35. Selaginella biformis A. Braun ex Kuhn, Forschungsr. Gazelle. 4(Bot. 6): 17. 1889.
二形卷柏 er xing juan bai
Selaginella flagellifera W. Bull; S. hirticaulis Warburg; S. utchinensis Koidzumi.
Plants terrestrial or epilithic, evergreen, erect or creeping, 15-45 cm, with creeping subterranean rhizome and stolons. Rhizophores restricted to creeping rhizomes and stolons. Main stems branched in upper part, pinnately branched, stramineous, stem 1-1.5 mm in diam. at lower part, angulate or subquadrangular, sulcate, unbranched main stem glabrous or pubescent in leafy branched part, apex of main creeping stems flagelliform; primary leafy branches 4-7 pairs, 2 times pinnately branched, leafy branches dorsiventrally flattened, pubescent on ventral side, leafy portion of main stem including leaves 4-5 mm wide at middle, ultimate branches 2-3 mm wide including leaves. Axillary leaves on branches slightly asymmetrical, ovate-lanceolate or elliptic, 1.8-2.4 × 0.8-1.2 mm, base exauriculate, margin ciliolate at base. Dorsal leaves on branches contiguous, ovate, 0.8-1.4 × 0.6-0.8 mm, not carinate, base obliquely cordate, margin very ciliolate, apex aristate. Ventral leaves on branches contiguous or imbricate, slightly ascending, oblong-falcate or falcate, 1.8-3.2 × 1.2-1.6 mm, apex acute; basiscopic base rounded, margin subentire except base with a few cilia; acroscopic base not enlarged, not overlapping stem and branches, margin ciliolate to denticulate. Strobili solitary, terminal, compact, tetragonal, 5-15 × 1.5-2 mm; sporophylls uniform, not white-margined, ovate, sharply carinate, margin denticulate or ciliolate, apex acuminate; megasporophylls in basal portion on lower side of strobili, or megasporophylls and microsporophylls at intervals, microsporangia elliptic; microspores yellowish orange, megaspores pale yellow, whitish, or dark brown, without equatorial flange, undulate-rugose.
Shaded places or on rocks in forests; 100-1500 m. Guangdong, Guangxi, Guizhou, Hainan, Yunnan [India, Indonesia, Japan, Laos, Malaysia, Myanmar, Philippines, Sri Lanka, Thailand, Vietnam].
Plants of Selaginella biformis are usually of two forms: main stems erect or creeping, creeping plants usually glabrous or less hairy. Branches are also flagelliform, forming new plants. Dahlen (Bot. J. Linn. Soc. 98: 277-302. 1988) reported that of 53 strobili of S. biformis with megasporangia, only five had mature or senescent megasporangia while the rest had only immature sporangia.