The grass genera of the world
From the Greek, leaf-spike.
Including Sinoarundinaria Ohwi
Habit, vegetative morphology. Arborescent or shrubby perennial; rhizomatous. The flowering culms leafy. Culms 300–2000 cm high; woody and persistent; to 20 cm in diameter; flattened on one side; branched above. Primary branches/mid-culm node 2 (but rebranching). Culm sheaths deciduous in their entirety. Culm internodes hollow. Rhizomes leptomorph. Plants unarmed. Leaves not basally aggregated; auriculate, or non-auriculate; with auricular setae. Leaf blades broad; pseudopetiolate; cross veined; disarticulating from the sheaths; rolled in bud.
Reproductive organization. Plants bisexual, with bisexual spikelets; with hermaphrodite florets.
Inflorescence. Inflorescence determinate; compound paniculate (of spicate, 1-spikeleted branchlets, aggregated into spatheate clusters); spatheate; a complex of partial inflorescences and intervening foliar organs (with or without foliage leaves). Spikelet-bearing axes racemes and very much reduced; clustered; persistent. Spikelets not secund.
Female-fertile spikelets. Spikelets 18–80 mm long; compressed laterally to not noticeably compressed; disarticulating above the glumes; disarticulating between the florets. Rachilla prolonged beyond the uppermost female-fertile floret; hairless (glabrous). Hairy callus absent.
Glumes one per spikelet, or two (or 3, and the lateral spikelets with an outer bract at the base); shorter than the adjacent lemmas; pointed; awnless. Lower glume many-nerved. Upper glume many nerved. Spikelets with female-fertile florets only, or with incomplete florets. The incomplete florets if present, distal to the female-fertile florets. Spikelets without proximal incomplete florets.
Female-fertile florets 1–4. Lemmas entire; pointed; awnless, or mucronate (?); carinate to non-carinate; many veined. Palea present; relatively long; apically notched; awnless, without apical setae to with apical setae; several nerved; 2-keeled. Lodicules present; 2, or 3; free; membranous; ciliate, or glabrous; heavily vascularized. Stamens 3. Anthers penicillate, or not penicillate; with the connective apically prolonged, or without an apically prolonged connective. Ovary glabrous; with a conspicuous apical appendage. The appendage broadly conical, fleshy. Styles fused (into one, long). Stigmas 2–3.
Fruit, embryo and seedling. Fruit longitudinally grooved. Hilum long-linear. Embryo small. Endosperm containing compound starch grains. 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. Intercostal papillae over-arching the stomata; several per cell. Mid-intercostal long-cells having markedly sinuous walls (thin walled). Microhairs present; panicoid-type (but variable in shape). Stomata common (outlines often more or less obscured by papillae). Subsidiaries low to high dome-shaped. Intercostal short-cells common, or absent or very rare; in cork/silica-cell pairs, or not paired; silicified. Intercostal silica bodies tall-and-narrow. Costal short-cells conspicuously in long rows, or neither distinctly grouped into long rows nor predominantly paired. Costal silica bodies saddle shaped; not sharp-pointed.
Transverse section of leaf blade, physiology. C3; XyMS+. Mesophyll with arm cells; with fusoids (rarely), or without fusoids (usually, or fusoids if present rare and/or inconspicuous). Leaf blade with distinct, prominent adaxial ribs (these low), 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 and 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 (with most bundles).
Cytology. Chromosome base number, x = 12. 2n = 24 (rarely), or 48, or 72. 2 ploid, or 4 ploid, or 6 ploid. Chromosomes small.
Taxonomy. Bambusoideae; Bambusodae; Bambuseae.
Distribution, ecology, phytogeography. About 50 species; eastern Asia.
Holarctic, Paleotropical, and Neotropical. Boreal. Indomalesian. Eastern Asian. Indian and Indo-Chinese. Caribbean.
Rusts and smuts. Rusts Stereostratum and Puccinia. Taxonomically wide-ranging species: Stereostratum corticoides, Puccinia longicornis, and Puccinia kusanoi. Smuts from Ustilaginaceae. Ustilaginaceae Ustilago.
Economic importance. Culms of P. aurea, P. bambusoides, P. glauca, P. nigra, P. vivax used for walking sticks, fishing rods, furniture, handicrafts etc; young shoots of P. aurea, P. bambusoides, P. glauca, P. nidularia, P. vivax eaten as vegetables.
References, etc. Leaf anatomical: Metcalfe 1960; this project.
Illustrations. • P. aurea: Nicora & Rúgolo de Agrasar (1987)
The descriptions are offered for casual browsing only. We strongly advise against extracting comparative information from them. This is much more easily achieved using 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, genera included in each family, and classifications (Dahlgren; Dahlgren, Clifford, and Yeo; Cronquist; APG).
Cite this publication as: ‘Watson, L., 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: 7th December 2015. delta-intkey.com’.