平卷柏 ping juan bai

Selaginella rubella W. M. Chu.

Plants terrestrial or epilithic, seasonally green, creeping, 15-25 cm. Rhizophores at intervals throughout length of main stem, borne on ventral side in axils of branches. Main stems branched throughout, pinnately branched, stramineous or reddish, 0.3-0.5 mm in diam. in lower part, angulate, sulcate; primary leafy branches 6-8 pairs, once or twice pinnately branched, secondary branches once or twice forked, branchlets sparse, adjacent primary branches on main stem 2.4-3 cm apart, leafy branches and stems dorsiventrally flattened, leafy portion of main stem including leaves 6-7.5 mm wide at middle, ultimate branches 4.3-6 mm wide including leaves. Axillary leaves on branches asymmetrical, ovate, 2-3 × 1-1.5 mm, base subcordate, margin minutely denticulate. Dorsal leaves ± symmetrical, those on branches contiguous or imbricate, ovate or ovate-lanceolate, 1.6-2.2 × 0.6-1.3 mm, slightly carinate, base subcordate, margin minutely denticulate or ciliolate, apex acuminate. Ventral leaves asymmetrical, those on branches spreading, ovate or ovate-triangular or ovate-lanceolate, 1.8-3.2 × 1.1-1.8 mm, apex acute; basiscopic margin denticulate; acroscopic base enlarged, broader, overlapping stem and branches, margin denticulate or ciliolate in basal portion. Strobili solitary or forked, terminal, lax, dorsiventrally complanate, 5-13 × 4-6 mm; sporophylls similar to sterile leaves in form and arrangement, strongly dimorphic, non-resupinate, not white-margined; dorsal sporophylls ovate, not keeled or slightly carinate, margin shortly ciliolate or denticulate, apex acuminate, without sporophyll-pteryx; ventral sporophylls ovate, oblong-ovate, or broadly ovate, not carinate, margin denticulate; megasporophylls in basal portion on lower side of strobilus; microsporangia orbicular; microspores orange-red, megaspores sulfur-colored or yellowish orange.

Pinus yunnanensis forests or mixed forests, on ditch banks, exposed places along roadsides on mountain slopes; 2000-2700 m. Sichuan, Yunnan [N India, Nepal].