THE GENUS SCHISTIDIUM (GRIMMIACEAE, MUSCI) IN HUNGARY ...

THE GENUS SCHISTIDIUM IN HUNGARY 81
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)
(calcareous rocks, often on concrete)
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
(= 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
Schistidium 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. helveticum (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 Schistidium.
Schistidium 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
Schistidium records (Cserehát Hills, Putnok Hills, Karancs–Medves Mts,
Fertõ Hills, Vend Region, Õrség, Hetés, Göcsej, Zselic, Külsõ-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).
Studia bot. hung. 39, 2008