Riverside Spineflower

Plants erect to infrequently spreading, (0.3-)0.5-2.5(-3) × 0.5-3(-5) dm, thinly pubescent. Leaves basal or nearly so; petiole 1-2(-3) cm; blade oblong or oblong-ovate to ovate, 0.3-1(-1.5) × 0.3-0.8(-1) cm, thinly pubescent adaxially, densely tomentose abaxially. Inflores-cences mostly flat-topped and openly branched, usually reddish; bracts persistent, 2, usually leaflike at proximal nodes and similar to proximal leaf blades only more reduced, short-petiolate, oblong-ovate to ovate, 0.3-0.8 cm × 2-6 mm, becoming sessile, reduced and scalelike at distal nodes, linear, acicular, often acerose, 0.1-0.4 cm × 0.5-1 mm, awns straight, 0.5-1 mm. Involucres in open clusters with 1 at node of dichotomies, reddish, cylindric, not ventricose, 3-4.5 mm, not corrugate, without scarious or membranous margins, thinly to densely pubescent; teeth spreading, unequal, 0.7-1.5 mm, 3 longer ones more erect than 3 shorter and less-prominent ones; awns uncinate, 0.5-1 mm. Flowers long-exserted; perianth rose to red, infrequently with white lobes, cylindric, 4.5-6 mm, pubescent; tepals connate ca. 2/ 3 their length, monomorphic to slightly dimorphic, narrowly oblanceolate, rounded apically, those of outer whorl occasionally slightly broader and longer than those of inner whorl; stamens 9, mostly included; filaments distinct, 4-6 mm, glabrous; anthers pink to red, oblong, 0.5-0.6 mm. Achenes brown, lenticular, 4-4.5 mm.

Chorizanthe xanti is a species of flowering plant in the buckwheat family known by the common name Riverside spineflower. It is endemic to California, where it grows in several of the mountain ranges from the Sierra Nevada to the Southern California Transverse Ranges in forest, woodland, and scrub habitats.