A new calcicolous crop-weed association from Northern France: the Papaverohybridi, Fumarietum densiflorae

The author presents a new crop weed association growing on limy sails in no rthern France. This association is characterized by Fumaria densiflora and Papaver hybridum; these weed taxa are very little quoted in phytosociologic al reports and are particularly developped in northern France. This syntaxo n belonging to Stellarietea mediae comes between Kickxietum spuriae Krus. & Vlieg.-type syntaxa, described fram northern Europe, and Adonidetum-type s yntaxa (Caucalido - Adonidetum flammeae Tx. and Adonido - Iberidetum amarae (All.) Tx.) from southern- or easternmore areas. Parallel variations have been brought to the fare between sub-associations presented here and those of Kickxietum spuriae Krus. & Vlieg.