Rhynchospora sect. Haplostylis
Of all the Malesian members of this section KÜKENTHAL calls the lower flower hermaphrodite, the upper 1-2 male (triandrous) or sterile. Only in R. rubra I found in a few spikelets a single stamen in the lower flower and the upper flower(s) generally triandrous. In the other species the lower flower is always female, the upper one male (diandrous).