| # The grass genera of the world |

L. Watson, T.D. Macfarlane, and M.J. Dallwitz

### 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, Omeiocalamus Keng f., Triglossum Roem. & Schult., Tschompskia Aschers. & Graebn.

Excluding (supposedly) Oligostachyum, Pleioblastus, Pseudosasa

Habit, vegetative morphology. Perennial. The flowering culms leafless, or leafy. Culms 200–800 cm high; woody and persistent; cylindrical; not scandent (usually); branched above (usually), or unbranched above. Buds from which the primary culm branches arise (where recorded) 1. Primary branches (1–)2–20; horizontally aligned, or clumped. The branching simple (rarely), or suffrutescent to dendroid. Culm leaf sheaths present; deciduous, or persistent; sometimes leaving a persisten girdle, or not leaving a persistent girdle; usually not conspicuously auriculate. Culm leaves with conspicuous blades. Culm leaf blades linear, or lanceolate, or ovate, or triangular. Culm internodes hollow. Unicaespitose, or pluricaespitose. Rhizomes leptomorph. Plants unarmed. Leaves not basally aggregated; with auricular setae. Leaf blades broad, or narrow (relatively small); pseudopetiolate; cross veined; where recorded, disarticulating from the sheaths. Ligule a fringed membrane to a fringe of hairs. Contra-ligule present, or absent.

Reproductive organization. Plants bisexual, all with bisexual spikelets; with hermaphrodite florets. The spikelets all alike in sexuality.

Inflorescence. Inflorescence usually determinate (with Oligostachyum excluded), or indeterminate (?); 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; oblong, or elliptic, or lanceolate, or linear; 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 distal to the female-fertile florets. The distal incomplete florets merely underdeveloped.

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 convolute; 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 apically glabrous, or apically 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.

Transverse section of leaf blade, physiology. Mesophyll without arm cells; without fusoids. Leaf blade 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.

Classification. Watson & Dallwitz (1994): Bambusoideae; Bambusodae; Bambuseae. Soreng et al. (2015): Bambusoideae; Arundinarodae; Arundinarieae; Arundinariinae. About 10 species (i.e., sensu stricto).

Distribution, phytogeography, ecology. In warm regions.

Commonly adventive.

Economic aspects. 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.

Rusts and smuts. Rusts — Puccinia. Smuts from Ustilaginaceae. Ustilaginaceae — Ustilago.

References, etc. Morphological/taxonomic: Chao and Renvoize 1989.

Special comments. Anatomical data wanting (i.e, for the genus sensu stricto).

Illustrations. • Arundinaria gigantea, as A. macrosperma: P. Beauv. (1812). • Arundinaria gigantea: Hitchcock and Chase (1950). • A. gigantea subsp. tecta: Hitchcock and Chase (1950). • A. racemosa: Camus (1913). • Abbreviations for Camus (1913) figures.

We advise against extracting comparative information from the descriptions. This is much more easily achieved using the DELTA data files or 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, and classifications. See also Guidelines for using data taken from Web publications.

Cite this publication as: ‘Watson, L., Macfarlane, T.D., 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: 15th June 2025. delta-intkey.com’.

Contents