Monographs Details: Ophioglossum
Authority: Mickel, John T. & Beitel, Joseph M. 1988. Pteridophyte Flora of Oaxaca, Mexico. Mem. New York Bot. Gard. 46: 1-580.
Description:Genus Description - Terrestrial (epiphytic in O. palmatum); stem short, upright, fleshy; roots fleshy, commonly giving rise to new plants from root buds; fronds generally small, simple, entire, 1-several per plant, glabrous, in two portions: a sterile trophophore laminate, simple, entire, with intricate net venation, without a true midvein (the sterile blade palmately lobed in O. palmatum), and an erect sporophore with fertile spike arising from the base of the sterile blade, with two vertical rows of large sporangia sunken into the axis tissue and opening by a horizontal slit (O. palmatum with several fertile spikes at the blade base and upper petiole); gametophytes subterranean, whitish or brownish, mycorrhizal, cylindrical, simple to branched.
Discussion:Lectotype (chosen by J. Smith, Hist. fil. 367. 1875): Ophioglossum vulgatum Linnaeus.
Cheiroglossa Presl, Suppl. tent, pterid. 56. 1845 . Type: Cheiroglossa palmata (Linnaeus) Presl [=Ophioglossum palmatum Linnaeus].
Ophioglossums are mostly small, terrestrial plants of disturbed grassy habitats, so inconspicuous that they can elude the casual eye. The genus is thought to consist of about 20-25 species, found through most of the world. There are few taxonomic characters, and the circumscription of species is difficult. Consequently, findings of great disjuncts are often interpreted as distinct species. Eight species are known in Mexico, but only three have been found in Oaxaca. The others are to be looked for. Ophioglossum reticulatum appears to be the most common species, but this may be due to its being larger and thus more conspicuous.
Reference: Clausen, R. T. 1938. A monograph of the Ophioglossaceae. Mem. Torrey Bot. Club 19: 1-177.