Psilostrophe villosa

Rydberg ex Britton
Man. Fl. N. States, 1006. 1901.
Synonyms: Psilostrophe tagetina var. cerifera (A. Nelson) B. L. Turner
Treatment appears in FNA Volume 21. Treatment on page 455. Mentioned on page 454.

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.

Phenology: Flowering (Mar–)May–Aug(–Oct).
Habitat: Grasslands, limestone soils, gypseous soils, caliche
Elevation: 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.

Selected References


Lower Taxa