The genus (Solanaceae, Capsiceae) in Mexico and Guatemala.

, the third most species-rich genus in the Solanaceae, is distributed in both the New and Old Worlds and is especially diverse in Mexico. Here we provide an identification key, taxonomic descriptions, distribution maps, and illustrations of specimens, trichomes, flowers, and fruits for the 53 known taxa of Mexico and Guatemala. The new combination (Mill.) M.Nee is made and replaces the name (Cav.) Bitter, which is placed in synonymy. Within , two varieties are recognized (Lycianthes scandens var. scandens and Lycianthes scandens var. flavicans (Bitter) J.Poore & E.Dean, ). In addition, one new species ( E.Dean, ) is described from eastern Mexico, and 10 names (either recognized taxa or synonyms of recognized taxa) are lectotypified, including the names Sendtn., Carrière, and Sendtn. The species Bitter and (Sendtn.) Bitter are excluded from the treatment, as research indicates that they do not occur in Mexico and Guatemala, however full synonymy for both names is given.