The new combination Jaltomata chihuahuensis (Bitter) Mione & Bye is based on Saracha chihuahuensis Bitter. This species is distributed in Mexico at the northern end of the Sierra Madre Occidental in the states of Chihuahua, Durango, and Sonora. Morphological characters, artificial hybridizations, and distinct names applied by the Tarahumara, all indicate that J. chihuahuensis is distinct from the more widely distributed but sympatric J. procumbens. Fruits of J. chihuahuensis are consumed raw by the Tarahumara people and are either purple or green at maturity. Chromosome number: n = 12. Jaltomata is a diverse genus of about 30 species of herbs and small shrubs that are distributed from Arizona, U.S.A., to southern Bolivia, on the Gahipagos Islands, and in the Greater Antilles. This paper is part of ongoing series of studies of the taxonomy, phylogeny, breeding biology, and ethnobotany of this genus (D'Arcy et al., 1992; Davis, 1986; Davis & Bye, 1982; Knapp et al., 1991; Mione, 1992; Mione & Coe, 1992; Mione et al., 1993; Mione et al., 1994). Ethnoecology. There are two races of Jaltomata chihuahuensis, one with purple fruits and the other with green fruits. Without mature fruits the two races appear to be morphologically indistinguishable. Based on greenhouse and garden studies of three accessions, we are certain that plants do not produce both types of fruits, nor do the mature green fruits become purple with age or exposure to sunlight. Information obtained (by R. B.) from the Tarahumara during ethnoecological studies in Chihuahua, Mexico, agrees with these observations. Based on greenhouse studies, fruits of the purple race are typically green when they drop and then become purple within a few days. The two races may occupy different niches. Preliminary observations (by R. B.) are that the greenfruited race tends to occur among white volcanic rocks in soil with higher apparent organic matter. The purple-fruited race, however, is not found among white volcanic rocks nor in soil with high organic matter. The rootstock (camote) of the purple-fruited race is eaten by the Tarahumara (Davis & Bye, 1982: 232). Further study is needed to explore the possibility of niche specificity of the two