Interrelations between segetal and ruderal flora in the Olsztyn Lake District

Abstract

The paper presents differences and similarities between segetal and ruderal flora in the Olsztyn Lake District. The investigation was conducted in rural areas and in areas of small towns. 415 taxa of vascular plants were noted altogether in the flora examined. The segetal flora includes 259 species, and the ruderal flora - 334 ones. A comparison between species of those two florae (table l, figure l), 81 species appear in segetal habitats, and 156 in ruderal habitats. Common species, for those two comparsing florae (segetal and ruderal) were 178. The following plants were classified as frequent or common in ruderal habitats of the Olsztyn Lake District, having (under certain conditions) a significant influence on the weed infestation of cultivated fields: <i>Amaranthus retroflexus, Artemisia vulgaris, Atriplex patula, Chamomilla suaveolens, Cirsium arvense, Conyza canadensis, Descurainia sophia, Galinsoga ciliata, Galinsoga parviflora, Geranium pusillum, Lapsana communis, Melandrium album, Poa annua, Polygonum aviculare, Rumex crispus, Sisymbrium officinale, Sonchus arvensis, Sonchus asper, Sonchus oleraceus, Tussil farfara</i>.