Annual. Stems erect, 20–70 cm, unbranched below inflorescence. Herbage glabrous to sparsely villous. Leaves alternate, sessile, ovate to elliptic, 3–8 cm long, entire, acute, mucronate, whorled at the base of the umbel. Inflorescence a terminal, compound umbel with white-margined, leaf-like bracts. Cyathia 3–4 mm long, villous, with 4 white, reniforn glands. Capsule 4–6 mm long, pubescent (
Lesica et al. 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).