Ophioglossum engelmannii Prantl

  • Authority

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

  • Family

    Ophioglossaceae

  • Scientific Name

    Ophioglossum engelmannii Prantl

  • Description

    Species Description - Stem erect, cylindrical, 2-4 mm diam., usually bearing several leaves in a single season; roots proliferous; fronds 5-22 cm long; sterile blade elliptic, 1-12 cm long, 0.5-3.5 cm wide, base cuneate, apex strongly apiculate; veins forming a double areolate pattern, with large primary areoles and included secondary areoles; stalk of sporophore 2-13 cm long; fertile spike 1.5-3.5 cm long.

  • Discussion

    Syntypes. United States. Texas: New Braunfels, Lindheimer 53\ Missouri, Engelmann s.n. (B?) (see Clausen, 1938: 139). The large, elliptical, apiculate blade with doubly areolate venation and cylindrical rhizome distinguish O. engelmannii from O. pycnostichum (q.v.) (obtuse, ovate blade with single areolate venation). A large form of O. nudicaule, which has traditionally been treated as O. ellipticum Hooker & Greville can be confused with the present species. (See Wagner et al., Castanea 49: 99-110. 1984, for details.)

  • Distribution

    Terrestrial on wooded slopes, presumably in limestone regions; Teotitlán; 1000 m. Mexico (BC, Chih, Coah, Hgo, Jal, Mex, DF, Oax, Chis); se & sw US.

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