Kaempferia noctiflora var. thepthepae (Zingiberaceae), a New Taxon from Thailand

Taxonomic study of Kaempferia subgen. Protanthium (Zingiberaceae) is difficult due to a high degree of intraspecific morphological variation in several species and the implied morphological overlap among the currently recognized species. Herein, we clarify the taxonomic circumscription of K. noctiflora, a rare species endemic to Chiang Mai Province (N Thailand), by describing K. noctiflora var. thepthepae Noppornch. & Somnoo, var. nova. It differs from K. noctiflora var. noctiflora especially by the labellum colouration and flowering time. The diagnostic characters of this novel variety are discussed and compared with those of morphologically similar taxa. Images of the plants, habit and dissected flowers, and information on the phenology, distribution and ecology are provided. Kaempferia noctiflora var. noctiflora and var. thepthepae are considered Vulnerable and Endangered, respectively.