Reproductive Biology And Pollination Of Two Species Of Polystachya Hook. In Southeastern Brazil: Evidence Of Pseudocleistogamy In Polystachyeae (orchidaceae) [biologia Reprodutiva E Polinização De Duas Espécies De Polystachya Hook. No Sudeste Do Brasil: Evidência De Pseudocleistogamia Em Polystachyeae (orchidaceae)]

Phenology, floral biology, pollinators, breeding system and natural fruit set of Polystachya estrellensis Rchb. f. and P. concreta (Jacq.) Garay & H. R. Sweet were studied in mesophytic forests at Serra do Japi, and in mangroves at a seashore plain at Picinguaba, respectively. Both study areas are natural reserves in southeastern Brazil. Both species flower in summer, are epiphytes and produce terminal inflorescences with up to 150 non-resupinate flowers. The flowers produce a citric fragrance, mainly in the warmest hours of the day. Both species are pollinated by solitary and social small native bees, which collect pseudopollen from the lip of the flowers. The pollinarium is placed frontally on the head of the bees, when they are collecting pseudopollen. Polystachya estrellensis and P. concreta are self-compatible. The majority of flowers of P. estrellensis (96,7%) is cleistogamous, while P. concreta produces only chasmogamous flowers. 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