Ophioglossum polyphyllum
Ophioglossum polyphyllum A. Braun ex Schub.
(Greek: poly, many, and phyllon, leaf; an unfortunate epithet since the species usually has only 1 or 2 leaves)
Local names: large adder’s-tongue, upright adder’s-tongue
Plants morphologically similar to O. engelmannii (distinguished as in the key) but remarkably different in range; leaves (blade portion and fertile portion combined) 1–2(–3) per stem; blade portion linear-lanceolate to narrowly ovate, apically apiculate; principal veins of blade forming large primary areoles within which are numerous secondary areoles; 2n = 240 (Mickel & Smith 2004). Ditches and low areas in Chihuahuan desert grassland; Brewster (Manning 896, 897, SRSC), Jeff Davis (Manning 915, SRSC), Presidio (Manning 925, SRSC), Pecos, and Reeves (Manning & Zech 1092, SRSC) cos. in the Trans-Pecos; AZ and TX; also Mexico (Chihuahua s to Oaxaca), Australia (Barker et al. 2005), Africa, Asia, and Polynesia (e.g., Hawaii). Leaves appearing Jun-Jul, but other times following rains. This native species was first reported for the U.S. (and the New World) in 1998 (Zech et al. 1998); it had previously been interpreted as a narrow-bladed form of O. engelmannii (Zech & Manning 1996). It is apparently most closely related to O. engelmannii—the two species both have finely bireticulate (= venation pattern where major areoles include minor areoles) blades. This species has an extremely widespread distribution, occurring on four continents and in Hawaii.