成层石松 cheng ceng shi song

Lycopodium alticola Ching; L. annotinum Linnaeus var. acicularis Christ; L. annotinum f. brevifolium Christ.

Stolons slender and creeping, up to 1.8 m, green, with sparse leaves; lateral branches ascending, 8-15 cm tall, 1-3 times forked, sparse, whole branches terete, stem together with leaves 7-11 mm in diam. Leaves spirally arranged, dense, angled upward and amplexicaul, lanceolate, 3.5-5 × 0.6-1.2 mm, leathery, midrib indistinct abaxially, visible adaxially, without transparent hairs, base cuneate, decurrent, sessile, margin entire, apex acuminate. Strobili solitary, terminal on branchlets, erect, terete, sessile, 2-3 cm × ca. 4 mm; sporophylls broadly ovate, ca. 3 × 2 mm, thinly leathery, with only narrow transparent membranous margin, apex acute. Sporangia enclosed.

● Shaanxi, Sichuan, Xizang, Yunnan [?India].

Because there are no critical differences in the morphology and habitat between Lycopodium alticola and L. zonatum, the former is here treated as a synonym of the latter.

Lycopodium zonatum seems to be an ecological substitute of L. annotinum in W alpine areas.

This species is small, and its leaves are densely arranged, strongly ascending, with entire margins.