Rare and critically endangered hummingbird endemic to Ecuador. Known only from a few mountains west and north of Quito. Male is dark bluish-green with white leg puffs and a blue vent. Female is brighter green with a golden tinge and has a blue throat patch and vent. Might be mistaken for the larger Sapphire-vented Puffleg but lacks blue on crown and has a shorter tail. Inhabits high elevation forest, where it feeds on small, tubular flowers. Most often encountered in the Yanacocha Reserve; occasionally visits feeders.