The grass genera of the world
The grass genera of the world |
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Habit, vegetative morphology. Annual. Culms 10–60 cm high; herbaceous; branched above. Leaves not basally aggregated. Leaf blades linear; broad to narrow; 5–15 mm wide. Ligule an unfringed membrane.
Reproductive organization. Plants bisexual, with bisexual spikelets; with hermaphrodite florets. The spikelets of sexually distinct forms on the same plant; hermaphrodite and male-only, or hermaphrodite and sterile. The male and female-fertile spikelets mixed in the inflorescence. The spikelets overtly heteromorphic; all in heterogamous combinations.
Inflorescence. Inflorescence of single, dorsiventral ‘racemes’ terminating the culm branches. Rachides hollowed, or flattened. Inflorescence spatheate. Spikelet-bearing axes spikelike; solitary; with substantial rachides; disarticulating; disarticulating at the joints. ‘Articles’ non-linear (inflated, clavate or turbinate); with a basal callus-knob; disarticulating transversely, or disarticulating obliquely. Spikelets paired; secund (the raceme dorsiventral, with the sessile members in two alternating rows on one side of the rachis); consistently in ‘long-and-short’ combinations; in pedicellate/sessile combinations. Pedicels of the ‘pedicellate’ spikelets discernible, but fused with the rachis. The ‘shorter’ spikelets hermaphrodite. The ‘longer’ spikelets male-only, or sterile (?).
Female-sterile spikelets. The pedicelled spikelets as large as the sessile, male or neuter, G1 smooth and asymmetrically or unilaterally winged, G2 variously keel-winged.
Female-fertile spikelets. Spikelets morphologically ‘conventional’ (but the G1 curiously winged, ornamented and awned); abaxial; compressed dorsiventrally; falling with the glumes (and with the joint plus the pedicelled spikelet from the same joint, by contrast with Manisuris sensu stricto). Rachilla terminated by a female-fertile floret. Hairy callus absent.
Glumes present; two; long relative to the adjacent lemmas; hairy, or hairless; without conspicuous tufts or rows of hairs; awned (the G1 1–2 aristate or tailed), or awnless (G. clarkei); non-carinate; very dissimilar (the G1 hardened, curiously ornamented and winged above, and aristate). Lower glume two-keeled; convex on the back; lacunose with deep depressions, or rugose, or tuberculate, or prickly (and laterally winged above the middle). Spikelets with incomplete florets. The incomplete florets proximal to the female-fertile florets. Spikelets with proximal incomplete florets. The proximal incomplete florets 1; sterile. The proximal lemmas awnless; 0 nerved, or 2 nerved; similar in texture to the female-fertile lemmas (hyaline).
Female-fertile florets 1. Lemmas less firm than the glumes (hyaline); not becoming indurated; entire; awnless; 0 nerved, or 2 nerved. Palea present. Lodicules present; 2; fleshy. Stamens 3.
Fruit, embryo and seedling. Hilum short. Embryo large.
Transverse section of leaf blade, physiology. C4; XyMS–.
Special diagnostic feature. Spikelets not arranged as in Manisuris (q.v.).
Taxonomy. Panicoideae; Andropogonodae; Andropogoneae; Rottboelliinae.
Distribution, ecology, phytogeography. 8 species; central and peninsular India. On rocks.
Paleotropical. Indomalesian. Indian.
References, etc. Morphological/taxonomic: Jain 1970.
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’.