Curcumamaxwellii and C.rubroaurantiaca (Zingiberaceae, Zingiberoideae), two new species from Thailand.

Curcumamaxwellii sp. nov. and Curcumarubroaurantiaca sp. nov. (Zingiberaceae, Zingiberoideae, Zingibereae), two new red-orange-flowered species from Thailand, are described. They are compared to the morphologically closest species from the Curcumasubgen.Ecomatae and detailed descriptions, colour plates and information on their distribution, ecology, phenology and uses are provided. Preliminary IUCN conservation assessments for both of these species are proposed as Least Concern.