Selaginella rupincola
Selaginella rupincolaUnderw.
(Latin: rupes, rock, and cola, inhabitant, dweller),
Local names: ledge spike-moss, rockloving spike-moss
Plant forming loose clumps, the aerial stems usually suberect to erect, rarely decumbent, to ca. 10 cm tall, with leaves without strongly upswept or upwardly curving appearance, the leaf-covered stems therefore appearing radially symmetrical, usually with rhizophores only on lower . (less commonly scattered along entire length); underground (rhizomatous) stems present, with rhizophores; rhizomes and aerial stems often with a bud-like arrested branch near base; leaves of aerial stems tightly appressed, of 1 kind, linear-lanceolate, 3–4.7 mm long, marginally long ciliate } from base to apex, apically with obvious bristle 0.65–1.85 mm long; strobili solitary, quadrangular, 5–25(–35) mm long; sporophylls apically bristled. On rock or soil, ledges, cliffs, rocky slopes, typically on igneous substrates; Brewster (Warnock 20893, BRIT; W.D Pohl & J.L. Blassingame 2944, BRIT; Warnock 21208, TEX-LL), Jeff Davis (O.E. Sperry T738, SRSC; Warnock20273B, TEX-LL), Presidio (J. Lott et al. 5378, SRSC, TEX-LL), and El Paso (Yarborough & Powell 2002) cos.; AZ, NM, and TX; also widespread in Mexico. Sporulating Jun–Oct. [Bryodesma rupincola (Underw.) Sojak, S. rupestris var. rupincola (Underw.) Clute] This species is presumed to be one of the parents of the somewhat similar S. ×neomexicana (Tryon 1955)—see that taxon for further discussion. It can sometimes be found in the same mat as S. arizonica or S. peruviana (both of which, however, have leaves that are upswept or curving upward— Yarborough & Powell 2002). Because of its rareness and limited distribution in the state, we consider this species to be of conservation concern in TX.