扁枝石松 bian zhi shi song

Diphasiastrum complanatum (Linnaeus) Holub; D. complanatum var. anceps Ascherson; D. wilceae Ivanenko; Diphasium anceps Á. Löve & D. Löve; D. complanatum (Linnaeus) Rothmaler; Lepidotis complanata (Linnaeus) P. Beauvois; Lycopodium anceps Wallroth (1840), not C. Presl (1825); L. wilceae X. C. Zhang; Stachygynandrum complanatum (Linnaeus) C. Presl.

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.

Forests, shrubs, grasslands of mountain slopes; 700-2900 m. Anhui, Guangdong, Guangxi, Guizhou, Hainan, Hubei, Hunan, Jiangxi, Sichuan, Xinjiang, Xizang, Yunnan, Zhejiang [widespread in temperate and subtropical regions].

Diphasiastrum wilceae, described from Sichuan and with additional distribution in Guangdong, Guizhou, Taiwan, and Yunnan, is provisionally treated as a synonym of Lycopodium complanatum considering the wide distribution and morphological variation of the latter.