imparis. Formica imparis Say, 1836: 287 (q.m.) U.S.A. Wheeler, W.M. 1930b: 16 (w.); Wheeler, G.C. & Wheeler, J. 1953c: 142 (l.); Hauschteck, 1962: 219 (k.). Combination in Prenolepis: Mayr, 1886d: 431. Senior synonym of americana: Emery, 1893i: 635; Dalla Torre, 1893: 178; of wichita: Dalla Torre, 1893: 178; Wheeler, W.M. 1930b: 15; of minuta, pumila, testacea: Creighton, 1950a: 414; of californica: Wheeler, G.C. & Wheeler, J. 1986g: 14. Current subspecies: nominal plus arizonica, colimana, coloradensis, veracruzensis. See also: Wheeler, W.M. 1930b: 16.