Botrychium sect. Hiemobotrychium
Novon 2: 267. 1992.
Roots 20–30, yellow to brown, 0.6–1 mm diam. 1cm from base. Plants over 6 cm. Common stalk with tracheidal idioblasts. Trophophore short-stalked and prostrate, arising from basal portion of common stalk near ground level; blades usually 2 per plant, appearing in late fall and dying in early spring, deltate, 2–3-pinnate, mostly 5–8 cm wide when mature, herbaceous. Leaf primordia with scattered hairs, hairs 0.6–1 mm. Leaf sheath closed. Pinna divisions reduced to tip. First pinnule on basal pinnae usually borne basiscopically. Sporophores long-stalked, arising from basal portion of common stalk near ground level, commonly absent without primordia; stalks and rachis broadly flattened, fleshy, to 1.4 mm wide. x =45.
Endemic to se United States.
Tracheidal idioblasts in Botrychium sect. Hiemobotrychium are enormous, elongate, spindle-shaped cells with helical or annular thickenings and are scattered along the vascular strand. They are unique among ferns.