Beautiful Hummingbird is a small species of hummingbird in the genus Calothorax. This genus is comprised of two species that are very similar, Beautiful and Lucifer (Calothorax lucifer) hummingbirds. Both species have long, slightly decurved bills, and the males have rather long, strongly graduated tails. Beautiful Hummingbird can be separated from Lucifer by its longer tail with more rounded outer tips and shorter, less decurved bill. Males are green above and white below with a purple gorget, long bill, and dusky green flanks. Females are buffy below with a pale postocular streak. Beautiful Hummingbird occurs only in southern Mexico in dry, montane shrublands.