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Selaginellaceae

Selaginella wrightii Hieron.

Kingdom: Plantae Rank: Species Parent: Selaginella Status: Invalid Reason: unverified

Common Names:

  • WRIGHT’S SPIKE-MOSS - English, United States of America

Morphological Description

Diagnosis: Plant mat-forming, the mats loose to dense; stems prostrate, with upper and lower surfaces different in appearance (leaves upswept or curving upward making the views of the leaf-covered stems from above and below distinctly different); rhizophores scattered along entire length of stem; leaves tightly appressed, all ± of one kind though leaves on underside of stems narrowly linear-lanceolate and falcate, usually pubescent and usually abruptly adnate at base or slightly decurrent, marginally ciliate, those on upper side slightly shorter, linear-lanceolate, pubescent and abruptly adnate at base, marginally ciliate; leaf apices gradually tapering to a yellowish somewhat hardened bristle 0.2–0.5 mm long (this sometimes breaking off but more persistent on underside leaves), the bristle sometimes poorly differentiated from blade tissue; strobili solitary per branch tip, quadrangular, erect, (7–)15–20(–26) mm long, often abundant; sporophylls lanceolate, with obscure bristle.

Other

Ecology: On rock, typically on limestone, ledges, cliffs, and rocky slopes; widespread in the Trans-Pecos and Edwards Plateau (e.g., Schleicher Co., J.W. Stanford 3543, BRIT) e to Bexar (Carr & P. Turner 12360, TEX-LL) and San Saba (Correll & Correll 12671, TEX-LL) cos.; NM and TX; also widespread in Mexico. Sporulating Mar–Dec.

Notes: Correll (1956) noted that it superficially resembles S. peruviana (treated by him as S. sheldonii) in the prostrate habit and upturned stem tips, but S. wrightii can be distinguished in various ways including the longer leaves (3.3–5 mm long vs. 2.3–4 mm) with longer marginal cilia and the short (0.2–0.5), yellowish, somewhat hardened bristle at the leaf tips. Velaspino (1993) considered this species to be of conservation concern. However, since it is so widespread and common we are not treating it as such. [Bryodesma wrightii (Hieron.) Soják, S. rupestris forma wrightii (Hieron.) Clute]