Breakdown of distyly and pin-monomorphism in Psychotria carthagenensis Jacq. (Rubiaceae)

摘要: Rubiaceae contains the largest number of distylous species in Angiosperms, but evolution and control distyly is poorly understood this group. Atypical populations have been described family associated with disturbance, pollination failure impaired reproductive success. Some these atypical taxa belong to Psychotria, genus family. In present study, we investigate breeding biology Psychotria carthagenensis Jacq., a widely distributed that has as typically distylous. Fieldwork was carried out mainly at Panga Ecological Station, Uberlândia, MG, Brazil. We phenological observations, floral studies hand experiments within Station population. complemented data herbarium field surveys from elsewhere The studied population bloomed beginning rains (September-December). main pollinators were Bombus small Halictidae bees. presented pin-monomorphism only two thrum individuals more than 100 flowering surveyed. Hand pollinations showed self-compatibility intramorph compatibility. Typical isoplethy found other areas both morphs appeared material. However, also observed distyly, homostyly concurrently Brazilian P. indicate alternative strategies, probably favoring selfing, appear developed independently species.