Cirsium eatonii var. clokeyi

(S. F. Blake) D. J. Keil

Sida 21: 212. 2004.

Common names: Clokey or Spring Mountains or white-spine thistle
EndemicConservation concern
Basionym: Cirsium clokeyi S. F. Blake Proc. Biol. Soc. Wash. 51: 8. 1938
Treatment appears in FNA Volume 19. Treatment on page 151. Mentioned on page 144.

Stems erect or ascending, stout, 40–150 cm. Leaf faces glabrous or nearly so. Heads usually short-pedunculate in erect, racemiform arrays or sometimes long-pedunculate in openly corymbiform arrays. Involucres 3–5 cm, glabrous or thinly arachnoid tomentose, individual phyllaries evident. Phyllaries green or purplish-tinged; outer pectinately spiny 1/2 their length with many lateral spines; apical spines stout. Corollas purple, 24–33 mm, tubes 3.5–7 mm, throats 11–14 mm, lobes 8–12.5 mm. Pappi 16–18 mm. 2n = 34 (as C. clokeyi).


Phenology: Flowering summer (Jul–Sep).
Habitat: Gravelly slopes, ravines, montane coniferous forests, subalpine forests, alpine scree
Elevation: 2300–3500 m

Discussion

Of conservation concern.

Variety clokeyi is endemic to the Spring Range of Clark County. Its range overlaps that of Cirsium arizonicum var. tenuisectum but no hybrids between the two are known.

Selected References

None.

Lower Taxa

None.
David J. Keil +
(S. F. Blake) D. J. Keil +
Cirsium clokeyi +
Clokey or Spring Mountains or white-spine thistle +
2300–3500 m +
Gravelly slopes, ravines, montane coniferous forests, subalpine forests, alpine scree +
Flowering summer (Jul–Sep). +
Endemic +  and Conservation concern +
Asteraceae tribe Cynarea +
Cirsium eatonii var. clokeyi +
Cirsium eatonii +
variety +