The objective of this work was to verify the influence of two distinct "cerrado" environments in the expression of reproductive and vegetative characters of Senna velutina. Ten individuals were randomly selected in each area in order to characterize plant height, number of flowers and fruits, fruit length, seed number and biomass, flowering period, foliole shape, stomata density and dimensions. Population density and spatial distribution were also verified. Fruit number and length, seed number and biomass were significant larger in the "cerrado" area when compared to palm swamp border area. On the other hand, the number of flowers and buds was significantly larger in the palm-swamp border area. No difference was detected between areas on plant height, foliole length and width, foliolar index, inflorescence length, number of viable seeds, stomata length and width and stomata density. The flowering period started lately in the palm swamp border area, but the reproductive period in the "cerrado" area was longer than the in palm swamp border area. A contagious spatial distribution was verified in both subpopulations. The phenotypic variations registered in S. velutina were restricted to reproductive traits, indicating large canalization and herdability on its somatic characteristics. The "cerrado" area offered better conditions for S. velutina reproductive success comparing to the palm swamp border area.
ecotypes; environmental heterogeneity; phenotypic variation
