Duration: Annual

Nativity: Native

Lifeform: Forb/Herb

General: Annual herb, 10-50 cm tall, from a taproot; stems erect, with numerous spreading branches; without milky sap; herbage glabrous.

Leaves: Alternate and sessile along the stems; blades narrowly elliptic to linear, 15-40 mm long and 2-8 mm wide; each leaf with a pair of red-brown stipules at the base, these 1-2 mm long.

Flowers: Tiny and dark purple, hanging on short curved pedicels in the leaf axils; flowers arranged in structures called cymules, with a single female flower surrounded by 4-6 male flowers, all dark reddish-purple and about 2 mm high; the female flower has a 6-lobed calyx, no petals, and a 3-lobed ovary; the male flowers each have a 4-lobed calyx, no petals, and 2 stamens.

Fruits: Capsules 3-lobed, nearly globose, 7-10 mm wide, with 3 locules; each locule contains 2 seeds, these 4-6 mm long.

Ecology: Found in sand dunes and very sandy soils, from 4,500-6,500 ft (1372-1981 m); flowers June-August.

Distribution: w KS, OK, and TX, west to n AZ and s UT; south to n MEX.

Notes: This sand dune specialist was traditionally considered part of the Euphorb famiy (Euphorbiaceae); look for it in that family in older texts. The flowers and fruit are classically euphorb-like, with a 3-lobed ovary surrounded by a few inconspicuous male flowers. Unlike flowers from the genus Euphorbia, this small collection of flowers is not encased in a cup-like structure (called a cyathium in that genus.) Also unlike most Euphorbs, this species lack milky sap. Reverchonia arenaria has small dangling dark reddish flowers; green globe-shaped 3-lobed seed pods; and narrow leaves.

Ethnobotany: Unknown

Etymology: Reverchonia is named for Julien Reverchon (1837-1905) a French-born botanist, doctor, and noted collector of Southwestern plants; arenaria means growing in sand.

Synonyms: None

Editor: AHazelton 2017