Hayfield tarweed

Hemizonia luzulifolia de Candolle in A. P. de Candolle and A. L. P. P. de Candolle, Prodr. 5: 692. 1836 (as luzulaefolia); H. congesta var. luzulifolia (de Candolle) Jepson; H. luzulifolia subsp. rudis (Bentham) D. D. Keck

Leaves pubescent, villous, or sericeous (distal with hairs not notably longer at margins), all or distal glandular. Heads in paniculiform arrays. Peduncles 0 or 1–30 mm, bracts not surpassing phyllaries. Calyculi 0. Phyllaries 3.5–6.5 mm, apices usually shorter than bodies. Ray florets 5–11; laminae white, abaxially purple-veined. Cypsela widths 0.5–0.6 times lengths. 2n = 28.

Flowering Mar–Dec. Disturbed sites, grassy slopes, valley bottoms, openings in chaparral and woodlands, often clayey soils, serpentine; 0–1000 m; Calif.

Subspecies luzulifolia occurs from the North Inner Coast Ranges and northern Great Valley through the San Francisco Bay area to the southern South Coast Ranges. Natural hybridization between subsp. luzulifolia and subsp. lutescens has been reported (E. B. Babcock and H. M. Hall 1924).