Weeds

Cynodon dactylon (L.)Pers - Bermuda Grass

Systematic position.

Family Poaceae, genus Cynodon Rich.

Biological group.

It is a rhizome perennial weed.

Morphology and biology.

It is a rhizome perennial plant. Stalks are 10-50 cm tall, ascending, branchy. Rhizome with long branching soboles located in ground at depth of 20 cm. Their length reaches 2-3 m and they have a thickness of 8-10 mm. Leaves are linear lanceolate, rigid, 7-10 cm long, or soft, 10-15 cm long, glabrous or hairy, glaucescent. Ligule is short, ciliated; inflorescence consisting of 3-8 spiciform branchlets up to 7 cm long. Spikelets are sessile, ovoid-lanceolate, overlapping. Caryopsis is elliptic, 1.5 mm long, 1 mm wide, dark-red or brown, glabrous. Weight of 1000 caryopsides is 0.18 g. Each inflorescence contains 150-250 spikelets, and one plant can produce 1000-2000 grains with significant bushiness. The weed propagates itself rather quickly by rhizomes, which grow extensively, forming large thickets or entirely covering significant field plots. This species is a heat-loving, luciphile, drought-resistant plant. It is a drought-resistant plant due to additional roots that are formed on nodes of rhizome, reaching depths of 2 m. Blossoms and fructifies in June-September.

Distribution.

This plant grows in southern areas of the European part of Russia, in Crimea, the Northern Caucasus, and Transcaucasia, in all areas of Central Asia and south-western part of Western Siberia (Altai). In the outside limits of the former USSR it occurs in the Atlantic and Middle Europe, in the Mediterranean, Asia Minor, Iran, the Himalaya, Japan, China, Southern Asia, Northern America (the southern part), South America, Africa and Australia.

Ecology.

Occurs in deserts and in southern part of steppe zone. Usually found in sandy and clay places, and does not avoid nutrient-poor or saline soils.

Economic significance.

One of the most hardy weed plants, being hardly extirpated in irrigated agriculture. It litters fields of cotton, lucerne, vegetable cultures, fruit plantations, vineyards, plantations of subtropical cultures. It dominates on fallows and along fine irrigation ditches. Agronomical control measures are based on poor resistance of rhizomes to drying and freezing, on inhibitory influence of shading, inability of short pieces of rhizomes (less than 10-15 cm long) to grow at ground depths of 30 cm.

Reference citations:

Keller B.A., Lyubimenko V.N., Maltsev A.I., Fedtshenko B.A., Shishkin B.K., Rodzevich R.Yu., Kamenskii K.V., eds. 1934. Weed plants of the USSR. V. 1. Moscow-Leningrad: AN USSR. 324 pp. (In Russian)
Nikitin V.V. 1983. Weeds in the flora of the USSR. Leningrad: Nauka. 454 p. (In Russian)
Ulyanova T.N. 1998. Weeds in the flora of Russia and other CIS states. St. Petersburg: VIR. 344 p. (In Russian)

© Luneva N.N.

 

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