pendent when epiphytic, consisting of a basal common stalk bearing at its apex a 

 simple to variously compounded sessile or stalked sterile blade and (if fertile) 

 one or more erect or pendent stalked spore-bearing spikes or panicles; sporangia 

 in two rows, naked, opening by a transverse slit, formed from the interior tissue 

 of the sporophyll; spores numerous, all alike, yellowish; prothallia subterranean, 

 not green. 



This family is composed of four genera and about 70 species in tropical and 

 temperate regions throughout the world. 



1. Ophioglossum L. Adder's-Tongue 



Small fleshy-succulent terrestrial or epiphytic plants of wet or moist soils, 

 with short (sometimes bulbous) subterranean rhizomes bearing fibrous roots; 

 fronds one or more from the same rhizome, erect in vernation, glabrous; common 

 stalks slender, terete; sterile blades simple or palmatifid (in the Floridian O. 

 palmatum L.), sessile or short-stalked, with the veins profusely reticulate; fertile 

 spikes slender, erect, long-stalked; sporangia large, coalescent in two ranks, sub- 

 globose; spores numerous, yellow; buds of the following season borne at the apex 

 of the rhizomes, exposed, free. 



About 40 species of wide distribution in both hemispheres. 



1. Rootstocks globose-bulbous; leaf blades (when spread out) with a cordate to 

 very broadly cuneate base 1. O. crotalophoroides. 



1. Rootstocks cylindric to subglobose, not globose-bulbous; leaf blades with a 



rounded to cuneate base (2) 



2(1). Blade distinctly and prominently apiculate; principal veins characteristically 

 forming large primary areoles in which are included numerous 

 veinlets forming secondary areoles 4. O. Engelmannii. 



2. Blade rounded to acute at apex, rarely minutely apiculate; principal veins 



forming areoles not enclosing smaller secondary areoles but some- 

 times with included free veinlets (3) 



3(2). Blade inserted near base of plant; rootstocks subglobose 



2. O. nudicaule var. tenerum. 



3. Blade inserted towards middle of plant; rootstocks cylindric (4) 



4(3). Blade small, usually less than 5 cm. long, typically ovate-lanceolate and 

 acute, with 4 to 8 parallel veins passing down through base of 

 blade 3. O. petiolatum. 



4. Blade larger, usually more than 5 cm. long, broadly elliptic to oblong-elliptic 



or very rarely ovate, rounded at apex, typically with 8 to 20 parallel 

 veins passing down through base of blade 5. O. vulgatum. 



1. Ophioglossum crotalophoroides Walt. Bulbous adder's-tongue. Fig. 9. 



Plants usually short, fleshy, to about 15 cm. tall; rootstock tuberous, globose, 

 hard when dry, averaging about 8 mm. in diameter, producing several fronds 

 during a single growing season; common stalk mostly less than 3 cm. long; sterile 

 blade orbicular-ovate to ovate, when spread out cordate to sometimes very broadly 

 cuneate at base, rounded to subacute at apex, abruptly contracted to a short 

 petiolulate base, often conduplicate and clasping the stalk of the spike, thick- 

 herbaceous, to 3.5 cm. long and 2.5 cm. wide; venation mostly obscured by the 

 thick texture of the blade, forming very unequal areoles with very few included 

 free veinlets; fruiting spike usually on a short stalk that is to 7 cm. long, thick 

 and abbreviated, sharp at the apex, 3-4 mm. in diameter; sporangia 3 to 12, 

 partly imbedded in the rachis. O. pusillum Nutt. 



In damp or wet pastures, moist sandy soil of open pine forests, and on grassy 

 slopes, only in Tex. in our region, rare in s.-cen. and s.e. Tex. (Bastrop, Hardin 



49 



