Selaginella atroviridis Spring var. trachyphylla (A. Braun ex Hieronymus) Warburg; S. doederleinii Hieronymus subsp. trachyphylla (A. Braun ex Hieronymus) X. C. Zhang.

Plants terrestrial, evergreen, suberect or ascending from decumbent base, 25-45 cm. Rhizophores branched from base to middle of main stem. Main stems branched from lower part upward, pinnately branched, stramineous, main stem 1-3 mm in diam. in lower part, oval or subquadrangular, 2 or 3 times pinnately branched, adjacent primary branches on main stem 1.5-3.8 cm apart, ultimate branches 4-7 mm wide including leaves. Axillary leaves on branches symmetrical, narrowly ovate to triangular, base exauriculate, margin denticulate. Dorsal leaves on branches approximate or contiguous, oblong-ovate or ovate-elliptic, 1.1-2.7 × 0.4-1.4 mm, strongly carinate, base cuneate, margin denticulate, apex aristate, parallel to axis. Ventral leaves on branches contiguous or overlapping, slightly ascending, oblong-falcate, 3.4-4.3 × 1-1.9 mm, adaxially spinose, apex obtuse, subacute, or apiculate; basiscopic base rounded, margin subentire, denticulate at base; acroscopic base enlarged, broader, overlapping stem and branches, margin denticulate. Strobili in pairs, terminal, compact, tetragonal, 5-30 × 1-2 mm; sporophylls uniform, not obviously white-margined, ovate-triangular, margin denticulate, apex acuminate, without sporophyll-pteryx; microsporangia elliptic-oblong, relatively thick; marginal cells differentiated, longer; microspores pale yellow, megaspores whitish.

Selaginella trachyphylla differs from S. doederleinii only in the length of the apex of the dorsal leaves and the presence of unicellular thorns on the ventral leaves.

● Terrestrial in forests; 100-400 m. Guangdong, Guangxi, Guizhou.