Psilostrophe tagetina (Nuttall) Greene var. cerifera (A. Nelson) B. L. Turner

Biennials or perennials (rarely flowering first year), 10–45(–60+) cm. Stems arachno-villous (gray to gray-green). Heads in ± crowded, corymbiform arrays. Peduncles (0.5–)1–3(–5+) mm. Involucres 4–5(–7) mm. Rays (2–)3(–5); laminae 3–4(–6) mm, spreading in fruit. Disc florets 5–8(–12). Cypselae usually glabrous, sometimes gland-dotted; pappi of 4–6 lanceolate to lance-subulate scales 2.5–3+ mm. 2n = 32.

Flowering (Mar–)May–Aug(–Oct). Grasslands, limestone soils, gypseous soils, caliche; 300–900 m; Kans., N.Mex., Okla., Tex.

In trans-Pecos Texas, Psilostrophe villosa has been collected within 10 km or so of the Rio Grande; it probably occurs in Mexico. Within 100 km or so of the New Mexico-Texas border, P. villosa and P. tagetina intergrade; B. L. Turner et al. (1988) treated P. villosa as P. tagetina var. cerifera.