Asplenium exiguum Bedd.

  • Authority

    Mickel, John T. & Beitel, Joseph M. 1988. Pteridophyte Flora of Oaxaca, Mexico. Mem. New York Bot. Gard. 46: 1-580.

  • Family

    Aspleniaceae

  • Scientific Name

    Asplenium exiguum Bedd.

  • Description

    Species Description - Rhizome erect or short-creeping; rhizome scales black, clathrate with occluded lumina, linear-lanceolate, 2.5-3 mm long, 0.5-0.8 mm wide, margin short-ciliate; fronds clumped, arching; stipe 1.5-5 cm long, 1/10-1/8 the frond length, bi-colorous, castaneous, sparsely scaly; blade 5-14 cm long, 1.5-3.5 mm wide, narrowly elliptic, pinnate-pinnatifid (to bipinnate-pinnatifid), basal pinnae reduced, the apex sometimes proliferous, flagelliform; rachis similar to stipe; pinnae 10-18 pairs, 6-16 mm long, 5-9 mm wide, pinna apex emarginate with proliferous bud, the bud usually dormant and developing further only in very moist situations; pinnules oblong, subentire to toothed, glabrous on upper surface, scattered brown clavate hairs on lower surface; veins obscure, not reaching margin, hydathodes lacking; sori 2-5 per pinna, mostly one per pinnule; indusia 1-1.5 mm long, 0.5 mm wide, suberose to erose.

  • Discussion

    Type. India. Nilgiri, Bed-dome s.n. (K!). Asplenium glenniei Baker, Syn. fil. ed. 2, 488. 1874. Syntypes. Mexico. Glennie s.n. (K!), Bourgeau 252 (K!; isosyntype P, frag. NY!). Athyrium gracile Fournier, Mexic. pl. 1: 102. 1872. Asplenium gracile (Fournier) Hemsley, Biol, centr.-amer.,Bot. 3:634. 1885, nom. illeg., non Don, 1825, nec Fée, 1852, nec Pappe & Raws, 1858. Type. Mexico. “Vallis Mexicensis pr. Pedregal,” Bourgeau 252 (P! — 3 sheets, frag. NY!). Asplenium exiguum is proliferous by apical buds on the pinnae, subterminal rachis buds, and radicant extended naked rachis when humidity is sufficiently high (Mickel, Amer. Fern J. 66: 81-82. 1976). No other Mexican species of Asplenium is so diversified in its means of vegetative reproduction. The sole collection from Chiapas (A. R. Smith, 1981) was at an elevation of only 1000 m, and in Guatemala (Stolze, 1980) the species occurs at 1000-2000 m. The Somers collection at 11,000 feet elevation is unusually high.

  • Distribution

    Terrestrial or epipetric on noncalcareous rocks; Ixtlán, Mixe; 1900(-3500) m. Mexico (Son, Coah, Chih, Dgo, SLP, Hgo, DF, Gro, Oax, Chis); US (Ariz); Guat; n India, s China.

    Mexico North America| China Asia| India Asia| Guatemala Central America| Arizona United States of America North America|