Erect annual, 1-5 dm, with numerous opposite, very slender branches, but usually maintaining a central axis; principal lvs opposite, narrowly elliptic or oblong, 3-5 cm, equilateral at base, those of the branches shorter, often narrowly linear or filiform; involucres mostly unisexual (some bisexual), minutely pediceled in the upper axils, 2-3 mm, pubescent; appendages 5; fr eventually exsert well beyond the involucre on a pedicel 2-4 mm; seeds gray, nearly cylindric, 2.5 mm, minutely tuberculate. Prairies, plains, and barrens; Minn. to Mont., s. to Mo., Tex., and N.M. July-Sept. (Zygophyllidium h.)

Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.

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