Dendrocalamus longivaginatus (Poaceae, Bambusoideae), A New Species from Vietnam

A new species of Dendrocalamus Nees (Poaceae, Bambusoideae), D. longivaginatus N. H. Xia, V. T. Nguyen & V. L. Le, is illustrated and described from Phu Tho, Vietnam. This species is known only from the northern provinces of Vietnam: Phu Tho, Yen Bai, and Ha Giang. It is morphologically similar to D. brandisii (Munro) Kurz, a widely distributed bamboo from Thailand, Myanmar, China, and Vietnam, but differs by the ligules of the culm sheath, which are irregularly fimbriate, slightly concave, and 7–9 mm, and by the pseudo-spikelets, which are (5–)13–16 mm with lemmas 9–11.5 mm.