Erythroxylum cocais a distylous species with a strong self‐incompatibility system linked with the floral dimorphism. The two sets of stamens in the flowers are usually unequal in length, but between individuals of both morphs there is considerable variation in the relative qengths of the two sets of stamens, which is unrelated to the incompatibility system. Pin flowers produce more pollen grains than thrum flowers, but thrum pollen is larger than pin pollen. Within each morph the two sets of stamens produce pollen grains of slightly different diameter.Erythroxylum novogranateweis also distylous. Pin flowers ofE. novogranatensevar.novogranatenseare partially self‐compatible, while thrum flowers ofE. novogranatensevar.truxillenseare self‐incompatible. Reports of tristyly and of four different morphs in species ofErythroxylumare probably misinterpretations, resulting from limited sampling, of the continuous variation in the relative lengths of the two sets of st