What is "calycogonium"

Calycogonium (common name, angleflower) is a polyphyletic genus of about forty species in the family Melastomataceae, native to the Caribbean, particularly Hispaniola, Jamaica, and Cuba. The genus is a member of a clade characterized by calyptra on flower buds, few hairs, and the presence of mite domatia on the underside of the leaves.