The genus Cycas (Cycadaceae) in Thailand

Abstract

The genus Cycas is revised for Thailand. Ten species are enumerated, five of them described as new (C. chamaoensis, C. clivicola, C. litoralis, C. nongnoochiae, C. tansachana), with one new subspecies (C. clivicola subsp. lutea). The species are placed within an infrageneric classification previously outlined. Distributions of the taxa are mapped, eight of the species are illustrated, and a key to species is provided. Previous records of C. circinalis and C. rumphii from Thailand (here not regarded as indigenous in Thailand) are discussed.