The grass genera of the world
~ Microcalamus Gamble, Racemobambos
Habit, vegetative morphology. Perennial; rhizomatous and caespitose. Culms 500–1000 cm high; woody and persistent; to 18 cm in diameter; cylindrical; scandent, or not scandent (then erect or leaning); branched above. Primary branches 4–30 (the central dominant). The branching dendroid. Culm leaf sheaths present; deciduous. Culm leaves with conspicuous blades to without conspicuous blades. Culm leaf blades when well developed, linear. Culm internodes solid to hollow. Unicaespitose. Rhizomes short- or elongated- pachymorph. Leaves without auricular setae. Leaf blades lanceolate, or elliptic; broad; 5–10/12–26 cm long, 8–15 mm wide, or 18–30 mm wide; pseudopetiolate; cross veined, or without cross venation. Ligule an unfringed membrane.
Reproductive organization. Plants bisexual, all with bisexual spikelets; with hermaphrodite florets. The spikelets hermaphrodite.
Inflorescence. Inflorescence determinate (the prophylls and glumes not subtending buds); without pseudospikelets (but sometimes with few sterile spikelets); few spikeleted to many spikeleted; of spicate main branches, or paniculate; spatheate; a complex of partial inflorescences and intervening foliar organs, or not comprising partial inflorescences and foliar organs.
Female-fertile spikelets. Spikelets unconventional; 18–35 mm long; ovate, or linear; compressed laterally to not noticeably compressed; disarticulating above the glumes, or not disarticulating (in N. setiger); in N. prainii, disarticulating between the florets. Rachilla at least in N. prainii, prolonged beyond the uppermost female-fertile floret; the rachilla extension with incomplete florets.
Glumes present, or absent (sometimes, in terminal spikelets); one per spikelet, or two to several; shorter than the spikelets; pointed; muticous or mucronate, awnless; the lower carinate, or non-carinate; persistent, membranous or chartaceous, very dissimilar to similar. Upper glume 3–5 nerved. Spikelets at least in N. prainii, with incomplete florets, or with female-fertile florets only (?). The incomplete florets distal to the female-fertile florets. The distal incomplete florets merely underdeveloped; awnless. Spikelets without proximal incomplete florets.
Female-fertile florets 1 (N. setiger), or 3–6 (N. prainii). Lemmas ovate; convolute (in N. setiger), or not convolute; membranous to chartaceous, less firm than the glumes to similar in texture to the glumes; smooth; not becoming indurated; entire; pointed (acute); awnless; hairless; glabrous; non-carinate; in N. prainii, 9–11 nerved. Palea present; relatively long (about as long as the lemma); convolute around the flower (in N. setiger), or not convolute; keel-less (in N. prainii), or 2-keeled. Lodicules present; 3, or 5 (in N. setiger); membranous; ciliate, or glabrous. Stamens 6 (N. prainii), or 26–32 (N. setiger). Anthers with the connective apically prolonged (N. prainii), or without an apically prolonged connective (?). Ovary apically hairy (N. prainii), or apically glabrous (?); with a conspicuous apical appendage. The appendage long, stiff and tapering (N. setiger), or broadly conical, fleshy (N. prainii). Stigmas 3 (N. prainii), or 5 (N. setiger).
Fruit, embryo and seedling. Fruit longitudinally grooved, or not grooved. Pericarp thin, or fleshy (N. setiger); fused.
Classification. Watson & Dallwitz (1994): not described separately. Soreng et al. (2015): Bambusoideae; Bambusodae; Bambuseae; Racemobambusinae. Supposedly 5 species (but only two described from flowering material).
Distribution, phytogeography, ecology. Bhutan, SW China, NE India, Vietnam.
References, etc. Morphological/taxonomic: Clayton et al. (2016), GrassBase; De-Zhu Li & Stapleton, FOC.
Special comments. The available descriptions hopelessly inadequate. Anatomical data wanting. Illustrations. • N. prainii (as Thamnocalamus, with Pseudosasa hindsii: Camus, 1913). • Abbreviations for Camus (1913) figures
We advise against extracting comparative information from the descriptions. This is much more easily achieved using the DELTA data files or the interactive key, which allows access to the character list, illustrations, full and partial descriptions, diagnostic descriptions, differences and similarities between taxa, lists of taxa exhibiting or lacking specified attributes, distributions of character states within any set of taxa, geographical distribution, and classifications. See also Guidelines for using data taken from Web publications.
Cite this publication as: ‘Watson, L., Macfarlane, T.D., and Dallwitz, M.J. 1992 onwards. The grass genera of the world: descriptions, illustrations, identification, and information retrieval; including synonyms, morphology, anatomy, physiology, phytochemistry, cytology, classification, pathogens, world and local distribution, and references. Version: 11th December 2017. delta-intkey.com/grass’.