the swampy sand-barrens and often covers large areas. So far as known, both the species and varieties are absent from the interior of the continent. The various disguises of this plant have always been a puzzle to botanists. It was first described as a variety of Lycopodiiun inundatuni, and when the forms were discovered they too were named as varieties. There is 120 DECUMBENT LYCOPODIUMS. no doubt, however, that it is distinct from Lycopodiuni iinindaium. The common name of '* fox-tail club- moss " has been given this species in allusion to the bushy spike of fruit like a fox's tail. "The Carolina Club-Moss. The Carolina club -moss {Lycopodiuni Carolinianuui) is one of the most diminutive of its race, and its claims to being the smallest North American species could not be contested with any prospects of success by any save the bog club-moss. In the northern part of its range, at least, it is clearly entitled to the honour, and it is only when we include the more robust plants of the South that any doubts arise. The sterile stems of this species are from one to four inches long and are appressed to the earth, clinging so closely by means of numerous roots that the plant can scarcely be got up entire without the use of knife or trowel. Owing to their position the stems are markedly dorsi-ventral, and the leaves are of two sorts, the larger often a quarter of an inch long, borne on the sides of the stem and spreading ; the others awl-shaped and borne on the upper side of the stem. The large leaves are ovate-lanceolate with a broad base, entire margins, and pointed apex. In these, one side is longer than the other, causing them to curve sidewise and throwing the tiny midrib a little to one side of the middle. Although so short, the stems usually produce one or two small spreading branches. The (ruiting-stems, of which there appears to be but one to a plant, no matter how robust the specimen, rise from the older portion and often reach a height of ten CAROLINA CLUB-MOSS. Lycopodinm Caroliniamun, DECUMBENT LYCOPODIUMS. 121 or twelve inches, — several times the length of the sterile stems. They are very slender, but are stiffly erect and sparsely clothed with small, linear, appressed, long-pointed leaves. At the top is borne the single cone, consisting of many close-set, yellow sporophylls, each subtending a roundish spore-case. The sporophylls are broad and rounded, with spreading tips, and the cone is about three times the diameter of the stem or peduncle. In the northern part of its range the fertile stems are usually short, and the cones are from half an inch to an inch long. In the South the stems are taller, and the fruiting portion often three or four inches long, though not much thicker than in the Northern plant. The Carolina club-moss is found from central New Jersey south to Florida and Louisiana, so far as known, only near the coast. It delights in open sandy swamps in the pine-barrens, and in its New Jersey haunt is fre- quently a neighbour of that rare little fern, ScJiizcea pusilla. It is not found in Europe, but according to Baker's '' Handbook of the Fern Allies " it occurs in Ceylon, Hong Kong, New Guinea, Tasmania, and the Cape of Good Hope. It is also reported to occur in South America as far south as Brazil. It is probable that many of these forms will ultimately turn out to be different species. Some are described as having stems a foot long. In the tropics, forms referred to Lycopodimn Carolinianuni sometimes bear tubercles on the sterile stems. THE PSILOTACE/E, THE PSILOTACE^. NE of the most curious of all the fern allies, and one of the rarest in our flora, is that relative of the lycopodiums which botanists call Psilotmn triqiietruin. This, in fact, is often considered as one of the Lycopodiaceae, and in many books will be found included as one of the four genera supposed to belong to that family ; but the typical Psilotum form is so different from that of Lycopodium that in the opinion of modern botanists we are war- ranted in placing the species in a separate family which has been named the Psilotaceae. In this family, as now recognised, there is the single genus Psilotmn, and in this genus less than half a dozen species. Baker's " Fern Allies " names but two species and several varieties. Others are inclined to give some of the most pronounced of these varieties specific rank, but in any event the genus will always remain with very few species. The family being so small, a descrip.tion of our single species will sufifice for an account of the whole family. Like many of its relatives among tropical lycopo- diums, our species {^Psilotum triqiictruiii) is epiphytic and usually grows on the trunks of trees, though it is occa- sionally found upon the earth, on fallen logs, or the like. The mature plant has no true roots, from which it is con- jectured that it is a saprophyte, like the mushrooms, 26 THE PSILOTACE/E absorbing its nourishment from decaying plant tissues by means of its root-like rhizomes. These rhizomes are curi- ous structures consisting of a great number of cord-like organs that form a tangled mass from six inches to a foot or more in extent. From various parts of. the rhizome the stems rise to a height of twelve inches or more, at the top forking repeatedly to form the fan-shaped branches. The base of the main stem is about one tenth of an inch in diameter and is three-angled, and the branchlets are three-winged. The leaves are reduced to tiny linear scales less than one twelfth of an inch long, and, though scattered along the angles of the stems and branches, are so inconspicuous that the plant always appears to be leafless. The sporangia occur singly along the branchlets, each small leathery spore-case held in a slight hollow of the stem by a forked sporophyll which looks like a pair of the stem leaves. The spore-cases are globular or top-shaped, three-lobed, three- celled affairs, opening at the top, when ripe, by three tiny oblong slits. Spore- cases of this type are often called synan- gia. From their appearance they have been likened to .tiny apple-dumplings, the spore-cases are produced in abundance and the spores are numerous, the plant has additional means of reproduction. When it grows in soil, it may send out certain slender subterranean shoots which pro- duce a great many buds or bulblets by which the plant multiplies rapidly. Occasionally these buds may re- main dormant for a long time. The prothallia of this species is unknown. Although r SI latum triquet)-um. THE PSILOTACE^. 127 The range of Psilotuin triqiictruin is from northern Florida southward. The species was once reported from South Carolina, but some doubt may be enter- tained as to its existence there at present. In central Florida it is not uncommon, usually growing on the palmetto, and it is probable that it may yet be dis- covered in other of the Gulf States near the coast. It is widely spread in the tropics, extending quite around the world and reaching Japan and New Zealand. It has long been known under the specific name of triquetruui in allusion to its three-angled branches, but recent works occasionally list it as Psilotuin uudiiin, Campbell, in his " Mosses and Ferns," is inclined to add to the Psilotaceae the genus Tincsipteris, which contains a single species growing in New Zealand. Other authors place this with the Lycopodiaceae. No fossil plants have yet been found that can with certainty be referred to the Psilotaceae, though various specimens from the Coal Measures are commonly regarded as belonging to this family. THE SELAGINELLACE/E, OR DWARF CLUB-MOSSES. THE SELAGINELLACE^. y N the time of Linnaeus the plants that are now referred to the genus Selaginella were thought to be true club-mosses, and such species as were then known will be found in old botanical works in the genus Lycopodhnn. There is, however, this important difference between them. In the lycopodiums the spore-cases bear many spores all of the same size and appearance, which produce ia of one kind, while in Selaginella the lower spore-cases in the fruit-spikes each bear about four large spores called megaspores, while the spore-cases higher up in the spike bear great numbers of smaller spores called microspores. When the microspores germinate they form very reduced prothallia bearing only anther- idia, and are therefore called male prothallia; while the megaspores produce larger prothallia with only archegonia, and hence are called female prothallia. Both sorts of prothallia begin to develop before the spores have left the sporangia, but even after the spores have fallen, the prothallia, unlike those of most of the Megaspore of Seiagt. ferns and fern allies, never leave '^'^^^'^;;;£';^;?;/^"'^^ the spores. When the prothallium in the megaspore has nearly attained its growth, the thick 132 SELAGINELLACE^. and rough walls of the spore split apart at the apex, exposing the part of the prothallium bearing the arche- gonia, and these, after fertilization, contain the develop- ing plants. On account of the early development of the prothallium, and various other features connected with the manner of spore production, the selagi- nellas are thought by many students to be more nearly related to the flowering - plants than are any other Pteridophytes. The fertile spikes differ very little from the flowers of the pines and their allies. The most noticeable distinc- tion is that the microspores of the pines (called pollen) are borne in separate catkins. In most other respects the selaginellas have a general resemblance to the lycopodiums, but except in tropical countries this is is not close enough to be confusing. Our North American species are easily distinguished by their much smaller size ; in fact they are so diminutive that they are much likelier to be confused with the mosses than with the lycopodiums. In our species the main stems seldom reach a length of more than six inches. Often they are trailing, but occa- sionally they are more erect. The trailing species, as in the lycopodiums, send out forking roots at frequent intervals, but the species with upright stems root only near the base. The stems are usually branched, though not dichotomously so, and the whole plant is generally very close to the earth. The leaves are minute and very abundant, clothing both stems and branches. The form of the leaves has been made the basis for dividing the genus into two sections. In one they are all alike and arranged in many Spike of Selaginella. PLATE VI. ROCK SELAGINELLA. Sclaginella rupesttis. CCPYRIGHT, 1905, BY FREDERICK A. STOKES COMPANY SELAGINELLACE^e. ^33 rows, and in the other they are of two forms and arranged in four rows. Of these four rows, two contain large leaves and two contain small ones. The large leaves are in the two rows on the sides of the stem, while the small ones are on the up- per side of the stem and alternate with them. The fruit is borne at the ends of the branches, a spore - case in the axil of each leaf. In some species the fertile spikes are hardly to be distinguished from the ordinary branches, while in others the spore- of Sa^ineHa bearing leaves are yellowish in Leaves. colour, morc or less changed in n^ shape, and are assembled in little cones as in most lycopodiums. Often these cones are distinctly four -sided. The sporangia are nearly spherical and open transversely at Leaf of , T-i • -if-^i^- Selaginella the apex. 1 he species mamly fruit late in rupestris. , -^ (Enlarged.) the year. There are nearly four hundred species of Selaghiella known to science, the great majority being found in the tropics, where their size and abundance render them a conspicuous part of the undergrowth in woods and on moist banks. In our region they are usually so small and moss-like as to be easily overlooked. The plants from the warmer parts of the world are often character- ised by a delicacy in form and colour that causes them to be in great demand for cultivation in conservatories nearer the Poles. Several of them are climbing species. The famous resurrection-plant, or resurrection-moss, sold under various other names to the curious, is a species of Sclagiiiclla. k 134 SELAGINELLACE>E. The name Sclaginclla is a diminutive of Sclago, the ancient name of one of the lycopodiums which our species greatly resemble. Formerly the quillworts (Isoetes) were united with the genus Selaginclla to form the Selaginellaceae, but as they are regarded at present they not only form a distinct family, but are included in another order. The Selaginellaceae, there- fore, may be said to consist .of the single genus Sclagi- nclla, Key To The Selaginellas. I. — Leaves narrow, all alike . , . , . Stems pendant, rooting throughout. Western S. Orega7ia Stems erect, rooting at base only. Western S. Bigelovu Stems creeping and tufted .... Branchlets under /s of an inch long. Western S. cinerascens Branchlets longer ..... Leaves tipped with a point. Western ►S". Watsoni Leaves tipped with a white bristle Leaves closely appressed. Southern 5. arenicola Leaves somewhat spreading. Eastern 5". rupestj-is Fertile stems larger than the sterile. Northern 5. spinosa II, — Leaves broader, of two sizes . , , . Plants weak, trailing, rooting throughout Fertile spike roundish, leafy . 5. apiis Fertile spike four-sided. Western .S'. Dmiglassi Plants slender, erect or ascending. Southern S. Liidom'ctana Plants stout, densely tufted, rooting only at base Leaves obtuse, awnless . S. lepidophylla Leaves awn-tipped . , S. Pri7iglei THE TRUE SELAGINELLAS, OR SELA- GINELLA RUPESTRIS GROUP " THE SELAGINELLA RUPESTRIS GROUP. botanists consider at the shape, size, d arrangement of the leaves of Selaginella are of sufficient importance to warrant the separa- tion of this genus into four sub-genera. The first of these is called Euselagineiia and contains, those species with leaves all alike and ar- ranged in many rows. From the fact that the common species in eastern North America are typical of this group, they are often spoken of as the Selaginella rn- pestris group. Although here called the true selagi- nellas they are relatively few in number, probably less than twenty-five in all, though distributed very widely over the earth. T^he Rock Selaginella* The student of the mosses is likely to be better acquainted with the haunts of the rock selaginella, ( Selaginella rupestris ) than the student of the fern allies himself, for it is a species of the dry ledges and mossy boulders, growing in situations shunned by I40 THE SELAGINELLA RUPESTRIS GROUP. others of its kin, and so small as to be easily overlooked unless one is on a special hunt for it. One who has once seen it, however, will seldom overlook it again, for the whole plant has a characteristic grey-green colour not common to mosses, that is sure to catch the eye and make recognition at some distance possible. The main stems of this species are from one to five inches long and nearly prostrate. From these issue great numbers of secondary branches, several times forked, but all so short that the topmost branch does not reach a height of three inches. The plants grow in communities, with branches so intertwined that the individuals are dif^cult to distinguish, the whole form- ing a dense little mat that often covers an area of several square feet. The leaves are arranged in about eight ranks, and so close together upon the stems and branches as to completely cover them. At the tips of the branches they are more or less spreading, but elsewhere they are rather closely appressed. They are frequently described as less than a sixteenth of an inch long, but in vigorous specimens they may reach more than twice this length, exclusive of the awn-like tip. They are narrow, with a deep groove on the back, and taper from the base to the rounded apex. Each leaf bears a slender white bristle at the tip, which is one third to one half the length of the leaf. It is these white bristles among the green that give the peculiar greyish colour to the plant. The leaves also bear numerous cilia on the margins, and the bristles also have very short ones. The fertile spikes are similar to ordinary branches in appearance, the most noticeable differences being that they are erect and distinctly four-sided. Thesporophylls ROCK St LAG IN ELLA. Selaginclla ritpcstris. THE SELAGINELLA RUPESTRIS GROUP. 141 differ from the ordinary foliage leaves only in being broader at base and having rather more numerous cilia. They are arranged in four ranks, a row on each of the four angles of the spike, with the bases closely over-lapping. The spikes are from half an inch to an inch long. After the spores have fallen, the sporophylls be- come reflexed, and the sporangia, split nearly into halves, spread out in the axils like small greenish flowers. The megas- porangia are supposed always to bear four megaspores, but all four do not always develop. They are bright orange yellow in colour and are large enough to be seen with the unaided eye. They are borne so plentifully by this species that they are often noticeable on the ground about the plants late in autumn. The megaspores and microspores are said to be borne in the same leaf axils. Until a few years ago Selaginclla rupcstris was consid- ered to be a widespread though somewhat variable species. Recently, however, it has become the fashion to describe each form as a distinct species, no matter what its characteristics, and about forty of these forms have been so described. It can scarcely be dou'bted that the species, as once regarded, covered too great a range of forms ; but it is equally certain that many of the newly described species are mere forms due to con- ditions of environment. The points most relied upon for separating them are the presence or absence of the bristle tips of the leaves and the number of cilia on the leaf margins. Only the more noteworthy forms can be Spike of Rock Selagfinella. (Enlarged.) 142 THE SELAGINELLA RUPESTRIS GROUP. treated here. The student who wishes to make further investigations is referred to the article by Dr. Hierony- mus in the volume 'of Hedwigia for 1900. A synopsis, with a key to the American forms, was published in the Fern Bulletin, Volume 10, 1902. A form from the mountain tops of North and South Carolina, in which the awns on the tips of the leaves are longer and twisted, was long ago described as a species and named Selaginella tortipila. It is more„com- monly called a variety. A plant allied to this, but with stems more erect, is the variety SJierivoodii {Selaginella Sheriuoodii, Underwood.) Still another form from the coastal plain of the Carolinas and Georgia has been named Selaginella acanthonoia. It differs from typical Selaginella rupestrisxn having about twelve cilia along the dorsal groove in the leaves and is probably best consid- ered a variety and called Selaginella rupestris aeanthonota. A densely tufted form from western Nebraska and Montana is the variety densa {Selaginella densa, Rydberg). A form with lax, less crowded leaves, and shorter awns, has been reported from Colorado and New Mexico as the variety Fendleri. Plants from New Mexico and Arizona with smaller megaspores and less angular fertile spikes is the variety riipincola (Selaginella rupineola. Underwood). In Baker's '^ Handbook of the Fern Allies " the range of Selaginella rnpestris is given as *' North and South Temperate zones of both the Old and New worlds, also on the Andes, Himalayas, and mountains of Brazil and Ceylon." In the early editions of Under- wood's " Our Native Ferns " it is recorded as growing from " New England to Florida, Texas, California, and northward." In the latest edition of the latter book its THE SELAGINELLA RUPESTRIS GROUP. 143 range is given as " New England and Ontario southward to Alabama and westward to California and British Columbia," — this latter probably being nearly correct for .our part of the world. It shows, however, how greatly the idea concerning this species has changed within ten years. Selagiiu'lla riipestris is usually found on dry rocks, and, , in the Eastern States at least, appears to have a pref- ferehce for granite, gneiss, and mica schist. It is exceed- ingly irregular in distribution, being abundant in some sections of its range and extremely rare in others. In the vicinity of New York it is a common species and may be found in the public parks as well as on a large number of the rocky outcrops in the surrounding country. It is likeliest to be found in thin soil on the tops of the ledges, and, being an evergreen species, is most easily found in early spring. This species is sometimes called " grey moss." Selaginella Watsoni. The plant recently named Selaginella Watsoni may be recognised at once by the fact that it looks like a luxuriant form of Selaginella rupestris. The leaves are rather larger and thicker than in Selaginella rupes- tris, with few or no cilia, and end in a short, pale green awn. Owir.g to the colour of the awn and the scarcity of cilia, tlie plant has a tinge of deeper green than is found in the common plant of the East. The main stems are from four to six inches long, nearly prostrate, and produce strong roots throughout their length. The fertile spikes are an inch or more long and sharply four-angled. This species is a plant of 144 THE SELAGINELLA RUPESTRIS GROUP. elevated regions and is found only in the West. It has been reported from various peaks in Utah, Nevada, and California, always at altitudes above 5,000 feet. A form very similar to this, but differing in having about eight cilia on the leaf-margins and no awn tips to the leaves, has been described as a species under the name of Selaginella niutica. The \\^ fact that the sporophylls usually have a short awn-tip seems to indicate that it is a form of Selaginella Watsoni, and this is further borne out by its habitat in the mountains of Colo- rado, New Mexico, and Arizona. We would therefore call it Selaginella Watsoni niutiea, and give its range as high mountains from Colorado to New Mexico and California. Brancli of Selaginella Watsoni. (Enlarged.) The Sand-Barren Selaginella. It is almost certain that the sand-barren selaginella {Selaginella arenieola) and the common species of the Northeastern States, sprang from the same stock ; but the former has lived so long in the sandy wastes that border the Gulf of Mexico that its appearance has been greatly changed in consequence. Possibly there may yet be found intergrading forms, but the typical plant is so distinct in appearance that it is properly con- sidered a separate species. This species is an excellent illustration of the adaptation of plants to their surround- ings. It grows in exposed sandy places, and accordingly its leaves are narrow, plentifully ciliated, and appressed closely to the stem, partly in an effort to avoid excessive transpiration, and partly, no doubt, to protect its green cells from the strong light. Selaginella Bigelovii. THE SELAGINELLA RUPESTRIS GROUP. 145 The stems, under the influence of the intense insola- tion, are nearly erect, but seldom become more than two inches hi^h. They are densely tufted, much branched, and form compact little mats on the sand. From the part nearest the earth, slender branching roots descend into the soil, and in the search for moisture extend for long distances, being often three times the length of the aerial parts of tlie plant. The leaves are smaller than those of any of our other selaginellas, and those on the sterile stems are not distinguishable from one another by the unaided eye. Under a lens they are seen to be very narrow, with a whitish awn at the apex and many minute cilia on the outer edges, while the usual channel runs lengthwise of the outer side. They are thickly clustered on the stems and branches, and so closely appressed that stem and leaves combined have a diam- eter of about a thirty-second of an inch. The fruiting-spikes are very numerous and terminate the ends of the branches. Although the whole plant is usually under three inches high these fertile spikes may reach a length of an inch or more. They are sharply four-angled, with a diameter somewhat greater than that of sterile branches. The sporophylls are much larger than the leaves and are borne in four closely SAND-BARREN SELA- GINELLA. Seia tri'fi clla a re n icola . 146 THE SELAGINELLA RUPESTRIS GROUP. imbricated rows, one row on each angle of the spike. They are often triangular in outline, broad at base, and end in a short awn. The margins bear abundant cilia that are so small as not to be easily seen. The megaspo- rangia are especially abundant and bright yellow in colour, quite distinguishable without a lens. The sand-barren selaginella has thus far been reported from Florida, Louisiana, and Texas, but it is likely to be found in suitable situations in any of the sand-bar- rens along the Gulf coast. Its slender, cylindrical, grey- green, erect stems will be easily identified when found. It was originally described ^s Selaginella arenaria. Selaginella Bigelovii. - In the days when it was customary to refer everything at all resembling Selaginella rupestris to that species, it was described as having stems from six inches to a foot long. The plant that is nowadays called Selaginella rupestris is much smaller, and at its best does not reach the minimum length quoted. An explanation of the discrepancy is found, however, when we take into con- sideration one of its forms recently named Selaginella Bigelovii. In this the stems ordinarily reach a length of six or eight inches, and in vigorous specimens are, of course, still longer. It is likely to surprise the beginner to learn that Selaginella Bigelovii was ever referred to Selaginella rJipesiris. Aside from its long stems, its habitat and manner of growth are sufficiently different to separate it. It is an erect or ascending species, with stems that pro- duce roots only near the base. For some distance above the soil, the stems are commonly unbranched, or. Selaztnella cinerascens. THE SELAGINHLLA RUPESTRIS GROUP. 147 if branched, the branches may be considered essentially like the main stems. Toward the apex the stems are pinnate, with short, alternate branches, the lowest from one to three inches long and increasing in length to the summit. These lateral branches are branched in the same way as the main stem, and their branches are again divided, the ultimate branchlets rarely reaching the length of half an inch. The leaves are narrowly linear, slightly channelled down the back, with numerous cilia on the margins and a short white awn at the apex. They are small, numerous, and closely appressed to the very slender branches. Those on the main branches are usually light brown, the rest being dark green. The fertile spikes are fairly plentiful and usually occupy the places of lateral branchlets a short distance from the tips of tlie branches. The cones are from a quarter to half an inch long, and quadrangular, the sporophylls being rather triangular, short, pointed at the apex, ciliated on the margins, and slightly eared at the base. The fruit may be found on the plant at all seasons of the year. Selaginclla Bigelovii is found in southern California only, but there it is not an unconvmon species. It grows in the foothills at altitudes up to about '3,000 feet, and prefers half-shaded clay soil or the cliinks of rocks. Like many of the mosses and ferns in this region, its chief period of growth is in the rainy or winter season. At other times it becomes dry and brittle, but revives at the next rainy season. Selaginella Cinerascens. Selaginella cinerascens is another of the segregates of Selaginella rupestris that has been described so recently 148 THE SELAGINELLA RUPESTRIS GROUP. as to have no common name. In general appearance it is most like Selaginclla Bigehvii, but may be at once dis- tinguished from that species by the fact that it is a pros- trate plant rooting from all parts of the stem. In robust specimens the main stems may reach a length of six inches or more, but they are usually shorter. These stems are pinnately branched, the branches short and rather numerous. From these branches still smaller branches, about a quarter of an inch long, arise, and upon these are usually borne a pair of branchlets so small as to be mere spurs, which, with the branch-tip, form a figure suggestive of the qox\mc\\\.\o\-\3\ Jleur-de-lis design. All parts of the plant are covered with leaves, those on the main stems being closely appressed, and those on the branch-tips more spreading. The leaves are rather broadly linear, acute or rounded at the apex, with a suggestion of a terminal awn, and with few or no marginal cilia. The spikes are short, and about twice the diameter of the stems, with the ovate-acute sporophylls in four ranks. The megaspores are of a pale lemon colour, and the mi- crospores dark orange. According to Mr. Eaton, who described this species, the megaspores and microspores are developed in separate spikes. Selaginella cinerasccns is found on dry, bare hills in southern California. For a time after it was described, it was confused with another species called Selaginclla hryoidcs, described by Nuttall, and some of the earlier references to it will be found under the latter name. T'he Oregon Selaginella. One of the most remarkable of the selaginellas is the Oregon selaginella {^Selaginella Oregana) which, until it Selnginella Or eg ana. THE SiLAGlNcLLA RUPESTRIS GROJ?. 149 was recently discovered in northwestern Washington by Mr. J. B. P^lett, was supposed to grow in Oregon only. Although its stems are less than a sixteenth of an inch in diameter, they are said occasionally to reach a length of six feet. As a consequence it is a pendent species, growing with mosses on the trunks of trees and emitting copious roots, from both stem and branches, that strike into the bark and hold the plant in place. The stems are pinnately branched like those of Selagi- nella Bigclovii, though the lateral branches are longer and farther apart, with fewer branchlets. The stems are light brown in colour, and so sparingly covered w^ith leaves as to be noticeable, especially in the older parts of the plant. The leaves are narrow, about a twelfth of an inch long, with a short white awn at apex and occasional cilia on the margin. Those on the branchlets are dark green and loosely spreading; on old branches they are light brown and half appressed. Some of the leaves early lose their terminal awns, and, in consequence, in some books this species has been described as awnless. The fruiting-spikes are slender, four-angled, and appar- ently not very abundant. This species is found in the dense forests near the Pacific coast and grows in tangled mats. Mr. Thomas Howell, author of a " Flora of Northwest America," writes that he found it growing from the branches and prostrate trunks of maple trees, from which it hung to a length of from six inches to three feet. It often grows among mosses, one of which, Hypnnvi lorciivi, might be mistaken for it at first glance. Mr. Howell is of the opinion that its season of growth is from September to June. The plant has always been spoken of as Selagi- nclla Oregana and will be found in most books under t5o THE SELAGINELLA RUPESTRIS GROUP. that name, but it was earlier given the name of Sclagi- nella strutJiioloidcs and tliis is one of the names by which it is likely often to be called in future. ^ The Prickly Mountain Moss. If the fern allies were placed in genera founded upon external appearances alone, that plant which the British call the prickly mountain moss [Sclaginella spinosii) would be found among the lycopodiums. It has a very decided resemblance to the marsh club-moss and is about the same size, but the fact that the fertile spikes bear both microsporangia and megasporangia for ever separates it from the true club-mosses. Like the bog club-moss, and unlike most of the selaginellas, there is a marked difTerence between the fertile and sterile stems. The latter are close to the ground, very slender and threadlike, with occasional short branches half an inch or more long. The entire sterile portion seldom reaches a length of more than four inches and bears roots only near the base. The leaves are loosely spreading and arranged on all sides of the stem. They are broadly lanceolate, acute, and the margins are beset with scattered teeth too stout to be called cilia. The fertile spikes grow from near the base of the main sterile stems and reach a height of three inches or more. They are quite erect and resemble the fruiting-stems of a Lycopodium since they consist of a leafy stal-k sur- mounted by a loose cone of sporophylls. The leaves on the stalk are similar to those on the sterile stem, though slightly larger and more closely appressed. As they merge into the sporophylls they become larger and PRICKLY MOUNTAIN MOSS. Selaginella sphiosa. (Slightly enlarged.) THE SELAGINELLA RUPESTRIS GROUP. 151 broader, with stronger teeth, and often stand at nearly right angles to the stem, making the cone quite conspic- uous. The cones are an inch or more long, and usually there is but one fertile spike on each plant. The lowest sporophylls bear three or four megaspores, which are as large as the seeds of many flowering-plants. The fertile spike is deciduous, but the sterile stems survive the winter. Selaginella spinosa is rare in the United States, being found only in the elevated parts of Maiu'e, New Hamp- shire, New York, Michigan, and Colorado. In British America it is more abundant and found at lower alti- tudes. It is also found in both Alaska and Greenland. In the Old World it is reported from the British Isles and across the northern part of the Continent, extending south to Germany. It delights in moist, grassy places, being much like the club-mosses in this respect. The name of prickly mountain moss is in allusion to the toothed leaves, though these are in no wise either spiny or prickly. The specific name also alludes to this cir- cumstance. In the days when this was thought to be a club-moss it was called Lycopodiiun selaginelloides, or the selaginella-like club-moss. Its transference to the genus Selaginella has made this specific name meaningless. THE CREEPING SELAGINELLA GROUP. THE CREEPING SELAGINELLA GROUP. HE genus Sclaginella contains by far the greater number of the fern allies, and the sub-genus StacJiygyjiandruni, to which our creeping species belong, comprises nearly three fourths of the species in the genus. The sub-genus, however, was not founded upon the creeping habit, for many of the spe- cies have erect or ascending stems, but all agree in having two sorts of leaves like our creep- ing species, thus sharply distinguishing them from the relatives of Sclaginella rupcstris. Notwithstanding the great number of species in this section it is very poorly represented in North America. It is a characteristically tropical group, and our species seem in the nature of un- usual extensions northward. 'The Creeping Selaginella. The creeping sclaginella par excellence, and the least conspicuous, is the one known to botanists as Sclaginella apus. What the curly grass or the little grape fern is to our other ferns, this species is to its relatives among the 156 THE CREEPING SELAGINELLA GROUP. fern allies. Owing to its small size, creeping habits, and general resemblance to the mosses and hepatics, it is very difficult to find for the first time; but when once its characteristic haunts are known, the collector finds it again with ease. The stems are from two to four, inches long and lie close to the earth, to which they are attaclied by numer- ous slender forking roots emitted from all parts of the CREEPING SELAGINELLA. Selaginella A/>us. plant. From the main stems, scattered, alternate, pros- trate branches are given off, the longest reaching a length of two inches or more and again branching. The leaves are borne on all parts of the stem and branches, and are remarkable not only for being of two sizes, but for being borne in two different planes. The larger leaves are scarcely an eighth of an inch long, ovate, acutish or obtuse, unequal-sided, with the broadest side toward the tip of the stem. They are very thin, witli serrulate margins and distinct mid-ribs, and are arranged alternately on the stem, from which they spread at THE CREEPING SELAGINELLA GROUP. right angles. Alternating with these larger leaves is a series of smaller ones attached to the stem on the upper side, to which they are closely appressed, with their tips pointing outward. These smaller leaves are about half the size of the others, and, like them, are somewhat unequal-sided. They are ovate at base and end in a tapering point. The fruit-spikes are half erect and are borne on the ends of the branches, from which they differ little in appearance except in being more leafy. They are ob- scurely four-angled, and the lens shows them to consist of four rows of sporo- phylls of equal size. This is explained upon the supposition that in the fruiting-spikes the two rows of small leaves on the stems have become as large as the others. The spikes are under half an inch long and are usually borne singly. The sporophylls are ovate, sharp-pointed, and keeled in the upper half. The majority of our selaginellas are found in dry situ- ations, but the present species is a lover of moisture and is found in wet meadows and pastures in company with mosses and sedges. It is frequently abundant on the bare soil at the base of sedge tussocks and on the sides of channels formed by tiny rills. It must often be sought on hands and knees, though it is occasionally so plentiful as to form close mats. In the vicinity of New- York it is frequently found on damp lawns. It is ex- ceedingly like some of the mosses of the genus Milium, but can always be distinguished from them by its leaves of two sizes. Its colour is of a characteristic and deli- Spike. (Enlarged.) 158 THE CREEPING SELAGINELLA GROUP. cate yellowish green, and in time becomes so well known as to be singled out by the eye at considerable distances. Most authorities consider this plant an annual, but this is clearly a mistake. It may be found as soon as the snow disappears, though the spores are not ripe until August or September. The beginner has the best chance of finding it early in spring, before the grass has begun to green. It is then most easily found in wet pastures and in grass fields damp enough to permit of a growth of mosses. The hue of its fronds makes it then very conspicuous. The creeping selaginella is found from Maine and Ontario to Florida, Texas, and British Columbia. In the greater part of its range it does not seem to be abundant, but its small size and resemblance to the mosses may often enable it to live undiscovered. Selaginella L,udoviciana. In the American tropics there are at least half a dozen species of Selaginella so nearly like the creeping sela- ginella that they might easily be mistaken for it, and the species called Selaginella Lndoviciana is one of this num- ber. Indeed it has often been suggested that Selaginella Lndoviciana may be only an erect variety of the com- mon creeping species, the differences it presents being accounted for by the different climate in which it grows. To one who has seen it in its native haunts, however, it does not appear to possess many of the characteristics oi Selaginella apus, except that in the shape and size of the leaves the two are nearly alike. The stems are from six to eight inches in length and strong enough to hold themselves nearly erect, and the roots usually appear Selaginella L iKhwiciana, THE CREEPING SELAGINELLA GROUP. 159 from only the lowest joints of the stem. The stem is bianclied as in Selaginella apiis, but the longer basal branches are nearly upriglit, though their branchlets, especially during the growing season, droop gracefully away from the main axis of the plant. This species begins growth early in the year, and by the middle of April the stems are mature. The sporan- gia are borne in the axils of the leaves at the tip of the branchlets, and the fruiting parts have more of a resem- blance to a cone than they have in Sciagiiiella apus, owing to the fact that the sporophylls are less spreading. The spikes of fruit are often more than half an inch long and are usually abundant. The spores are ripe in May or earlier. Although both kinds of leaves are like those of Sela- ginella apiis, it may be noted that they are slightly longer for their width and somewhat thicker than in that species. The sporophylls also have longer tips. These differences, however, are not apparent until viewed with a lens. Selaginella Lndovieiaua has thus far been found only in a few scattered localities in Florida, Alabama, and Louisiana. It was first discovered by Drummond at Covington, in the latter State. The author has collected it at Pearl River, and it has been found in several other places in the vicinity of New Orleans. Its favourite haunts are the more open spots in the sandy pine barrens. It does not appear to be quite so dependent upon mois- ture as the creeping selaginella but it is by no means a dry-ground species. It is probably not uncommon in suitable situations along the Gulf coast and may yet be found in Texas. The illustration is made from plants collected by Prof. R. S. Cocks at Mandeville, Louisiana. i6o THE CREEPING SELAGINELLA GROUP. Selaginella Douglasii. The species named Selaginella Douglasii is one of the rarest of the fern allies in collections. It is reported to grow in northern California, Oregon, Washington, and British Columbia, but it appears to be seldom found. It is more rigid than Selaginella apns, but has much the same appearance, spreading over the ground and rooting from various parts of the stem. This is a somewhat larger plant than the creeping selaginella, often reaching a foot in length. It is regu- larly and alternately branched, and these branches are Selaginella Douglasii, branched once or twice more in the same manner. The leaves are similar in size to those of Selaginella apns, but firmer in texture. The lateral rows are very blunt, but the small leaves, though blunt, are tipped with a short whitish point. The leaves are thickly crowded on the branches and branchlets, the lateral ones, as usual, PLATE VII. SELAGINELLA LUDOVICIANA. CCPyRlOHT, 1906, BY FREIERICK A. STCKES COMPA^ THE CREEPING SELAGINELLA GROUP. i6i spreading at nearly right angles to the stem, and the upper leaves nearly parallel to it. Both kinds are occa- sionally ciliate at base. The spores are borne in distinct four-sided cones, about half an inch long, on the tips of the branches. The tips of the sporophylls are blunt, and until maturity are closely appressed to the stem. The cone alone is nearly sufficient to distinguish the species. Our illustration was made from specimens col- lected in northern Oregon, kindly sent by Mr. J. B. Flett. The Resurrection Moss. There are two principal ways by which the scanty vegetation of the more arid parts of the earth manages to exist in spite of the lack of moisture. In plants like the cactus, with a thick epidermis, the moisture accumu- lated during the occasional rains is carefully hoarded and very slowly given back to the air. In other plants, lack- ing this thick epidermis, it has been found possible to dry up in the intervals between rains and revive again at the first return of moisture. Many ferns and various flowering-plants have this faculty, but none are better known because of it than the little plant called the resurrection moss {^Selaginella IcpidopJiylld). This is due in large measure to the itinerant venders, who, in their efforts to sell specimens of it, have told many won- derful stories about it. It is commonly asserted that it needs only to be placed in water for a day to develop a handsome spike of flowers. The truth of the matter is that, when dried, the plant curls up, forming a compact brown ball which may be preserved in that condition for months, and then, upon being placed in water, will uncoil 1 6: THE CREEPING SELAGINELLA GROUP. and become fresh and green again in a few hours, — a fact in itself ahiiost as marvellous as the stories told of it. The plants may be thus alternately dried and relaxed many times, but it should not be supposed that such plants are alive and will grow. The spreading of the fronds is simply due to the way in which the tissues absorb water. When rooted in the soil of their native home, however, they do not die during drouth, and when they relax again in the rainy season new growth really takes place. Selaginella lepidophylla is a native of our arid South- west, and there grows on the tops of the sunbaked rocks in regions where rain does not fall for a year or more at a time. During such periods its fronds remain com- pactly folded, their colours blending with the dry earth. When rain comes they at once awake and spread out in bright green rosettes, appearing as luxuriant as if drouths were unknown. Notwithstanding the trying conditions to which they are subjected, they often cover considerable areas as thickly as dandelions on a lawn. The branches, flattened dorsi- vent rally, rise from a central crown and produce roots only near the base. They are very numerous, from two to four inches long, with branchlets that fork at the ex- tremities in such a manner as to be nearly fan-shaped. The leaves are arranged in four rows as usual, those on the sides of the stem being an eighth of an inch or less in length, thick, oblong, minutely ciliate, and very obtuse ; those on the Branch of Resurrection Moss. >C X'^x. ::^f^^Wfl^ RESURRECTION MOSS. Selaginella LcpidopJiylla, THE CREEPING SELAGINELLA GROUP. 163 upper surface are nearly as long and scarcely differ in shape. The lateral leaves are ascending, but the upper rows are nearly parallel with the branchlets that bear them. Both kinds are closely imbricated, and are likely to be faintly white-margined. The fruiting-spikes are borne on the end of the branchlets. They are square, half an inch or less long, with triangular sporophylls strongly keeled on the back. In old plants the leaves turn a reddish-brown on the under surface. In recent years a considerable trade in this plant has sprung up, the large dealers ordering in lots of ten thousand or more. They are sold mostly to collectors of curios. Mr. J. H. Ferriss tells me that in the yards of settlers at the mouth of the Pecos River in Texas he has seen waggon-loads of this plant drying, preparatory to being shipped to Eastern dealers. Selaginella IcpidopJiylla is found in Arizona, New Mexico, and Texas in suitable situations. Though not widely distributed within our limits it is a very common species, and its range extends southward across the tropics to Peru. It is often called " bird's-nest moss," in allusion to the way the fronds roll up when dry. It is, however, most widely known as the resurrection plant. Selaginella Pringlei. This species, named for the veteran collector, C. G. Pringle, resembles Selaginella lepidopJiylla very much, spreading out in similar green rosettes in moist weather and rolling up when dry. The leaves are of the same size, but more pointed, and are further distinguished by being tipped with a hard, whitish, awn-like point nearly i64 THE CREEPING SELAGINELLA GROUP. as long as the body of the ieaf. The fruiting-spikes are short, with less triangular sporophylls. The plant has been collected in Mexico and was found in the Chenate Mountains of Texas by Neally. Owing to its being easily confusecl with Sclaginclla lepidophylla, but little is known about it, and even its range cannot be properly defined. More notes concern- ing it are very much needed. Both this species and the preceding, when growing, have a strong resemblance to the exotic selaginellas commonly cultivated, and, owing to their manner of growth in circular tufts, are desirable additions to the conservatory for their contrast to the other species. Selaginella Pilifera. According to Baker's "Fern AW'xqs,'' Selaginella pili- fera has been collected in Texas by Wright, but no recent collector has found it, and the opinion is held by most American students that the plant does not now occur within our limits. Its habitat is the plateau of central Mexico, and it may possibly stray northward in the Southwest. The following description should aid collectors in identifying it should they find it. The lateral leaves are ovate, oblique, very small, pale green, rigid, and tipped with a short point. They are serrulate, with the upper side of the base dilated and ciliated. The upper leaves are half as long as the others, lanceo- late, and also cuspidate. The spikes are square, less than half an inch long, with ovate-lanceolate strongly keeled sporophylls. From the foregoing it will be seen that it is a plant much like Selaginella Pringlei, and col- RESURRECTION MOSS. Selagindla Lepidophylla. When dry. THE CREEPING SELAGINELLA GROUP. 165 lectors who find the latter plant should look carefully for this one. In 1904 Mr. C. F. Saunders discovered in southern California an apparently undescribed selaginella, of the Selaginella rupestr is group, which has not yet been named. In the same year Mr. A. A. Eaton brought back from a trip to southern Florida specimens which have since been referred to the tropical Selaginella Caribensis a near ally of the creeping selaginella. This plant is not uncom- mon in the West Indies, but is likely never to be more than a rare or adventive plant in our territory. It is a stronger and heavier plant than the creeping sela- ginella and will be recognized at once from its resem- blance to that species. THE SALVINIACE/E, THE SALVINIACE/E, •INCE all vegetation requires a cer- tain amount of water for its processes, it is not unusual for various species of plants to be found growing in swamps and bogs, or even in lakes and ponds, but cases in which plants have entirely severed their connection with the earth and taken to floating on the surface of the water are far less common. In a survey of the vegetable kingdom, however, we find that all the great groups have species or even whole families that have adopted this mode of life. Among the flowering-plants the little duckmeats {Lcinna) are likely first to come to mind, but there is the great water hyacinth {Piaropus), of Southern waters, and many another, like the bladdervvorts, nearer home. Among the liverworts various species of Riccia are found float- ing, and even the ferns have provided an instance in that remarkable floating fern, Ccratopteris tJialictroides. It is not surprising, then, to find a family of the fern allies like the Salviniace^ committed to such an existence. Indeed it is sometimes suggested that the Salviniaceae ijo THE SALVINIACE/E. have arisen through some sucli ancestor as the floating fern, though as a matter of present relationships the species of this group appear to have closer affinities for the filmy ferns (Hymcnoplu'llace.x), especially as regards the formation of their sporocarps. In any event they arc probably more closely allied to the ferns than any of the other fern allies except the Marsiliacea^, and some are so much like ferns in their structure as to have received the common name of water-fern. As a class they are, with the Marsiliace^e, sometimes spoken of as the Hydropterids (which may be translated as water-ferns), or as Rhizocarps, which refers to the way the sporocarps are borne in these families. The Salviniaceae contain but two small genera, Sa/- vinia and Azolla, and these differ markedly in structure. All of them, owing to their position on the water, are dorsi-ventral, the stem growing horizontally. In Azolla, roots are sent down into the water, and at first glance this seems to be the case in Salvinia also, but a closer inspection shows that what appear to be roots in this genus are really dissected leaves and that the species are rootless. Above the water the vegetative leaves spread out, those of Salvinia oblong and entire, while those of Azolla are cut into more fern-like shapes. In most species numerous lateral branches are given off by the main stem, and these readily separate from the plant when the water is agitated, and form new plants. A rough day on the water, therefore, greatly assists in multiplying their numbers. The spores are of two kinds, as in Selaginella and Isoetes, and are borne in structures called sporocarps, or conceptacles which appear to be special forms of an indusium. They are much like what would result if the THE SALVINIACE/E. 171 urn-like indusia of tlie filmy ferns should completely enclose the sporangia. In Salvinia the sporocarps are borne on the submerged leaves, usually in clusters of three ; in Azolla they are borne in pairs in the axils of the aerial leaves. Some of the sporocarps in each cluster of Salvinia always bear megasporangia. There are about ten in each sporocarp, and each megasporangium bears a single large ovoid megaspore. The microsporangia are more numerous, globose, and contain a large number of microspores. In Azolla the pairs of sporocarps are usually of two sizes, the smaller bearing a single megaspore, and the larger producing several microspo- rangia and numerous microspores. The mature sporo- carps drop from the plant and promptly sink to the bottom of the water, where they continue to enclose the spores for some time. The latter are finally liberated by the decay of the walls surrounding them. The micro- spores of y4-S6'/Z^ are usually held together by a solid sort of protoplasm which produces hooked processes from the outer surface. The sporocarp appears to be an outgrowth Cross-seclion of Salvinia sporocarps. (Enlarg-ed.) Sporocarps of Azolla. (Enlar^ad.) of the leaf that, becrinnine with rounding the sporangia, slowly increases until it has completely enclosed them. Before this has happened, however, certain alge. to science, most of them in tropical waters. The name Azolla is derived^ from two Greek words meaning " to dry " and " to destroy," and is most appropriately applied to these delicate little plants whose life is so closely dependent upon moisture. There are less than half a dozen species in the world. Like the salvinias they delight in the warm waters of tropical regions. The species in both genera are very small, the largest having leaves not more than two inches long, while in a majority they do not reach a length of half an inch. All are supposed to be short-lived, possibly annual plants, but a few seem to live to a greater age. A dozen or more species of Salvinia have been found in a fossil state, but usually in deposits of no very great age. SALVINIA. SALVINIA. |t may be seriously doubted whether any species of Salvinia is native to North America. In all books devoted to the Pteridophytes we are credited with one species, Salvinia natans, but the evidence to show that it is a native or even natural- ised is far from convincing. It was re- ported from western New York by Pursh about a century ago, but the exact locality has always remained unknown, if it ever really existed. The only other record is the station at Oscher's Lake in the Bois Brule bottoms in Perry County, Missouri, where it was collected by C. H. Demetrio in November, 1886. Mr. Demetrio has kindly favoured the author with part of the original collection in fine fruit and with an account of his finding it. It was collected but once, with Azolla, while on a fishing-trip to the lake, and was not noticed among the other specimens until they were being pre- pared for the press at home. It has apparently never been seen since at this station, nor has it ever been collected elsewhere in a location entirely free from the suspicion that it may have been introduced, and it seems but fair to conclude that the plant is- not native to North America. Paradoxical as it may seem, this plant, so rarely found 76 SALVINIA. Salvitiia nalans. in this country, is really quite abundant, but always in cultivation. Few greenhouses in which there are tanks of water plants are without it, and it has become domes- ticated, as it were, in many-small ponds, fountains, and artificial lakes. So far as known it has show n no tendency to spread to other waters unless its occurrence at 0*s c h e r ' s Lake is an in- stance. The main axis of Salvinia natans may reach a length of two or three inches, but is usually shorter. Along this the leaves are thickly clustered in several longi- tudinal rows. Two of these rows on the under side of the stem are finely dissected into thread-like divisions, and go down in- to the water functioning as roots, since there are no true roots ; the others float on the surface. These latter are half an inch or less in length, bright green, almost as broad as long, with a very blunt tip, and slightly heart-shaped base. Above they are thickly set with very short, Sporocarps of SaWinia. soft, branching hairs that, though apparently so insignifi- cant, are of great importance to the plant, since they keep it right side up in the water. It is practically im*. possible to make these plants float with the upper surface downward, for the tiny hairs hold great numbers of air SALVINIA. 177 globules among them, which push the plant back as soon as it is overturned. Thus the plants can ride secure in the heaviest storms. On the under side of the leaves there are also numerous fine brown pellucid hairs. The sporocarps are from four to eight in a cluster, and are borne on a common stalk arising from the submerged leaves. With the exception of the two questionable stations in the United States, Salvinia natans is found only in the Old World, extending from the south of France to India and northern China. It thrives well in sunny pools, spreading rapidly by division of the plant body. It is also easily grown in a dish of water in the house. Crayfish are said to feed upon the plant when other food is scarce. THE AZOLLAS THE AZOLLAS, c£^|i. HE azollas are the members of the Salvin- iaceae oftenest called the water ferns, 7^'^K and their finely divided fern-like fronds ^^- ' well merit the name. Thous^h few in ,^^..%,^ number of species, and small and deli- ^"'^' cate as individuals, they have a wide distribution and are found in all the warmer parts of the world. In North Am.erica we have two species, one Western and the other with a wider range. A^olla Caroliniana. If asked to name the smallest of the North American fern allies one need have no hesitancy in mentioning Azolla Caroliniana. With the exception of its Western congener there are no others that even approach its diminutive proportions. Three or four full-grown plants may be hidden under a single copper cent, and yet so abundant is this species that vast stretches of water are often completely covered by it. Taken singly, the plant is a handsome one. Its stems, so slender as to be invisible to the eye, fork several times, and are covered with the tiniest of two-lobed over- lapping leaves, from pale green to deep red in colour. iS2 THE AZOLLAS. As they float on the surface of quiet pools their resem- blance to small green and red snowflakes is more than an idle fancy. From the stems slender rootlets go down into the water, and should it happen that the. plant is stranded by reason of the lessening of the pools in summer, the rootlets ape able to strike into the mud and so continue the existence of the plant. There is some reason for be- lieving that the difTerences in the colour of the fronds are due to differ- ences in habitat, those growing on the water in full sun being usually tinged with red, while those that root in the Azoiia caroiiniana. ^ud are nearly always deep green. (Enlarged.) This spccics is supposcd to be an annual, but the author has found it, though in lessened numbers, in mid-winter in New Orleans, often in pools liable to have a thin coating of ice. It develops very rapidly with the return of warm weather, and by mid- April the pools back of the levees along the lower Mississippi are entirely covered by it. Some idea of its possibilities of growth may be gained from a note by Prof. R. S. Cocks, in the Fern Bulletin for 1904, in which he says that in Audubon Park, New Orleans, between the months of June and September, there was removed from the surface of a pond about a quarter of an acre in extent no less than fourteen cartloads of this plant, with a total weight of seven tons. The sporocarps are borne in the axils of the leaves, and in addition to the spore-cases nearly always contain the resting bodies of a certain alga {Anabcena acollce.) As soon as the spores begin to geriliinate, these resting bodies of the alga do the same, and as soon as the J% SB- '■#^/- J THE HOME OF AZOLLA. THE AZOLLAS. 183 Azolla leaves are developed, they creep into the hollow interior through a pore at the base of the larger lobe of the leaf, and there form colonies. These colonies are nearly always found in Azolla leaves. Azolla Caroliniana appears to grow naturally as far north as New York, but in the northern part of its range it is never so abundant or so conspicuous as it is nearer the equator. It is found throughout the South and extends to Arizona and Washington. It occurs in the Mississippi valley at least as far north as Iowa, but its northern range is not well defined. Beyond our limits it is found in suitable places as far south as northern Patagonia. It delights especially in still waters and is seldom found in streams. It is easily cultivated in ponds where it does not gr'ow naturally, and has been thus naturalised in many places, one of the best known of which is on Staten Island, New York. Azolla Filiculoides. With the exception that Azolla filiculoides is a slightly larger plant than Azolla Caroliniana, it is almost exactly like it to the unaided eye. Study with the lens, however, shows that the branching in the present species is inclined to be pinnate in form and the fronds elon- gated, while in Azolla Caroliniana they are more deltoid in outline. The large lobe of the leaves in Azolla fili- culoides is ovate, while that of the other is rhombic- oblong and obtuse. Azolla filiculoides is widely distributed in South America, being most abundant on the Pacific slope, and, according to Baker, is found in the Andes up to an ele- vation of 16,000 feet. Within our limits it extends to 1 84 THE AZOLLAS. California only, but is often abundant- there. It has tlie same habitat as our common species and appears to thrive in cultivation. Mr. Eaton states that he has seen ditches in California covered two inches deep by the multitudes of this plant. Azolla Filiciiloides, (Enlarged.) THE MARSILIACE/E, OR PEPPER- WORTS. THE MARSILIACE^. f^^N account of the way in which the spores originate, the Marsiliaceae and Salviniaceye are believed to be closely allied. They present several differences, however, quite as strik- ing as their resemblances. All are lovers of the water, but while the species of Salviniacea^ are floating, those of the Marsili- aceae are rooted in the mud in swampy places or at the bottom of ponds. The species of the first are all regarded as annual, while those of the latter are said to be perennial. Both bear their spores in sporocarps, but these are very different structures in the two families. In the Salviniaceae the sporocarp represents a single sorus like that of ordinary ferns ; in the Marsiliaceae the sporocarp is really a modified leaf and contains several sori. It may be likened to the berry-like structure that encloses the sori in the sensitive fern {Onoclea). Like the Salviniaceae, this family also consists of two small genera, Marsilia and Pihilaria, both most abundant in the waters of the warmer parts of the globe. Although more closely related to the ferns than any of the other fern allies, the Marsiliaceae are far from ferns in appearance. Nor do they have a greater resemblance i88 THE MARSILIACE^. Veiningin leaf of Marsilia. to any of the fern allies. The leaves of the marsilias are always four-parted, with slender petioles and much resemble those of oxalis or four-leaved clovers. Those of Piliilaria are slender tapering organs, in outward ap- pearance like the leafstalks of their relatives. In both genera the leaves rise from a jointed branching rootstock growing parallel to the earth and sending down abun- dant rootlets from the joints or occa- sionally from other parts of the stem. The leaves are coiled in the bud, like those of the ferns, and in Marsilia they are veined like them. The sporocarps are from one to six in number and are borne on short pedi- cels that spring from the petiole of the leaf. Usually they are so close to the stem as to appear to be borne in the axils of the leaves, though in one exotic species, Marsilia polycarpa, they often number as many as twenty, and are strung along the petiole for some distance, each on a separate pedicel. In Piliilaria they are usually solitary. In Marsilia the sporocarps are oblong, and in Piliila- ria they are round. From their shape and size, like peppercorns, the mem- bers are sometimes called pepperworts. The Pilnlaria sporocarp contains from two to four chambers, each of which contains a single sorus bearing megasporangia at the base and microsporangia at the tip. The megasporangia each contain but a single megaspore, while the microsporangia contain numerous microspores. In Marsilia each half of the sporocarp may be considered as a single cell, but Spo roc a rp of ATars ilia . (Enlarged.) mmm THE MARSILIACE^. 189 these arc separated by many transverse divisions, each containing a sorus. Around the inner wall of the sporo- carp runs a gelatinous ring to which the sori are attached, and, when the sporocarp opens, this ring absorbs water and increases enormously in size, by this means pushing out of the sporocarp and drawing the sori with it. The whole process may be completed in half a day, and may be witnessed by any who will take the trouble to soak a Marsilia sporocarp in waten Before soaking, a small part of the outer covering of the sporo- carp should be chipped off, so that the water may enter. The small oblong sori, attached to the almost transparent ring ^^^M^^^ of jelly, make it a most interesting object. ff ..,, . f . -iiir 1 1 Cross-section of An illustration 01 it will be tound at the PUuiaria sporocarp. U • • r ,.1 • 1 4. T7 1 (Enlarged.) beginning 01 this chapter. h.ach sorus contains both megasporangia and microsporangia, the former few in number and each containing a single ivory- white megaspore. The sporocarps have a very thick, hard wall almost impervious to water, and may remain beneath the water for a long time without opening. So nearly impervious to liquids are the sporocarps when uninjured, that they have been kept in 95^ alcohol for nearly six years, and then the spores still had vitality enough to germinate. Sporocarps dried and kept in the herbarium for eighteen years have also produced spores capable of growing. The sporocarps of Marsilia finally open by splitting into halves. Those of Pilnlaria split into four valves from the apex. Since the sporocarps are modified leaves, the four valves of the .Pilnlaria sporocarp may be taken to indicate that the original leaf was like that o{ Marsilia. Baker therefore states that the leaf in Pilnlaria is now I90 THE MARSILIACE^. merely a filiform petiole. The prothallia are very rudi- mentary and develop with great rapidity. According to Campbell they may develop from the spores and produce mature sex-organs in twenty-four hours. There are nearly fifty species in the genus Marsilia, mostly in tropical regions. Of Piliilaria there are about six species, widely distributed. Marsilia was named for an early Italian naturalist, Aloysius Marsili. Pilularia is from the Latin word for a '* little pill," and is in allusion to the small pilWike sporocarps. Key to the Marsilias. Sporocarps usually two on each peduncle. Eastern. M. qiiadrifolia Sporocarps rarely more than one on a peduncle Plant nearly smooth. Southern . . M. uncinaia Plant densely hairy. Western . . M. vestita Plant larger, less hairy. Southwestern M. inacropoda THE MARSILIAS. THE MARSILIAS. HERE is scarcely a genus of plants anywhere whose species have a more general resemblance to one another than the genus Marsilia. The four-leaved clover is the un- varying pattern after which the leaves are cut, and when the collector has once seen a single species he will have no trouble in referring sub- sequent finds to its proper genus at least. Specific differences are found in such matters as size, hairiness, and the number and arrangement of the sporocarps. At least four good species are known within our limits, only one being found in the Eastern States, the others beincr confined to the West and Southwest. Marsilia ^luadrifolia. Marsilia quadrifolia is a common species of the Old World extending from southern Europe to India, China, and Japan. In America it has been found at only a single station, Bantam Lake, Connecticut, and this cir- cumstance has suggested the idea that it is not really native to our country. But, if not a native, the plant has become so thoroughly settled in its home that it may justly be claimed as a naturalised member of our 196 THE MARSILIAS. flora. From the original station plants have been sent to many other places, and in each they have grown luxuriantly, vying with the natives in their ability to hold their territory and to gain more. The pretty oxalis-like leaves resting upon the water or rising a short distance above it may be counted as an addition to our lakes and ponds, while the ease with which it may be grown makes it a general favourite. It may even be grown in a tub in the back yard, and is often seen in conservatories. In its native haunts Marsilia qtiadrifolia usually roots in the mud beneath shallow water, the very slender rootstock, a yard or more long, creeping above the soil and sending up. great numbers of leaves on slender petioles that elongate until they reach the surface. While this is the usual habitat, it may often be found quite out of water at midsummer. The leaves are then quite short, but such plants are usually very fruitful. The joints of the stem are short, and from each is pro- duced a tuft of roots and a leaf. In the bud these leaves are coiled and the four divisions folded together, but as they reach the air they unfold and spread out on the water like the leaves of the water-lily. In vigorous specimens the petioles often hold the young leaves above the water. In outline the blade is nearly circu- lar, from half an inch to two inches or more in diam- eter, and is divided into four equal leaflets, wedge-shaped at base and rounded on the outer margins. The divisions are marked by numerous fine veins that run from the petiole to the margin, forking several times. The young leaves are more or less hairy, but when full grown they are smooth. The .cporocarps are about half the size of peas and are PLATE VIII. MARSILIA QUADRIFOLIA. COPYRIGHT, I9C5, BV FREDERICK A. STOKES COMPANY THE MARSILIAS. i97 borne two or three together near the base of the leaves. The common peduncle is about half an inch long, with a short stalk for each sporocarp and is usually united for a short distance with the petiole of the leaf. In colour the ripe fruits are dark purplish brown. When young they are clothed with minute yellowish hairs, but at maturity these disappear. The fruit is most abundant in shallow water. At the point where the pedicel appears, to join the sporocarp there project from it two small points called teeth. In this species the teeth are very short and obtuse. There are from sixteen to twenty sori in each sporocarp. Like the clover and oxalis, which it resembles, this species has the habit of closing its leaves at night. This is done by two of the leaves rising, folding face to face, and then being enfolded by the other two in the same position they had in the bud. The reason for this so- called sleep position is doubtless to be found in the fact that, like most water plants, the stomata or openings for transpiration are found on the upper surface, and this folding is in some way concerned with their protec- tion. It is noticeable that only the young leaves or those rising above the water display these movements. When taken out of the water the leaves quickly close as in the night position. Baker spells the specific name quadrifoliata, but American writers do not. Marsilia Uncinata. Mar si Ha uncinata is commonly regarded as a rare species, and in the latest edition of Underwood's text- book it is recorded from but two stations in the United 198 THE MARSILIAS. States. Ill reality it is an abundant plant in Louisiana, at least, being common for more than two hundred miles along the Mississippi. It probably occurs in moist grounds throughout the State. In the city of New Orleans it may be found along many roadside ditches, and in one street that the author knows of it grows quite across the street. In books devoted to the fern allies, all the dimensions of the marsilias are rarely given. The length of the petiole depends almost entirely upon the depth of the water in which the plant grows, yet measurements of it are usually included, while nothing is ordinarily said about the length of the rootstock. In the present species the author has found rootstocks more than a yard long, and longer ones are probably common. Observations on this point for all our species are much to be desired. In the size and shape of the leaf this species is almost like Marsilia qiiadrifolia. The blade, however, is likely to be sparsely hairy, even at maturity. The plant requires a wet soil, but is probably as common out of water as in it. It is often found, however, rooted in the shallow water on the edges of the bayous and sending long floating stems into deeper water. It bears fruit only on the stunted plants in drier situations, so that fruited herbarium specimens rarely indicate the beauty of this plant at its best. The sporocarps are as big as peas and are borne singly on peduncles half an inch to an inch or more long, which appear to rise from the axils of the leaves. They are sparingly clothed with pale -brown hairs, even when ripe. The peduncle terminates in two rather conspicu- ous teeth, the upper of which is usually hooked, from which circumstance the plant derives its specific name. Mars Ilia Quadri folia. MiU'silia Uncznata, THE MARSILIAS. 199 There are often twenty-four or more sori in each sporo- carp. A specimen is illustrated on page 188. Marsilia uncinata is now known to occur from Louis- iana to eastern Texas, and it is probable that its range will be still farther extended. It appears to be plentiful in the delta region of the Mississippi. When first described it was thought to be a variety of Marsilia ves- tita, but its longer rootstock, less hairy leaves, and spo- rocarps will distinguish it from that species. In its natural habitat Marsilia uncinata may be singled out from the surrounding vegetation for some distance by the peculiar fresh green colour of the leaves. During the winter months either the plants disappear, or the rootstocks remain in a resting condition without leaves, though they reappear early in the new year. Marsilia Vest it a. The smallest of our marsilias, and the one with the least predilection for a watery habitat, appears to be Marsilia vestita. While it often grows in shallow water it is usually found on wet muddy banks, where it may either grow in dense tufts or put forth short exten- sions of its rootstock. The petioles are from one to five inches long, and the leaves quite small, usually under an inch in diameter. Both leaf and petiole are clothed with soft, short, white hairs that may be either spreading or appresseil. These are so numerous on the younger parts of the plants as to give them a hoary appearance. The outer edge of the leaflets is rounded, entire or occasionally slightly toothed. This is a variable plant, however, and all the characters do not hold for single specimens. 200 THE MARSILIAS. The sporoCcirps are smaller than those of Marsi/ia unciiiata, but larger than those of MarsiUa quadrifolia. They probably average a little less than a quarter of an inch long. They are borne on peduncles so short as to appear sessile or nearly so, and are densely covered with the fine whitish hairs found on other parts of the plant. The lower tooth of the sporocarp is short and blunt; the other is slightly longer and curved. Marsiliavestita\?> found from Dakota and Washington to Texas and California. Southward it extends into Mexico. It has been reported as naturalised in central Florida, and according to Baker it is found in British Columbia also. Mr. A. A. Eaton notes that in the San Joaquin Valley, California, it is called '' horse-clover " and is greedily eaten by horses. Prof. C. E. Bessey, how- ever, reports in the Fern Bnlletin that it is becoming a weed in several wet meadows in Nebraska. Campbell asserts that it is an annual, but upon this point more notes are desirable. Mr. Eaton is of the opinion that while the leaves may die the rootstock does not. Like an exotic species, Marsilia Jiirsuta^ it is said occasionally to bear tuber-like bodies on the ends of certain branches of the rootstock, which under proper conditions may pro- duce new plants. Marsilia Macropoda. The species called Marsilia macropoda is like Marsilia vcstita in being more or less hairy, but it has a longer rootstock, much larger leaves, and sporocarps that are borne in clusters of from two to four instead of singly. It also probably lives longer than Marsilia vest it a. Marsilia Vestita, THE MARSILIAS. 2o[ The rootstock of this species is like that of Marsilia qiiadrifolia in being wide-creeping. It grows beneath the water and sends up its large leaves to the surface. These are often two inches or more across, with deltoid seg- ments having a rounded outer edge. Both sides bear silky whitish hairs that seldom fall off at maturity. The sporocarps are about a quarter of ajT inch long and are very densely covered with long, tawny, hair-like scales. The teeth are very small, the lower one often absent. There are about twenty sori in each sporocarp. Marsilia iiiacropoda has been thus far found only in southwestern Texas and New Mexico. The woolly nature of the leaves and fruit suggests that it may be an extreme form of Marsilia vestita that has been modified by its different habitat. While it is a lover of water it may often be exposed to the air by the drouths of sum- mer, and appears to be most fruitful when growing with the minimum of moisture, as do most of the marsilias. Baker writes the specific name macropiis. Marsilia Tenuifolia. So far as known, the plant called Marsilia ienuifolia has been collected but twice, both times in western Texas. It has a close resemblance to Marsilia vestita and by some is thought to be a form either of that species or of Marsilia macropoda. It is described as being slenderer than Marsilia vestita with an extensively creeping root- stock. According to Underwood the leaves are villous with appressed hairs and toothed on the margins ; accord- ing to Baker they are nearly or quite smooth, with entire margins. The sporocarps are said to be borne singly upon short pedicels and to be tomentose. I 202 THE MARSILIAS. The plant has been so seldom seen as to be practically unknown, and it is small wonder that the authorities disagree regarding it. Until we have more definite information it seems permissible to consider it a form of Mars ilia vest it a. Ma?' si Ha Macropoda, THE PiLLWORT. THE PILLWORT, IE only American representative of the genus Pilulnria is that rare little plant called Pilnlaria Americana. In structure it resembles a very small species of Marsilia without leaf -blades. It grows among grasses and sedges in wet places, but is seldom found in standing water, though it may be in- undated at certain seasons of the year. The rootstock is fine and thread-like and creeps close to the soil, sending down a tuft of roots from each joint of the stem, while above rise the slender leaves. In our plant these are seldom more than two inches long, are very slender, and taper to a point like those of the quillworts. Like the leaves of the ferns they are coiled in the bud. The sporocarps are borne on short stalks in the axils of the leaves and are a /i 2o6 THE PILLWORT. little more than one twelfth of an inch in diameter. They are round and dark brown and contain four cells, in each of which is a sorus bearing megasporangia and microsporangia. From the shape of the sporocarps this plant gets its name of '* pillwort," while an allied species is known abroad, by the name of *' water-pepper," from the same circumstance. PihUaria Americana has been found in a few localities in California and Oregon, and is reported from Arkansas also. It is quite likely that it grows in many other places where its size and shape, so much like the imma- ture rushes and sedges surrounding it, may aid it to go undetected. This species has also been found in Chili. An allied species is found throughout Europe. Mr. S. B. Parish, writing of the habitat of our species in the Fern Bulletifi, says : " In winters of abundant rainfall little pools form in the hollows of the clay mesas about San Diego, and on the surface of these pools and on their muddy margins these plants find a congenial home. Often successive years pass with rainfall insufficient to maintain these pools, and consequently without affording the pilularias an opportu- nity for growth." The plants are thus apparently annuals, though all the species of Marsiliaceae are regarded as perennials. PILLWORT. Pihdaria Americana. THE ISOETACE/E, OR QUILLWORTS THE ISOETACE^E, HERE is doubtless no fam- ily of plants so little known to the botanists of the regions in which they grow as the Iso- etaceae, or quillworts. The flowers, fruits, and leaves of the flowering-plants make them conspicuous ; the ferns, lacking flowers, are still noticeable from the beauty of their fronds ; and even the fern allies, with the present exception, may attract attention by reason of their strange forms and curious manner of growth ; but the quillworts, most of which pass their whole existence beneath the waves of lake or river, far removed from the other objects of the botan- ist's pursuit, ordinarily escape observation, or, if seen, are dismissed with the thought that they are immature specimens of some sedge or rush. Even the botanists themselves for a long time paid little attention to them, usually referring such forms as were found to the single 210 THE ISOETACE^. species Isoctes laciistris. Although numerous species are now known to occur in the waters of the Eastern States, the eai'ly volumes on the flora of the region make no mention of them. Scarcely fifty years have passed since botanists began to study these plants understand- ingly, and students are yet by no means agreed as to the limits which shoulc| separate various species or the posi- tion they should occupy as a group in botanical classi- fication. Baker, in his '' Fern Allies," places them in the Selaginellaceae ; Campbell, in ** Mosses and Ferns," considers them closely related to such ferns as the adder's-tongue {OpJiioglossuni) and the moonwort {Botry- cJiiiini) ; while still others believe that their structure indicates a closer connection with the pines and their relatives. They are nowada3's usually placed in a sepa- rate order, family, and genus, as we have placed them in this volume. Notwithstanding the close superficial resemblance be- tween the quillworts and other water vegetation, the difference between them is quickly recognised as soon as one has become acquainted with a single species. A quillwort is essentially a rosette of short, hollow, cylin- drical, pointed leaves with sporangia in their axils. The central axis to which these leaves are attached is short and flat, so that there is never"produced an elongated stem, as in the other fern allies. If one can imagine a fruit-spike of Selaginella in which the axis has failed to develop, and in which the sporophylls have lengthened into quill-like though flaccid leaves, he will have a good idea of the typical quillwort. The resemblance of the plant body to the bulbs of flowering-plants has also been frequently noted. The trunk, main axis, or rootstock, though flat and THE ISOETACE^. 211 tuber-like, has a central vascular bundle surrounded by a region of growing cells that annually produce new bark on one side and add to the vascular tissue on the other. At two or more points this tissue is more active than at others, with the result that mature rootstocks are either two, three, or more lobed. In the hollows between these lobes, the roots are given off, and these are peculiar for forking two or three times like the selaginellas, instead of branching irregularly as those of most plants do. The leaves number from ten to two hundred and are arranged spirally on the upper part of the rootstock. At the point where they join It they are wide and somewhat triangular in cross-section, but above they approach cylindrical in form. In length they range from less than two inches to more than two feet. Running lengthwise through the centre of the leaf is a bundle of bast which, with the surrounding tissue, separates the hollow interior into four parallel chambers containing many cross-parti- tions. In addition to the cen- tral strand of bast there are frequently four others, called peripheral bast bundles, near the surface. One of these is at the back on the outer side, another is in the middle of the inner face, and the two others are found on either side of this on the inner edges of the leaf, of our species the peripheral bast bundles are ^'"™" absent ; when two are present they will be found to be the dorsal bundle and the one in the middle of the inner face. The two on the inner edge of the leaf are usually absent. Cross-section of leaf near base. Leaf In most ^h°^'"^ All iiiKjsL sporan- 212 THE ISOETACE^. Only the outer earlier whorls of leaves produce sporan- gia. When the spores are ripe the fertile leaves slowly decay, but the sterile, somewhat rudimentary leaves remain green through the winter. In the terrestrial species these leaves may form somewhat spiny processes. The tips of ordinary leaves usually end in a long taper- ing point, which, with the hollow interior, is probably responsible for the name of quillwort applied to the plants. The quillworts are usually about four years old when they begin to bear spores, and, as might be expected, their manner of fruiting shows most plainly their rela- tionship to the fern allies. Their resemblance to the selaginellas is particularly striking, since they bear two kinds of spores. These are produced in the axils of the outer leaves in a hollowed-out portion of the leaf. In each of these hollows is a single oblong sporangium which may occasionally reach a length of more than a quarter of an inch. Over this sporangium the substance of the leaf projects in the form of a thin indusium or velum, in a few cases entirely covering the sporangium, but usually leaving a third or more exposed. The sporangia are said to be one-celled, but they contain partitions that divide them into several incomplete chambers. This feature is also found in fossil Icpidoden- drons. Just beyond the sporan^^ium there arises from the inner surface of the leaf a small, thin, triangular flap called the ligule. It is most strongly developed in ter- restrial forms, but its use is unknown. In many species some of the cells in the walls of the sporangium become thickened, giving it a spotted appearance which is some- times considered of diagnostic importance. The spots, however, are not visible to the unaided eve. THE ISOETACE^. :»3 The sporangia in the outermost leaves contain numer- ous large spores called megaspores, macrospores, or gynospores, while nearer the centre of the plant similar sporangia bear a much larger number of smaller spores called microspores or androspores. The megaspores always produce female prothallia, and the microspores those of the opposite sex. The megaspores are about one fourth the size of a pin's head, but are large enough to be seen with the unaided eye. Under a lens strong enough to resolve their structure they appear as spheres of dazzling white encircled by an elevated ridge near the middle, called the equator, and with three other ridges called commissures going from the equator to meet in the centre of the upper hemisphere. One half of the spore is thus divided into three nearly equal areas, while the other is with- out ridges. Between the ridges, especially on the upper hemisphere, the surface is thrown into many curious patterns in which spines, crests, pits, Megaspores. (Greatly enlarged.) and labyrinthine forms predominate. Each separate species has its own pattern of marking, and thus the spores afford important characters for identification. The white coating of the spores has been found by Mr. Raynal Dodge to be silica, the same flinty matter that gives roughness to the stems of the scou ring-rush. The microspores are about one thousandth of an inch in length and very numerous. According to Dodge there may be as many as a million spores in a single sporangium. They are usually oblong, somewhat triangu- 214 THE ISOETACE.E. lar in cross-section, and have a smooth papillose or spiny surface mimicking the megaspores. The size of the spores is usually given in thousandths of a millimeter, the Greek letter f^ standing for a single thousandth. Three hundred and fifty thousandths of a millimeter would be written 350". The prothallia of the quilhvorts lack '/-^ chlorophyll, and, like the prothallia of /.;;'^jr C^^L^A Sclaginella, do not separate from the ^*^^^^r"^ spores. At maturity the spore simply Microspores. opcns along the three commissural (Greatly enlarged.) . . • . i \ • i • ridges, exposmg the arcnegonia, and ni this position the eggs are fertilized by the* sperms. Some of the aquatic forms have the power of producing buds in place of sporangia, and these finally float away and become new plants. Of the fifty or more species of Isoetes a large number dwell constantly on the bottom in lakes, ponds, and slow-moving streams, at depths of from one to ten feet beneath the surface of the water. Others, however, occur in such situations that the receding water in sum- mer exposes them to the air, while a few are rarely if ever submerged, though they always grow in wet places. Those that are exposed to the air have stomata or breathing-pores, but those always beneath the surface have none. It is interesting to observe that in those species that are only occasionally exposed to the air, the stomata are found only on the tips of the leaves, in the position where they would be most useful to the plant should the water leave any part of it exposed. The species of Isoetes are so much alike externally that for exact identification a compound microscope is neces- sary. An examination of the ripe mcgaspores alone is THE ISOETACE.€. 215 usually sufficient to indicate the ^roup to which the l^lant belongs, but other considerations must often be taken into account in naming the species. In the fol- lowing pages, illustrations of the megaspores only have been given. These all have the same magnification, so that the comparative size of the spores may be easily seen. It is expected that when the plants are better known than at present the species will be more easily distinguished, because more accurately described. Fur- ther notes on all our species are greatly desired. The word Isocics is said to be derived from two Greek words meaning ** equal " and "year," and was applied to these species because of the perennial character of the leaves. The species are widely distributed throughout the world, but are most plentiful in the glacial lakes and the streams leading from them in the northern hemi- sphere. They are an isolated group not closely con- nected with any other living forms, but exhibiting in their structure certain features that seem to indicate that the modern monocotyledons, to which the grasses, lilies, and orchids belong, may have arisen from the same parent stem. As recognised at present, Isoetes is the only genus in the family Isoetaceae, and this family the only one in the order Isoetales. Key to the Isoetes. I. — Plants normally submerged Spores with low tubercles or warts, /. Bohiftderi Spores with slender spines . . /. echinospora Spores with short rounded crests . /. Macoimi Spores with worm-like crests . /. hieroglyphica Spores with thin crests sparingly anastomosing /. lacustris Spores with many anastomosing ridges /. Tuckertnani II. — Plants normally exposed in summer Indusium complete Spores with fine warts . . /. vieIn7iospora Spores with heavy tubercles . I.Jiaccida Indusium incomplete Spores with faint crests and warts /, Hcnuelli Spores with numerous truncate spines /. Gravesii Spores with spines and short crests Mostly spinulose . . /. saccharata Crests often anastomosing /. 7iparia Spores reticulated Ridges sub-continuous . /. Canadensis Ridges anastomosing Ridges thin . . /. Engelmanni Ridges moderately thick /. vah'da Ridges very thick . /. foveolata III. — Plants seldom if ever submerged Spores smooth . . . /. Orcnffi Spores faintly warty Warts few . . . /. Niittallii Warts many Commissures wide . /. vielanopoda Commissures narrow . /. Buileri Spores with short spines . . /. inininia THE AQUATIC QUILLWORTS. THE AQUATIC QUILLWORTS SERIES of Isoetes specimens could easily be selected which would show every gradation from the most deeply sub- merged plants to those habit- ually living in dry ground, but such a series would of ne- cessity include specimens of many species. The water-loving species, however, keep close to their own element, and it is only under excep- tional circumstances that they appear above the surface ; while the terrestrial forms are for a great part of the year entirely above water, though growing in moist places. Between these two there are certain species that always live for a part of the year under water and a part of the year exposed, so that for purposes of study it is very convenient to divide the genus into three groups containing aquatic, amphibious, and terres- trial species respectively, though a hard and fast line between them cannot be drawn. The species of the first group have been selected for description in this chapter. Brauns ^uillwort. If, while floating upon the quiet surface of some small mountain lake, the collector should dis<:ern. two or three 220 THE AQUATIC QUILLWORTS. feet below the surface, a colony of plants like small green rosettes, he may conclude that he has found Braun's quillvvort {Isoctes ecJihiospora Braunii). Since all the aquatic quillworts have the same general plan for the plant body, it is possible that such a conclusion may have to be modified later and his specimens referred to some other species, but Braun's quillvvort is so abundant and so widely distributed that until its spores have been ex- amined one is fairly safe in assuming that any new find is this species. The leaves are from ten to thirty in number and occa- sionally reach a length of ten inches, though the average is probably less than five. They are dark green, occasion- ally reddish at base, and while in the water are half erect. When fresh from the water they are somewhat rigid and inclined to curve backward. There are a few stomata present on the tips of the leaves, but the peripheral bast bundles are absent, as is usual in the submerged species. The sporangium is pale spotted, and the velum or in- dusium about half covers it. The principal distinguishing charac- ter is found in. the megaspores. These are from 350 /" to 550/^ in diameter and covered with broad spinules which are often forked or toothed and sometimes recurved. Occasionally, too, the spin- ules may become confluent into short Megasporeof crcsts. The microsporcs are from 26/^ Isoetes echinospora Braunii. ^q 30 /^ in length, white or grey in colour, smooth, and very numerous. Three hundred thousand microspores have been found in a single sporangium. The spores retain their vitality for some time, and plants have been raised from the spores taken from herbarium specimens. BRAU N 'S QU I L LWORT. Isoetes echinospora Braimu. THE AQUATIC QUILLWORTS. 221 The typical Isoctcs ecJiinospora is an Old World species found in the lakes of northern and central Europe. It differs from our plant in having an unspotted sporangium, a narrower indusium, and no stomata. These differences have been considered sufificient to make our plant a sepa- rate variety. There can scarcely be a doubt that the two forms have arisen from a common ancestor. Our plant holds the same position in North America that the type does in Europe. In the "Ferns and Fern Allies of New England," Dodge gives its habitat as ''margins of ponds often wholly submerged ; also on the muddy shores of streams or on the tidal tracts of rivers, often where the water is very brackish." The author has seen it in many of the small glacial lakes of northern Pennsylvania, but he has never collected it in a locality in which it was ever likely to be above water. There seems, therefore, to be some difference in its habitat in different parts of its range. The fact that it bears stomata may be taken as an indica- tion that it is prepared for an occasional exposure to the air. Our plant ranges from Pennsylvania, Utah, and Wash- ington to Alaska and Greenland. Ac- cording to Baker it is also found in Iceland. The American plant has several forms or varieties. A stouter plant with more numerous leaves and abundant stomata is called the variety robtista, and a form with long slender 1 ^1 -'111.1 ]Mej,'aspore of spmules on the megaspores is called the isoeus echinospora ,-, . . . vniricnta. variety Boottii. Kobiista is recorded as growing in Vermont and New Hampshire, and Boottii has never been found except in the few localities in Massachusetts where Boott first found it. These forms THE AQUATIC QUILLWORTS. Megaspore of Isoetes ech inosporc Flettii. appear to be trivial ones produced by the habitat in which they grow. Most botanists now give little atten- tion to them. According to Eaton Boottii is found in sand, and this may account for its characteristic slender leaves. Isoetes ecJdnospora imiricata is a more pronounced form. The leaves are longer, slenderer, and inclined to be spiral and the mega- spores are slightly larger, and covered with shorter, thicker, and more con- fluent spinules. In deep water the slender leaves are inclined to take on a spiral form. This variety is found from Nova Scotia to New Jersey. Isoetes ecJdnospora Flettii comes from a few lakes in Washington and British Columbia, and differs from the type in having stout leaves, and the spines of the megaspores few, very short, almost wart-like. This is an extreme form and by some might be considered a distinct species. In spore char- acters it approaches the various other species of the Northwest, and except for the size of the spores might be considered a variety of Isoetes Bolanderi, A stout plant, also from northwestern America, has been named Isoetes ecJiino- spora truneata. This has megaspores thickly covered with short truncate columns. The spores are noticeably flattened on the hemispheres contain- ing the commissures, and are not easily confused with those of other species. This form is reported from Vancouver Island to Alaska, but is as yet not common. The author would Megaspore of Isoetes truneata. THE AQUATIC QUILLWORTS. 223 be inclined to call this a distinct species and to name it Isoctcs t rune at a. In 1888 Underwood described anew species from speci- mens collected on Vancouver Island, to which he gave the name of Isoctcs niaritiina. This, Mr. Eaton is con- vinced, is but a variety of Isoctcs cc]iinospora. When it was described it was supposed to be a terrestrial species, and the resemblance of its megaspores was not considered important ; but inquiries of the collector having since shown that it is regularly inundated by the tide, Mr. Eaton seems warranted in calling it Isoctcs ccJiinospora maritima. It is described as having from eight to twelve rigid leaves one to two inches long. The megaspores are covered with rather thick, bluntish spines. In many lakes and ponds Isoctcs ecJiinospora and its varieties form an almost unbroken carpet over large areas, the width depending upon the rate with which the water deepens, being widest in shallow ponds and ending usually when depths of three or more feet are reached. It grows either in sand or mud, though it is said to prefer mud, and is most luxuriant where exposed to the sunlight. It appears to be also fairly abundant in certain rivers, usually only where it is covered with water most of the time. Until one has become accus- tomed to its appearance it is often likely to be mistaken for the other water plants with which it grows. Should our common plant ever be considered distinct from the European species it would have to have a new name, since Braiinii is preoccupied as a specific name. Braun has suec^ested that in this event it be called Isoctcs am- bigiia. The crisp bulbs of this species are favourite mor- sels with muskrats, and cattle are said to feed upon the leaves of any species that are accessible. 224 THE AQUATIC QUILLWORTS. T^he Lake ^luillwort. The lake quilhvort {Isoetcs lacustris) was not named because it is the typical quilhvort of our lakes, but be- cause it was first found and is quite abundant in the lakes of Europe. There are good botanists who doubt that it has ever been found in America, though it was often re- ported by early collectors. At that time, however, it was customary to refer all our plants to Old World species Me^aspore of of similar appcarauce, and this probably Isoetes lacustris. i • j_i i^ r • . explauis the many reports of its occur- rence in regions where nowadays it cannot be found. Isoetes lacustris is described as having from ten to thirty dark-green leaves from three to six inches long. There are no stomata in the leaves, and the indusium cov- ers about one third of the unspotted sporangium. The megaspores are from 500^ to 800 /" in diameter, marked all over with short, thin, wavy ridges. The microspores are 35 /^ to 45 /" long, light grey, and smooth. The Ameri- can plant differs from the European in the larger mega- spores, and Durieu proposed that it be called Isoetcs viacrospora. It would seem wise, in view of the appar- ent absence of true Isoetes lacustris^ to refer all our plants to Isoetes inacrospora. Mr. A. A. Eaton concurs in this opinion, but since Isoetes lacustris has long had a place in our flora we have here included Isoetes inacrospora with it. The typical Isoetes lacustris is spread widely through the lakes of northern Europe, and is well enough known to receive the common name of '' Merlin's grass." It grows in from one to six feet of water. Fish are said to be fond of the tender leaves, and are reported some- THE AQUATIC QUILLWORTS. 225 times to root them up. The fleshy corms or rootstocks have occasionally been eaten in Europe, but are said to have an eartliy taste that is scarcely palatable. The American range of this species is given as from New Jersey, Lake Superior, Colorado, and California north- ward. The plant originally described by Engelmann as Isoetes laciistris, \di\-\(ity pauper cu la, is considered by Mr. Eaton as entitled to specific rank. It has fewer, thinner, and shorter leaves and smaller spores. It is found in Colorado and California. This form was also collected by Henderson, who named it Isoetes occidentalis. "Tuckermari s ^luillwort. In Tuckerman's quillwort {Isoetes Tiickennani) we have a plant with much the habit of Braun's quillwort, but with spore characters that link it more closely with Isoetes lacustris and Isoetes riparia. It may be distin- guished at sight, however, by the leaves, which are very slender and tinged with red. They are from two to five inches long and usually spirally twisted. It was long thought that this species lacks stomata, but it is now known occasionally to bear them in small numbers, especially if e^row- Megasporeof ^ Isoetes Tucker vuini. ing in situations where they may be exposed to the air. The sporangia are small, sparingly pale spotted, and the upper third is covered by the in- dusium. The megaspores are 450^ to 560/' in diameter, marked with parallel and anastomosing ridges on the upper segments, and somewhat more reticulated below. 226 THE AQUATIC QUILLWORTS. Ill New Hampshire, Mr. Eaton has discovered plants in which the spores were of various diameters up to 750/^ but otherwise like the type. The microspores are smooth and 26/" to 32/" long. So far as known, Tuckerman's quillwort is confined to the New England States. It was formerly considered rare, but a more careful study of the material has shown that much of what was once referred to Isoetes lacustris and Isoetes riparia really belong to this species. Mr. A. A. Eaton asserts that within its range it is likely to occur in any large pond with sandy shores, especially if a little silt has been deposited upon the sand. It grows in from one to four feet of water, forming extensive colonies, and is rarely found in situations where the water is not at least a foot deep during the drouths of summer. The depth at which it grows suggests the possibility that the red colouring-matter in the leaves may aid in assimilation, just as the same colour is known to do in the red seaweeds. Plants from Maine and New Hampshire, in which the leaves are longer and stouter, have been named the variety borealis. This is said to have enough likeness to plants of Isoetes lacustris to be almost entitled to rank as a form of that species. Still another form, described as Isoetes Harveyi, has recently been found in Maine. In this the leaves are stout and very numerous, often one hundred or more, though less than three inches in length. The sporangia are small, unspotted, and about one-third indusiate. The megaspores are 525 ^ to 650/^ in diameter, but may occasionally be found of diameters up to 800/^. The spores are similar to those of typical Tiickerinani, but the leaves are very different. In the opinion of the describer, however, it is not sufficiently THE AQUATIC QUILLWORTS. 227 distinct to be called a species, and it has recently been reduced to a variety of Isoetes Tucker niani. Under the name of Isoetes Jieterospora Mr. A. A. Eaton has described a species from Mount Desert Island, Maine, which the author would be inclined to call a form of Isoetes Tttckennani also. In this form the leaves are two or three inches long, from fifty to seventy- five in number, and lack stomata. The sporangia are thickly spotted and are one third or more indusiate. The megaspores are normally 540/^ to 675/" in diameter, but specimens with a diameter of 1150/^ are often found. They are densely covered with thick, jagged, anastomos- ing crests, often honeycombed below. The microspores are 30/^ to 40^ in length, dark brown, and papillose. The megaspores often have neither commissures nor equato- rial ridge. Occasionally what answers to the latter is present, but misplaced, often enclosing but a small area on one side of the spore. This seems to indicate an aberrant plant. Thus far it has been found in but two localities, both on Mount Desert Island, Maine. Bo lander s ^uiilwort. In the western part of America the lakes occasionally contain a species of Isoetes called Bolander's quill wort {Isoetes Bolanderi), which by the single item of the spore markings may be separated from all our Eastern species. In its own region, however, it is easy to confuse with other species, which are marked much like it. In appearance this species has a resemblance to the mem- bers of what, for convenience, may be called the Isoetes ecJiinospora group. Its leaves are erect, bright green, from five to twenty-five in number, and from two to four inches long. They generally have few stomata 228 THE AQUATIC QUILLWORTS. and no peripheral bast bundles. The sporangia are broadly oblong or elliptical, and sparingly spotted. The megaspores are 300 '^ to 450^ in diameter, marked with small dots or warts which rarely run together to form wrinkles. The micro- spores are deep brown, 26/^ to 31 '^ long, spinulose or rarely smooth. This species is found in western Colorado, Utah, and Megaspore of California, and grows in streams as well isoeies Boian.ieri. ^^ j^^ ponds. The form Called Sonnei was described from plants collected at Donner Lake, Cali- fornia. In 1866, Bolander, after whom this species was named, found at Mono Pass, on the eastern slope of the Sierra Nevada, at an altitude of 7,000 feet, a peculiar form which has since been known as Isoetes pyguKEti. Its resemblance to Isoetes Bolanderi is so marked that there should be no doubt of their being two forms of the same species. The principal difference is that the plants of Isoetes pygnicea have shorter leaves, seldom reaching an inch long. The microspores also are less spinulose. To the author this seems but a mere form of the better- known species, and he would call it Isoetes Bolanderi pygmcea. Its small size is undoubtedly due to its place of growth in a cold mountain stream. The megaspores are exactly like those of Isoetes Bolanderi^ only a trifle smaller. It has been collected but once, though often searched for during the past half century. Isoetes Hieroglyphica. From certain lakes in Maine have been collected specimens of an Isoetes which, to judge from spores alone, is distinct from all others. This has recently been THE AQUATIC QUILLWORTS. 229 named Isoctcs Jiicroglyphica. It is described as having ten to twenty leaves two or three inches long, which are recurved and somewhat blunt at the tip. The sporangium is unspotted and about one third indusiate. The megaspores are very characteristic, being from 485/" to 590/^ in diameter, and marked, except near the equator, with rather large wormlike ridges. The body of the spore is quite smooth and greyish in colour. The microspores are from 31 /" to 44/^ \ox\^ and are warty. ^ ^^ 5^ -^ Megaspore of In outward appearance the plant has i^ortes hierogiyphica. great resemblance to Isoetes Tuckennani, to which it is no doubt closely related, though tlie spore characters are distinctive. Isoetes Macount. Isoetes Macoitni is known to grow only on Atka Island, off the coast of Alaska, from whence it was brought by J. M. Macoun in 1891. The plants were found in a pool on the side of an extinct volcano, and apparently in such a position as to be always submerged. The leaves are from five to twelve in number, about two inches long, and quite stout. The megaspores average about 450/^ in diameter and are set with stout blunt spinules usually about twice as long as broad. The microspores are finely and Megaspore of ^ -^ Isoetes Macouni. dcuscly papillose and about 40/^ long. It is possible that this is still another form of Isoetes ecJiino- spora. It has considerable resemblance to the variety Flettii, and the differences it presents may be due to its habitat. THE AMPHIBIOUS QUILLWORTS THE AMPHIBIOUS QUILLWORTS, HE aquatic quilhvorts are naturally found in lakes and ponds, since few other situations present the unvary- ing water-level and other conditions favourable to their growth. The amphibious quilKvorts, on the con- trary, are more frequently to be found along rivers and streams where the receding waters leave them exposed to the air fOr at least a part of the summer. The few members of this group that grow in lakes and ponds are to be found close to the margin, in which situations they are usually above the water for a part of the summer at least. Engelmann s ^luillwort. Among American students of the Isoctes there are few whose names are more closely associated with the genus than that of the late Dr. George Engelmann, of St. Louis, and it is most fitting, therefore, that the species, Isoetes Engebnanniy which commemorates his name, should be both common and widely distributed. This species may at once be distinguished from the aquatic quilhvorts by its much longer leaves. In the quiet waters of lake and pond the leaves of the quill- worts are inclined to be short and arranged in a distinct 234 THE AMPHIBIOUS QUILLWORTS. rosette ; but in rivers where the species are exposed to more or less current the leaves are likely to be longer, and, though arranged in circles, the rosette appearance is often obscured because the flaccid leaves all extend in the direction taken by the current. In the present species the leaves are sometimes up- ward of a hundred in number and twenty or more inches long. Ordinary forms, however, are usually less than a foot in length. Being exposed to the air for a large part of the year, the Megasporeof leaves have abundant stomata, and Jsoetes ±.ngeli)ia7im. ' the peripheral bast bundles necessary to give strength to the aerial leaves are also present. The plants usually grow on the margins of streams. During winter and spring they are covered by the water, but as the waters diminish with the warm weather the leaves are soon exposed to the air, either by floating on the surface of the shallow water or by being left entirely exposed. The leaves found early in spring are the ones that bear the sporangia. They are long and flaccid, and upon exposure to the air are likely to decay, being replaced by circles of shorter recurved leaves, some of which, if the season is long enough, may also perfect sporangia. It is probable that these leaves are normally sterile and alternate with the fertile leaves. The sporangia are unspotted and have a narrow in- dusium. The spores are released by the decay of the sporangium, and for some time after the leaves have fallen the sporangia may be found attached to the plant. The megaspores are from 350 /" to 550/^ delicately honey- comb reticulated. The microspores are 24/^ to 28^ in length, and nearly smooth. In the southern parts of this ENGELMANN'S QUILLWORT. Jsoetes Engel. inanm. THE AMPHIBIOUS QUILLWORTS. 235 Meg^aspore of Isoctes Engelmanni Caroliniana. species' range the spore-markings are less constant and the species breaks up into varieties. The variety /ora inarititna (Undervv.) Isoetes mar it i in a Undervv. Isoetes echinospora niuricata (Dur.) Isoetes Engelnianni A. Br. Isoetes Engelinanni Caroliniana A. A. Eaton Isoetes Engelnianni /. fontana (A. A. Eaton) Isoetes E7igelmanni fo7itatia A. A. Eaton Isoetes Engelnianni f, Georgiana Engelm. Isoetes flaccida Shuttlvv. Isoetes flaccida f, Chapinani Engelm. Isoetes flaccida f, rigida Engelm, Isoetes foreolata A. A. Eaton Isoetes foveolata jdenospora A. A. Eaton Isoetes Gravesii A. A. Eaton Isoetes hieroglyithica A. A. Eaton Isoetes Howellii Engelm. Isoetes nuda Engelm. Isoetes Underwoodii Renders, Isoetes Howellii Piperi (A. A. Eaton.) Isoetes Piperi A. A. Eaton. Isoetes lacustris L, Isoetes lacustris 2>aiipercala Engelm. Isoetes patcpercula A. A. Eaton Isoetes occidenialis Renders. 26o CHECKLIST OF THE FERN ALLIES. Isoefes Macotiiiii A, A. Eaton Isoetes iu(ici'€>spora Diir. Isoetes melanopoda J. Gay Isoetes meliinopodft f, pallida Engelm. Isoetes melanopoda f, Califot'tiiea A. A. Eaton Isoetes inelaiiospora Engelni. Isoetes minima A. A. Eaton Isoetes Nuttallii A. Br. Isoefes Suksdorfz'i Baker Isoetes Orcattl A. A. Eaton Isoetes riparia Engelm. Isoetes saceharata Engelm. Isoetes saceharata /. I*almeri A. A. Eaton Isoetes saceharata f, reticulata A. A. Eaton Isoetes Tucker numi A. Br. Isoetes I'uckermatii Harreyi (A. A. Eaton) Isoetes Harveyi A. A. Eaton Isoetes Tnckennani heterospora (A. A. Eaton) Isoetes heterospora A. A. Eaton Isoetes Tucker mani /. horealis A. A. Eaton Isoetes truncata (A. A. Eaton) Isoetes echinospora trimcata A. A. Eaton Isoetes valida (Engelm) Isoetes Engelman7ii valida Engelm. Isoetes Eatoni Dodge LYCOPODIUM. Lycopodiuin alopecaroldes L, Lycopoiliam alopecaroldes adpressuni Chapm. Lycopodium adpressum (Chapm.) lycopodittm Chapmaiuii Underw. Lycopodlam alopecnroidesf, piiinatum Chapm. lycopodium piniiatiDti (Chapm.) Lycopodium alpinum L. Lycopodium atinotinum L. Lycopodium, annotiuani jmngens Spring, Lycopodium Caroliuietinim L. Lycopodium ceruuum L. 262 CHECKLIST OF THE FERN ALLIES. Lycopodiani clavatuni L. Lycojtodiuni clavatuni /. rnonostachyoti Hook. Lycopodiuni coniplanatum L. Lycopodiuni coniplauatutti rJtainwcyparissus (A. Br.) Lycopodium chamcEcyparissus A. Br. Lycopodium tristachyon Pursh. LiycopodiiuH coniplanatum f, flahelli forme Fernald Lycopodhini coniplanatuni /. Wibhei Haberer Lycopodinni lucidtiluni Michx. Lycopodium lucidtilum 2}orophylum (Lloyd &Underw.) Lycopodium porophyhun Lloyd & Under w. Lycopodium lucitlidum f. occidentale Clute Lycopodium inundatum L. Lycojjodiuiu inundatum f. Sigelovii Tuckerm. Lycopodium obscurum L. Lycopodiuni dendroideum Michx Lycopodium sahincefolium Willd. Lycopodium selago L. Lycopodium Sitchense Rupr. MARSILIA. Marsilia quadrifolia L. Mfirsilia macropoda Engelm. Marsilia uucinata A. Br. Marsilia vestita H. «& G. PILULARIA. Pilularia Americana A. Br. PSILOTUM. Psilotum triquetrum S\v. Psilotuvi nudum (L.) SELAGINELLA. Selaginella apus Spring, Selaf/inella arenicola Underw. Selaginella arenaria Underw. Selaginella Higelovii Underw. 264 CHECKLIST OF THE FERN ALLIES. SelagineUa cinerascens A. A. Eaton Selaginella bryoides (Nutt.) SelagineUa JJouglasii (H. & G.) Selaginella lepidophylla Spring. Selaginella Ludoviciana A. Br. SelagineUa Oregana D. C. Eaton Selaginella striithioloides (Presl) Selaginella Pringlei Baker Selaginella rupesU'is (L.) SelagineUa rupestris Sherivoodii (Underw.) Selaginella Sherivoodii (Underw.) Selaginella rupestris Fendleri Underw. Selaginella rupestris acanthonofa (Underw.) Selaginella acanthonola (Underw.) SelagineUa rupestris torfijHla (A. Br.) Selaginella toriipila A, Br. . Selaginella rupestris rupincola (Underw.) Selaginella rti^inrola Underw. Selaginella rupestris flensa (Rydb.) Selaginella densa Rydb. Selaginella spinosa Beauv. Selaginella selaginoides (L.) Selaginella Watsoni Underw, Selaginella Watsoni jnittica (U. C. Eaton) Selaginella mutica D. C. Eaton SALVINIA. Salvinia natans Hoffm. EXCLUDED SPECIES. JPlquisetuni Mexicanuni Milde Equisetuni ramosissimuni Desv. Marsilia fenuifolia Enoelm. Selaginella jnlifera A. Br. 266 CHECKLIST OF THE FERN ALLIES. Authors' Names Abbreviated in the Checklist of Fern Allies. A. Br. A. Braun. Beauv. P. de Beauvois. Chapm. A. W. Chapman. Desf. R. L. Desfontaines. Dur. Durieu, Ehrh. F. Ehrhart. Engelm. G. Engelmann. H. & G. Hooker & Greville. Renders. L. F. Henderson. Hoffm. G. F. Hoffman. Hook. W. J. Hooker. Willd. K. Kuhl. Kuhlewein. L. Linnaeus. Lam. J, B. de Lamarck. Michx. A. Michaux. Nutt. Thomas Nuttall. Rupr. Ruprecht. Rydb. P. A. Rydberg. Schleich. Schleicher. Sw. O. Swartz. Tuckerm. E. Tuckerman. Underw. L. M. Underwood. Willdenow. GLOSSARY. Aculeate. — Armed with prickles. Acuminate.— Tapering to a slender point. Acute. — Pointed ; ending in a sharp point. Adventitious. — That which comes from abroad ; as a plant intro- duced by chance. Adventitious Buds. — Buds produced without order on any part of the plant. Amphibious. — Said of plants that are covered with water for a part of each year. Anastomosing. — Forming a network ; as veins uniting with one another. Androspore. — The smaller spore in Isoetes and various other fern allies ; a microspore. Annulus. — A ring, especially that which surrounds the spore-cases in most ferns. Antheridia. — The male organs on the prothallium. Apiculate. — Terminating abruptly with a small point. Appressed. — Turned upward against the stem ; said of small leaves. ArcheGONIA. — The female organs on the prothallium. Areola (Pl. Areola). — A space enclosed by anastomosing veinlets- Areolate. — Having areolae. Articulated. — Jointed or having the appearance of a joint. AURICLED.— Eared. Auriculate. — With ear-like appendages. Bast, — Strands of strengthening tissue. BiPiNNATE. — Twice pinnate. Bipinnati FID. —Twice pinnatifid. Blade. — The expanded, leafy portion of a frond. Bristle. — A stiff hair ; any slender outgrowth from the plant, as in the fruiting parts of filmy ferns. Bulbiferous. --Bearing little bulblets. 268 GLOSSARY. BULBLET. — A small bulb, especially such as are borne upon leaves or in their axils. Carina (Pl. Carina). — A small ridge, especially the ridges on the stems of Equiseiiun. Catkin. — A name given to. the fruiting parts of many fern allies. Caudate. — With a slender, tail-like appendage. Caudex. — A trunk, especially that of a tree-fern. Chaff. — Slender, papery scales. Chartaceous. — Having the texture of parchment. Chlorophyll, — The green colouring matter of plants. Ciliate. — Fringed with fine hairs. Circinate. — Coiled, as the buds of ferns, from tip to base. Clay ATE.— Club-shaped. Compound. — Divided into two or more portions ; said of the frond. Conceptacle. — The structure that encloses the sori in certain fern allies ; a sporocarp. Cone. — A name applied to the fruiting parts of Eqidsetum. Confluent. — Blended together. Cordate. — Heart-shaped ; ovate with a sinus at base. Coriaceous.— Like leather in texture. Crenate. — With rounded teeth ; said of margins. Crenulate. — Scalloped with small rounded teeth. Crosier. — An uncoiling frond. Crown. — The growing end of the rootstock or caudex. Cuneate. — Wedge-shaped. Cuspidate. — Terminating in a sharp, hard point. Deciduous. — Not evergreen ; subject to being shed at certain sea- sons. Decompound. — Several times compounded or divided. Decumbent. — Not erect ; bending along the ground. Decurrent. — Extended downward along the rachis ; said of the bases of pinnas, etc. Deflexed. — Bent abruptly downward. Dentate. — Toothed ; said of the margins. Denticulate.— Finely toothed. Depauperate. — Starved ; prevented from coming to its natural size through lack of nourishment. DiCHOTOMOUS. — Forked in pairs ; two-forked. GLOSSARY. 269 Dimidiate.— Halved, or as if one half were wanting, as in the pinnules of some adiantums. Dimorphous, — Of two forms ; said of ferns whose fertile and sterile fronds are not alike. Dissected. — Cut into many lobes or divisions. DORSI-VENTRAL.— Having an evident upper and under surface ; flat- tened in a plane parallel with the earth. Elater. — One of the two bands into which the outer coat of the Eqiiisetiun spore splits at maturity. Elliptical. — Oblong with rounded ends. Emarginate. — Notched at the summit. Entire. — Not divided ; said of fronds or pinnules whose margins are without notches or teeth. Falcate. — Scythe-shaped ; curved upward. Fertile. — Producing spores. FiBRO-VASCULAR. — Consisting of wood-fibres and ducts, as in the stems of the fernworts. Filiform. — Thread-like. Flabellate. — Fan-shaped. FovEOLATE.— Honeycombed. Frond. — A fern leaf. Properly the word frond includes both stipe and blade, but frequently it is used simply to designate the leafy portion. Fruit. — Sporangia. Fruit-dot. — A sorus. Fugacious.— Short-lived ; falling early. Glabrous, — Smooth. Gland. — A minute globular or pear-shaped organ which usually secretes a resinous, waxy, gummy, or aromatic product. Glandular. — Furnished with glands. Glaucous. — Covered with a very fine powdery substance, as plums, are. Glutinous. — Covered with a sticky exudation. Gynospore. — The larger spore in Isoctcs and other fernworts; a megaspore. Habit. — The general appearance of a plant. Habitat. — The natural dwelling-place of an animal or plant. Heterosporous. — Producing spores of two sizes or kinds. 270 GLOSSARY. Hirsute. — Having coarse stiff hairs. liMBRlCATED. — Overlapping or breaking joints, like shingles on a roof. Incised. — Cut into deep, sharp teeth. INDUSIUM (PL. INDUSIA).— The thin, scale-like covering of immature sori. Internode. — The spaces between the nodes of the stem, especially in Equi'selKm. Involucre. — The cup-shaped process surrounding the sporangia in the filmy ferns ; an indusium. Isosporous. — Producing spores of one kind. Laciniate. — Cut into deep, narrow, irregular lobes ; slashed. Lanceolate. — Rather narrow and tapering to the apex ; occasion- ally tapering at base also. Lampna. — A blade ; the leafy portion of a frond. Leptosporangiate. — Producing sporangia from the superficial tissues of the frond. Ligule. — A small triangular tongue-like organ on the leaves of Isoetes. Linear. — Long and narrow. Lobe, — One of the small divisions of a frond. Lunate. — Shaped like a half-moon. Macrosp.ORE. — A megaspore. Marginal. — Situated on, or close to, the margin. Megaspore. — The larger spore in those species having two sizes of spores, especially in Isoetes. Membranaceous. — Like a membrane ; very thin and flexible. Microspore. — The smaller spore in those species with spores of two sizes, especially in Isoetes, Midrib. — The prolongation of the stipe through an undivided frond or pinna. Midvein. — The principal vein in a pinnule or segment. Mucronate. — Having the midvein prolonged beyond the pinnule, forming a point. Node. — The swollen regions of a stem from which the leaves grow, especially in Equisetum. Oblanceolate.— The reverse of lanceolate ; broadest near the apex. Oblong.— Two or three times longer than broad. GLOSSARY. 271 Obovate. — The reverse of ovate. OirruSE. — Blunt; without point. Orbicular.— Circular. Ovate. — Egg-shaped ; the broadest part near the base. Paleaceous. — Clothed with chaff. Palmate. — With spreading divisions, like the fingers of the hand. Panicle. — A cluster of fruit in which the stems branch more or less. Papyraceous,— Paper-like. Pedicel. — A tiny stalk ; especially the stalk of the sporangium. Peduncle. — A stalk ; especially the stalk of the fruiting parts in Lycopodhim . Peltate. — Shield-shaped ; said of scales and indusia that are attached to the frond by their centres. Persistent. — Not falling away ; remaining on the plant. Petiole. — Same as stalk and stipe. Pinna (Pl. Pinn^). — One of the primary divisions of a frond. Pinnate. — Consisting of several leaflets arranged on each side of a common petiole or rachis. PiNNATiFlD. — Divided in a pinnate manner, but with leaflets not entirely separate. Pinnule. — One of the small divisions of a pinnate leaf. Procumbent.— Lying along the ground. Proliferous. — Giving rise to new plants. Prothallium (Pl. Prothallia). — The minute scale-like growth from the spore of a fern wort. Pubescence.— A covering of soft, short hairs. Pubescent.— Covered with fine, soft hairs. Quadripinnate.— Four times pinnate. Rachis. — The continuation of the stipe through a compound frond. Receptacle. — The part of the frond to which the sporangia are attached, especially in the filmy ferns. Reflexed. — Abruptly bent downward or backward. Reniform.— Kidney-shaped. Revolute. — Rolled backward, as the margins of some fronds. Rhizome. — An underground stem ; a rootstock. RooTSTOCK, — Same as rhizome. The portion that produces the fronds or stems in most of our species. Scales. — The chaff on the stems of ferns. 272 GLOSSARY. SCANDENT.— Climbing. Segment. — One of the smaller divisions of a pinnatifid frond. Serrate. — With saw-like teeth ; said of margins. Sessile.— Without a stalk. Sheath. — The circle of confluent leaves in Eqicisehtm. Sinuate. — Wavy ; said of margins. Sinus. — The re-entering space between two lobes. SORUS (PL. SORl). — An assemblage of sporangia ; a fruit dot. Spatulate.— Spoon-shaped. Spike. — A name given to the fruiting parts of the fern allies. Spine. — A sharp point ; a thorn. Spinulose. — Thorny; set with small spines. Sporangium (Pl. Sporangia.)— A tiny globe in which the spores are produced. Spore. — A one-celled body, the fruit of the higher cryptogams ; it is produced asexually and is the analogue of a seed. Spore-case. — Same as sporangium; the case in which the spores are borne. Sporocarp. — A capsule-like structure enclosing the sori in certain fern allies, as in Marsilia. Sporophyll. — A leaf that bears spores, often modified for the pur- pose. Stalk. — Same as stipe. Sterile. — Barren. Said of leaves or stems that do not produce spores. Stipe. — The petiole or stalk of the fern leaf which bears the leafy portion aloft. Stolon. —A trailing, or often underground, branch. Stomata. — Minute openings in the leaves of plants. Subulate. — Awl-shaped. Ternate. — With three nearly equal divisions. Tomentose. — Covered with matted wool. Tomentum. — Close matted woolly hairs. Tooth. — The smallest division of a frond ; a slender prolongation from the sheath in Equisettiin. Tortuous.— Bent or twisted in different directions. Tri pinnate. — Three times pinnate. Truncate.— Appearing as if cut off abruptly. GLOSSARY. 273 Undulate. — Wavy-margined. Vallecula (Pl. Vallecul/e). — A hollow; especially the grooves in the stem of Equisetum. Vallecular. --Pertaining to the vallecula. Vascular. —Containing vessels, ducts, etc., as the stems of ferns. Vein.— One of the small branches in the framework of a leaf. Velum. -The indusium in Isoetes. Venation.— The manner in which the veins are arranged in the leaf. Vernation. — The arrangement of leaves in the bud. Viviparous. —Producing young upon various parts of the plant. Whorl. — A circle ; as of leaves on a stem. Winged. — Bordered with tissue, as the rachis of some ferns. Index to the Common Names, Bamboo, 23. Bird's-nest moss, 163. Bog club-moss, 114. Bolandei's quillvvort, 227. Bottle-brush, 49, 58. Branched scouring-rush, 33. Braun's quillwort, 219. lUick-grass, 85. Buck-horn, 84. Bunch evergreen, loi. C ALA MITES, 6. Carolina club-moss, 120. Cat's-tail, 49. Colt's-tail, 49. Common club-moss, 81. Common scouring-rush, 19. Coral evergreen, 85. Corn horsetail, 49. Creeping-jenny, 93. Creeping selaginella, 155. Crowfoot, lor. D.U'icH rush, 24. Dwarf scouring-rush, 38. Eaton's quillwort, 236. Engelmann's quillwort, 233, Fkstoon ground-pine, Field horsetail, 43. Fir club-moss, 112. 93- Fox-tail, 49, 84. Fox-tail club-moss, 116. Frog's fishing-poles, 24. Good hick, 85, 114. Great scouring-rush, 26. Great water horsetail, 53. Grey moss, 143. Ground-cedar, 93. Ground-fir, 93, Ground-pine, 84, 88, Gunbright, 23. Heat}! cypress, 95. Hemlock club-moss, no. Hog-bed, 93. Horse-pipes, 24. Interrupted club-moss, 87. Ivory horsetail, 50. Joint-grass, 23, 62. Joint-rush, 23, 49. Lake quillwort, 224. Lamb's-tail, 85. Lepidodendron, 6. Liberty, 93. Mare's-tail, 49. Marsh horsetail, 62. Matte-grass, 85. Meadow pine, 49. Merlin's-grass, 224. INDEX TO THE COMMON NAMES. 275 Mountain rush, 24. -Mud horsetail, 53, 62. Nakkd horsetail, 23. Orkgon selaginella, 148. PADUoCK-pipes, 24, 49, 62, Pepperwort, 18S. Pill wort, 206. Pine-grass, 49. Pine-top, 49. Pipes, 24. Polishing-rush, 23. Prickly mountain moss, 150. Princess pine, 93. Rksurrection moss, 161. Resurrection plant, 163. River-bank quillwort, 239. Rock selaginella, 139. Running moss, 85. Running pine, 84, 93. Salvinia, 175. Savin-leaved club-moss, 95. Scouring-rush, 23. Scrub-grass, 23. Shade horsetail, 53. Shave -grass, 23. Shining club-moss, 107. Shore horsetail, 65. Sigillarias, 6. Smoke-rush, 49. Smoke-weed, 24. Smooth scouring-rush, 30. Snake-grass, 49. Snake-moss, 85. Snake-rush, 24. Snake-weed, 24. Stag-horn, 84. Stag-horn club-moss, loi Stiff club-moss, 86. Swamp evergreen, no. Tad-pipes, 49. Toad-pipes, 49. Toad-tail, 85. Trailing Christmas-green, 84, 93. Tree club-moss, 99. Tuckerman's quillwort, 225. Variegated scouring-rush, 36. Virgin Mary's furze, 114. Water fern, 170, 181. Water horsetail, 58. Water-pepper, 206. Winter-rush, 24. Wolf s-claw, 85. Wood horsetail, 53. Index to the Scientific Names, Synonyms and exotic s/cc/i's are italicised. Anab.^na. Azolhc, 182. AZOLLA. Caroliniana, 181. filiculoides. 183. Equisetum. arvense, 43. f. canii5estre, 48. f. decumbens, 47. f. diffusum, 47. f. pseudosilvaticum, 47 Ferrissi, 28. fluvialile, 58. f. limosum, 62. Funstoni, 34. giganteum, 33. hiemale, 19. f. intermedium, 25. robustum, 26. laevigatum, 30. liltorale, 65. Mexicannm, 33. palustre, 62. pratense, 53. rainosissijniiin, 2)3- scirpoides, 38. silvaticum, 53. telmateia, 50. variegatum, 36. Alaskan um, 38. ISOETKS. anibigua, 223. Bolanderi, 227. pygmaea, 228. Butleri, 252. inimaculata, 252. Canadensis, 237. Robbinsii, 238. Dodgei, 237. Eatoni, 236. echinospora, 221. Braunii, 220. Boottii, 221. Flettii, 222. maritima, 223, muricata, 222. robusta, 221. truncata, 222. Engelmanni, 233. Caroliniana, 235. fontana, 235. Georgiana, 235. gracilis, 235. vaiida, 236. flaccida, 244. Chapman i, 245. rigida, 245. foveolata, 241. plenospora, 242. Gravesii, 242. INDEX TO THE SCIENTIFIC NAMES. 277 ffarveyi, 226. heterospora, 227. hieroglyphica, 228. Howelli, 245. Piperi, 246. lacustris, 224. paupercula, 225. Macouni, 229. macrospora, 224. mar it i ma, 223. nielanopoda, 250. Califoniica, 2^\. pallida, 252. melanospora, 246. minima,. 254. Hilda ^ 246. Nuttallii, 252. Occidentalism 225. Orcutti, 253. paupercula, 225. Piperi^ 246. pygmcea, 228. riparia, 239. sacchaiata, 240, A me sit, 241. Palmeri, 241. reticulata, 241. Tuckermani, 225. borealis, 226. heterospora, 227. truncata, 222, Underwoodii, 246. Lycopodium. adpressnm ,118. alopecuroides, 117. adpressum, 118. polyclavatum, 119. C/iapmani, 118. alpinum, 94. annotinum, 86. pungens, 87. Carolinianum, 120. chamcecyparisstis, 91. cernuum, lor. C/iapmaiii, 118. clavatum, 81. f. monostaciiyon, 84. complanatum, 88. chamaecyparissus,' f. flabelliforme, 91. ti'istachyon, 92. f. Wibbei, 92. inundatum, 1 14. f. lUgelovii, 116. lucidulum, 107. f. occidentale, in. porophylum, in. monostaciiyon, 84. nikoense, 97. obscurum, 99. porophylum, in. pinnatum, 119. sabinaefolium, 96. sclaginelloidcs, 151. selago, 1 12. f. patens, 11 1, hicidulnm, 113. Sitchense, 98. tristachyon, 92. Marsilia. hirsuta, 200. macropoda, 200. macropns, 201. polycarpa, 188. quadrifolia, 195. qjiadrifoliata, 197. tenuifolia, 201. uncinata, 197. vestita, 199. PsiLOTUM. nudum, 127. triquetrum, 125. Salvinia. natans, 175. 278 INDEX TO THE SCIENTIFIC NAMES. Selaginella. acanthonota, 142 apus, 155. arenaria, 146. arenicola, 144. Bigelovii, 146. bry aides, 148. Caribensis, 165. cinerascens, 147. densely 142. Douglasii, 160. lepidophylla, 161. Ludoviciana, 158. viHtica, 144. Oregana, 148. Pilifera^ 164. Pringlei, 163. rupestris, 139. acanthonota, 14: densa, 142. Fendleri, 142. rupincola, 142. Sherwoodii, 142. tortipila, 142. rupincola., 142. She?'7iioodii, 142. spinosa, 150. Stnithioloides., 1 50. tortipila, 142. Watsoni, 143. mutica, 144. RETURN BIOLOGY LIBRARY TO— » 3503 Life Sciences BIdg. 642 m^ LOAN PERIOD 1 1 -MONf H-MONOGR APH ALL BOOKS MAY BE RECALLED AFTER 7 DAYS Renewed books are subject to immediate recall DUE AS STAMPED BELOW ^^s^'^ jUN-1^9^ Ma^ ^^URNEo 2 7 \m Bioteof tm^w FORM NO. DD4 UNIVERSITY OF CALIFORNIA, BERKELEY, CA 94720 UC BERKELEY^UBR^ARIES i COBblS^m ],![3RAR UNIVERSITY OF CAUFORNIA UBRARY '1S^