Lycopodium complanatum L.

Plants small to medium-sized, terrestrial; stolons completely or mostly subterranean; leaves on stolon spatulate or ovate, membranous or thickly membranous, grayish brown or dark brown; aerial shoots creeping, up to 100 cm. Lateral branches suberect, up to 15 cm tall, dichotomously branched with well-differentiated lateral branchlets much branched, branchlets obviously flattened; sterile branchlets light green or grayish green abaxially. Leaves arranged in 4 rows, dense, triangular, 1-2 × ca. 1 mm, herbaceous, midrib indistinct, base appressed on branches, sessile, margin slightly involute, entire, apex acute. Strobili (1-)3-5(or 6), terminal on peduncles (10-20 cm), pale yellow, terete, 1.5-3 cm; sporophylls broadly ovate, imbricate, ca. 2.5 × 1.5 mm, margin membranous, with irregular teeth, apex acute, caudate. Sporangia enclosed.

Moist coniferous woods, from lowlands to moderate elevations in the mountains of Western N. America.