Description from Flora of China
Selaginella doederleinii Hieronymus subsp. scabrifolia (Ching & Chu H. Wang) X. C. Zhang.
Plants terrestrial, evergreen, suberect or ascending from decumbent base, rarely creeping, 30-60 cm. Rhizophores branched throughout length of stem and branches, or restricted to middle of suberect main stem. Main stems branched from near base upward, pinnately branched, 0.6-2.4 mm in diam. in lower part, oval or subquadrangular; primary leafy branches 6-12 pairs, 3 times pinnately branched, secondary branches once or twice pinnately branched, tertiary branches forked or once pinnately branched, branchlets dense and regular, adjacent primary branches on main stem 2-5 cm apart, leafy portion of main stem including leaves 4.5-7 mm wide at middle, ultimate branches 2.5-4 mm wide including leaves. All leaves spinose on adaxial surface. Axillary leaves on branches symmetrical, ovate, 1.2-2.5 × 0.5-1.5 mm, base exauriculate, margin denticulate. Dorsal leaves on branches approximate, parallel to axis or overlapping at leaf apex, ovate, obovate, or ovate-elliptic, 0.8-1.4 × 0.3-0.8 mm, slightly carinate, base cuneate, margin denticulate, apex rather long aristate. Ventral leaves on branches contiguous or overlapping, somewhat slightly ascending, ovate-triangular or ovate-lanceolate, 1.7-4 × 0.5-1.5 mm, apex subacute or obtuse; basiscopic base rounded or decurrent, margin subentire, entire or denticulate at base, slightly involute; acroscopic base enlarged, broader, overlapping stem and branches, margin denticulate. Strobili solitary, terminal, compact, tetragonal, 4-26 × 2-3 mm; sporophylls uniform, not obviously white-margined, ovate-triangular, carinate, margin denticulate, apex acuminate, without sporophyll-pteryx; microsporangia elliptic-oblong, relatively thick; marginal cells differentiated, longer; microspores pale yellow, megaspores whitish.
Selaginella scabrifolia differs from S. trachyphylla in the length of the arista on the dorsal leaves and the presence of unicellular thorns on the ventral leaves. The above three taxa might be ecological variations.
● Forests, shaded places along streams; (600-)900-1800 m. Hainan.