Grass Genera of the World

L. Watson and M. J. Dallwitz

Melocanna Trin.

Including Beesha Kunth

Habit, vegetative morphology. Perennial (shrubs or trees); rhizomatous. The flowering culms leafy. Culms 1000–2000 cm high; woody and persistent; to 9 cm in diameter; branched above. Primary branches/mid-culm node many. Culm sheaths often persistent (leathery). Culm internodes hollow. Rhizomes pachymorph (metamorph type II). Plants unarmed. Leaves not basally aggregated; auricles inconspicuous; without auricular setae. Leaf blades broad; 20–90 mm wide; pseudopetiolate; without cross venation; disarticulating from the sheaths; rolled in bud.

Reproductive organization. Plants bisexual, with bisexual spikelets; with hermaphrodite florets. Sometimes viviparous.

Inflorescence. Inflorescence indeterminate; with pseudospikelets; paniculate (large, compound, with spatheate, oblong, tight groups of few to several spikelets imbricate and secund on the branches); spatheate (the spikelet fascicles bracteate); a complex of ‘partial inflorescences’ and intervening foliar organs. Spikelet-bearing axes paniculate; persistent. Spikelets secund (the fascicles secund on the spicate inflorescence branches).

Female-fertile spikelets. Spikelets 10–15 mm long; disarticulating above the glumes (?); disarticulating between the florets (?). Rachilla prolonged beyond the uppermost female-fertile floret, or terminated by a female-fertile floret.

Glumes two to several (to four); shorter than the adjacent lemmas; pointed; awnless; similar (ovate-lanceolate). Spikelets presumably? with incomplete florets. The incomplete florets proximal to the female-fertile florets (assuming the ‘several glumes’ may represent sterile lemmas). Spikelets with proximal incomplete florets (?). The proximal incomplete florets 1–2 (?); sterile.

Female-fertile florets 1. Lemmas ovate-lanceolate, pungent; less firm than the glumes to similar in texture to the glumes; entire; pointed; awnless. Palea present; relatively long; several nerved (?); keel-less. Lodicules present; 2; free; membranous (narrow); ciliate; heavily vascularized (3–5 nerved). Stamens 5–7; with free filaments, or monadelphous to triadelphous (irregularly united). Anthers not penicillate; without an apically prolonged connective. Ovary glabrous; with a conspicuous apical appendage. The appendage long, stiff and tapering. Styles fused (ovary attenuate into a long style). Stigmas 2–4 (feathery, recurved).

Fruit, embryo and seedling. Fruit large (reaching 7–12 cm long in M. baccifera); pyriform. Pericarp fleshy. Embryo large (but not visible). Seed ‘non-endospermic’ (or hardly so, when mature: the abnormally large scutellum absorbs nearly all the endosperm, and the seed germinates while fruit still attached to parent plant). Embryo with an epiblast; with a scutellar tail; with a negligible mesocotyl internode. Embryonic leaf margins overlapping.

Abaxial leaf blade epidermis. Costal/intercostal zonation conspicuous. Papillae present (confined to stomatal bands). Intercostal papillae over-arching the stomata. Intercostal zones with typical long-cells to exhibiting many atypical long-cells (the long-cells short). Mid-intercostal long-cells having markedly sinuous walls (thin). Microhairs present; panicoid-type; 63–66 microns long (in M. bambusoides); 6–7.5 microns wide at the septum. Microhair total length/width at septum 8.4–11. Microhair apical cells 33.6–37.5 microns long. Microhair apical cell/total length ratio 0.52–0.57. Stomata common (obscured by papillae); 24–27 microns long (in M. bambusoides). Intercostal short-cells common; in cork/silica-cell pairs; silicified. Intercostal silica bodies tall-and-narrow. Costal short-cells predominantly paired (occasionally in short rows). Costal silica bodies saddle shaped; not sharp-pointed.

Transverse section of leaf blade, physiology. C3; XyMS+. Mesophyll with arm cells; with fusoids (conspicuous). The fusoids external to the PBS. Leaf blade with distinct, prominent adaxial ribs (ribs slight, widely spaced), or adaxially flat; with the ribs more or less constant in size. Midrib conspicuous; having complex vascularization. Bulliforms present in discrete, regular adaxial groups; in simple fans (mostly), or associated with colourless mesophyll cells to form deeply-penetrating fans. All the vascular bundles accompanied by sclerenchyma. Combined sclerenchyma girders present (with most bundles); forming ‘figures’ (many bundles, somewhat so).

Taxonomy. Bambusoideae; Bambusodae; Bambuseae.

Distribution, ecology, phytogeography. 3 species; eastern Asia.

Paleotropical. Indomalesian. Indo-Chinese.

Economic importance. Culms of M. baccifera yield pulp for high quality papers; splits are used in handicrafts; and the large fruits are edible.

References, etc. Leaf anatomical: Metcalfe 1960; this project.

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.’ 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).