Aspectos evolutivos morfológicos e fenológicos da floração em espécies de Centrosema (DC.) Benth. (Leguminosae-Papilionoideae)

Abstract

Flowers of five species of Centrosema (DC.) Benth. were studied in their morphlogical and fenological aspect, in order to get evolutionary information about them. The analysed parameters were: a) parts which constitute the flower of each species; b) beginning of flowering and period of duration in two different places: Piracicaba-SP and Santa Maria-RS. Standart, wing, keel, gynoecium, androecium, shape of calyx, bract and bracteole number, shape of anter, shape and arrangement of ovules, didn't show any variation in the analysed parameters. These characteres are probably being kept by directional selection, keeping, this way, similar characteristics that standardize the plants into the species which they are related. Number of lacinia of the calyx, color of flowers, shape of pollen grain and number of flowers by inflorescence kept high phenotypic plasticity, due to specific functions of each character, into each species, to keep their perpetuation and survival. The behaviour individuality of each species acording to the flowering period showed differences related to the sensibility of the genotypes to the diferente environrnent at which they were submmited.