Stephanomeria exigua subsp. exigua

Illustrated
Synonyms: Stephanomeria pentachaeta D. C. Eaton Stephanomeria exigua var. pentachaeta (D. C. Eaton) H. M. Hall Stephanomeria schottii
Treatment appears in FNA Volume 19. Treatment on page 354. Mentioned on page 353, 355.

Heads in paniculiform arrays. Peduncles 10–40 mm, glabrous or sparsely glandular. Calyculi of appressed bractlets. Involucres glabrous or sparsely glandular. Florets 5–8. Cypselae 2.6–3.2 mm; pappi of 5–13 white to light tan bristles (widened bases persistent, bases connate in groups of 2–4, if bristles 5, breaking off completely, bristles plumose on distal 50%). 2n = 16.


Phenology: Flowering May–Jul.
Habitat: Sandy soils, deserts, sagebrush, creosote bush, pinyon-juniper woodlands, Joshua Tree communities
Elevation: 100–2000 m

Distribution

V19-556-distribution-map.gif

Ariz., Calif., Colo., Idaho, Nev., N.Mex., Oreg., Tex., Utah, Wash., Mexico (Baja California).

Discussion

Subspecies exigua is morphologically variable. Plants with pappi of 5 bristles (often called Stephanomeria pentachaeta) are found throughout its distribution; they are fully interfertile with plants having more bristles. Stephanomeria schottii A. Gray from southern Yuma County, Arizona, described as having a pappus of 4–6 bristles, “sparsely short-plumose toward the summit,” appears to be a synonym of subsp. exigua.

Selected References

None.

Lower Taxa

None.
L. D. Gottlieb +
Nuttall +
Ariz. +, Calif. +, Colo. +, Idaho +, Nev. +, N.Mex. +, Oreg. +, Tex. +, Utah +, Wash. +  and Mexico (Baja California). +
100–2000 m +
Sandy soils, deserts, sagebrush, creosote bush, pinyon-juniper woodlands, Joshua Tree communities +
Flowering May–Jul. +
Trans. Amer. Philos. Soc., n. s. +
Illustrated +
Stephanomeria pentachaeta +, Stephanomeria exigua var. pentachaeta +  and Stephanomeria schottii +
Stephanomeria exigua subsp. exigua +
Stephanomeria exigua +
subspecies +