The grass genera of the world
The grass genera of the world | |
Sometimes referred to Saccharum
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, 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 glabrous.
Fruit, embryo and seedling. Fruit not noticeably compressed. Hilum short.
Phytochemistry. Leaves without flavonoid sulphates (1 species).
Cytology. Chromosome base number, x = 5 (?). 2n = 30. 6 ploid.
Taxonomy. Panicoideae; Andropogonodae; Andropogoneae; Andropogoninae.
Distribution, ecology, phytogeography. 2 species; Indo-Malaysia.
Paleotropical. Indomalesian. Indo-Chinese and Malesian.
Hybrids. Intergeneric hybrids with Saccharum, Sclerostachya.
Rusts and smuts. Smuts from Ustilaginaceae. Ustilaginaceae — Sphacelotheca.
Special comments. Anatomical data wanting.
This description is offered for casual browsing only. We strongly advise against extracting comparative information from it. This is much more easily achieved using 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 specified attributes, summaries of attributes within groups of taxa, geographical distribution, classification, and species sampled for anatomy.
Cite this publication as: ‘Watson, L., 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 February 2012. http://delta-intkey.com’.