Plants terrestrial or epilithic, evergreen or subterranean rhizomes evergreen and aerial part seasonally green, creeping, creeping stems 10-20 cm, fertile stems erect. Rhizophores restricted to lower part of erect fertile branches or at intervals throughout length of creeping stem and branches, borne on ventral side in axils of branches. Main stems branched throughout, pinnately branched; erect fertile stems 5-15(-25) cm high, stramineous, terete, not sulcate; primary leafy branches 5 or 6 pairs, branches once or twice forked, branchlets sparse, adjacent primary branches on main stem 1.5-2.5 cm apart, ultimate branches 2-6 mm wide including leaves. Axillary leaves on main stems larger than those on branches, triangular, base not peltate, obtuse; axillary leaves on branches symmetrical, ovate or ovate-lanceolate, 1-2.5 × 0.6-1.6 mm, base exauriculate, margin rather long ciliolate at base. Dorsal leaves asymmetrical or ± symmetrical, those on main stems not obviously larger than those on branches; dorsal leaves on branches approximate or imbricate, ovate or ovate-elliptic, 1-1.2 × 0.4-0.8 mm, carinate, base subcordate or obtuse, not peltate, margin ciliolate, apex acuminate or aristate, arista 0.3-0.6 mm. Ventral leaves strongly asymmetrical, those on main stem not obviously larger than those on branches; ventral leaves on branches distant or approximate, slightly ascending, ovate-triangular, 1.6-3.8 × 0.6-1.6 mm, margin denticulate, apex acute or acuminate; basiscopic margin entire or with 1 or 2 cilia at base; acroscopic base rounded, overlapping stem and branches, margin rather long ciliolate at base, subentire upward. Strobili solitary, terminal, compact, tetragonal, 6-8 × 2-3 mm; sporophylls dimorphic or strongly dimorphic, resupinate, white-margined; dorsal sporophylls ovate-lanceolate, sharply carinate, margin ciliolate, apex acute or acuminate, with sporophyll-pteryx incomplete and ciliolate; ventral sporophylls ovate, carinate, margin ciliolate; megasporophylls and microsporophylls at intervals, or megasporophylls throughout lower side or in basal portion of lower side of strobilus; microsporangia orbicular, rather thin, marginal cells differentiated, smaller with thin walls; microspores orange-red, megaspores sulfur-colored.
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