Selaginella nipponica

Plants terrestrial, seasonally green, creeping; fertile stems erect, 5-12 cm, without stolons, without elongate tuber at base of stem. Rhizophores restricted to sterile prostrate stems and branches at intervals throughout length of main stem, borne on ventral side in axils of branches. Main stems branched from near base upward, stramineous, 0.2-0.4 mm in diam. in lower part, angulate, sulcate; primary leafy branches 3 or 4 pairs, simple or forked or once pinnately branched, branchlets sparse, adjacent primary branches on main stem 1-2 cm apart, leafy branches and stems glabrous, dorsiventrally flattened, leafy portion of main stem including leaves 4.5-5.4 mm wide at middle, ultimate branches 2.8-4.2 mm wide including leaves. Axillary leaves on branches of sterile stems symmetrical or asymmetrical, ovate-lanceolate or elliptic, 1.5-1.8 × 0.8-1 mm, base exauriculate, margin denticulate. Dorsal leaves ± symmetrical, those on main stems not obviously larger than those on branches; dorsal leaves on branches contiguous or imbricate in apical portion, oblong-ovate, ovate, ovate-lanceolate, or elliptic, 1.6-2 × 0.6-0.9 mm, not carinate, base obtuse, margin not obviously denticulate, apex acuminate or acute. Ventral leaves asymmetrical, those on main stem not obviously larger than those on branches; ventral leaves on branches often deflexed, broadly ovate or ovate-triangular, 1.8-2.2 × 1-1.6 mm, apex acute; acroscopic base enlarged, broader, overlapping stem and branches, minutely denticulate. Fertile branches erect, 2.5-12 cm including strobilus. Strobili solitary or once or twice forked (or 3 times forked), terminal, lax, usually dorsiventrally complanate, 18-50 × 2-4.6 mm; sporophylls ± similar to sterile leaves in form and arrangement, dimorphic or slightly dimorphic, usually non-resupinate, not keeled, not white-margined, margin denticulate, apex acuminate; megasporophylls in basal portion on lower side of strobilus; microsporangia elliptic, relatively thick, with relatively large cells in central part; microspores orange-red, megaspores yellowish orange.