A Móra Ferenc Múzeum Évkönyve, 1968. (Szeged, 1968)

Gallé, László: The xerothermic lichen species cladonia magyarica VAIN

In connection with the investigation of the chemical and morphological character the lichen, T. AHTI (1966:388) is writing as follows: „This species contains atranorin besides fumarprotocetraric acid, but morphologically it closely resembles C. pyxidata and CI. pocillum. Its status has been in doubt but after a thorough analysis PISŰT (1961) came to the conclusion that it is an independent species rather than, for instance, a chemical strain of CI. pyxidata. The writer accepts this opinion, admitting that some specimens are difficult to distinguish from CI. pyxidata on a morphological basis alone." Ecological conditions Cladonia magyarica prefers the depressions of sand surfaces where the soil is relatively the wettest even it the period of a great aridity. As a result of a prolonged drought and heat in Spring and Summer and of warm winds, the lichen thalluses are withering, becoming fragile. They break to pieces under the steps of animals and people, are pulverized. The temperature maxima fall on the months July—August. These maxima are in the habitats of Cladonia magyarica — according to the generally corresponding data of several researchers - as follows: Year Area Temperature Exposition Name of researcher 1934 Szeged

—Szatymaz 55—60° С S L. BAKONYI 1937 Nagykőrös, sandhill „Strázsadomb" 55° С on the surface of soil Z. HARGITAI 1961 Csengéié wood 62—66° С » L. GALLÉ 1961 Csengéié wood 62—62° below a sand layer of 1 mm L. GALLÉ 1965 Ásotthalom, „Emlékerdő" wood 56° С S. E. L. GALLÉ Cladonia magyarica tolerates well, besides a high temperature, also the strong fall in temperature in winter characterizing the lowland conditions of the Hungarian steppe. The long and cold winters were often weathered out by our plants in that way, as the drop in temperature reached not rarely -25, -27° C, approaching even - 30° C. The lichen thalluses have preserved below the snow, or even without being covered by any snow, their fresh green colour. Their thallus and podetialsquamae have not rolled up as they did during the summer heat. To be sure, they have stiffened from the frost; thit stiffness, however, has not increased their fragility. On the thallus squamae and podetia we have not observed any demages or fissures caused by frost. The tolerance of this high temperature interval, corresponding to 80-90° C, is due first of all to the fact that in the lichen thallus there are not formed real tissues, as yet, and the hypha network, on the other hand, is assuring an exaltion. In the apothecia the asci and in those the spores are defended by 249