an annual herb, 1/2–1 ft. high, glabrous in all parts; stem usually with a pair of branches arising from its base, sometimes simple, usually dividing into a 5-rayed umbel 2–6 in. in diam. at the top; primary rays dividing into 3 secondary rays, which are 1–3-times forked; leaves alternate on the stem, whorled or opposite on and at the base of the umbel, sessile or tapering into a petiole, 1/2–1 1/3 in. long, 1/4–1 in. broad, cuneately obovate, rounded at the apex, denticulate; involucre solitary in the forks of the rays and terminal, subsessile, 1–1 1/4 lin. in diam. and 1 lin. deep, cup-shaped, yellowish-green, with 4 glands and 5 oblong or subquadrate minutely toothed lobes; glands 1/2 lin. in their greater diam., transversely oblong, entire, flat, yellowish-green; ovary obtusely trigonous, conspicuously 3-grooved between the angles, glabrous, exserted on a curved pedicel 1 1/3–1 3/4 lin. long; styles about 1/3 lin. long, free almost to the base, not diverging, shortly 2-lobed at the apex; capsule 1 3/4 lin. in diam. and 1 1/4 lin. long, 3-lobed as seen from above, smooth; seeds 1–1 1/6 lin. long, ellipsoid or subglobose, with a raised network all over their surface, dark brown, with a small yellowish caruncle. null