„Flax specialists”-weed species extinct in Poland?

„Flax specialists”-weed species extinct in Poland? The results of a research on segetal weed communities in fibre flax in Poland are presented, with respect to different regions of cultivation, and changes in the level of infestation during the past forty years. Observations on composition and abundance of weed infestations were made in fields in six experimental farms at the Institute of Natural Fibres and Medicinal Plants. The observations conducted in the period 1967-2008 did not show the occurrence of weed species from the group of so-called "flax specialists": Lolium remotum Schrank, Spergula arvensis L. subsp. maxima (Weiche) O. Schwarz, Camelina alyssum (Mill.) Thell. and Cuscuta epilinum Weihe Ex Boenn. In Poland, weed populations in fibre flax consist of species typical for cereals and root crops: Chenopodium album L., Polygonum convolvulus L., Viola arvensis Murr., Stellaria media Vill., Lamium amplexicaule L., Thlaspi arvense L., Elymus repens (L.) Gould, and Polygonum nodosum Pers.