engleski

New national and regional bryophyte records, 62

The species was collected in the Pannonian region of Croatia, on sandy banks in the lower course of the Garešnica River, a tributary of the Ilova, belonging tot he Sava River catchment and Black Sea Basin. At the site, the river has a lowland character, but the river bed is heavily regulated and recent channelisation has resulted in extremely steep banks and the complete loss of aquatic vegetation. Several tufts of Physcomitrium sphaericum were found in the narrow open zone along the river where a pioneer ephemeral dwarf- cyperaceous vegetation of periodically flooded habitats had developed on exposed sand. The plants were typically developed, about 4 mm high including seta and semiglobose capsules, displaying characteristic leaf morphology with margins entire or obscurely crenulate above, leaf apex blunt with costa ending below the apex. Physcomitrium sphaericum is an ephemeral species of rare and sporadic occurrence, dependant on seasonally exposed mud on the margins of rivers, ponds, lakes and reservoirs It belongs in the vegetation class Isoëto- Nanojuncetea Br.-Bl. et Tx. in Br.-Bl. et al. Physcomitrium sphaericum was found along with other typical species of this vegetation type: Cyperus michelianus (L.) Link, C. fuscus L., C. glomeratus L., Gnaphalium uliginosum L., Gypsophila muralis L., Lindernia dubia (L.) Pennell, L. procumbens (Krock.) Philcox, Ludwigia palustris (L.) Elliott and a terrestrial form of Riccia fluitans L. Physcomitrium sphaericum is a Eurasian Temperate element, distributed throughout Europe, but rarely found in Southeastern Europe, where it has been reported only from Romania, Bosnia and Herzegovina and Serbia, being considered Vulnerable in the latter. Our record is the first for Croatia.

Croatia, ephemeral bryophytes, Isoëto-Nanojuncetea, Physcomitrium sphaericum, river margin, Garešnica River

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