Chorizanthe uniaristata

Torrey & A. Gray

Proc. Amer. Acad. Arts 8: 195. 1870.

Common names: One-awn spineflower
Treatment appears in FNA Volume 5. Treatment on page 460. Mentioned on page 448, 461.

Plants spreading or ascending, 0.2–0.6(–0.8) × 0.5–4(–5) dm, appressed-pubescent. Leaves basal; petiole 0.5–2 cm; blade oblanceolate, 0.5–1.5(–2) × 0.2–0.8 cm, thinly pubescent. Inflorescences with involucres in small open clusters 0.5–1.5 cm diam., greenish to grayish or reddish; bracts 2, sessile, usually leaflike, oblanceolate to elliptic, 0.5–1.5 cm × 1.5–5 mm, gradually reduced and becoming scalelike at distal nodes, linear, aciculate, acerose, 0.4–1.2 cm × 1–2(–3) mm, awns straight, 1.5–4 mm. Involucres 3–10, grayish to reddish, urceolate, slightly ventricose basally, 2–3 mm, without scarious or membranous margins, slightly corrugate, densely grayish-pubescent; teeth widely spreading to divergent, unequal, 0.3–0.5 or 3–6 mm; awns straight or uncinate, unequal, with longer anterior one straight, 2.5–5.5 mm, others spreading, uncinate, 0.3–0.5 mm. Flowers included or only slightly exserted; perianth bicolored with floral tube greenish white and tepals white, cylindric, 2–3 mm, sparsely pubescent; tepals connate 2/3 their length, dimorphic, linear-oblong, those of outer whorl spreading, narrowly oblong, 1.5 times longer than those of inner whorl, rounded but with minute cusp or 3 teeth apically, those of inner whorl erect to slightly spreading, acute, entire apically; stamens 3, included; filaments distinct, 1–2 mm, glabrous; anthers white, ovate, 0.4–0.5 mm. Achenes brown, globose-lenticular, 2–3 mm. 2n = (78), 80, (82).

Phenology: Flowering Apr–Jul.
Habitat: Sandy to gravelly talus or clay flats and slopes, mixed grassland and chaparral communities, pine-oak woodlands
Elevation: 800-1900 m


Chorizanthe uniaristata is scattered in the Inner Coast Ranges and across the Transverse and Tehachapi ranges to the southern Sierra Nevada.

One-awn spineflower is a polyploid, but whether an autopolyploid or an autoallopolyploid has not been determined. It has the smallest meiotic chromosomes observed by C. B. Hardham (1989).

Selected References


Lower Taxa

... more about "Chorizanthe uniaristata"
James L. Reveal +
Torrey & A. Gray +
One-awn spineflower +
800-1900 m +
Sandy to gravelly talus or clay flats and slopes, mixed grassland and chaparral communities, pine-oak woodlands +
Flowering Apr–Jul. +
Proc. Amer. Acad. Arts +
Chorizanthe sect. Anisogonum +, Chorizanthe sect. Eriogonellopsis +  and Chorizanthe sect. Herbaceae +
Chorizanthe uniaristata +
Chorizanthe sect. Ptelosepala +
species +