The grass genera of the world
Including Zingeriopsis Probat.
Habit, vegetative morphology. Annual. Culms 20–50 cm high; herbaceous. Leaves non-auriculate. Leaf blades narrowly linear; narrow; 0.5–2 mm wide; flat (usually), or folded, or rolled; without cross venation. Ligule an unfringed membrane; not truncate; 1–4 mm long.
Reproductive organization. Plants bisexual, all with bisexual spikelets; with hermaphrodite florets. The spikelets all alike in sexuality.
Inflorescence. Inflorescence delicate, paniculate; open. Inflorescence with axes ending in spikelets. Inflorescence espatheate; not comprising partial inflorescences and foliar organs. Spikelet-bearing axes persistent. Spikelets not secund; pedicellate.
Female-fertile spikelets. Spikelets 1–3 mm long; slightly compressed dorsiventrally; disarticulating above the glumes. Rachilla terminated by a female-fertile floret. Hairy callus present. Callus very short.
Glumes two; relatively large; very unequal (Z. verticillata), or more or less equal; (the longer) shorter than the spikelets to about equalling the spikelets; long relative to the adjacent lemmas; hairless; glabrous; pointed (acute); awnless; non-carinate; similar (ovate, membranous). Lower glume 1 nerved. Upper glume 3 nerved. Spikelets with female-fertile florets only.
Female-fertile florets 1. Lemmas decidedly firmer than the glumes; not becoming indurated (papery in fruit); entire; blunt; awnless; hairy (with clavate hairs); non-carinate; without a germination flap; 3 nerved. Palea present (similar to the lemma); relatively long; textured like the lemma; not indurated; 2-nerved; 2-keeled. Lodicules present; 2; free; membranous; glabrous; toothed, or not toothed; not or scarcely vascularized. Stamens 3. Anthers 0.5–1.3 mm long. Ovary apically glabrous. Styles free to their bases. Stigmas 2.
Fruit, embryo and seedling. Fruit adhering to lemma and/or palea (often), or free from both lemma and palea; small (0.3–1.7 mm long); compressed dorsiventrally. Hilum short. Pericarp thick and hard; free. Embryo small.
Abaxial leaf blade epidermis. Costal/intercostal zonation conspicuous. Papillae present; costal and intercostal. Intercostal papillae over-arching the stomata (slightly, in Z. trichopoda), or not over-arching the stomata; consisting of one oblique swelling per cell (costally), or consisting of one symmetrical projection per cell (intercostally). Long-cells differing markedly in wall thickness costally and intercostally (costals thicker). Mid-intercostal long-cells rectangular, or rectangular and fusiform (Z. kochii); having straight or only gently undulating walls. Microhairs absent. Stomata common; (25–)27–30(–32) microns long. Subsidiaries low dome-shaped, or parallel-sided. Guard-cells overlapped by the interstomatals. Intercostal short-cells absent or very rare. Costal zones with short-cells. Costal short-cells neither distinctly grouped into long rows nor predominantly paired. Costal silica bodies horizontally-elongated crenate/sinuous, or horizontally-elongated smooth (a few), or rounded (very few); not sharp-pointed.
Transverse section of leaf blade, physiology. C3; XyMS+. Mesophyll without adaxial palisade. Midrib not readily distinguishable; with one bundle only. The lamina symmetrical on either side of the midrib. All the vascular bundles accompanied by sclerenchyma. Combined sclerenchyma girders present (with the largest bundles). Sclerenchyma all associated with vascular bundles.
Cytology. Chromosome base number, x = 2. 2n = 4, 8, and 12. 2 ploid (2n = 4), or 4 ploid, or 6 ploid. Chromosomes large.
Classification. Watson & Dallwitz (1994): Pooideae; Poodae; Aveneae. Soreng et al. (2015): Pooideae; Poodae; Poeae; Coleanthinae. 4 species.
Distribution, phytogeography, ecology. Southeast Russia, Western Asia.
Mesophytic; species of open habitats; glycophytic. Meadows and streamsides.
References, etc. Leaf anatomical: this project.
Illustrations. • Z. trichopoda: 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’.