About Costus dubius (Afzel.) K.Schum.
Costus dubius (Afzel.) K.Schum. has underground rhizomes that produce leafy stems and inflorescences on separate stalks. Its round inflorescences bear green bracts, and each bract grows one single white flower, with a labellum that is yellow at the center. This species produces a large number of seeds. It is sometimes mistaken for other African Costus species, including Costus afer and Costus dinklagei. It is the only African Costus species that is capable of self-pollination. Costus dubius has a broad native range across tropical Africa. It has been introduced to multiple areas, where it has become naturalized or invasive: Queensland in Australia, Java in Indonesia, and Hawaii in the United States of America. In its native African habitat, it can be found growing in a wide variety of forest types, along riverbanks and roadsides, and within plantations. It favors wet tropical biomes, and does not seem to be able to survive in subtropical regions.
