- To +1m tall, 5mm thick near base, 1mm thick near inflorescence, glabrous to somewhat pubescent, glaucous, erect, herbaceous, from a deep taproot and caudex, single or multiple from base, with milky sap.
- Alternate below, opposite in and near inflorescence, entire, oblong to oblong- linear, to 6.5cm long, 1.5cm broad, sessile or with very short petioles, rounded or blunt at apex, glabrous or with a few sparse strigose hairs near at apex.
- Terminal, flat-topped corymbs or paniculate (depending on variety, see below).
- Cyathia with 5 white appendages. Appendages to 4mm long, 3mm broad, glabrous, often notched at apex. Green glands at base of appendages 1.2mm broad. Staminate flower with white filaments. Filaments to .8mm long, glabrous. Anthers yellow, biglobose, .7mm broad. Pistillate flowers with 3 styles. Styles to .7mm long, glabrous, divided. Cyathia densely pubescent internally. Capsules to +4mm long, 3-locular, one seed per locule.
- Smooth, 3-parted capsule to 4mm long, white, ovoid.
- May - October.
- Prairies, pastures, open woods, glades, roadsides, railroads.
- Native to U.S.
- Steyermark divides this species into 3 varieties. Variety
has the lower surface of the leaves and at least the upper portion of the stem pubescent. Variety
is mostly glabrous and the cyathia, including the white appendages, is 7-10mm broad. Variety
is mostly glabrous and the cyathia, including the appendages, are 5-7mm broad. This variety also has a more dense, panicle-like inflorescence and is fairly rare.
This species will secrete a white, latex substance when cut or bruised and is mildly toxic.
The plant is quite frequent in dry portions of the habitats listed above.
Photographs taken at the Current River Conservation Area, Reynolds County, MO., 8-10-1, and in Brown Summit, NC., 6-18-02.