Estudios sobre rubiáceas mexicanas XXXI Trichosiphon Y Gymnosiphon borhidi sect. Nov. Subgén. Bouvardiastrum (Bouvardia Salisb.) Con seis especies nuevas

Six new species of Bouvardia Salisb. have been discovered from the states Oaxaca and Guerrero. All are belonging to the subgenus Bouvardiastrum W. H. Blackwell, actually represented by 30 species in the flora of Mexico. Ten of them have corolla tube naked in the inside a character uncommon in the genus. Based on this important feature, two new sections are proposed to distinguish: Gymnosiphon sect. nov. for 10 species with naked corolla tube in the inside and Trichosiphon sect. nov. for the other 20 species. Descriptions of the new species and sections are described, respectively, and a new analytic key for identification of all the species belonging to the subgenus