The White-bellied Woodstar is among the smallest hummingbirds like most woodstars, however it is colorful and conspicuous. The body is mostly green, with a white collar that joins a white line coming out of the eye. The gorget is metallic purple due to iridescence, so it looks dark sometimes. The black bill is long, thin and just slightly curved down. The vent and belly also show white plumage. It flies in a typical bee fashion, with smooth movements instead of the rapid bursts that larger hummingbirds do.
The Rufous-shafted Woodstar is a very small hummingbirds even when compared with other woodstars, like the Purple-throated. Their plumage is also less colorful, consisting of an olive green back, brown wings and cinnamon belly. The female has has olive green on the top of the head, a thin white line that stems from the eye, then a dark ear patch, and a white throat with a dark line on the center. The male has a glittering purple gorget and lacks the cinnamon belly, which is metallic green instead. Like all other woodstars, this species is very small and flies in a bee-like fashion, with swifter movements than larger hummingbirds.
The Purple-throated Woodstar bears some resemblance to the White-bellied Woodstar, even though they do not belong to the same genus. Their flying behavior is more like a bee, in that they move swiftly and without sharp turns like most hummingbirds do. As they fly over, they do sound like bees. They are also pretty small, like most woodstars. It does not have the glittering green body of the White-bellied; instead, the back is a duller green color, and the belly is olive with orange feathers covering the legs and white vent. A white ring almost surrounds completely the neck. The female has a white-gray throat, while the male has an iridescent purple throat (as the name would suggest) that looks rather dark from some angles.