Weeds
Carduus uncinatus Bieb. - Uncinate Thistle.
Systematic position.
Family Asteraceae, genus Carduus L.Biological group.
Biennial weed.Morphology and biology.
The plant has rather long and rigid thorns, 30-60 cm in height. Stalk straight, sometimes branchy, costate-striated, arachnoid-pubescent, narrow-winged; wings irregular, strongly barbed along margin. Leaves arachnoid from above, felted from below; lower leaves situated on winged petioles, 4-12 (25) cm in length, widely pinnatilobate with triangular lobes; middle and top leaves oblong or linear, weakly sinuate, with short and point thorns. Flower pedicles pannose-felted, irregularly winged, rarely (under calathidia) wingless. Calathidium single, large, 3-5 cm in diameter, almost spherical, gray-green, with arachnoid-pannose involucre. Involucral leaflets rigid, bent downward; outer ones much shorter than the rest. Corolla dark pink or orange-pink. Pappus is formed of white hairs, shorter than corolla. Hemicarps 2-2.5 mm in length, gray-olive, weakly costate, with thin longitudinal and transversal lines and with indistinct tubercle. Blossoming and fructification May until August.Distribution.
Middle Europe, Asia Minor. In the territory of the former USSR, the plant is found in the European part, Crimea, Caucasus, and Central Asia.Ecology.
Plants grow on hills, dry slopes, chalk deposits, along boundaries, roads, irrigation ditches and channels, being a weed in fields.Economic significance.
The weed meets in grain, oil-yielding, and grass crops. Control measures include stubbling, autumn plowing, use of bare fallows, soil treatment and sowing without gaps, destruction of the weed in uncultivated places, herbicide treatments if necessary.Reference citations:
Keller B.A., ed. 1934. Weed plants of the USSR. V. 1. Leningrad: AN SSSR. 324 p. (in Russian).Keller B.A., ed. 1935. Weed plants of the USSR. V. 4. Moscow & Leningrad: AN SSSR. 416 p. (in Russian).
Maevskii P.F. 1954. Flora of middle belt of the European part of the USSR. Moscow & Leningrad: Selkhozgiz. 912 p. (in Russian).
Vasilchenko I.T. & Pidotti O.A. 1975. Keys to weed plants of areas of irrigated agriculture. Leningrad: Kolos. 375 p. (in Russian).