White tack-stem

Stems, distal branches, and phyllaries gland-dotted, glands straw-colored. Involucres 10–15 mm. Ligules white, often with fine reddish veins abaxially, 2–3 cm. Cypselae dark tan to brown, shallowly grooved between ribs, faces weakly cross-rugulose. 2n = 14.

Flowering Mar–Jun. Gravels derived from limestone, volcanics, granites, and caliche soils on plains, rocky mesas and slopes, stream bottoms, desert pavement and washes, Upper Sonoran and Lower Sonoran zones, Colorado and Mohave deserts, often in creosote or mesquite associations; 100–1600 m; Ariz., Calif., Nev., N.Mex., Tex., Utah; Mexico (Baja California, Sonora).