Hemizonia halliana D. D. Keck, Madroño 3: 12. 1935

Annuals, 15–120 cm. Stems fistulose. Leaves: proximal blades entire or serrate, faces glabrous (margins and midribs sometimes scabrous or hispid). Heads in open, corymbiform, racemiform, or paniculiform arrays. Bracts subtending heads usually not overlapping involucres. Phyllaries evenly stipitate-glandular, including margins and apices, usually with some non-glandular, non-pustule-based hairs as well. Paleae in 1 series. Ray florets (8–)10–14; laminae deep yellow, 5–10 mm. Disc florets 28–60, all functionally staminate; anthers yellow or brownish. Pappi 0 (reportedly sometimes rudimentary). 2n = 20.

Flowering Apr–May. Grasslands, edges of alkali sinks, open muddy slopes, heavy, ± alkaline, clayey soils; of conservation concern; 300–1000 m; Calif.

Deinandra halliana occurs in the Inner South Coast Ranges. Evident population sizes vary greatly from year to year; active plants may be absent in dry years and form dense stands in some wet years. Madia radiata is morphologically similar to D. halliana; the two species sometimes co-occur and can be difficult to distinguish without close examination of phyllaries and cypselae.