Chlorostilbon
| Chlorostilbon | |
|---|---|
| Blue-tailed emerald | |
| Scientific classification | |
| Domain: | Eukaryota | 
| Kingdom: | Animalia | 
| Phylum: | Chordata | 
| Class: | Aves | 
| Clade: | Strisores | 
| Order: | Apodiformes | 
| Family: | Trochilidae | 
| Tribe: | Trochilini | 
| Genus: | Chlorostilbon Gould, 1853 | 
| Type species | |
| Chlorostilbon prasinus = Trochilus pucherani Gould, 1853 | |
| Species | |
| See text | |
Chlorostilbon is a genus of hummingbird in the family Trochilidae, known as emeralds (as are some hummingbirds in the genera Amazilia and Elvira). A single species, the blue-chinned sapphire is variously placed in the monotypic genus Chlorestes or in Chlorostilbon. The taxonomy of the C. mellisugus superspecies is highly complex and, depending on view, includes 1-8 species. All species in this genus have straight black or black-and-red bills. The males are overall iridescent green, golden-green or bluish-green, and in some species the tail and/or throat is blue. The females have whitish-grey underparts, tail-corners and post-ocular streak.
The genus Chlorostilbon was introduced in 1853 by the English ornithologist John Gould to accommodate a single species to which Gould gave the binomial name Chlorostilbon prasinus. This taxon is now considered as a subspecies of the glittering-bellied emerald Chlorostilbon lucidus pucherani.