| # The grass genera of the world |

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

### Ampelocalamus Chen, Wen & Shang

~ Sinarundinaria

Habit, vegetative morphology. Perennial; shortly to long- rhizomatous and caespitose, or decumbent. The flowering culms leafy. Culms 100–1000 cm high; woody and persistent; cylindrical (the nodes flush or swollen); scandent, or not scandent; self-supporting, or decumbent, or scrambling, or scandent; branched above. Primary branches 4–20; in an irregular line, or clumped. The branching fastigiate, or suffrutescent, or dendroid (the branches subequal, or one or two dominant). Culm leaf sheaths present, or absent; deciduous, or persistent; leaving a persisten girdle, or not leaving a persistent girdle; conspicuously auriculate, or not conspicuously auriculate. Culm leaves with conspicuous blades. Culm leaf blades linear, or lanceolate. Rhizomes pachymorph, or leptomorph. Leaves auriculate, or non-auriculate. Leaf blades apically muticous or pungent, linear to lanceolate, or elliptic; pseudopetiolate; obscurely cross veined to without cross venation. Ligule an unfringed membrane, or a fringed membrane.

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

Inflorescence. Inflorescence determinate (seemingly), or indeterminate (A. patellaris); with pseudospikelets (A. patellaris only exhibiting spikelets with basal axillary buds), or without pseudospikelets; few spikeleted, or many spikeleted; when not much reduced, of spicate main branches, or paniculate; spatheate, or espatheate; a complex of ‘partial inflorescences’ and intervening foliar organs, or not comprising ‘partial inflorescences’ and foliar organs. Spikelets solitary; not secund; sessile to pedicellate.

Female-fertile spikelets. Spikelets morphologically ‘conventional’ to unconventional; 8.3–60 mm long; oblong, or lanceolate, or ovate, or linear; compressed laterally; disarticulating above the glumes; disarticulating between the florets; with conventional internode spacings, or with distinctly elongated rachilla internodes between the florets. Rachilla prolonged beyond the uppermost female-fertile floret; the rachilla extension with incomplete florets, or naked.

Glumes one per spikelet to two (A. patellaris, i.e. distal to the bud-bearing ones), or two; very unequal; shorter than the spikelets; shorter than the adjacent lemmas; pointed (acute to acuminate); awnless; non-carinate; chartaceous to herbaceous, lanceolate or oblong, similar. Lower glume 2–5 nerved. Upper glume 4 nerved, or 5 nerved. Spikelets with incomplete florets. The incomplete florets distal to the female-fertile florets. The distal incomplete florets merely underdeveloped; awnless.

Female-fertile florets (1–)2–6(–7). Lemmas orbicular, ovate or lanceolate; chartaceous to herbaceous, similar in texture to the glumes; smooth; not becoming indurated; entire; usually pointed; acute or acuminate, awnless; hairless; glabrous (usually), or scabrous; carinate, or non-carinate. The keel when present, wingless. Lemmas 7–11 nerved. Palea present; apically notched; dentate, awnless, without apical setae; membranous, or more often chartaceous, thinner than the lemma to textured like the lemma; not indurated; several nerved (4 or 10–11); mostly 2-keeled (or the uppermost keel-less). Palea keels glabrous, or hairy. Lodicules present (usually), or absent; 1–3; when present, membranous; ciliate, or glabrous. Stamens 3 (usually), or 6; monadelphous (in A. patellaris only?), or with free filaments. Ovary apically glabrous (in some species?), or apically hairy; with a conspicuous apical appendage (A. patellaris only), or without a conspicuous apical appendage. The appendage broadly conical, fleshy. Stigmas 1–3.

Fruit, embryo and seedling. Fruit medium sized. Hilum short. Pericarp fused. Embryo large to small.

Classification. Watson & Dallwitz (1994): genus not recognised. Soreng et al. (2015): Bambusoideae; Arundinarodae; Arundinarieae; Arundinariinae. 13 species.

Distribution, phytogeography, ecology. India and China.

Special comments. This attempt at a description has been compiled from the Clayton et al. (2016) species descriptions, omitting those known only from vegetative material. Most are hopelessly non-comparative, and that of A. patellaris, with pseudospikelets, monadelphous stamens, etc., renders the generic circumscription highly questionable. Fruit data and proper details of the ovary wanting. Anatomical data wanting.

Illustrations. • Ampelocalamus patellaris (as Dendrocalamus, with D. latifolius): Camus, 1913. • Abbreviations for Camus (1913) figures. • A. patellaris, culm leaf-sheath: J. Bomb. Nat. Hist. Soc. (1991).

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’.

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