Description
Annual composite, rayless, heads subsessile or short-pedunculate; leaves pinnately dissected, the divisions linear, often confused in collections with Heterosperma pinnatum Cav.
Distribution
Southwestern New Mexico, southern Arizona and Mexico (S. Ariz., B.C, Zac, Ags., D.F. as listed in McVaugh 1984; Rzedowski 1985 adds VC. to this list).
Habitat
Hillsides, grassy openings in dry sparse oak forest or open woodland of oak, pine, and juniper, 2,500-2,700 m (McVaugh 1984); Rocky slopes, 4,500-7,000' (Martin and Hutchins 1981); Sandy open places (Carter s.n.); Lava fields (Pringle 11489); Ridge (Wagner 1730); Granite slopes (Clark 1236); Bosque de pino, 2,500 m (González & Acevedo 2043); Bosque de pino-encino, 2,240 m (González 4120); Bosque de pino-encino (Quercus spp., Pinus con presencia de Alnus), 2,800 m (González & Rzdowski 2288); Bosque de pino, crece in partes soleadas, lugares abiertos y pantanosos, 2,560 m (Soule & Lockerman 2806); Bosque de pino-encino, 2,650 m (Fernández 1135).
Important Literature
Martin, W.C. and C.R. Hutchins. 1981. A Flora of New Mexico, vol. 2. J. Cramer, Vaduz.
Kearney, T.H. and R.H. Peebles. 1969. Arizona Flora, 2nd ed. (with supplement by J.T. Howell, Elizabeth McClintock, et al.). Univ. California Press, Berkeley. 1085 pp.
McVaugh, R. 1984. Flora Novo-Galiciana, vol. 12, Compositae. Univ. Michigan Press, Ann Arbor.
Rzedowski, J. 1985. Bidens, pp. 525-532 in J. Rzedowski and G. D. de Rzedowski (eds), Flora Fanerogamica del Valle de México, vol. II, Dicotyledonae (Euphorbiaceae-Compositae). Escuela Nacional de Ciencias Biológicas e Instituto de Ecología, México.
Sherff, E.E. 1937. The genus Bidens. Field Mus. Nat. Hist. Bot. Ser. 16:1-709