Adder's Tongue

Ophioglossum pusillum is inconspicuous and may be much more common than collections indicate. It differs from O . vulgatum in having an ephemeral, membranous basal sheath.

Roots yellow to tan, to 15 per plant, 0.3-1 mm diam., producing proliferations. Stem upright, to 2 cm, 3mm diam., 1 leaf per stem. Trophophore stalk expanding gradually into blade. Trophophore blade erect or spreading, usually plane when alive, pale green, dull, mostly oblanceolate to obovate to ovate, widest point in middle, to 10 × 3.5 cm, soft, herbaceous, base tapering gradually, apex rounded; venation complex-reticulate, with included free veinlets in areoles. Sporophores arising at ground level, 2.5-4.5 times length of trophophore; sporangial clusters 20-45 × 1-4 mm, with 10-40 pairs of sporangia, apiculum 1-2 mm. 2 n =960.

B.C., N.B., N.S., Ont., Que.; Alaska, Calif., Conn., Idaho, Ill., Ind., Iowa, Ky., Maine, Md., Mass., Mich., Minn., Mont., Nebr., N.H., N.J., N.Y., N.Dak., Ohio, Oreg., Pa., R.I., S.Dak., Vt., Va., Wash., W.Va., Wis.

Leaves appearing midspring. Frequent and widespread, open fens, marsh edges, pastures, and grassy shores and roadside ditches, north of the southern boundary of Wisconsin glaciation; 100-2000m.

Ophioglossum vulgatum Linnaeus var. pseudopodum (S.F. Blake) Farwell

Ophioglossum pusillum is a species of fern in the family Ophioglossaceae known by the common name northern adder's tongue.

It is native to northern North America, where it is widespread in moist areas such as marshes, fens, and meadows. It is found from northern California through Alaska on the west, and from central Appalachia through the northern Great Plains and the Great Lakes regions, across the Northeastern United States and Eastern Canada.