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bulbous Adder's-tongue

herbe sans couture, southern Adder's-tongue


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

to 20 per plant, 0.3-0.9 mm diam., producing proliferations.


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.

upright, to 1 cm, 3 mm diam., leaves 1 per stem.


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.

stalk formed abruptly at base, to 5mm, sometimes more, 0.05 times length of trophophore blade.;

trophophore blade erect to spreading, usually plane when alive, dark green, somewhat shiny, mostly ovate to ovate-trowel-shaped, widest in proximal half, to 10 × 4cm, firm, herbaceous, base tapering abruptly, apex rounded;

venation complex-reticulate with included free veinlets in areoles.


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.

arising at ground level, stalk 2-4 times length of trophophore;

sporangial clusters 20-40 × 1-4 mm, with 10-35 pairs of sporangia, apiculum 1-1.5mm.



Ophioglossum crotalophoroides

Ophioglossum vulgatum

Phenology Leaves appearing mainly in late winter and early spring, sometimes also appearing later in season after heavy rains. Leaves appearing spring–early summer.
Habitat Second-growth fields, vacant lots, roadside ditches, and lawns Shaded secondary woods, rich wooded slopes, forested bottomlands, and floodplain woods, south of Wisconsin glaciation
Elevation 0-100 m (0-300 ft) 0-800m (0-2600ft)
from FNA
AL; AR; FL; GA; LA; MO; MS; NC; SC; TX; Mexico; Central America; South America; widespread in tropical highlands; West Indies
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from FNA
AL; AR; AZ; DE; FL; GA; IL; IN; KY; LA; MI; MO; MS; NC; NJ; OH; OK; PA; SC; TN; TX; VA; WV; Mexico; Eurasia
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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.)

In addition to characteristics given in the key, Ophioglossum vulgatum differs from O. pusillum in having an unusually persistent leathery basal leaf sheath (B.W. McAlpin 1971; W.H. Wagner Jr. 1971b) rather than an ephemeral one and in having smaller spores (mostly 35-45µm in O. vulgatum compared with 50-60 µm in O. pusillum). The chromosome number of O. vulgatum in India and Europe has been reported as 2n =480, and that may be the number of most North America populations, which are small spored. In the Appalachians, however, a distinctive large-spored form has a chromosome number of 2n =ca. 1320.

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

Source FNA vol. 2. FNA vol. 2.
Parent taxa Ophioglossaceae > Ophioglossum Ophioglossaceae > Ophioglossum
Sibling taxa
O. californicum, O. engelmannii, O. nudicaule, O. petiolatum, O. pusillum, O. vulgatum
O. californicum, O. crotalophoroides, O. engelmannii, O. nudicaule, O. petiolatum, O. pusillum
Synonyms O. pycnostichum, O. vulgatum var. pycnostichum
Name authority Walter: Fl. Carol. 256. (1788) Linnaeus: Sp. Pl. 2: 1062. (1753)
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