B. Papp szerk.: Studia Botanica Hungarica 39. 2008 (Budapest, 2008)

Erzberger, P.; Schröder, W.: The genus Schistidium (Grimmiaceae, Musci) in Hungary

20a Plants green, olive or brownish, rarely black, in loose tufts or decumbent; hair-point often > 0.2 mm, slightly flattened at base and often decurrent; exothecial cells not forming an irregular pattern, stomata usually few (0-6) S. crassipilum (calcareous rocks, often on concrete) 20b Plants usually black, glossy, in compact cushions; hair-point absent or short (up to 0.2 mm), coarse and coarsely spinulose with short and broad, patent to squarrose spinulae, terete, not decurrent; exothecial cells forming an irregular pattern, stomata absent S. belveticum (— singarense) (calcareous rocks) FREQUENCY AND RARITY OF TAXA IN HUNGARY Fig. 34 shows the proportion of each taxon in a total of 448 sites of all Scbistidium specimens examined. The most frequent taxa are: S. crassipilum (43.5%), S. brunnescens subsp. brunnescens (16.3%), S. apocarpum ( 14.1%), S. lancifolium (7.6%), S. elegantulum (7.6%), and S. belveticum (4.0%). The other taxa are known from less than 8 sites each: S. robustum (7 sites), S. pruinosum and S. brunnescens subsp. griseum (6 sites each), S. dupretii (4 sites), S. flaccidum (3 sites), S. confertum (2 sites), S. confusum, S. papillosum and S. platyphyllum (1 site each). From a glance at the geological map of Hungary (RADÓ 1979) it is evident that, apart from large parts of the country (in the lowlands) covered by quaternary deposits and thus less inviting for colonisation by saxicoles, there is (in the mountains and hills) a high diversity in both carboniferous and siliceous rocks, i.e. potential sites for taxa of Scbistidium. Scbistidium has been recorded in 30 out of 43 bryogeographical regions in Hungary (after Boros 1968). This clearly does not reflect the true distribution, since weedy species like S. crassipilum, which colonise walls and concrete, are to be expected in all regions. Among the regions without Scbistidium records (Cserehát Hills, Putnok Hills, Karancs-Medves Mts, Fertő Hills, Vend Region, Őrség, Hetes, Göcsej, Zselic, Külsö-Somogy, Little Hungarian Plain, Nyírség, Dráva Region), there are even some siliceous mountains (Karancs-Medves Mts). They were not visited by Hungarian bryologists as frequently as the other mountain areas, since they were thought to be less interesting and poorer in species (BOROS 1968).