Stripe-tailed Hummingbirds are distinguished from other hummingbirds by its rufous wing patch, although that characteristic is shared with the Blue-tailed (rare in Costa Rica) and Black-bellied Hummingbirds. It has a white vent and tail underside, along with the outer two feathers of the tail being white on the upperside. The male shows a dark blue patch on the throat which continues until the chest. During flight, the wings look almost entirely rufous, with only a lining of green feathers on the shoulders. The female has a white throat and chest. Both sexes resemble the Coppery-headed Emerald, although the latter is smaller.
The Lesser Violetear belongs to the same genus as the Brown Violetear, however they look pretty different due to the overall color. This species is by the most part green, however it has a big violet ear patch that is visible from any angle (not caused by iridescence) and also shows some blue-violet glow on the chest. The wing is dark brown above and light brown on the underside. After perching, this species of hummingbird has an habit of stretching its wings to the back for a moment.