Porophyllum ruderale var. macrocephalum
Madroño 20: 255. 1970.
Basionym: Porophyllum macrocephalum de Candolle in A. P. de Candolle and A. L. P. P. de Candolle, Prodr. 5: 648. 1836
Synonyms: Porophyllum ruderale subsp. macrocephalum (de Candolle) R. R. Johnson
Treatment appears in FNA Volume 21. Treatment on page 234.
Annuals, 15–50+ cm; internodes mostly 15–30+ mm. Leaf blades oval or elliptic to obovate, 15–35+ × 8–25+ mm. Phyllaries 5, linear, 15–25+ mm. Florets mostly 30–50+; corollas greenish to purplish, 9–12.5 mm. Cypselae 9–12 mm; pappi: longer bristles 7–10 mm. 2n = 22.
Phenology: Flowering late summer–fall.
Habitat: Ephemerally wet sites in desert mountains
Elevation: 1000–1500 m
Distribution

Ariz., N.Mex., Tex., Mexico, West Indies (Antilles), Central America, South America.
Discussion
Selected References
None.
Lower Taxa
None.