Orchidaceae is one of the largest plant families, and each of its subfamilies have a delimited distribution. The genus Laelia, with 7 subsections, 5 of which occuring in Brazil, shows interestingly evolutionary characteristics. Laelia sect. Parviflorae, which occurs mainly in Minas Gerais (Brazil) is an example of "explosive evolution" still in process. The taxonomic treatment of the orchid family is not uniform from taxa to taxa which leads to many small genera in some groups and few large genera in some other groups.
Orchid distribution; Orchidaceae; systematics; evolution