Received: 10.03.1999 Accepted: 20.08.1999

The genus Riccia L. (Ricciaceae) is one of the richest genera in the Turkish Liverwort Flora, with 16 species reported up to this time (1, 2). Ricciocarpos Corda is the only other Turkish genus of the family, with only one aquatic species collected from Sakarya in 1989 (3). The first Riccia species (R. bifurca Hoffm.) was recorded from Turkey in 1905 by Penther and Zederbauer (4). This was followed by R. macrocarpa Levier in 1908, reported by Schiffner (5). Two further additions were made by Bornmüller (6) in 1931 and Jovet-Ast (7) in 1957. Thus, prior to 1960, the total number of Riccia species recorded was only four. Since 1960, investigations by Jovet-Ast (8), Walther (9), Crundwell and Nyholm (10), Çetin (11) and the authors of the present study (1-3) have increased the number of species to 16 for this genus