[++][++] Leaves of two forms, few-ranked; stems or branches flattened.
8. L. Caroliniànum, L. ([Pl. 21.]) Sterile stems and their few short branches entirely creeping (leafless and rooting on the under side), thickly clothed with broadly lanceolate acute and somewhat oblique 1-nerved lateral leaves widely spreading in 2 ranks, and a shorter intermediate row appressed on the upper side; also sending up a slender simple peduncle (2–4´ high, clothed merely with small bract-like and appressed awl-shaped leaves), bearing a single cylindrical spike.—Wet pine-barrens, N. J. to Va., and southward.
9. L. complanàtum, L. (Ground-Pine.) Stems extensively creeping (often subterranean), the erect or ascending branches several times forked above; bushy branchlets crowded, flattened, fan-like and spreading, all clothed with minute imbricated-appressed awl-shaped leaves in 4 ranks, 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. Chamæcyparíssus has narrower, more erect and bushy branches, and the leaves less distinctly dimorphous.—Woods and thickets; common, especially northward. (Eu.)
Order 134. SELAGINELLÀCEÆ.
Leafy plants, terrestrial or rooted in mud, never very large; the stems branching or short and corm-like; the leaves small and 4–6-rowed, or subulate and elongated; sporangia one-celled, solitary, axillary or borne on the upper surface of the leaf at its base and enwrapped in its margins, some containing large spores (macrospores) and others small spores (microspores). 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. Selaginella. Terrestrial; stems slender; leaves small; sporangia minute and axillary.
2. Isoetes. Aquatic or growing in mud; stems corm-like: leaves elongated and rush-like; sporangia very large, enwrapped by the dilated bases of the leaves.
1. SELAGINÉLLA, Beauv. ([Pl. 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 are on opposite sides all along the spike. (Name a diminutive of Selago an ancient name of a Lycopodium, from which this genus is separated, and which the plants greatly resemble in habit and foliage.)
[*] Leaves all alike and uniformly imbricated; those of the spike similar.