Hemionitis palmata L.

  • Authority

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

  • Family

    Pteridaceae

  • Scientific Name

    Hemionitis palmata L.

  • Description

    Species Description - Rhizome erect, 2-3 mm diam.; rhizome scales linear, stramineous, 4-5 mm long, 0.8 mm wide; fronds 7-27 cm long, 4.5-10 cm wide, clumped, dimorphic, the sterile much shorter and spreading with rounder lobes, the fertile fronds about twice as tall as the sterile ones; stipe ½-5/6 the frond length, to 1.8 mm diam., castaneous, grooved to flattened on upper surface, with narrow, light brown scales, those at base grading into multicellular sharp-pointed or capitate hairs and short (0.1 mm) glandular hairs; blade palmately pinnatifid with 3-5 acute lobes; margin crenu-late, not recurved, buds in the larger sinuses but usually only one developing into a new plant (under exceptionally high humidity buds sometimes in many of the minor notches as well); veins netted without included veinlets, the five major veins dark; upper and lower surfaces pilose with jointed, somewhat curved, multicellular, sharp-pointed hairs 1.0-1.5 mm long; sori along all veins; spores light yellow-orange.

  • Discussion

    Type. Several citations, incl. Plumier, Descr. pl. Amér., t. 33. 1693. This species crosses with H. pinnatifida in Oaxaca (Mickel, 1974) forming an abortive-spored triploid hybrid. Apparently H. pinnatifida already has a genome of H. palmata in it since the hybrid has 30 pairs and 30 univalents (Smith & Mickel, 1977). Specimens of H. palmata x pinnatifida from Oaxaca are found among wooded and exposed rocks, 750-1050 m, in the districts of Juquila (6133b) and Villa Alta (1113). The hybrid is distinguished from H. palmata by the abortive spores, spottily bicolorous scales, the dark portion of the veins extending out on minor veins, pinnate (5-)7 major dark veins, and small buds in minor sinuses in addition to larger bud in a major sinus. Hemionitis palmata also crosses with H. rufa (Linnaeus) Swartz in Jamaica. Where these two occur together in Central America the hybrid should be sought.

  • Distribution

    Terrestrial, in soil on moist rocky slopes in mesic forests; Cuicatlán, Ixtlán, Ju-chitán, Juquila, Tuxtepec; 60-1000 m. Mexico (Col, Gro, Tam, SLP, Ver, Pue, Oax, Chis, Tab, Yuc); Guat to Pan; WI, Trin; Col to Guy, to Bol & Braz.

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