The Latin American panther is the black jaguar.
In jaguars, the mutation is dominant hence black jaguars can produce both black and spotted cubs, but spotted jaguars only produce spotted cubs when bred together.
The black jaguar was considered a separate species by indigenous peoples.

-From Wikipedia

There are no authenticated cases of truly melanistic pumas.
Black pumas have been reported in Kentucky, one of which had a paler belly. There have also been reports of glossy black pumas from Kansas and eastern Nebraska. These are known as the North American Black Panther (NABP).
None have ever been photographed or shot in the wild, and none have been bred. There is wide conensus among breeders and biologists that the animal does not exist and is a cryptid. Sightings are current attributed to mistaken species identification by non feline experts, and memetic exaggeration of size.

-From Wikipedia