Darkness or low light can dim the bright purple-blue plumage of the adult to make them look dusky or brownish, although the forehead shield color differentiates them from similar species such as common gallinules.

Juvenile birds are light brown with hints of green-bronze on the wings and back, and white under-tail coverts.

[4] Purple gallinules have long toes that help them walk onto floating vegetation, by distributing their weight across a large surface area.

They are resident species in southern Florida, the Gulf and Pacific coast of Mexico, parts of Central America, and the Caribbean.

[6] The species has the greatest pattern of vagrancy amongst rails, with individuals recorded as far west as California and the Galápagos Islands, as far north as Iceland and Labrador, as far south as Tierra del Fuego, and as far east as Great Britain, Portugal and Cape Verde.

Following the principal display, one or both of the birds will strut and cut across the path of the other with half-lowered wings, or they will make a deep bow as they approach each other.

[8] The floating nest is placed within the dense vegetation along the shallow margins of lakes, rivers, and marshes' shorelines.