Thelypteris albicaulis (Fée) A.R.Sm.

  • Authority

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

  • Family

    Thelypteridaceae

  • Scientific Name

    Thelypteris albicaulis (Fée) A.R.Sm.

  • Description

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    Species Description - Rhizome long-creeping, to 8 mm diam.; stipe glabrous or glabrescent, epaleate or nearly so, 25-75 cm long, 4-7 mm diam.; rachis glabrous or sparsely hairy; lamina to 70 cm long, often narrowed rather abruptly toward the somewhat elongate tip; lower and longest pinnae (10-) 15-25 cm long, (0.9-) 1.4-2.5 cm wide, never auricled, narrowed at base especially along basiscopic side, incised 0.5-0.7 their width; segments oblique, falcate, acute at tip, (2-)3-4 mm wide at base; veins 10-16 pairs per segment, lowest pair (or two pairs) of veins from adjacent segments connivent at the raised sinus membrane; costae, veins and leaf tissue below without hairs or very sparsely hairy along costae and costules, above glabrous except for sparse hairs 0.1 mm long along costae; costae below with a few dark-castaneous short-hairy scales; sori medial to supramedial; indusia glabrous or infrequently sparsely hairy, usually drying pinkish or reddish-brown; spores with a short-spinulose perispore.

  • Discussion

    Aspidium albicaule Fée, Mém. foug. 8: 102. 1857. Type. Mexico. Valley of México, Schaffner 245 (P!). Aspidium geropogon Fée ex Fournier, Mexic. pl. 1: 95. 1872. Dryopteris geropogon (Fournier) Christensen, Index filic. 267. 1905. Dryopteris augescens (Link) Christensen var. geropogon (Fournier) Christensen, Kongel. Danske Vidensk. Selsk. Skr., Naturvidensk. Afd. VII, 10: 185. 1913. Syntypes. Six collections from southern Mexico and one from Cuba, Bourgeau 1319 (P! — 3 sheets; isosyntypes C!, GH!) and Ga-leotti 6311 (P!) are this species. Thelypteris albicaulis is most closely related to T. puberula and T. grandis, from which it differs in the glabrous indusia and glabrous or sparsely hairy costae below. From T. hispidula, T. den-tata, and T. kunthii it differs in lacking hairs and glands on the lamina above (costa excepted). This species is suspected of hybridization with T. puberula (A. R. Smith, 1971). Several putative hybrids have been seen from Oaxaca: Kenoyer 1554 (GH); Mickel 5078b (NY); and A. Smith 489 (MEXU), 490 (UC). This last number has been examined cytologically and found to show about 36II + 36I meiosis. Spores of the hybrid are malformed.

  • Distribution

    Wooded banks, near streams, in pine-oak forests; Juquila, Pochutla; 1200-1900 m. Mexico (Jal, Mich, Gro, Mex, Mor, Ver, Oax, Chis).

    Mexico North America|