A Morphological Study of the Development of Reproductive Structures of Phaseolus coccineus Lam.1

Abstract

The scarlet runner bean, Phaseolus coccineus , although self-compatible, is primarily cross-pollinated. Morphological characteristics of the reproductive system which facilitate cross-pollination include the relative position of anthers and stigma at the time of pollen deshicence. Pollen is shed primarily onto stylar and stigmatic hairs or the style, rather than onto the stigmatic surface. The long period of stigma receptivity, from the mature bud stage through anthesis, also favors cross-pollination and accounts for the small degree of self-pollination which occurs in mature buds. Movement of stigmatic hairs may result in some transfer of pollen onto the stigma.