The genus Maclurochloa K. M. Wong (Wong 1993) was separated from Dinochloato accommodate one species, Maclurochloa montana (Ridl.) K. M. Wong from Malaysia (Wong 1993, 1995). Maclurochloa is distinguished from Bambusa Schreber, which it otherwise superficially resembles, by its one or two perfect flowers in spikelet and fewer transition glumes, always small compared with the lemmas. The genus differs from Dinochloa Buse and Melocalamus Bentham which also are climbing bamboos (Wong 1993) by its non-fleshy fruit. During a field trip in March 2005 to Cau Hai Village, Chan Mong Commune, Doan Hung District, Phu Tho Province, Vietnam, the authors found several populations of bamboo widespread through degraded natural forest. Specimens of rhizomes, branches, culm leaves, and flowering branches were collected. All collected specimens were dissected and studied. We confirmed the presence of sympodial rhizomes in this bamboo with clambering culms, and the branch complement at each node bearing several branches, with the middle one dominant, rachilla internodes short and disarticulating below the lemma, 1 – 2 fertile florets and an apical sterile one. Th e structure of the inflorescence in collected specimens is basically similar to that of Maclurchloa. In addition, the internodes are 50 – 58  3.0 – 3.5 cm, the culm leaf is erect, and the pseudo-spikelet have two (rarely one) perfect florets. Because of this combination of characters, along with other features described in detail below, is not found in any other described bamboo species in the genus Maclurochloa, we propose to recognize this taxon as a new species named M. tonkinensis.
Maclurochloa tonkinensis H. N. Nguyen et V. T. Tran
Distribution, habitat and phenology
Maclurochloa tonkinensisis known from northeastern Vietnam, in the provinces Ha Tay, Phu Tho and Tuyen Quang. It grows in degraded natural forests, after forest disturbance, mixed with broad-leaved trees and Schizostachyum, Indosasa, and forms small pure populations, at 100 – 900 m a.s.l. The flowering and fruiting occurred in early 2005 and in June – August 2010, and new shoots were developed at the same time.
H. N. Nguyen and V. T. Tran