Boros István (szerk.): A Magyar Természettudományi Múzeum évkönyve 8. (Budapest 1957)

Baksay, L.: The chromosome numbers and cytotaxonomical relations of some European plant species

no secundary associations, irregularities or polyvalents could be observed. We succeeded to observe a sexual chromosome in the first metaphase. The chromosome numbers of but a few Mercurialis species are known. The members of the x = 8 basic number series are : 16, 32, 48, 64. Of these, AL annua 2x is a weed of Mediterranean origin, the 4x and 8x species are the above mentioned ones, M. leiocarpa 6 x is perennial, ranging in SE Asia. AL perennis, a species with the basic number x = 21 (?), is genetically further away from M. ovata; the cytological examination of still more species of the genus could explain the origin of this basic number. The range of M. longistipes is (according to the data of M e u r m a n) in Northern and Central Europe, in the Balkans, at least in its Northern part. In M. longistipes, the margin of the leaf is finely crenate, its stalk shorter than 1 cm, never adnate as in ovata. Regarding its habitus, it stands between M. ovata and AL perennis, and this misleading circumstance is heightened also by the sexual dimorphism. In the case of all three species, the leafes of the pistillate specimens are a broader oval, those of the staminate specimens are more narrow and longer, to which morphological changes in leaf shape are further contributed by oecological circumstances (e. g. sunshine, shadows) of the locality. M. longistipes is similar to M. ovata in its oecological behaviour, it occurs in calcareophilous lanuginous-oak forests and hornbeam-oaklands, in Carex alba beech forests, on rocky places ; but in beech forests only M. perennis thrives. S a x e r regards this latter as a species of very high adaptability, and this view is due to the fact that, in reality, we are dealing with two species, genetically different and also diverging in their oecological claims. There is no M. perennis in the Pulsatilla steppe-forest mentioned by him, but AL longistipes. During mitosis examinations of M. perennis, we have once counted 2n = 84 chromosomes. Author wishes to treat the species detailedly in another paper. 9. ! Onsoma tornensis Jáv. 2n = 14 (2 x). The seeds came, by way of the botanical garden of Kosice (Czechoslovakia), from the Várhegy of Torna. An endemic plant of the Torna-karst. 0. arenaria has 2n = 12. m % g& 10. Hesperis matronalis ssp. Vrabélyiana (Schur.) Soó. 2n = 24 (2 x). Tarkő, Mts. Bükk, Fagetum. An endemic subspecies, the nominate species having chromosome numbers 24 and 28. 11. Arabis alpina L. 2a — 16 (2 x). Gerennavár, Ablakoskö valley, Mts. Bükk, Acereto-Fraxinetum association. Arabis alpina f. glabrescens Borb. 2n = 16, the Szádelő valley, from the Slovakian Karst. Also a tetraploid variation is known from Europe. Its glacial relict character in the Carpathian Basin is supported also by its chromosome number. 12. Arabis hirsuta (L.) Scop. 2n = 16 (2 x). Szarvashegy, Budapest, Fageto-Ornetum association fragment. Rich in forms, a polyploid serial conspe-