Selaginella rupestris (Linnaeus) Spring f. sibirica Milde, Filic. Europ. 262. 1867; Bryodesma sibiricum (Milde) Soják; S. rupestris f. manchuriensis Milde; S. schmidtii Hieronymus.

Plants epilithic, xerophytic, summer-green, creeping, 10-25 cm, growing indefinitely, without stolons. Rhizophores at intervals throughout length of creeping stem and branches, borne on dorsal side in axils of branches, densely hairy. Main stems anisotomously branched throughout, glabrous; leafy branches glabrous, radially symmetrical. Leaves spirally arranged on all sides of stem and branches, monomorphic throughout, linear, 1.9-2.2 mm (seta excluded), 0.3-0.4 mm wide, with long apical seta 1/5-1/3 as long as leaves, margin long ciliolate, apex attenuate or obtuse. Strobili solitary on erect branchlets, tetragonal, 5-10(-25) × 1.5-2 mm; sporophylls monomorphic, ovate-triangular or ovate-lanceolate.

Dry cliffs. Heilongjiang, Nei Mongol [Korea, Russia; North America].