Sparse-lobed grapefern, southern grapefern

Osmunda biternata Savigny in Lamarck et al., Encycl. 4: 650. 1797; Botrychium dissectum Sprengel var. tenuifolium (L.Underwood) Farwell; B. tenuifolium L.Underwood

Trophophore stalk 4--20 cm, 2--2.5 times length of trophophore rachis; blade green to dark green, plane, 2--3-pinnate, to 18 × 28 cm, herbaceous. Pinnae to 7 pairs, usually remote, horizontal, distance between 1st and 2d pinnae not or slightly more than between 2d and 3d pairs, undivided except in proximal 2/3--1/2. Pinnules elongate, obliquely lanceolate to narrowly lanceolate, margins nearly parallel and finely denticulate, apex short-acuminate, venation pinnate. Sporophores 1--2-pinnate, 2--3 times length of trophophore. 2 n =90.

Leaves green over winter, sporophores seasonal, new leaves appearing in late spring--early summer. Frequent in low woods and brushy fields; 0--600 m; Ala., Ark., Del., Fla., Ga., Ill., Ind., Ky., La., Md., Miss., Mo., N.J., N.C., Ohio, Okla., Pa., S.C., Tenn., Tex., Va., W.Va.

Botrychium biternatum often grows with B . dissectum and B . jenmanii . The name B . biternatum was misapplied by L.Underwood to B . lunarioides (W.H. Wagner Jr. 1961).