"This is a black female Jaguar that I captured at the amazing WHF in Kent. The Jaguar is the largest feline on the American continent, and is the only one of the world's 'big' cats to be found in the New World." AKA a panther.
A black panther is typically a melanistic color variant of any Panthera species. Black panthers in Asia and Africa are leopards (Panthera pardus). Black panthers in the Americas are black jaguars (Panthera onca).