Distribution: Species found south of Rio de Janeiro, Brazil and north shore and lowlands of Santista, in Sao Paulo and Southeast of Minas Gerais (Versieux & Wanderley 2007b). Occurs from sea level up to 1000 m.s.m. in the Serra do Mar, and may be observed between the municipalities of Itaguai (RJ, photographic record), eastern distribution limit, up to Sao Vicente, in lowlands of Santista (southern boundary) and in the serra da Mantiqueira in Minas Gerais (Northern and Western limit). It is important to note that during this work the species was found in Sao Paulo, where its occurrence was mentioned by Baker (1889), despite being ignored by subsequent authors. The flowers are nocturnal and at anthesis are pollinated by bats (Martinelli 1994). The wide distribution, ex situ cultivation and the occurrence in conservation units give the species the low-risk category of threat.

Etymology: According to Grant (1995c), regina is the Latin word for Queen and pays homage to D. Maria I of Portugal, who ruled the Portuguese Empire of 1786 to 1816.