The genus Hyla is one of approximately 38 genera in the family of tree frogs (Hylidae). They have a very broad distribution; species can be found in Europe, Asia, Africa, and across the Americas. There were more than 300 described species in this genus, but after a major revision of the Hylidae family most of these have been moved to new genera so the genus now only contains 33 species".
The genus was established by Josephus Nicolaus Laurenti in 1768. It was named after Hylas in Greek mythology, the companion of Hercules. The name is unusual in that though Laurenti knew that Hylas was male, the name is unambiguously treated in the feminine grammatical gender for reasons unknown. The etymology of the name is also oftentimes incorrectly given as being derived from the Greek word ὕλη (hūlē, "forest" or "wood").
A tree frog is any frog that spends a major portion of its lifespan in trees, known as an arboreal state. Several lineages of frogs among the Neobatrachia have given rise to tree frogs, even though they are not closely related to each other.
Many millions of years of convergent evolution have resulted in almost identical morphology and ecologies. In fact, they are so similar as regards their ecological niche that in one biome where one group of tree frogs occurs, the other is almost always absent. The last common ancestor of some such tree frog groups lived long before the extinction of the dinosaurs.