双沟卷柏 shuang gou juan bai

Lycopodioides bisulcata (Spring) Kuntze; Selaginella bisulcata var. spinulosa Spring.

Plants terrestrial, evergreen, creeping, 20-35 cm. Rhizophores at intervals throughout length of main stem, borne on ventral side in axils of branches. Main stems branched from near base upward, pinnately branched, stramineous, main stem 1.2-1.8 mm in diam. in lower part, subquadrangular, sulcate; primary leafy branches 5-8 pairs, 1-3 times pinnately branched, branchlets sparse or dense, adjacent primary branches on main stem 6-10 cm apart, leafy portion of main stem including leaves 9-12 mm wide at middle, ultimate branches 5-8 mm wide including leaves. Axillary leaves on branches symmetrical, elliptic, 3-4.6 × 1.1-1.6 mm, base exauriculate, margin denticulate or sparsely ciliolate. Dorsal leaves contiguous or imbricate, asymmetrical, 1-2.4 × 0.6-1.5 mm, base obliquely cuneate, margin sparsely ciliolate, apex mucronate or aristate with arista curved, up to 1/2-4/5 as long as leaf, 0.4-0.8 mm. Ventral leaves asymmetrical, those on main stem not obviously larger than those on branches; ventral leaves on branches distant, slightly ascending or spreading or deflexed (on main stem), oblong, 3.2-5 × 1.2-2 mm, apex apiculate; basiscopic margin entire or subentire, but denticulate at apex, not revolute, not involute; acroscopic base not enlarged, not overlapping stem and branches, margin ciliolate or denticulate in basal and apical portions, entire in middle. Strobili solitary, terminal, compact, dorsiventrally complanate, 6-10 × 3.5-5.5 mm; sporophylls unlike sterile leaves, strongly dimorphic (very basal sporophylls on ventral side similar to lateral sterile leaves), resupinate, not obviously white-margined; dorsal sporophylls oblong-lanceolate, carinate, margin ciliolate, apex acuminate or aristate, with sporophyll-pteryx incomplete and ciliolate; ventral sporophylls ovate-lanceolate or oblong-ovate, carinate or not carinate, base dilated, margin ciliolate or lacerate-ciliolate; megasporophylls in basal portion on lower side of strobilus, or megasporophylls and microsporophylls at intervals; microsporangia orbicular, relatively thick, cells uniform; microspores pale yellow, megaspores gray or dark brown.

Terrestrial on rather dry slopes in light shade; 400-2400 m. Sichuan, Yunnan [Bhutan, N India, Indonesia (Java), Myanmar, Nepal, Thailand, Vietnam].

Selaginella bisulcata is very closely related to S. pennata but differs in the stems creeping, the rhizophores borne also in distal portion, and the dorsal leaves acute to mucronate at apex.