Tiny, poorly-known hummingbird with extremely limited range in western Panama. Males are greenish above with rusty flanks, a pinkish-red throat, and a white collar. Note dark tail with rufous edging. Compare with male Scintillant Hummingbird, which has a mostly rufous tail and an orange throat. Female Glow-throated has a speckled throat, buffy flanks, and greenish upperparts. The central tail feathers are greenish while the rest of tail is rufous with a black band and buffy tips. Female Scintillant is very similar and may not be separable in the field, but has more extensive rufous edges on central tail feathers. Found at the edge of montane forest from around 750–1,800 m.