Weeds

Anthemis arvensis L. - Corn chamomile

Taxonomy:

Family Asteraceae Dumort., Genus Anthemis L.

Biology type:

Spring or winter annual

Morphology and biology:

Appressed downy, a little ash-grey plant. Stems, growing from one root, are numerous, branched, 15-30 (40) cm in length. Leaves are oblong, pinnate into narrow, linear-cuneate sharp segments. Flower stalks are elongated, incrassate, sepals of hispid involucre are ovate-oblong, outers are sharp, the rest are blunt , on the top with dry wide chaffy edges. Chaffs of oblong-conical receptacle are lanceolate, carinate, abruptly converted into firm mucro, which exceeds disk florets. Flower heads are 2-3 cm in diameter, ligules of pistillate ray-florets are elliptic, tube of disk florets is incrassate at the base. Achenes are a little tetrahedral, longitudinally grooved, glabrous, outers are plumpish, inners are with sharp short peristome on the top instead of undeveloped corona. It flowers in May-September, produces fruits in July-September. One plant produces 4500 achenes.

Geographical range:

European part of Russia, Caucasus, Western and Eastern Sibiria, Far East (adventitious plant), Central Asia, Scandinavia, Mediterranean.

Ecology:

This weed prefers dry places and relatively rich soil. Maximum depth of seed germination is 5-6 cm. Minimum temperature of seed germination is 2-3?C, maximum - 22-28?C.

Economic value:

It infests grain and tilled crops. Control measures: Skim plowing, autumn plowing, pre-sowing tilling (harrowing, cultivation), timely sowing, interrow tillage in tilling crops, maintenance of crop rotation, herbicide treatment when necessary.

Related references:

Chesalin G.A. 1975. Weeds and their control. Moscow, Kolos. 256 p.
Fisyunov A.V. 1984. Reference book on weed control. Moscow, Kolos. 255 p.
Flora of the USSR. 1961. V.26. Ed.V.L.Komarov. Moscow-Leningrad, Ac.Sc.USSR. P.35-36.

© I.N.Nadtochji