SELACINK.LLArE^. 697 



♦- ••- Spikes peduncled, i. e. the leaves minute on the fertile branches. 

 ++ Leaves homogeneous and equal, mnn>/-r(inled ; stems terete. 



7. L. Clavatum, L. (Common- Cllb-Moss.) Stems rreepinpr exten- 

 sively, with siinihir juscendiiig sliort and vory leafy liraiiches ; the fertile ter- 

 minated by a slender peduncle (4 - G' long), hearing about 2-3 (rarely 1 or 4) 

 linear-cylindrical spikes; leaves linear-awl shaped, incurved spreading (light 

 green), tipped, as also the bracts, with a fine bristle. — Dry woods; common, 

 especially northward. July. (Ku.) 



■>-*■ ++ Leaves of two forms, few-ranked ; stems or branches flattened. 



8. L. Carolini^num, L. (1*1. 21.) Sterile stems and their few short 

 branches entirelj/ creeping (leaHess and rooting on the under side), thickly 

 clothed with broadly lanceolate acute and somewhat oblique 1-nerved lateral 

 leaves wideltf spreading in 2 ranks, and a shorter intermediate row appressed 

 on the upper side; also sending up a slender simj)le peduncle (2-4' high, 

 clothed merely with small bract-like and appressed awl-sliaped leaves), ieanHy 

 a single ci/lindrical spike. — Wet pine-barrens, N. J. to Va., and southward. 



9. L. complanatum, L. (Ground-Pine.) Stems extensively creeping 

 (often subterranean), the erect or ascending branches several times forked 

 above; bushy branchlets crowded, fattened, fan-like and spreading, all clothed 

 with minute imbricated-appressed awl-shaped leaves in 4 »-a;jAs, with decurrent- 

 united bases, the lateral rows with somewhat spreading tooth-like tips, those 

 of the upper and under rows smaller, narrower, wholly appressed ; peduncle 

 slender, bearing 2-4 cylindrical spikes. — Var. CHAMA:CYPARfssi's has nar- 

 rower, more erect and bushy branches, and the leaves less di.stinctly dimor- 

 phous. — Woods and thickets; common, especially northward. (Eu.) 



Order 134. SELAGINELLACE^. 



Leafy plants, terrestrial or rooted in mud, never very large ; the stems 

 branching or short and corm-like; the leaves small and 4-n-rowed, or 

 subulate and elono;ated ; sporangia one-celled, solitary, axillary or l)yrne 

 on the upper surface of the leaf at its base and enwrapped in its margins, 

 some containing large spores (macrospores) and others small spores {micro- 

 spores). The macrospores are in the shape of a low triangular pyramid 

 with a hemispherical base, and marked with elevated ribs along the angles. 

 In germination they develop a minute prothallus which bears archegonia 

 to be fertilized by antherozoids developed from the microspores. 



1. Selagrinella. Terrestrial; stems slender ; leaves small ; sporangia minute and axillary. 



2. Isoetes. Aquatic or gi-owing in mud ; stems corm-like ; leaves elongated and rusL-like ; 



sporangia very large, enwrapped by the dilatetl bases uf the leaves. 



1. SELAGINELIiA, Beauv. (PI. 21.) 



Fructification of two kinds, namely, of minute and oblong or globular spore- 

 cases, containing reddish or orange-colored powdery microspores ; and of mostly 

 2-valved tumid larger ones, filled by .3 or 4 (rarely 1 -6) much larger globose- 

 angular macrospores ; the former usually in the upper and the latter in the 

 lower axils of the leafy 4-ranked sessile spike, but sometimes the two kinds 



