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The grass genera of the world

L. Watson, T.D. Macfarlane, and M.J. Dallwitz

Vietnamocalamus T.Q. Nguyen

Type species: V. catbaensis.

Habit, vegetative morphology. Perennial; rhizomatous. The flowering culms leafy. Culms erect, 150–250 cm high; woody and persistent; to 10 cm in diameter; cylindrical; branched above. Primary branches 1. The branching suffrutescent. Culm leaf sheaths present. Rhizomes leptomorph. Leaves auriculate (these falcate); with auricular setae. Leaf blades lanceolate; broad; 20–26 cm long, 30–45 mm wide; not pseudopetiolate. Ligule an unfringed membrane; truncate; 0.5 mm long. Contra-ligule absent.

Reproductive organization. Plants bisexual, all with bisexual spikelets; with hermaphrodite florets. The spikelets hermaphrodite.

Inflorescence. Inflorescence axillary, basally embraced by the subtending leaf, reduced to a single spikelet, or few spikeleted. Spikelets solitary; not secund; pedicellate.

Female-fertile spikelets. Spikelets fairly morphologically ‘conventional’; 15 mm long; linear; compressed laterally to not noticeably compressed (subterete); disarticulating above the glumes; disarticulating between the florets; with conventional internode spacings. Rachilla prolonged beyond the uppermost female-fertile floret; the rachilla extension with incomplete florets. Hairy callus absent.

Glumes persistent, several (three); shorter than the spikelets; awnless; chartaceous, non-carinate; lanceolate, similar. Spikelets with incomplete florets. The incomplete florets distal to the female-fertile florets. The distal incomplete florets merely underdeveloped; awnless.

Female-fertile florets 3–4. Lemmas lanceolate; chartaceous, similar in texture to the glumes; without grooves, smooth; not becoming indurated; entire; pointed; awnless; non-carinate; 7 nerved. Palea present; not convolute; chartaceous, textured like the lemma. Lodicules present; 3. Stamens 3. Anthers 3 mm long. Ovary without a conspicuous apical appendage. Stigmas 2.

Fruit, embryo and seedling. Pericarp fused.

Classification. Watson & Dallwitz (1994): not described separately. Soreng et al. (2015): Bambusoideae; Arundinarodae; Arundinarieae; Arundinariinae. 1 species (V. catbaensis).

Distribution, phytogeography, ecology. China and Indo-China.


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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: 13th November 2017. delta-intkey.com/grass’.

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