The grass genera of the world
Habit, vegetative morphology. Culms herbaceous; branched above. Culm nodes glabrous. Leaves not basally aggregated; non-auriculate. Leaf blades broad; slightly cordate; without cross venation; persistent.
Reproductive organization. Plants bisexual, all with bisexual spikelets; with hermaphrodite florets. The spikelets all alike in sexuality.
Inflorescence. Inflorescence of spicate main branches (pectinate racemes); espatheate; not comprising partial inflorescences and foliar organs. Spikelet-bearing axes persistent. Spikelets solitary; secund.
Female-fertile spikelets. Spikelets 5 mm long; compressed laterally; falling with the glumes. Rachilla terminated by a female-fertile floret. Hairy callus absent.
Glumes two; relatively large; more or less equal; shorter than the adjacent lemmas; lateral to the rachis; hairy (with stiff, tubercle-based hairs over the lower part of the keel); pointed; awnless (apiculate); carinate; with the keel conspicuously winged (over its top third); similar. Lower glume 4–5 nerved. Upper glume 3–6 nerved. Spikelets with incomplete florets. The incomplete florets proximal to the female-fertile florets. Spikelets with proximal incomplete florets. The proximal incomplete florets 1; paleate; male. The proximal lemmas awnless; 11 nerved; decidedly exceeding the female-fertile lemmas; less firm than the female-fertile lemmas; not becoming indurated.
Female-fertile florets 1. Lemmas decidedly firmer than the glumes; not becoming indurated; entire; pointed; awnless; hairless; carinate; having the margins inrolled against the palea; 5 nerved. Palea present; relatively long; 2-nerved; 2-keeled. Lodicules present; 2; free; fleshy; glabrous; not or scarcely vascularized. Stamens 3. Anthers not penicillate; without an apically prolonged connective. Ovary apically glabrous. Styles fused. Stigmas 2; white (seemingly, from dried material).
Abaxial leaf blade epidermis. Costal/intercostal zonation conspicuous. Papillae absent. Intercostal zones exhibiting many atypical long-cells. Mid-intercostal long-cells rectangular; having markedly sinuous walls. Microhairs present; panicoid-type; 51–54 microns long; 30–31.5 microns wide at the septum. Microhair total length/width at septum 6–6.1. Microhair apical cells 8.4–9 microns long. Microhair apical cell/total length ratio 0.58–0.59. Stomata common; 40–45 microns long. Subsidiaries triangular. Guard-cells overlapping to flush with the interstomatals. Intercostal short-cells absent or very rare. Costal short-cells conspicuously in long rows. Costal silica bodies panicoid-type; dumb-bell shaped (the cross-bars seemingly missing in the material seen, thus simulating saddles and crescents).
Transverse section of leaf blade, physiology. C3; XyMS+. Midrib conspicuous; with one bundle only. All the vascular bundles accompanied by sclerenchyma. Combined sclerenchyma girders present. Sclerenchyma all associated with vascular bundles.
Classification. Watson & Dallwitz (1994): Panicoideae; Panicodae; Paniceae. Soreng et al. (2015): Panicoideae; Panicodae; Paspaleae; Paspalinae. 3 species.
Distribution, phytogeography, ecology. Madagascar.
References, etc. Leaf anatomical: this project.
Special comments. Fruit data wanting.
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: 13th November 2017. delta-intkey.com/grass’.