Phytologia 12: 468, fig. pp. 472, 473. 1966.
Subshrubs or shrubs, (10–) 30–100 cm. Stems erect, usually much branched. Leaves cauline; mostly opposite (distal often alternate); petiolate; blades 1-nerved or 3-nerved, ovate, deltate, or rhombic to lanceolate, margins entire or toothed [lobed, 2-pinnatifid], faces usually stipitate-glandular. Heads discoid, borne singly or in loose, corymbiform arrays. Involucres ± obconic, 4–6 mm diam. Phyllaries persistent, 30–35 in 3–4+ series, (herbaceous to chartaceous) 1-nerved or 3-nerved, ovate to lanceolate, unequal. Florets 25–30; corollas white, throats narrowly cylindric (lengths 4–6 times diams.); styles: bases not enlarged, glabrous, branches ± clavate. Receptacles flat or convex, epaleate. Cypselae prismatic, 4–5-ribbed, scabrellous; pappi persistent, of 3–6 (–12) subulate-aristate scales plus 3–6 (–12) coarse, barbellate bristles in 1 series. x = 9.
w United States, nw Mexico
Species 3 (1 in the flora).
"fine" is not a number.