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