6-8, see text Mountaingems are a genus of hummingbirds, Lampornis, which inhabit mountainous regions from the south-western United States to the Isthmus of Panama.

However, the southern group has apparently evolved in a very short time and their conspicuous differences in appearance are not yet reflected in molecular divergence; as mates are of course chosen according to their appearance and not their molecular differences, it seems prudent to split the group according to throat color as advocated by the American Ornithological Society.

In addition, L. amethystinus may constitute two species, but not the violet-throated subspecies margaritae but the southernmost, red-throated forms are the most distinct ones.

García-Moreno's team refrains to date the emergence of the genus because of the absence of fossils or other robust evidence.

It can be assumed though that Lampornis was present at the closing of the Isthmus of Panama, about 3.8 MYA, and that by that time, the northernmost lineage(s) had already diverged.

These results are interesting, because they agree with a general trend for southern Mexican taxa (including to colonize the Isthmus and there form distinct species.