Chiefly moss-like plants; often with long running and branching stems, the sporangia solitary in the axils of the mostly awl-shaped leaves. Spores all of one kind.
* Spore-cases in the axils of the ordinary dark-green rigid lanceolate leaves.
1. L. sela'go, L. Stems erect and rigid, forking, forming a level-topped cluster. Leaves uniform. - Atl. Prov. and northward..
2. L. lucid'ulum, Michx. Stems less rigid than the last, forking. Leaves at first spreading; then de-flexed, arranged in alternate zones of longer and shorter leaves.
* * Spore-cases only in the axils of the tipper bract-like leaves, forming a spike.
+ Leaves of the spike not very different from those of the stem.
3. L. inundatum, L. A low plant with weak, creeping, sterile stems, and solitary erect fertile stems bearing a short, thick, leafy spike. Stem-leaves lanceolate, acute, soft, spreading, mostly entire, those of the spike closely resembling them. - Sandy bogs.
Var. Bigelovii, Tuckerm., has taller stems and leaves more upright and denticulate. - Atl. Prov.
+ + Leaves of the catkin-like spike quite different from those of the stem.
4. L. anno'tinum, L. Stems creeping, 1-4 feet long. Branches 4-9 inches high, once- or twice-forked. Spike sessile, the leaves of it yellowish and scale-like, ovate or heart-shaped, the others spreading or reflexed, rigid, pointed, nearly entire, pale green. - Cold woods.
5. L. dendroi'deum, Michx. (Ground Pine.) Root-stock creeping underground, nearly leafless, Stems much resembling little hemlocks, 6-9 inches high; numerous fanlike spreading branches with shining lanceolate entire leaves. Spikes sessile, nearly as in No. 4, 4-10 on each plant. - Moist woods.
6. L. clavatum, L. (Club-Moss.) Stem creeping or running extensively. Spikes mostly in pairs, raised on a slender peduncle (4-6 inches long). Leaves linear, awl-shaped, bristle-tipped. - Dry woods.
7. L. Complanatum, L. Stem creeping extensively. Branches flattened, fan-like and spreading, forking above, the branchlets crowded. Leaves awl-shaped, small, in 4 ranks. Spikes 2-4, cylindrical, on a slender peduncle. - Dry woods; mostly with evergreens.