Current and historical occurrence as well as coenotic affinity and ecology of <em>Carex secalina </em>in the Czech Republic and Slovakia are presented. The study is based on revision of herbarium specimens from 25 herbaria, literature data excerption and a field survey carried out during 2004-2010. Altogether, 168 sites were documented in the Czech Republic divided to two separate areas. Stabile occurrence trend was found in last decades, because 45 localities were documented in period 1975-1999 (27% of sites) and recent occurrence was confirmed at 42 localities (24% of sites). On the basis of our current knowledge the species was included into the IUCN threat category VU (vulnerable). In Slovakia, 19 localities of the species were recorded in total, but only 4 sites were confirmed recently (21% of sites recorded). However, only a small number of individuals was recorded there (less than 50 individuals in total) and half of this sites is acutely threatened by destruction (ploughing, secondary succession). Therefore, the <em>C. secalina </em>status in the Slovak Red List was changed to the IUCN category "critically endangered" (CR). Results of the study are summarised in the maps of historical and current species distribution. <em>C. secalina </em>usually occurred in halophytic grassland communities, especially in association <em>Agrostio stoloniferae-Juncetum ranarii </em>Vicherek 1962. However, it may occur in many other communities which suggest that the species had not well-defined coenotic relationships. On the basis of our knowledge, we consider <em>C. secalina </em>as an obligate halophyte.
Contributions to the distribution and ecology of Carex hordeistichos Vill. in the Czech Republic and Slovakia
