Plants terrestrial, evergreen or seasonally green, erect, (5-) 10-25 cm, without creeping rhizomes or stolons, sometimes very long compared with fertile branches. Rhizophores restricted to lower part of stem, borne on ventral side in axils of branches. Main stems branched from near base upward, pinnately branched, stramineous, 0.3-1.2 mm in diam. in lower part, terete, sulcate, glabrous; primary leafy branches 5-8 pairs, once or twice pinnately branched, secondary branches forked or once pinnately branched; tertiary ultimate branches simple, sparse and regular; adjacent primary branches on main stem 1.5-3.5 cm apart; ultimate branches 2.4-4 mm wide including leaves. Axillary leaves on main stems larger than those on branches, orbicular or elliptic, base not peltate, attenuate; axillary leaves on branches symmetrical, elliptic, 1.5-2.2 × 0.5-1.4 mm, base exauriculate, margin slightly denticulate. Dorsal leaves ± symmetrical, those on main stems not obviously larger than those on branches, base oblique, margin minutely denticulate, apex aristate; dorsal leaves on branches not approximate, elliptic or narrowly ovate, 0.8-1.5 × 0.2-0.4 mm, base attenuate, not peltate, margin minutely denticulate, apex long aristate (as long as rest of leaf), parallel to axis or often reflexed or apical arista curved. Ventral leaves asymmetrical, those on main stem obviously larger than those on branches; ventral leaves on branches distant, slightly ascending, ovate-lanceolate or oblong-ovate, 1.7-2.4 × 0.7-1.1 mm, apex acute; basiscopic margin subentire or minutely denticulate; acroscopic base enlarged, broader, overlapping stem and branches, margin minutely denticulate. Strobili solitary, terminal, compact, dorsiventrally complanate, 4-18 × 1.7-3.2 mm; sporophylls unlike sterile leaves, strongly dimorphic, resupinate; dorsal sporophylls oblong-lanceolate, margin minutely denticulate, not keeled, apex subacute or obtuse, with sporophyll-pteryx incomplete (almost up to apex along vein) and denticulate; ventral sporophylls ovate-triangular, not carinate, margin ciliolate, apex long aristate; megasporophylls in basal portion on lower side of strobilus; microsporangia suborbicular, rather thin, cells uniform; microspores orange-red, with dense spherules, megaspores reddish brown, finely rugose.
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