Calycadenia oppositifolia

Plants 10-30 cm; self-incom-patible. Stems simple or sparingly branched (very slender), strigose and sparsely spreading-hairy. Leaves mostly or all opposite, 1-5 cm (little reduced distally), strigillose and ± long-hairy (at least proximally). Heads in congested, axillary glomerules (appearing whorled). Peduncular bracts lanceolate (flat, stiff, sometimes ± cylindric near apices), 4-10 mm (hispidulous, ± bristly and/or pectinate-fimbriate, especially proximally), apices ± rounded, tack-glands (0-)1-5+. Phyllaries (often reddish) 4-7 mm, abaxial faces sometimes minutely scabrous, often sparsely bristly, tack-glands usually 0, sometimes 1+. Paleae 4-7 mm. Ray florets 2-4; corollas white to reddish, tubes ca. 2 mm, laminae 6-9 mm (central lobes ± equaling or narrower than laterals, elliptic, nearly symmetric, widest near middles, sinuses equaling laminae). Disc florets 4-20; corollas white to pink, ca. 6 mm. Ray cypselae ca. 3 mm, usually smooth, glabrous. Disc cypselae ca. 3 mm, ± appressed-hairy; pappi of 8-10 usually lanceolate, acuminate scales ca. 2 mm (often 2-4 shorter, blunt). 2n = 14.

Flowering spring-early summer. Open, dry meadows, hillsides; 50-900 m; Calif.

Calycadenia oppositifolia is known only from the Sierra Nevada foothills of Butte County. Its closest relative may be C. multiglandulosa.