Heterostyly is a unique form of
polymorphism and
herkogamy in
flowers. In a
heterostylous species, two or three morphological types of flowers, termed
morphs, exist in the population. On each individual plant, all flowers share the same morph. The flower morphs differ in the lengths of the
pistil and
stamens, and these traits are not continuous. The morph
phenotype is genetically
linked to
genes responsible for a unique system of
self-incompatibility, termed
heteromorphic self-incompatibility, that is, the pollen from a flower on one morph cannot fertilize another flower of the same morph.
