The grass genera of the world
Habit, vegetative morphology. Annual; caespitose. Culms 15–30 cm high; herbaceous; unbranched above. Culm nodes glabrous. Leaves not basally aggregated; auriculate. Leaf blades linear (acuminate); narrow; to 3 mm wide; flat; without cross venation; persistent. Ligule an unfringed membrane.
Reproductive organization. Plants bisexual, all with bisexual spikelets; with hermaphrodite florets. The spikelets all alike in sexuality.
Inflorescence. Inflorescence a false spike, with spikelets on contracted axes (the clusters each reduced to two spikelets). Rachides flattened. Inflorescence espatheate; not comprising partial inflorescences and foliar organs. Spikelet-bearing axes disarticulating; disarticulating at the joints. Spikelets paired; not secund; the pairs alternately distichous.
Female-fertile spikelets. Spikelets about 15 mm long; compressed laterally; falling with the glumes (and with the joint). Rachilla prolonged beyond the uppermost female-fertile floret; hairy; the rachilla extension with incomplete florets.
Glumes two; more or less equal; long relative to the adjacent lemmas; subulate; awned; non-carinate; similar (leathery, narrow, awn-like above). Lower glume 3 nerved. Upper glume 3 nerved. Spikelets with incomplete florets. The incomplete florets distal to the female-fertile florets. The distal incomplete florets 1; merely underdeveloped.
Female-fertile florets 1. Lemmas attenuate into the awn; similar in texture to the glumes (and similar to them in form); not becoming indurated; entire; pointed; awned. Awns 1; median; apical; non-geniculate; hairless (scabrid); about as long as the body of the lemma to much longer than the body of the lemma (4–7 mm long, erect); entered by several veins. Lemmas hairy, or hairless; non-carinate; 5 nerved. Palea present; relatively long; awnless, without apical setae; 2-nerved; 2-keeled. Lodicules present; 2; free; membranous; ciliate; toothed, or not toothed. Stamens 3. Anthers not penicillate. Ovary apically hairy. Styles free to their bases. Stigmas 2; white.
Fruit, embryo and seedling. Fruit adhering to lemma and/or palea; medium sized; longitudinally grooved; compressed dorsiventrally; with hairs confined to a terminal tuft. Hilum long-linear. Embryo small.
Cytology. Chromosome base number, x = 7. 2n = 14. 2 ploid. Haplomic genome content K.
Classification. Watson & Dallwitz (1994): Pooideae; Triticodae; Triticeae. Soreng et al. (2015): Pooideae; Triticodae; Triticeae; Hordeinae. 1 species.
Distribution, phytogeography, ecology. North Africa & the Orient.
Xerophytic; species of open habitats. In dry grassland.
References, etc. Morphological/taxonomic: Löve 1984.
Special comments. Anatomical data wanting. Illustrations. • C. delileana: Fl. Iraq, 1968
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’.