The grass genera of the world
Habit, vegetative morphology. Robust perennial; stoloniferous. Culms 200–300 cm high; herbaceous. Culm internodes solid. Leaf blades broad to narrow; 4–30 mm wide (up to 1 m long); flat, or folded; pseudopetiolate; without cross venation. Ligule an unfringed membrane.
Reproductive organization. Plants bisexual, all with bisexual spikelets; with hermaphrodite florets. The spikelets all alike in sexuality; homomorphic.
Inflorescence. Inflorescence paniculate; contracted (narrow, dense, woolly); espatheate; not comprising partial inflorescences and foliar organs. Spikelet-bearing axes racemes; with very slender rachides; disarticulating; disarticulating at the joints. Articles non-linear (clavate); not appendaged; disarticulating transversely; somewhat hairy (at base, ciliolate on the lower margins, glabrous above). Spikelets paired; not secund; sessile and pedicellate; consistently in long-and-short combinations; in pedicellate/sessile combinations. Pedicels of the pedicellate spikelets free of the rachis. The shorter spikelets hermaphrodite. The longer spikelets hermaphrodite.
Female-fertile spikelets. Spikelets 2–3 mm long; compressed dorsiventrally; falling with the glumes (pedicellate spikelets falling from the pedicels, sessile ones falling with the adjacent joint and pedicel). Rachilla terminated by a female-fertile floret. Hairy callus present.
Glumes two; more or less equal; long relative to the adjacent lemmas; free; hairless (shiny, brown); awnless; carinate (G2), or non-carinate (G1); very dissimilar (leathery, the G1 dorsally flattened, the G2 keeled). Lower glume not two-keeled; flattened on the back; not pitted; relatively smooth. Spikelets with incomplete florets. The incomplete florets proximal to the female-fertile florets. Spikelets with proximal incomplete florets. The proximal incomplete florets 1; epaleate; sterile. The proximal lemmas awned, or awnless; similar in texture to the female-fertile lemmas (hyaline); not becoming indurated.
Female-fertile florets 1. Lemmas truncate; less firm than the glumes; entire; blunt; non-carinate; 0 nerved, or 1 nerved. Lodicules present; ciliate (?). Stamens 3. Ovary apically glabrous.
Fruit, embryo and seedling. Fruit not noticeably compressed. Hilum short.
Phytochemistry. Leaves without flavonoid sulphates (1 species).
Special diagnostic feature. The adaxial surface of the leaf blade not as in Hydrothauma (q.v.).
Cytology. Chromosome base number, x = 5 (?). 2n = 30. 6 ploid.
Classification. Watson & Dallwitz (1994): Panicoideae; Andropogonodae; Andropogoneae; Andropogoninae. Soreng et al. (2015): Panicoideae; Andropogonodae; Andropogoneae; Saccharinae. 2 species.
Distribution, phytogeography, ecology. Indo-Malaysia.
Hybrids. Intergeneric hybrids with Saccharum, Sclerostachya.
Rusts and smuts. Smuts from Ustilaginaceae. Ustilaginaceae Sphacelotheca.
Special comments. Anatomical data wanting. Illustrations. • N. fallax: www.zhiwutong.com
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’.