SUMMARY In order to obtain basic information about floral biology of the species: C. brasilianum (L) Benth., C. virginianum (L.) Benth., C. shottii (Mill.) K. Sch. and C. pascuorum (Mart.) Benth., three biological parameters were studied comparatively: number of ovules per ovary, number of seeds per pod that reached maturity and, viable pollen grains. Datas were collected at ESALQ/USP -Experimental camp of Genetics Instituto, Piracicaba -SP and at the Botanic Garden of the Biology Department of UFSM (Federal University of Santa Maria), Santa Maria, RS. The differences which occured in the analyzed parameters showed, in a way, the behavior individuality of each species, resulting from specific sensitiveness and variability. All of studied species, had a production of fertile ovules over 78% and viable pollen over 95%, which reflected a high percentage of viable seeds (except C. shottii and C. pascuorum, Santa Maria-RS), assuring, this way. the species perpectuation.
reproduction; biology; Centrosena