Ophioglossum
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Authority
Mickel, John T. & Smith, Alan R. 2004. The pteridophytes of Mexico. Mem. New York Bot. Gard. 88: 1-1054.
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Family
Ophioglossaceae
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Scientific Name
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Description
Genus Description - Terrestrial (epiphytic in O. palmatum); stems short, upright, fleshy; roots fleshy, commonly giving rise to new plants from root buds; fronds generally small, simple, entire, 1–several per plant, glabrous, composed of (1) a sterile blade which is simple, entire, with intricate reticulate venation, without a true midvein (the sterile blade palmately lobed in O. palmatum), (2) an erect fertile spike arising from the base of the sterile blades, 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 bases and distal part of petioles), the fertile spikes terminated by an apiculum to 1.5 mm long, and (3) a common stalk (petiole); spores tetrahedral-globose, yellowish; gametophytes subterranean, whitish or brownish, mycorrhizal, cylindrical, simple to branched; x = 30.
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Discussion
Lectotype (chosen by J. Smith, Hist. Fil. 367. 1875): Ophioglossum vulgatum L. Cheiroglossa C. Presl, Suppl. Tent. Pterid. 56. 1845. Type: Cheiroglossa palmata (L.) C. Presl [= Ophioglossum palmatum L.].
Ophioglossum is a genus of mostly small, terrestrial plants of disturbed grassy habitats, so inconspicuous that they can elude the casual eye. This cosmopolitan genus is thought to comprise 20–25 species. 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.