[4] The South American Classification Committee of the American Ornithological Society, the International Ornithological Committee, and the Clements taxonomy assign these three subspecies to the white-bellied parrot:[5][3][6] BirdLife International's Handbook of the Birds of the World (HBW) treats all three as separate species, the "black-legged", "yellow-tailed", and "green-thighed" parrots respectively.

[8][9] Subspecies P. l. xanthomerius has an apricot-orange crown and nape, yellow thigh feathers, and blackish legs and feet.

[8] The white breast feathers of the white-bellied parrot are often stained a chestnut brown (or "isobel") color.

This may be due to tannin staining, as result of their particular affinity for bathing by rubbing their bodies against wet leaves and other plant matter.

[10] The head and nape plumage of the white-bellied parrot has been observed to fluoresce strongly under ultraviolet light.

The nominate subspecies is also found in small numbers in drier forests at the southern reaches of its range.

[8] Little is known about the white-bellied parrot's foraging technique or diet, though the latter includes fruits of trees and palms and also flowers.

It also makes "from loud high-pitched “kree-ee-ee” or “skeeew” notes to more melodious whistles and subdued “kee-ah-u” or “kew” calls" when perched.

It "is suffering from the loss, degradation and disturbance of its forested habitat, and may potentially be susceptible to hunting."