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.