Guarianthe (abbreviated Gur. in the horticultural trade) is a small genus of epiphytic orchids in the family Orchidaceae, order Asparagales. The genus comprises around four accepted species plus one natural hybrid, all native to wet montane and lowland forests stretching from southern Mexico through Central America and into northern South America, including Colombia, Venezuela, and Trinidad.
The genus was described in 2003 by Robert Dressler and Wesley Higgins (published in Lankesteriana 7: 37) after phylogenetic analysis of nuclear DNA sequence data demonstrated that the bifoliate Cattleyas traditionally placed in Cattleya formed a distinct clade. Prior to that, all Guarianthe species were treated as members of Cattleya. Like typical Cattleya-alliance orchids, Guarianthe species are epiphytic, producing pseudobulbs with one or two apical leaves and bearing showy flowers that make them popular in cultivation and in the ornamental orchid trade.
The most culturally prominent member is Guarianthe skinneri, known in Costa Rica as Guaria morada and recognized as the national flower of that country. It ranges from Chiapas, Mexico, south through every country in Central America to Costa Rica. Guarianthe bowringiana is native to Mexico, Belize, Guatemala, and Honduras, while Guarianthe aurantiaca is widespread from Mexico to Costa Rica. A natural hybrid, Guarianthe × laelioides (formerly Cattleya × laelioides), arises between G. aurantiaca and G. skinneri in Chiapas, Belize, Guatemala, Honduras, and Nicaragua.
Taxonomy Notes
Guarianthe was erected by Dressler & W.E. Higgins in 2003 (Lankesteriana 7: 37), separating the bifoliate members of Cattleya into their own genus on the basis of nuclear DNA phylogenetic evidence. The natural hybrid Guarianthe × laelioides was transferred to the genus by Van den Berg in 2015. The abbreviation Gur. is used in the horticultural trade.
Distribution
Guarianthe is native to wet forests in southern Mexico (Chiapas), Belize, Guatemala, Honduras, Nicaragua, Costa Rica, Colombia, Venezuela, and Trinidad. G. skinneri has the widest Central American range, while G. aurantiaca extends from Mexico to Costa Rica.
