The grass genera of the world
Habit, vegetative morphology. Perennial (shrub). The flowering culms leafy. Culms woody and persistent; to 11 cm in diameter; cylindrical; not scandent; branched above. Buds from which the primary culm branches arise (where recorded) 1. Primary branches (1–)3(–10). The branching dendroid. Culm nodes 2 ridged. Culm leaf sheaths present; usually deciduous; not leaving a persistent girdle; conspicuously auriculate, or not conspicuously auriculate. Culm leaves with conspicuous blades. Culm leaf blades linear, or lanceolate, or ovate, or triangular. Rhizomes leptomorph. Leaves not basally aggregated; with auricular setae. Leaf blades broad (large); pseudopetiolate; where recorded, disarticulating from the sheaths, or persistent (then demarcated). Contra-ligule consistently absent.
Reproductive organization. Plants bisexual, all with bisexual spikelets; with hermaphrodite florets.
Inflorescence. Inflorescence weakly indeterminate, or determinate (usually); with pseudospikelets; comprising short espatheate branches loosely grouped about a node, the spikelets in tight clusters; spatheate, or espatheate; a complex of partial inflorescences and intervening foliar organs, or not comprising partial inflorescences and foliar organs (I. hispidula approaches a compound inflorescence, with spathiform bracts). Spikelet-bearing axes persistent. Spikelets solitary; sessile.
Female-fertile spikelets. Spikelets unconventional; where recorded, linear; compressed laterally (?); disarticulating above the glumes; disarticulating between the florets. Rachilla prolonged beyond the uppermost female-fertile floret; the rachilla extension with incomplete florets.
Glumes two; similar. Spikelets with incomplete florets. The incomplete florets distal to the female-fertile florets. Spikelets without proximal incomplete florets.
Female-fertile florets 3–20 (several to many). Lemmas leathery; awnless (?). Palea present; not convolute. Lodicules present; 3; membranous; ciliate to glabrous; heavily vascularized. Stamens 6. Anthers without an apically prolonged connective. Ovary where known, without a conspicuous apical appendage. Styles fused. Stigmas 3.
Fruit, embryo and seedling. Fruit large (8 mm long in I. sinica); ellipsoid.
Classification. Watson & Dallwitz (1994): Bambusoideae; Bambusodae; Bambuseae. Soreng et al. (2015): Bambusoideae; Arundinarodae; Arundinarieae; Arundinariinae. About 12 species.
Distribution, phytogeography, ecology. Asia, especially China and Vietnam.
Shade species; glycophytic. Forest and roadsides.
References, etc. Morphological/taxonomic: Chao and Chu 1983, Chao and Renvoize 1989.
Special comments. Morphological description poor. Fruit data wanting. Anatomical data wanting. Illustrations. • I. glabrata: Dai, Qihui, Huang, Yingquin (1987). • I. longispicata: Dai, Qihui, Huang, Yingquin (1987)
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: 11th December 2017. delta-intkey.com/grass’.