2. Chorizanthe membranacea Bentham, Trans. Linn. Soc. London. 17: 419, plate 17, fig. 11. 1836.
Eriogonella membranacea (Bentham) Goodman
Plants 1-6(-10) × 0.5-3(-5) dm, woolly-floccose. Leaves basal and cauline; petiole 0.1-0.5(-0.8) cm; blade linear to narrowly oblance-olate, (1-)1.5-5 × 0.1-0.3 cm, thinly to densely floccose adaxially, densely tomentose abaxially. Inflorescences strict, white to greenish, open; bracts usually 2, opposite, rarely in whorls of 3-5, short-petiolate, acerose, similar to proximal leaf blades only reduced, 0.3-3 cm × 1-3 mm, awns straight, 0.5-1 mm. Involucres usually congested in small terminal clusters of 1-3 at node of dichotomies, urceolate, ventricose basally, 3-angled, 6-ribbed, 3-4 mm, not corrugate, with conspicuous, white margins extending across sinuses, tomentose to floccose or glabrate with age, greenish to brownish; teeth 6; awns uncinate, 0.7-1.5 mm. Flowers 1(-2), slightly exserted; perianth white to rose, subcylindric, (1.5-)2.5-3 mm, densely pubescent abaxially; tepals connate 2/ 3 their length, slightly dimorphic, entire and rounded apically, those of outer whorl obovate, those of inner whorl spatulate; stamens slightly exserted; filaments 1.5-2.5 mm, glabrous; anthers pink to red, oval, 0.2-0.3 mm. Achenes 2.5-3 mm. 2n = 38, 40, (42), 80, 82, 84.
Flowering Apr-Jul. Sandy to gravelly or rocky flats and slopes, mixed grassland and chaparral communities, oak-pine woodlands; 40-1400(-1600) m; Calif., Oreg.
Chorizanthe membranacea has long been considered an isolated element among the spineflowers. The strict, upright habit, numerous basal and cauline leaves, and broad, continuous, membranous margins of the involucre all reflect that isolation. Pink spineflower is widespread and often locally common in the Coast Ranges of southwestern Oregon and California and on the western foothills of the Sierra Nevada southward to the Transverse Ranges and the Tehachapi Mountains of Ventura and Kern counties, California.