Ceratanthus
Content
Description
Herbs.
Leaves opposite (or basal ones subverticillate).
Flowers usually small, in few-flowered verticillasters, forming a terminal raceme-like inflorescence.
Stamens 4, in 2 pairs;
Distribution
Asia-Tropical: Thailand (Thailand present), Australasia: Queensland (Queensland present), Continental SE. Asia present, S. New Guinea present, SW. China present
About 10 spp., largely in continental SE. Asia (Thailand, Indo-China, and SW. China), 1 sp. in Malesia (S. New Guinea) and Queensland.
Notes
LAM () has suggested that the genus would be an artificial assemblage of Plectranthus species with spurred corolla, which would then explain the Malesian disjunction. As the genus is differing from that genus by more characters, however, I find this unlikely; there are more genera showing this disjunction, especially those bound to a seasonal climate, such as Anisomeles malabaricus, Germainia, etc.