Zs. P. Komáromy szerk.: Studia Botanica Hungarica 12. 1977 (Budapest, 1977)
Radics, Ferenc: The identification of Rorippa species and hybrids (Cruciferae) based on external morphological features of their seeds
repens BORB. (R. amphibia x silvestris), R, prostrata (BERG. ) SCHINZ and THELL (R. amphibia x islandica ? ). In the same book, he mentioned also 10 further hybrids, occurring sporadically or to be recognized with difficulty, e. g. R. neogradensis BORB. (R. islandica x austriaca), R. menyhártiana BORB. (R. islandica x silvestris), R. küllődensis PROD. (R. kerneri x amphibia). Recently SOO (1968) discriminated in his synopsis altogether 112 taxa due regard to the territory of present-day Hungary, taking into account the above systématisations and with the results of researches from abroad. He begins the description of the Rorippa genus with the following words: "This genus is the most difficult one among the Cruciferaet it is a complex of species, hybridogen stabilized species, transition forms and hybrids of species. Origin and value of various taxa can be cleared up later only, by genetic examinations and analyses of population. " (1. c. 359). SOO described four basic species in detail: R islandica (palustris resp. JONSELL 1968), R. austriaca , R. amphibia and R. silvestris ; and one subspecies: R. silvestris ssp. kerneri and three hybrids: Rorippa x prostrata (BERG. 1786 sub Myagro) SCH. et TH. 1913; Rorippa x astylis (RCHB. 1932 sub Nasturtio) RCHB. 1838 = syn. R. barbaraeoides (TAUSCH 1840 sub Nasturtio) CE LAK, 1874 and R. armoracioides TAUSCH (1840 sub Nasturtio) FUSS 1866. The second hybrid has 3 subspecies: R x astylis ssp. astylis (barbaraeoides var. astyla typica NYAR 1955), R. x astylis ssp. reichenbachii (KNAF in OPIZ 1852 sub Nasturtio) SOÓ 1966 and R. x astylis ssp. capillipes (BORB. 1379 p. sp. ) SOO 1966. As to this latter, he says that it is -the hybrid R. austriaca x silvestris (1. c. 365). Two subspecies belong to the third hybrid: R. x armoracioides (var. pinnatifidum TAUSCH) and R. x armoracioides ssp. terrestris (TAUSCH 1840 sub Nasturtio p. sp. ) JAV, 1924. According to SOO, R. x prostrata is probably a stabilized hybrid of R. silvestris and R. amphibia . R. astylis is originated from R. islandica x R. silvestris . and R. x armoracioides from R. austriaca and R, silvestris As to this latter hybrid, he refers to FRÖHLICH (1914). Further on, he enumerates 9 hybrids saying that the origin of hybrids is "partly dubious". Moreover, he enumerates 8 hybrids (I.e. 367). Lately, a revision made by TOMSOVIC ( 1969) stated the occurrence of 5 basic species in the territory of present-day Czechoslovakia, thus partly in the Carpathian Basin: R. amphibia , R. palustris , R. austriaca , R. silvestris and R. pyrenaica , further 3 hybrids: R. x hungari ca BORB. 1877 (R. amphibia x austriaca), R. x barbaraeoides (TAUSCH) (5ELAK. 1874 (= R. amphibia x silvestris) and the R. x armoracioides (TAUSCH) FUSS 1866 (= R. austriaca x silvestris). He also inserted H. x prostrata (BERG. ) SCH. et TH. into the sphere of R. x barbaraeoides (TAUSCH) £ELAK and R. terrestris <5ELAK, into that of R. x armoracioides . Formerly, BORBAS (1878) thought that the taxon
