Cenchus

Cenchrus is a genus of herbaceous plants belonging to the Poaceae family. It is native to temperate and tropical regions of the globe.

Description

They are annual or perennial plants, cespitose or rhizomatous; polygamous plants. Ligule a ciliolate membrane; blades linear, flattened. Inflorescence a zigzag terminal spike of bristly spiny or more or less straight cypsels of bristly fascicles disjointed as a unit; spines and bristles cylindrical or flattened, usually retrorsously scabrous, sometimes antrorsously scabrous; ruffled cypsels and fascicles with 1–7 permanently retained spikelets, spikelets almost completely hidden in ruffled cypsels or visible on fascicles; spikelets compressed dorsally, with 2 florets; membranaceous glumes, the lower one short, the upper one more than 1/2 the length of the spikelet; lower lemma as long as spikelet or shorter; lower floret sterile or staminate, upper floret rigid; lodicules absent or 2; anthers 3; styles 1 or 2. Fruit a caryopsis; embryo 1/3–9/10 the length of the caryopsis; dotted or elliptical thread.

Economic importance

These are weed species: C. biflorus, C. brownii, C. ciliaris, C. echinatus, C. incertus, C. longispinus, C. myosuroides, C. pauciflorus, C. tribuloides. Cultivated forages: C. ciliaris (drought resistant, tolerant of intensive grazing), C. setiger. Important native grass species: C. biflorus, C. ciliaris, C. pennisetiformis, C. setigerus.

Taxonomy

The genus was described by Carlos Linnaeus and published in Species Plantarum 2: 1049. 1753. The type species is: Cenchrus echinatus L.

Etymology

The name of the genus derives from the Greek kegchros (millet, Panicum miliaceum).

Cytology

The basic chromosome number of the genus is x = 9 and 12, with somatic chromosome numbers of 2n = 34, 35, 36, 40, 44, 45 and 68, since there are diploid species and a polyploid series. Relatively "small" chromosomes.

Species

• Cenchrus agrimonioides Trin. (1826)
• Cenchrus biflorus Roxb. (1820)
• Cenchrus brownii Roem. & Schult. (1817)
• Cenchrus caliculatus Cav. (1799)
• Cenchrus ciliaris L. (1771)
• Cenchrus distichophyllus Griseb. (1866)
• Cenchrus echinatus L. (1753)
• Cenchrus elymoides F.Muell. (1873)
• Cenchrus gracillimus Nash (1895)
• Cenchrus incertus M.A.Curtis (1837)
• Cenchrus longispinus (Hack.) Fernald (1943)
• Cenchrus mitis Andersson (1864)
• Cenchrus multiflorus J.Presl (1830)
• Cenchrus myosuroides Kunth (1816)
• Cenchrus palmeri Vasey (1889)
• Cenchrus pennisetiformis Steud. (1854)
• Cenchrus pilosus Kunth (1816)
• Cenchrus platyacanthus Andersson (1854)
• Cenchrus prieurii (Kunth) Maire (1931)
• Cenchrus robustus R.D.Webster (1987)
• Cenchrus setiger Vahl (1806)
• Cenchrus somalensis Clayton (1977)
• Cenchrus spinifex Cav. (1799)
• Cenchrus tribuloids L. (1753)