Two new species of Kaempferia subgenus Protanthium (Zingiberaceae) from northern Thailand

Kaempferia aurora sp. nov. Noppornch. & Jenjitt., from Tak province near the Thailand‐Myanmar border, and K. caespitosa sp. nov. Noppornch. & Jenjitt., from Lampang province, northern Thailand, are described as new species of K. subgen. Protanthium (Horan.) Baker. Their diagnostic characters are compared with those of similar species. Detailed illustrations, photographs of dissected flowers, information on phenology, distribution and ecology, and preliminary conservation statuses are provided for both new species. An identification key to the species of Kaempferia subgen. Protanthium in Thailand is also revised and presented.