How common is heterodichogamy?

The sexual systems of plants usually depend on the exact spatial distribution of the gamete-producing structures. Less well known is how the exact timing of male and female function might influence plant mating. New papers by Li et al. on a group of tropical gingers describe differential maturing of male and female structures, such that half the individuals of a population are in the female stage when the other half is in the male stage. This new case of heterodichogamy is unique in involving reciprocal movement of the styles in the two temporal morphs.