A floristic inventory of segetal flora was carried out in abandoned fields and adjacent crop fields on rendzina soils in the Zamość region in the year 2010. This study found a total of 130 weed species belonging to 30 botanical families. The following families were represented most frequently: Asteraceae, Fabaceae, Poaceae, Lamiaceae, Scrophulariaceae, and Brassicaceae. In the segetal flora, apophytes are dominant (55% of the total flora), with the highest number of meadow and xerothermic grassland species among them. Archeophytes (38%) predominate in the group of anthropophytes. The species characterized by the highest constancy classes and reaching the highest cover indices posed the greatest threat to crops in the study area. The following weeds are most frequently found in fallow fields: <em>Consolida regalis</em>, <em>Cichorium intybus</em>, and <em>Sinapis arvensis</em>, while <em>Papaver rhoeas</em> is the greatest threat to cereal crops grown on rendzina soils.

A b s t r a c tFloristic research on segetal communities was carried out in 2000 on arable fields in the Skierbieszów Landscape Park and its protected zone. Three communities of segetal weeds in cereal crops, and two communities of segetal weeds in root crops were separated in the arable fields of the Skierbieszów Landscape Park. The community Vicietum tetraspermae typicum commonly occurred in cereal crops on brown soils developed from loess soils. The community Echinochloo-Setarietum, which belongs to root crops, was noted in the same habitat. The greatest richness of species was found in Consolido-Brometum and Lamio Veronicetum politae, with the average of 25 species in one record. Both communities were abundant in rare segetal species which are considered to be endangered in our country: Adonis aestivalis, Euphorbia exigua, Lathyrus tuberosus, Muscari comosum, Thlaspi perfoliatum, Veronica polita, Agrostemma githago.

<p>The study presents the results of a floristic survey conducted using the Braun-Blanquet method (50 phytosociological relevés) in permanent grasslands in three river valleys of the Zamość region (Por, Huczwa, Wieprz). The goal of the survey was to determine the floristic diversity and fodder value of the <em>Phalaridetum arundinaceae</em> association (Koch 1926 n.n.) Lib. 1931. </p><p>A total of 93 plant species from 25 botanical families were identified in the areas under study. The species richness of the <em>Phalaridetum arundinaceae</em> differed among river valleys. It was observed that these are often transitional forms similar to the association of the <em>Molinio-Arrhenatheretea</em> class, <em>Molinietalia</em> order. Predominance of hemicryptophytes and a relatively large share of geophytes was recorded. Based on the fodder value score calculated for the dry matter of the association, the community under study can be classified as having a medium or poor nutritional value.</p>