Zs. P. Komáromy szerk.: Studia Botanica Hungarica 15. 1981 (Budapest, 1981)

Szujkó-Lacza, Júlia: Distribution and diversity of three Astragalus taxa (Leguminosae)

and they can always grow in different steppe communities (cf. SZUJKO-LACZA I.e.). Astragalus dasyanthus is more extended and the different populations of this species grow in different communities from the margin of oak-forestB to the steppe. Comparing the areas of Astragalus exscapus (Albania, Austria, Bulgaria, Czechoslovakia, Germany, Greece, Switzerland, Spain, Hungary, Italy, Rumania, cf. CHATER 1968) and A. dasy anthus (S.E. Europe extending northwards to Hungary to C.53 in C. Russia, Bulgaria, Hungary, Yugoslavia, Rumania Rs). (C,W,E) (c.f. CHATER I.e.) with the localities of the two species in the Carpathian Basin and in the Great Hungarian Plain we can come to the conclusion that there is an spatial "overlap" in these territories. Geographically, the eastern border of the area of A. ex scapus and the western one of A. dasyanthus is in Hungary (except only some locality of both species in Rumania and Czechoslovakia respectively see Map 1) . A

. dasyanthus has only one loci in Czechoslovakia at Urminu (Ürmény) (Com. Nitra) (cf. DOSTAL 1950) near the Hungarian localities. The overlap exist between the two species areas only in two localities. One of these is in outskirts of Budapest s.l. and the other Is in Deliblat, between the rivers Duna and Tisza. In Hungary A

. dasyanthus prefer hills, except the localities between the rivers Duna and Tisza (see Map 1). In Deliblat both species grow on lowland on calcifilous sandy soil. Probably (similarly to the numerous other continental and East- and West-Illirlan species) the Deliblat or beside it the hills were that of the territories introducing the A. exscapus and A. dasyanthus from the opposite direction towards the Great Hungarian Plain. (Both species are absent in the Transdanubia; see Map 1). Taking into consideration the areas of the two species generally and concretely in Hungary, A. exscapus is a Mediterranean-Alp-Balkan-Pannonian or South- and Central EuropeanBalkan-Pannoni an species and A. dasyanthus is a continental East-Illirian-Pannonian one. The number of localities of the three taxa is decreasing rapidly in consequence of increase of cities, towns, villages but also due to the intensivities of agriculture. (Where the A. dasyanthus occurs the soil is rich In humus, and it is suitable for afforestation

. in the Great Hungarian Plain and for agriculture, too c.f. MAGYAR 1933, 1961.) A. exscapus and A. exscapus var. caulifer disappear from the sandy soil around Budapest though numerous herbarium sheets were collected from "Óbuda", "Rákos", "Soroksár", etc.. They occur in Astrogalo-Festucetum ruplcolae danubiale assotiation at Dunavarsány "Varsány hegy" approximately 30 km south of Budapest which is probable the nearest locality around the capital of Hungary today. (Probably both species grow in Buda hills e.g. "Zugliget", "Disznófő" up to the present.) In the BP there are 78 sheets of A. exscapus and 51 sheets of A. exscapus var. caulifer, and there are numerous in Czechoslovakia, too. The number of the sheets of A. dasyanthus is 74 all together but numerous sheets were collected from the same localities, or some of them did not contain any information of the type of 'soil where one or another Astragalus species grow. Therefore, Table 1 contains fewer numbers of localities than the number of herbarium sheets refering to the species respectively. Table 1. Distribution of specimens of the three Astragalus taxa according to soil types Type of soil/^ Name Calcifilous sand Acidifilous Calc. rocks Loess Andesitic Basaltic Clay Saline A

.exscapus A.exscapus var. caulifer A.dasyanthus 28 20 6 1 2 3 1 2 1 1 3 2 1 3 1 3 A. exscapus N = 35 S = 5 H' = 1.1119 J = 0.4788 A. e.var.c. N = 25 S = 4 H' = 0.9961 J = 0.4980 A. dasyanthus N = 18 S = 7 H' = 2.5157 J = 0.8961