The dioecious species of the genus Blyxa can be divided into 2 groups, those with 6 stamens and those with 9 stamens in the male flowers. The first group is restricted to tropical Africa and needs further study. The second group occurs in Asia and Australia and up to now was considered to consist of 2 very distinct species, Blyxa octandra (Roxb.) Planch, ex Thw., characterized by a basal rosette of long, smooth, linear leaves, and B. novoguineensis den Hartog which is caulescent with short serrulate leaves. B. octandra is widely distributed in India, Burma, Indo-China, New Guinea, and the tropical part of Australia. B. novoguineensis is known with certainty only from New Guinea. Recently a third species, very similar in its habit to B. octandra, was found by Dr. C. F. van Beusekom and Mr. R. Geesink in Thailand. From a study of herbarium material it appeared that this species had already been collected several times but had not been recognized as a separate species, probably because of the absence of seeds in these plants.