Practice question

Distyly represents heterostyly where species exhibits two distinct floral morphs pin with long style and short stamens and thrum with short style and long stamens, reciprocal herkogamy promoting legitimate cross-pollination between morphs. Dichogamy refers to temporal separation of anther dehiscence and stigma receptivity protandry or protogyny, herkogamy spatial separation within same flower preventing autogamy, monoecy male and female flowers on same individual. Distyly controlled by supergene S locus, classic example Primula vulgaris and some Rubiaceae, ensures disassortative mating reduces selfing, textbook case studied by Darwin on heterostyly and insect-mediated legitimate pollination.