Ranunculus repens L. - Creeping Buttercup, Creeping Crowfoot
Systematic position.Family: Ranunculaceae, genus: Ranunculus L.
Biological group.Perennial weed.
Morphology and biology.Weed is 10(15)-30(50) cm tall. Stalks are ascending, hollow, glabrous, less often hairy and growing from shortened rhizome. There are also long above-ground creeping shoots rooting at nodes. Leaves located on long petioles (except for the uppermost ones), usually glabrous, less often hairy. Leaves trilobate; median lobe located on long petiole, lateral lobes on short ones. Lobes of the first order deeply trisected or tripartite, forming obovoid serrated lobes of the second order. Pedicles short, striated. Flowers are 1.5-2.5 cm in diameter. Sepals are not adjacent to petals, glabrous, twice shorter than petals; the latter are glossy, golden-yellow. Receptacle is sparsely haired. Fruits are rounded-ovoid, flattened laterally, bordered, with punctuated surface and almost straight long rostellum. It blossoms from May until August. Produces fruit from June through September. Propagates itself by seeds and vegetatively. One plant produces as many as 350 nutlets.
Distribution.This species is distributed throughout the entire European part of Russia and CIS countries except for the Far North, the Caucasus, Western and Eastern Siberia, the Far East. General distribution includes Western Europe, Anterior Asia; adventive in Northern America.
Ecology.Inhabits damp meadows and pastures, lowland grassy bogs, banks of rivers and lakes, fallows and abandoned lands, damp garbage places that are rich in nitrogen.
Economic significance.It is a ruderal-segetal weed. Strongly litters fields of agricultural crops with over-moistened soil (winter and summer grain cereals, tilled crops, perennial grasses). Control measures include autumn treatments of soil with the use of stubbling by disk hoeing plough to depths of 10-12 cm; deep plowing of topsoil after the weed sprouts. In spring the treatments include re-plowing with simultaneous harrowing or disking. With late harvesting only the stubbling is used in autumn, and plowing in spring.
Reference citations:Nikitin V.V. 1983. Weeds in the flora of the USSR. Leningrad: Nauka. 454 p. (In Russian)
Shishkin, B.K., ed. 1957. Flora of the Leningrad Region. V. 2. Leningrad: Leningrad University. 240 p. (In Russian)
Ulyanova T.N. 1998. Weeds in the flora of Russia and other CIS states. St. Petersburg: VIR. 344 p. (In Russian)