Phylum PTERIDOPHYTA 



Ferns and Fern Allies 



Fam. 1. PSILOTACEAE Matsuba-ran Ka Psilotum Family 



Frequently epiphytic, herbaceous, erect or pendulous perennials with dichotomously branched creeping rhizomes; leaves 

 (branch-tips) flattened and leaflike or scalelike; sporangia homosporous, solitary and terminal on the branch-tips, rather large 

 and prominent, 2- or 3-locular and 2- or 3-lobed; spores many. Two genera with about 3 species, in the Tropics and sub- 

 tropics. 



1. PSILOTUM Sw. Matsuba-ran Zoku 



Rhizomes wiry, creeping, branched; stems simple in the lower half, much forked toward the top into slender flattened or 

 triquetrous branchlets; leaves (branch tips) scalelike, minute, 3- or 2-ranked; sporangia coriaceous, sessile, depressed at apex, 

 3-locular, 3-lobed, loculicidally split; spores oblong, 1-ribbed. ^Two species, of wide distribution, mosdy in warmer regions. 



1. Psilotum nudum (L.) Beauv. Lycopodium nudum angia depressed-globose, about 2 mm. across, 3-grooved and 



L.; P. triquetrum Sw. Matsuea-ran. Rhizomes 1-2 mm. obtusely 3-angled. Epiphytic on tree trunks or on rocky 



across, brown-villous; stems 10-35 cm. long, 1-1.5 mm. thick, cliffs; Honshu (Kanto Distr. and westw.), Shikoku, Kyushu; 



erect, slender, green, glabrous, loosely scaly, dichotomously rare. s. Korea, Ryukyus, Formosa, China, and generally in 



forking in upper half; sterile scales entire, the fertile bifid; spor- the Tropics. 



Fam. 2. EQUISETACEAE Tokusa Ka Horsetail Family 



Perennial herbs with creeping rhizomes; stems green, all alike or of two kinds (the sterile stems green, the fertile without 

 chlorophyll), simple or branched, grooved, with a ring of smaller cavities around the central cylinder; leaves very small, con- 

 nate and forming a sheath above the nodes, the sheaths with as many teeth as the grooves on stems; spikes terminal, the 

 stipitate-peltate sporangiophores spirally arranged on a common axis; spores all alike, green, provided with 4 elastic, hygroscopic, 

 clavate bands. A single genus. 



1. EQUISETUM L. Tokusa Zoku 



Characters of the family. About 23 species, nearly cosmopolitan, absent in Australia. 



lA. Spikes obtuse to subacute, not apiculate; stems annual. 

 2A. Stems dimorphic, the fertile whitish or flesh-colored, soft and succulent, the sterile green and branched. 



3A. Internodes nearly smooth or with minute scabrid tubercles; teeth of primary sheaths brown throughout, those on the branches sub- 

 ulate-triangular I.E. arrensc 



3B. Internodes minutely spiny on the ridges; teeth of primary sheaths with broad, scarious, white margins, those on the branches 



broadly deltoid 2. E. prateiise 



2B. Stems all alike, green. 



4A. Stems spinulose on the ridges; teeth of primary sheaths with very broad membranous margins; branches spreading or drooping. 



5A. Sheaths of branches with erect deltoid teeth; branches simple 2. E. pralense 



5B. Sheaths of branches with spreading subulate-linear teeth; branches ramulose, drooping above 3. £. sylraliciim 



4B. Stems smooth, with minute tubercules; teeth of primary sheaths with scarious margins; branches ascending, usually simple. 



6A. Primary sheaths loose, with 10 or fewer broadly lanceolate teeth rather prominently scarious on the margin; stems with 



slender central cavity A. E. palusire 



63. Primary sheaths tight, with 15-20 subulate-lanceolate teeth scarcely or very narrowly scarious on margin; stems with a large 



central cavity 5. E. fluviatile 



IB. Spikes apiculate to obtuse; stems evergreen. 

 7A. Teeth caducous. 



8.^. Sheaths nearly as wide as long, becoming blackish at both ends, with 12-30 caducous teeth; stems mostly simple. . . 6. E. hyemale 



8B. Sheaths longer than wide, pale green, with 5-15 caducous teeth; stems branched at least near base 7. E. ramosissimum 



7B. Teeth persistent. 



9A. Stems hollow; teeth elongate, much longer than broad 8. E. variegatum 



9B. Stems solid; teeth as broad as long 9. E. scirpoides 



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