Melocalamus Benth.
Habit, vegetative morphology. Perennial. The flowering culms leafy. Culms 500–3000 cm high; woody and persistent; to 2.5 cm in diameter; scandent (tufted, spreading, arching); branched above. Primary branches/mid-culm node several to many. Culm sheaths persistent (brittle). Culm internodes hollow. Rhizomes pachymorph. Plants unarmed. Leaves not basally aggregated; auriculate (the auricles hirsute, reflexed, caducous); with auricular setae. Leaf blades lanceolate to elliptic; broad; 22–50 mm wide (and 14–26 cm long); not cordate, not sagittate (rounded at base); pseudopetiolate (the petiolule hairy); without cross venation; disarticulating from the sheaths; rolled in bud; ligule present (narrow, entire).
Reproductive organization. Plants bisexual, with bisexual spikelets; with hermaphrodite florets. The spikelets of sexually distinct forms on the same plant; hermaphrodite and sterile (panicle ‘with several fertile and many sterile spikelets’). Sometimes viviparous.
Inflorescence. Inflorescence indeterminate; with pseudospikelets; paniculate (a large, compound, interrupted panicle of small sub-globose heads); spatheate; a complex of ‘partial inflorescences’ and intervening foliar organs (the panicle often leafy). Spikelet-bearing axes capitate; persistent. Spikelets not secund; not in distinct ‘long-and-short’ combinations.
Female-fertile spikelets. Spikelets 1.7–2.5 mm long; 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.
Glumes two; more or less equal; shorter than the adjacent lemmas; hairless; awnless (shortly mucronate); similar (broadly oval, ventricose). Spikelets with incomplete florets. The incomplete florets distal to the female-fertile florets. The distal incomplete florets 1; merely underdeveloped. Spikelets without proximal incomplete florets.
Female-fertile florets 2. Lemmas similar in texture to the glumes; not becoming indurated; entire; awnless, or mucronate (?); fertile lemma often ciliate on margins. Palea present; relatively long; apically notched; awnless, without apical setae; not indurated; several nerved (4–5 nerves between the keels); 2-keeled. Palea keels hairy (ciliate). Lodicules present (large); 3; free; membranous; ciliate; not toothed (blunt); heavily vascularized. Stamens 6; with free filaments (these short). Ovary glabrous; with a conspicuous apical appendage. The appendage broadly conical, fleshy. Styles fused. Stigmas 2, or 3 (short, plumose).
Fruit, embryo and seedling. Fruit large (2.25–3 cm in diameter); subglobose. Pericarp fleshy; free. Seed ‘non-endospermic’.
Abaxial leaf blade epidermis. Costal/intercostal zonation conspicuous. Papillae present. Intercostal papillae over-arching the stomata (four or more overarching each stoma). Long-cells markedly different in shape costally and intercostally (the costals rather longer). Intercostal zones exhibiting many atypical long-cells (a short form). Mid-intercostal long-cells having markedly sinuous walls. Microhairs present; panicoid-type. Stomata common (obscured by papillae). Intercostal short-cells common; in cork/silica-cell pairs; silicified. Intercostal silica bodies vertically elongated-nodular. Costal short-cells predominantly paired. Costal silica bodies saddle shaped (mostly, tall), or tall-and-narrow; not sharp-pointed.
Transverse section of leaf blade, physiology. C3; XyMS+. Mesophyll with arm cells; with fusoids. Leaf blade adaxially flat (save near midrib). Midrib conspicuous; having complex vascularization. Bulliforms present in discrete, regular adaxial groups; in simple fans. All the vascular bundles accompanied by sclerenchyma. Combined sclerenchyma girders present (with all the bundles); forming ‘figures’ (larger bundles with this tendency).
Taxonomy. Bambusoideae; Bambusodae; Bambuseae.
Distribution, ecology, phytogeography. 1 species; India, Burma. Forests.
Paleotropical. Indomalesian. Indo-Chinese.
References, etc. Leaf anatomical: Metcalfe 1960; this project.
Special comments. Fruit data wanting.
Cite this publication as: Watson, L., and Dallwitz, M. J. (1992 onwards). ‘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.’ http://biodiversity.uno.edu/delta/. Version: 18th August 1999. Dallwitz (1980), Dallwitz, Paine and Zurcher (1993 onwards, 1998), and Watson and Dallwitz (1994), and Watson, Dallwitz, and Johnston (1986) should also be cited (see References).