Description from Flora of China
Microcalamus Gamble, J. Asiat. Soc. Bengal, Pt. 2, Nat. Hist. 59: 207. 1890, not Franchet (1889).
Climbing or scrambling bamboos. Rhizomes short necked, pachymorph. Culms unicaespitose, scrambling, slender, hollow to solid; internodes terete, long, very smooth; nodes level to slightly raised with persistent sheath-base collar. Branches many, central dominant, approaching size of culm, others short and subequal. Culm sheaths deciduous after branching, narrowly triangular, basally very tough, apically papery; ligule inconspicuous, auricles and oral setae absent; blade erect, acicular, short. Leaves broadly linear-lanceolate, small, venation indistinct, apex acicular. Inflorescence bracteate, lateral spikelets subtended by a bract and basally prophyllate. Prophyll and glumes not subtending buds. Spikelets sessile, several flowered, followed by a terminal incomplete floret. Rachilla disarticulating and florets separately deciduous. Glumes 1, or absent in terminal spikelets; lemma glabrous. Palea 2-keeled, usually equal in length to lemma. Lodicules 3. Stamens 6; filaments free. Ovary oblong or ovate, upper portion pubescent or glabrous; style 1; stigmas 3. Caryopsis shortly terete, grooved.
Although Neomicrocalamus has often been synonymized within the Malesian genus Racemobambos Holttum, there are substantial differences in vegetative and floral morphology, and molecular evidence has confirmed that they are not closely related.
In addition to the species treated below, Neomicrocalamus microphyllus Hsueh & T. P. Yi (in C. Y. Wu, Fl. Xizang. 5: 50. 1987) was described from SE Xizang (Mêdog). This name was previously published by the same authors (J. Bamboo Res. 2(1): 35. Jan 1983), but not validly so because the generic name was not validly published until July 1983. The new combination "Racemobambos microphylla" (P. C. Keng & T. H. Wen, J. Bamboo Res. 5(2): 13. 1986) was not validly published because its basionym was not validly published until 1987.
About five species: Bhutan, SW China, NE India, Vietnam; two species (one endemic) in China.
(Authors: Li Dezhu (李德铢); Chris Stapleton)