Bambusa Schreb. (Poaceae, Bambusoideae) is a large and complex tropical and subtropical Asian genus that is currently being taxonomically remodeled through morphological and molecular phylogenetic approaches. The type and type alliance of the genus is, however, morphologically well distinguished. Preliminary documentation suggests there could be some 60-70 species of Bambusa in Vietnam, although confirmation requires more rigorous herbarium-based vouchering. A new species of bamboo belonging to the type alliance, Bambusa gurgandii K. M. Wong & M. H. Diep, is described, known only from cultivated specimens in Vietnam. It belongs to the group of unarmed Bambusa species including Bambusa burmanica Gamble, Bambusa farinacea K. M. Wong, Bambusa nutans Wall. ex Munro, Bambusa polymorpha Munro, Bambusa teres Buch.-Ham. ex Munro and Bambusa tulda Roxb. but is distinguished by details of the pseudospikelets and flowers.

This paper aims to clarify and stabilize the nomenclature of the singular fire-adapted South-East Asian bamboo genus Vietnamosasa Nguyen (1990: 221), and the specific taxa it comprises, by designating lectotypes and neotypes to allow accurate application of the published names. Little attention has been given to this genus in the last 10 years, partly because its three published species are difficult to distinguish from each other, but mostly due to the fact that the type specimen of the type species is reportedly lost, and the fact that the original description is inadequate and does not include illustrations of the new taxa. The genus is readily recognizable by its special “grass-mound” appearance and the morphology of its subterranean organs: rhizomes as well as subterranean vegetative axes growing horizontally, which allow the bamboo to thrive in fire prone areas (Dransfield 2000).

Cephalostachyum chevalieri A. Camus is found to be a new synonym of Kinabaluchloa wrayi (Stapf) K. M. Wong, extending the species range from the Malay Peninsula to Vietnam. Its type, Chevalier 4485, and other specimens collected from the type locality, have the same culm leaf, pseudo‐spikelet and flower characteristics as K. wrayi.