The Plovercrest's characteristic long, tapered crest, small size, and short tail distinguish it from all other hummingbirds. The male is mostly glossy green with an iridescent violet throat and breast. Males of the nominate race have green crowns and crests, while those of the race S. l. loddigesii from the southern part of the range have blue crowns and crests. The female is similar, but has a shorter crest and is dull white below. This species occurs in forest understory and edges, where it forages for nectar at all strata. It occurs in southern Brazil, eastern Paraguay, and northeastern Argentina (Missiones).