Xanthisma spinulosum

Xanthisma spinulosum, the spiny goldenweed or cutleaf ironplant, is a multi-stemmed perennial subshrub of the Asteraceae native to dry plains, mesas, sandy prairies and rocky openings of western and central North America from southern Canada and the Great Plains through the Rocky Mountain and Great Basin states south into northern Mexico. It develops a stout, woody taproot and crown that gives rise each year to many erect to ascending stems 10-50 cm tall, frequently brittle at the base and clothed in short stiff hairs. The alternate leaves are 1-4 cm long, deeply once or twice pinnately divided into narrow, rigid, bristle-tipped segments that give the plant a prickly, almost spinose appearance. From summer through autumn the stems bear numerous solitary, terminal flower heads 1.5-3 cm across, with 10-25 yellow ray florets surrounding a yellow disc, subtended by imbricate, often glandular, sometimes recurved bracts. Achenes are small, hairy and tipped with a tawny pappus of slender capillary bristles. Several varieties and segregate microspecies are recognised across its broad range.