The grass genera of the world
Habit, vegetative morphology. Perennial; rhizomatous. Culms 140–300 cm high; herbaceous; to 2.5 cm in diameter; unbranched above. Culm internodes solid (spongy). Leaves not basally aggregated (3–5 laminate leaves per culm, with several bladeless sheaths at the base); without auricular setae. Leaf blades lanceolate; broad; 35–105 mm wide (22–112 cm long); sagittate; flat; pseudopetiolate (the petiole 16–100 cm long); pinnately veined; cross veined; with a conspicuous articulation at the base. Ligule present; an unfringed membrane; not truncate; 35–80 mm long.
Reproductive organization. Plants probably bisexual, all with bisexual spikelets (but known only from material with smutted, imperfect spikelets - i.e., as yet inadequately described); probably with hermaphrodite florets.
Inflorescence. Inflorescence paniculate; open (much branched, up to 35 cm long, the lower branches often in verticils); espatheate; not comprising partial inflorescences and foliar organs. Spikelet-bearing axes persistent (apparently). Spikelets not secund; pedicellate.
Female-fertile spikelets. Spikelets 3.5–4.3 mm long; ovate. Rachilla terminated by a female-fertile floret (seemingly).
Glumes two; long relative to the adjacent lemmas; pointed; awnless; similar. Lower glume 5–7 nerved. Upper glume 7–9 nerved. Spikelets without proximal incomplete florets (seemingly).
Female-fertile florets 1 (seemingly). Lemmas entire; pointed; awnless; 3 nerved.
Abaxial leaf blade epidermis. Costal/intercostal zonation conspicuous. Papillae absent. Mid-intercostal long-cells rectangular; having markedly sinuous walls. Microhairs present; panicoid-type. Stomata common. Subsidiaries seemingly dome-shaped and triangular. Intercostal short-cells common; not paired (seemingly solitary). Costal short-cells conspicuously in long rows. Costal silica bodies panicoid-type; not sharp-pointed.
Transverse section of leaf blade, physiology. C3; XyMS+. Mesophyll with non-radiate chlorenchyma; without arm cells; with fusoids. The fusoids external to the PBS. Leaf blade adaxially flat. Midrib conspicuous (very much so, with large air spaces); having complex vascularization. Bulliforms present in discrete, regular adaxial groups. All the vascular bundles accompanied by sclerenchyma. Combined sclerenchyma girders present. Sclerenchyma all associated with vascular bundles.
Classification. Watson & Dallwitz (1994): Bambusoideae; Oryzodae; Phareae. Soreng et al. (2015): Oryzoideae; Phyllorachideae (?). 1 species (S. sagittifolia).
Distribution, phytogeography, ecology. Sudan.
Hydrophytic to helophytic.
References, etc. Morphological/taxonomic: Renvioze 1984.
Special comments. Morphological description very incomplete. 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: 11th December 2017. delta-intkey.com/grass’.