The genus Cochlearia L. (Brassicaceae) in the Eastern Carpathians and adjacent area

Abstract

Most European scurvy grasses (including those of the Carpathian Mountains) belong to the nominate section Cochlearia. We analyse the status of two East Carpathian (Romanian) Cochlearia populations by comparing them with the two native species from the Western Carpathians, the diploid Cochlearia pyrenaica (2n = 2x = 12; 2C = 0.78 pg) and hexaploid C. tatrae (2n = 6x = 42; 2C = 2.09 pg). Using karyological methods and flow cytometry, differences between these taxa were detected. Because of differences in morphology, chromosome number (2n = 8x = 48) and DNA content (2C = 2.82 pg), we propose that the East Carpathian (Romanian) populations represent a separate species, Cochlearia borzaeana (Coman et Nyár.) Pobed. The lectotype of C. borzeana is designated. The new subassociation Carici flavae–Cratoneuretum Kovács et Felföldy 1958 cochlearietosum borzeanae is described. An isolated population of C. pyrenaica s.l. from Ukraine (outwith the Carpathian territory) (2n = 2x = 12; 2C = 0.91 pg) has been also studied, because of its unclear taxonomic position. The diploid chromosome number, 2n = 2x = 12, is given for this single known population of C. pyrenaica s.l. in Ukraine. However, there is considerable difference in genome size and chromosome size between West Carpathian C. pyrenaica s.s. and Ukrainian plants, and taxonomic evaluation of the latter population needs further study. A comparative table with morphological characteristics and a short description of the phytosociological behaviour of C. borzaeana in Romania and taxa from the Western Carpathians are included.