The green links below add additional plants to the comparison table. Blue links lead to other Web sites.
enable glossary links

bulbous Adder's-tongue

Adder's-tongue family

Habit Plants perennials, terrestrial or epiphytic.

to 20 per plant, blackish, usually extremely narrow, often almost hairlike, less than 0.1 mm diam., proliferations not reported.

lacking root hairs, unbranched or with a few narrow lateral branches, in 1 species dichotomously branched.


spheric, 3-12 mm diam., succulent, cormlike with perforation at apex, apical meristem located at bottom of cavity through which leaves emerge at top, leaves 2 per stem.

simple, unbranched, upright, with eustelic vascular tissue.


bases dilated, clasping, forming sheath, open or fused, surrounding successive leaf primordia;

primordia glabrous or with long, uniseriate hairs.


exposed or embedded, 0.5–1.5 mm diam., thick-walled, with thousands of spores.


all 1 kind, trilete, thick-walled, surface rugate, tuberculate, baculate (with projecting rods usually higher than wide), sometimes joined in delicate network, mostly with ± warty surface.


not green, usually fleshy, round or linear, subterranean, mycorrhizal.


stalk to 0.6cm, 0.1-0.2 times as long as trophophore blade.;

trophophore blade lying nearly flat on ground, not folded longitudinally, pale green throughout, deltate to cordate, to 3 × 2 cm, contracted abruptly at truncate to cordate base, apex with apiculum.

blades compound to simple, rarely absent, veins anastomosing or free, pinnate, or arranged like ribs of fan.


coarsely reticulate with included veinlets.


arising at ground level, 1-5 times as long as trophophore;

sporangial clusters usually short, less than 1 cm, 2-3 mm wide, with 3-8 pairs of sporangia, apiculum to 1.5 mm.

pinnately branched or simple.


absent or of widely scattered, long, uniseriate hairs, especially on petioles and rachises.

Ophioglossum crotalophoroides


Phenology Leaves appearing mainly in late winter and early spring, sometimes also appearing later in season after heavy rains.
Habitat Second-growth fields, vacant lots, roadside ditches, and lawns
Elevation 0-100 m (0-300 ft)
from FNA
AL; AR; FL; GA; LA; MO; MS; NC; SC; TX; Mexico; Central America; South America; widespread in tropical highlands; West Indies
[WildflowerSearch map]
[BONAP county map]
Nearly worldwide
[BONAP county map]

Ophioglossum crotalophoroides is very remarkable morphologically for its highly modified stem and threadlike nonproliferous roots. The gametophyte is disclike (M.R. Mesler 1973). It is especially common in lawns and cemeteries in the southeastern United States.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Ophioglossaceae comprise two clearly defined subfamilies, Botrychioideae and Ophioglossoideae, which are sometimes recognized as distinct families. Ophioglossaceae may be only distantly related to the ferns and more closely related to Marattiales and certain seedplants, especially Cycadales, in such characteristics as stelar type, cork cambium, dilated leaf bases, conduplicate vernation, intercalary leaf growth, collateral leaf traces, circular-bordered pits, eusporangia, massive gametophytes, sunken archegonia, and presence in some species of endoscopic embryos.

(Key to genera of Ophioglossaceae)

Genera 5, species ca. 70–80 (3 genera, 38 species in the flora).

(Discussion copyrighted by Flora of North America; reprinted with permission.)

1. Blades mostly pinnately divided or lobed; veins free; margins entire to dentate to lacerate; sporangial clusters pinnately branched, sporangia sessile or terminating short stalks.
1. Blades undivided or palmately lobed; veins anastomosing; margins entire; sporangial clusters with sporangia embedded in compact linear spike.
→ 2
2. Trophophore blades simple, unlobed, to 4.5 cm wide; main areoles mostly less than 6 mm wide; sporophore 1 per leaf at ground level or above ground level, or absent; plants terrestrial.
2. Trophophore blades palmately lobed, to 30 cm wide; main areoles large, mostly more than 30 mm; sporophores several to many per leaf at base of blade; plants epiphytic.
Source FNA vol. 2. FNA vol. 2, p. 85.
Parent taxa Ophioglossaceae > Ophioglossum
Sibling taxa
O. californicum, O. engelmannii, O. nudicaule, O. petiolatum, O. pusillum, O. vulgatum
Subordinate taxa
Botrychium, Cheiroglossa, Ophioglossum
Name authority Walter: Fl. Carol. 256. (1788) Agardh
Web links