Oreobambos K. Schum.
Sometimes referred to Dendrocalamus
Habit, vegetative morphology. Arborescent perennial. The flowering culms leafy. Culms 450–1800 cm high; woody and persistent; to 10 cm in diameter. Culm nodes glabrous. Primary branches/mid-culm node several, on dominant. Culm internodes hollow. Pluricaespitose. Rhizomes pachymorph. Plants unarmed. Leaves not basally aggregated; without auricular setae. Leaf blades lanceolate to elliptic; broad; 25–60 mm wide; pseudopetiolate; without cross venation; disarticulating from the sheaths; rolled in bud.
Reproductive organization. Plants bisexual, with bisexual spikelets; with hermaphrodite florets. Not viviparous.
Inflorescence. Inflorescence indeterminate; with pseudospikelets; a false spike, with spikelets on contracted axes (with involucrate, cupuliform clusters of pseudospikelets on bare branches); spatheate (each cluster subtended by a deciduous spathe, and associated with broad, leathery bracts). Spikelet-bearing axes very much reduced (the spikelet clusters of 3 or more spikelets or pseudo-spikelets each subtended by a pair of leafy bracts); persistent. Spikelets associated with bractiform involucres.
Female-fertile spikelets. Spikelets 12–15 mm long; compressed laterally to not noticeably compressed; falling with the glumes. Rachilla prolonged beyond the uppermost female-fertile floret; hairless; the rachilla extension naked. Hairy callus absent.
Glumes one per spikelet; long relative to the adjacent lemmas; hairless (papery); glabrous; not pointed; awnless; non-carinate. Upper glume 11–18 nerved. Spikelets with female-fertile florets only; without proximal incomplete florets.
Female-fertile florets 2 (subequal). Lemmas similar in texture to the glumes to decidedly firmer than the glumes (papery to thinly leathery); not becoming indurated; entire; blunt; awnless; hairless; glabrous; without a germination flap; 11–23 nerved. Palea present; relatively long; apically notched; awnless, without apical setae; not indurated; several nerved (5–11); 2-keeled. Lodicules absent. Stamens 6. Anthers not penicillate; with the connective apically prolonged. Ovary hairy; with a conspicuous apical appendage. The appendage broadly conical, fleshy. Styles fused (into one). Stigmas 1.
Fruit, embryo and seedling. Pericarp thick and hard; free (and with a crustaceous, hairy apical appendage).
Abaxial leaf blade epidermis. Costal/intercostal zonation conspicuous. Papillae present. Intercostal papillae over-arching the stomata; several per cell. Long-cells similar in shape costally and intercostally; differing markedly in wall thickness costally and intercostally. Mid-intercostal long-cells having markedly sinuous walls. Microhairs present; panicoid-type. Stomata common (obscured by papillae). Subsidiaries dome-shaped, or triangular (?-outlines obscure). Intercostal short-cells common; in cork/silica-cell pairs. Costal short-cells predominantly paired. Costal silica bodies saddle shaped (rather variable); not sharp-pointed.
Transverse section of leaf blade, physiology. C3; XyMS+. Mesophyll with non-radiate chlorenchyma; with arm cells; with fusoids. Leaf blade adaxially flat. 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; forming ‘figures’.
Taxonomy. Bambusoideae; Bambusodae; Bambuseae.
Distribution, ecology, phytogeography. 1 species; tropical East Africa. Forest.
Paleotropical. African. Sudano-Angolan. Somalo-Ethiopian and South Tropical African.
References, etc. Leaf anatomical: Metcalfe 1960.
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).