The chromosome number of myoga ginger (Zingiber mioga (Thunb.) Roscoe: Zingiberaceae) has been reported as 2n = 22 for Chinese plants and 2n = 55 for Japanese plants. We checked the chromosome number of Z. mioga in plants collected in Jeollabuk-do and Jeollanam-do, Korea, and counted 2n = 44, the first report of this number for the species. As the basic chromosome number of Z. mioga is thought to be x = 11, Z. mioga plants in China, Korea, and Japan appear to be diploids, tetraploids, and pentaploids, respectively. In finding the tetraploid race of Z. mioga in Korea, we can hypothesize that the pentaploid race in Japan is derived through the fertilization of reduced gametes of the diploid race and unreduced gametes of the tetraploid race.

Recent botanical explorations in the province of Palawan, Philippines, have resulted in the discovery of two new ginger species, namely Boesenbergia eburnea Docot and Boesenbergia leonardocoi Funak. & Docot, which are described and illustrated here, including information on their distribution, habitat, phenology, ecology and conservation status. Additionally, a key to Boesenbergia species in the Philippines is provided.

The genus Vanoverberghia currently includes three species namely V. sepulchrei and V. rubrobracteata from the Philippines and V. sasakiana from Taiwan. New material targeting the Alpinia eubractea clade of the tribe Alpinieae was used to test the monophyly of Vanoverberghia. A combined analysis of the ITS and trnK/matK regions reveals that these three species form a strongly supported monophyletic clade with Alpinia diversifolia and Alpinia vanoverberghii. The morphological descriptions of all species were updated after examining recent collections and comparing with types and protologues. The original description of A. diversifolia did not include information on the flowers which are described here. The morphology of A. diversifolia and A. vanoverberghii is for most parts in accordance with the previous perception of the genus but a few characters are added and a recircumscription of Vanoverberghia is subsequently provided here. Vanoverberghia diversifolia is reinstated and A. vanoverberghii is combined in Vanoverberghia. Furthermore, collections from northern Luzon documents the presence of V. sasakiana and all species of Vanoverberghia thus occur in the Philippines. A key to the five species is provided including a comprehensive taxonomic revision and designation of three lectotypes.

Vanoverberghia Merr. is formerly considered monotypic and endemic to the Philippines, but a new species, Vanoverberghia sasakiana H. Funak. & H. Ohashi is proposed here. The new species is distinguished from the other species, V. sepulchrei, by smaller habit with sessile leaves, translucent white bracts and smaller flowers without nectary. The new species was found at Lanyu Is., Taiwan, where is known for its rich flora containing many Philippine floristic elements. Description, illustration, and color photos of the new species are provided.