Many-flowered wild buckwheat

Herbs, 5-20 × 3-6 dm, reddish. Aerial flowering stems slender or stout, 4-15 dm, floccose to tomentose. Leaves: petiole 0.3-1 cm (rosette), or 0.2-0.5 cm (cauline), tomentose to floccose; blade narrowly lanceolate to narrowly elliptic or oblong to narrowly ovate, 1.5-5(-8) × 0.3-2.2(-2.5) cm, densely tomentose abaxially, tomentose or floccose to glabrate adaxially, sometimes thickened and auriculate-subclasping proximally; margins entire or crisped, rarely revolute. Inflorescences 50-200 × 20-100 cm; bracts triangular, 1-3 mm. Peduncles 0.1-0.4 cm, tomentose to floccose. Involucres turbinate to turbinate-campanulate, 2-2.5 × 1.5-2(-2.5) mm, tomentose to floccose or occasionally glabrous abaxially, tomentose adaxially; teeth 5, 0.3-0.8 mm. Flowers 1.5-2.5 mm; perianth white to reddish brown; tepals: those of outer whorl oblong-cordate, 1.5-2 × 1.5-2 mm, those of inner whorl lanceolate to oblong, 1.5-2.5 × 0.2-0.5 mm; stamens slightly exserted, 1.5-3 mm. Achenes 1.5-2 mm.

Varieties 2 (2 in the flora): c United States.