Wiggins 1964, Kearney and Peebles 1969

Duration: Perennial Nativity: Native Lifeform: Forb/Herb General: Perennial with ascending to erect, slender stems 3-40 cm long, 0.5-1.5 mm diameter; from slender woody taproot; herbage puberulent to glabrous. Leaves: Ovate to linear-lanceolate, 4-25 mm long, puberulent to glabrous, gray-green, markedly asymmetrical basally, acute to obtuse at apex, serrate along lower margin, entire on upper, less commonly alike on both margins. Flowers: Cyathia rarely solitary, usually in cymose glomerules, peduncles 0.5-3 mm long, involucres campanulate to obconic, 1.3-1.7 mm in diameter, hairy on inside of narrowly triangular lobes, these exceeding glands; glands orbicular to transversely oval, .2-.5 mm wide, stipitate; appendages entire, white or pinkish. Fruits: Capsule 1.3-1.9 mm long, seeds quadrangular in cross section, ovate vertically; back wrinkled with small irregular, transverse depressions. Ecology: Found on hillsides, in washes and on dry sites; 1,500-5,000 ft (457-1524 m); flowers March-October. Distribution: AZ, NM, sw TEX; south to s MEX. Notes: Distinguished by being ascending to erect perennials with mostly short hairs, ovate leaves with only half-serrate margins; dense inflorescences, sometimes forming roundish clusters (capitate); cyathia with large, white appendages (resembling petals) and more or less short-haired to long soft-haired capsules <2mm. Ethnobotany: Unknown, but other species in the genera have multiple uses. Etymology: Euphorbia is named for Euphorbus, Greek physician of Juba II, King of Mauretania, while capitellata means having a small head. Synonyms: Chamaesyce pycnanthema, Euphorbia capitellata, Euphorbia pycnanthema Editor: SBuckley 2010, FSCoburn 2015