Wheeler's spineflower

Chorizanthe insularis R. Hoffmann

Plants erect to spreading, 0.5-2(-2.5) × 1-2 dm, thinly pubescent. Leaves basal; petiole 0.5-3 cm; blade elliptic to oblong, 0.5-2 × 0.2-0.6 cm, thinly pubescent adaxially, tomentose abaxially. Inflorescences mostly flat-topped, openly branched, greenish to reddish; bracts persistent, 2, usually leaflike at proximal nodes and similar to leaf blades, short-petiolate, oblong, 0.5-1.2 cm × 2-4 mm, sessile, reduced and scalelike at distal nodes, linear, acicular, often acerose, 0.1-0.5 cm × 0.5-1 mm, awns straight, 0.5-1 mm. Involucres in dense terminal clusters with 1 at node of dichotomies, reddish, cylindric, not ventricose, 2-2.5 mm, corrugate, without scarious or membranous margins, thinly pubescent with stoutish, recurved hairs; teeth spreading, unequal, 0.3-0.8(-1) mm, with 3 longer ones more erect than 3 shorter and less-prominent ones; awns uncinate, 0.3-0.5 mm. Flowers exserted; perianth white or rose or red with white lobes, cylindric, 2.5-3 mm, glabrous except for few scattered hairs ca. midlength along midrib abaxially; tepals connate 1/ 2 their length, monomorphic to slightly dimorphic, oblong, rounded apically, those of outer whorl usually slightly broader and longer than those of inner whorl; stamens 6, included; filaments distinct, 1.5-2 mm, glabrous; anthers pink to red, oblong, 0.3-0.4 mm. Achenes brown, lenticular, 2.5-3 mm.

Flowering Apr-Jun. Gravelly to rocky slopes, coastal scrub communities; 0-400(-600) m; Calif.

Chorizanthe wheeleri is a rare insular endemic known only from Santa Cruz and Santa Rosa islands.