New species of Cuphea (Lythraceae) from Mexico

Five new species are described, three of which, C. crassiflora, C. paucipetala, and C. trochilus, belong to sect. Heterodon, a group of predominantly annual, western Mexican species. The perennial C. rasilis is a new member of sect. Melvilla and the perennial C. spectabilis is new to sect. Diploptychia. Chromosome numbers for the annual species and two additional ones, C. procumbens and C. koehneana, closely related to the novelties, are reported for the first time.