Selaginella pilifera
Selaginella pilifera A. Braun
(Latin: pilus, ball, hair, and -ifera, a suffix from Latin fero, to bear, = hair-bearing)
Local names: hairy resurrection plant, resurrection plant, doradilla
Plant forming striking open rosettes; rhizophores only on basal part of rosette; main branches much branched, flattened in overall aspect when moist and even when dry still flattened or only somewhat erect; leaves in 4 distinct ranks, 2 lateral, 2 medial, conspicuously overlapping, all with obvious bristles ca. 1⁄3–1⁄2 as long as leaf (0.5–1.5 mm long) and with only inconspicuous whitish transparent margins, the two types of leaves different in size and shape—the lateral leaves usually 3–3.5 mm long, elliptic to elliptic-ovate, the medial smaller, usually 2–3 mm long, lanceolate and slightly falcate; strobili solitary, 5–10 mm long, quadrangular; sporophylls apically with long bristle. Terrestrial or on rock, sheltered areas of rocky slopes, cliffs, canyon floors, typically on limestone, but sometimes on igneous substrates; Brewster (Correll 13593, BRIT, TEX-LL), Culberson (McVaugh 8006, BRIT, TEX-LL), El Paso (Wright s.n., 1849, isotype: US), Hudspeth (BRIT), Presidio, and Terrell (Turner et al. 2003) cos. in the Trans-Pecos and Val Verde Co. (Seminole Canyon [e of the Pecos River]—Yarborough & Powell 2002) in the extreme w part of the Edwards Plateau; known in the U.S. only from NM and TX; also n Mexico. Sporulating Jun–Oct. [S. pilifera var. pringlei (Baker) C.V. Morton; S. pringlei> Baker] Like the similar but more common S. lepidophylla, this species is a “resurrection plant” capable of drying out and then resuming growth when rehydrated. The obvious long bristles at the leaf apices, which give the plants a “bristly” or “hairy” appearance, easily distinguish it from S. lepidophylla, the only other rosette-forming spike-moss in TX. Also unlike that species (whose rosettes become ball-like when dry), in hairy resurrection plant the lateral stems comprising the rosettes are flattened not only when moist, but remain almost flat to merely forming a somewhat erect cluster even when dry. It is interesting to note that molecular studies (Korall & Kenrick 2002) show that the “resurrection” type morphology has evolved independently a number of times in the genus and that the two resurrection plants in TX, S. lepidophylla and S. pilifera, are only distantly related. Velaspino (1993) considered this species to be of conservation concern.