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
The identification of Rorippa species and hybrids (Cruciferae) based on external morphological features of their seeds Ferenc RADICS Botanical Department of the Hungarian Natural History Museum, Budapest F. Radies: The identification of Rorippa species and hybrids (Cruciferae) based on external morphological features of their seeds. - Studia Bot. Hung. 12:55-70, 1977. ABSTRACT: Author's extensive comparative examinations made it possible to separate the basic forms of Rorippa species and hybrids on the basis of the shape and size of the seed and hilum, and colour and pattern of testai surface. A reliable identification of most Rorippa hybrids is not yet cleared up to now, moreover too much number of sub-taxa of their species has also been recently discriminated morphologically. The first scientist engaged in the study of Rorippas of the Carpathian Basin givin a detailed and comprehensive summary of each, was BORBAS (1878, 1879a). He described some 60 species, varieties, forms or hybrids together with a precise morphological description and analysis of many specimen. The majority of these specimens were collected by himself. In several cases he compared them with specimens received from abroad. Occasionally, he did not hesitate to express his doubts regarding the correctness of his statements. The principles of his identification key were the following: occurrence on dry ground (Xerobiae Boiss. Fl. Orient. ); in water or at water side (Helobiae); this later is divided into two subgroup presence of big flowers (Macranthae: floribus calice evidenter maioribus), or of Small flowers (Micranthae); finally, in the former group: shape of pods (Siliculosae ellipsoideae, sphaerocarpae, subsiliquosae, Eusiliquosae). On the other hand, when going into details, he also emphasized that the various Rorippa specimens, originating from the same parents, frequently differ from each other substantially, when they occur either on different or at the same places (BORBAS 1879a: 13). This phenomenon can be attributed, according to him, to the fact, that "the number of Rorippa species is rather small, their reproductive and vegetative organs do not show great differences from each other. Perhaps this is the very reason why the Rorippa s within the group of Cruciferae otherwise so obstinate against hybridization, show a striking disposition to interbreeding. "BORBAS found also many Rorippa hybrids whose probable parents did not occur at all on that place, but were characteristic for the region concerned: e. g. Rorippa kerneri MENYH. (near Budapest, Rákosmező) Rorippa armoracioides TAUSCH (near Nagyvárad, Transylvania), Rorippa terrestris var. pinnatifida TAUSCH (Ipolylitke) and Rorippa barbaraeoides var. subsiliquosa
