Arundinaria Mich.
From the Latin arundo, a reed.
Including Bashania Keng f. & Yi, Butania Keng f., Ludolphia Willd., Clavinodum Wen, Macronax Raf, Miegia Pers., Nipponocalamus Nakai, Oligostachyum Wang & Ye, Omeiocalamus Keng f., Pleioblastus Nakai, Triglossum Roem. & Schult., Tschompskia Aschers. & Graebn.
Excluding Pseudosasa
Habit, vegetative morphology. Perennial. The flowering culms leafless, or leafy. Culms 200–800 cm high; woody and persistent; cylindrical; not scandent (usually). Primary branches/mid-culm node 1 (branching into 3–7 secondaries). Culm internodes hollow. Unicaespitose, or pluricaespitose. Rhizomes leptomorph. Plants unarmed. Leaves not basally aggregated; with auricular setae. Leaf blades neither leathery nor flimsy; broad, or narrow (relatively small); pseudopetiolate; cross veined; disarticulating from the sheaths; a fringed membrane to a fringe of hairs.
Reproductive organization. Plants bisexual, with bisexual spikelets; with hermaphrodite florets. The spikelets all alike in sexuality.
Inflorescence. Inflorescence determinate; without pseudospikelets; reduced to a single spikelet, or few spikeleted, or many spikeleted; of spicate main branches, or paniculate (i.e. variable, regardless of problems with terminology - generally open racemose or paniculate, sometimes both forms combined in the one plant, sometimes the ‘branches’ reduced to single spikelets); open; spatheate; a complex of ‘partial inflorescences’ and intervening foliar organs, or not comprising ‘partial inflorescences’ and foliar organs (?). Spikelet-bearing axes ‘racemes’, or paniculate; persistent. Spikelets pedicellate.
Female-fertile spikelets. Spikelets 10–80 mm long; compressed laterally; disarticulating above the glumes; disarticulating between the florets. Rachilla prolonged beyond the uppermost female-fertile floret; hairy; the rachilla extension with incomplete florets. Hairy callus absent.
Glumes one per spikelet, or two; very unequal, or more or less equal; shorter than the adjacent lemmas; awnless; similar. Lower glume 4–7 nerved. Upper glume 8–13 nerved. Spikelets with incomplete florets. The incomplete florets both distal and proximal to the female-fertile florets. The distal incomplete florets merely underdeveloped. Spikelets with proximal incomplete florets. The proximal incomplete florets 1 (or more?); male, or sterile (?). The proximal lemmas awnless; 9–11 nerved; exceeded by the female-fertile lemmas; similar in texture to the female-fertile lemmas; not becoming indurated.
Female-fertile florets 4–20 (?). Lemmas often acuminate or setaceous-tipped; similar in texture to the glumes; not becoming indurated (papery); entire; usually pointed; awnless, or mucronate, or awned. Awns when present, 1; apical; non-geniculate; much shorter than the body of the lemma to about as long as the body of the lemma (?). Lemmas 9–15 nerved. Palea present; relatively long, or conspicuous but relatively short; not indurated; several nerved (4 to 13 observed); 2-keeled (dorsally sulcate). Lodicules present (relatively large); 3; free; membranous; ciliate; not toothed; heavily vascularized. Stamens 3 (rarely 6?). Ovary glabrous, or hairy; without a conspicuous apical appendage. Stigmas 2 (in Bashania), or 3.
Fruit, embryo and seedling. Fruit medium sized to large (1–1.2 cm long); longitudinally grooved. Hilum long-linear. Embryo small. Endosperm hard; without lipid; containing compound starch grains.
Abaxial leaf blade epidermis. Costal/intercostal zonation conspicuous. Papillae present. Intercostal papillae over-arching the stomata, or not over-arching the stomata; several per cell (in one or more rows per cell). Mid-intercostal long-cells having markedly sinuous walls (these thin). Microhairs present; panicoid-type (distal cells often variable in shape). Stomata common. Subsidiaries low to high dome-shaped (usually), or triangular (rarely). Intercostal short-cells common, or absent or very rare; in cork/silica-cell pairs; silicified, or not silicified. Intercostal silica bodies when present, often tall-and-narrow, or vertically elongated-nodular. Costal short-cells predominantly paired, or neither distinctly grouped into long rows nor predominantly paired, or conspicuously in long rows (sometimes, over main veins). Costal silica bodies saddle shaped (commonly), or oryzoid to ‘panicoid-type’ (sometimes tending to cross-shaped, then sometimes tending to be vertically elongated).
Transverse section of leaf blade, physiology. C3; XyMS+. Mesophyll without adaxial palisade; with arm cells; with fusoids. The fusoids external to the PBS. Leaf blade with distinct, prominent adaxial ribs; with the ribs more or less constant in size, or with the ribs very irregular in sizes. Midrib conspicuous; having complex vascularization. The lamina distinctly asymmetrical on either side of the midrib. Bulliforms present in discrete, regular adaxial groups; in simple fans (mostly), or 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; forming ‘figures’. Sclerenchyma all associated with vascular bundles.
Culm anatomy. Culm internode bundles in three or more rings to scattered.
Cytology. Chromosome base number, x = 12. 2n = 48 (usually). 4 ploid (usually), or 2 ploid (rarely). Chromosomes ‘small’. Nucleoli persistent.
Taxonomy. Bambusoideae; Bambusodae; Bambuseae.
Distribution, ecology, phytogeography. About 50 species; in warm regions. Commonly adventive.
Holarctic, Paleotropical, Neotropical, and Cape. Boreal. African and Indomalesian. Eastern Asian and Atlantic North American. Sudano-Angolan and West African Rainforest. Indo-Chinese. Andean. Canadian-Appalachian and Southern Atlantic North American. Sahelo-Sudanian, Somalo-Ethiopian, and South Tropical African.
Rusts and smuts. Rusts — Puccinia. Smuts from Ustilaginaceae. Ustilaginaceae — Ustilago.
Economic importance. Culms of (e.g.) A. amabilis used for fishing rods, ski poles, umbrella shafts, furniture construction etc.; many others are cultivated as ornamentals or used in bonsai.
References, etc. Morphological/taxonomic: Chao and Renvoize 1989. 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.’ 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).