Plagiothecium undulatum
Plagiothecium undulatum (Hedw.) Schimp.
Plagiotheciaceae
Conservation status. Vulnerable [VU D2].
Morphology and biology. Perennial pleurocarpous moss forming flat, lax, green to yellow-green tufts. Shoots prostrate, simple to weakly branched, 6–15 cm long, complanate. Leaves broadly ovoid, shortly pointed, transversely undulate. Nerve short and double, or lacking. Margin entire or finely denticulate at leaf apex. Unisexual, rarely with sporophytes. Spore capsule inclined, cylindrical, curved, lid with curved rostrum.
Habitats and populations. Grows on wet soil and rocks covered with soil along streams in the beech belt and above it. The populations have restricted distribution and low density.
Distribution in Bulgaria. Balkan Range (Western – south of locality Golyamo Mochuriste, and under Kom peak; Central – near chalet Levski).
General distribution. Balkan Peninsula (Bosnia and Herzegovina, Bulgaria, Slovenia), C and W Europe, Asia Minor, Siberia, North America. Northern oceanic (mountain) species.
Threats. Major factor is habitat degradation due to forest felling, pollution, drainage and climate aridisation, which leads to lowering of the air humidity and overgrowing of habitats by competitive species of higher plants. The small number of populations and low reproductive potential make the species vulnerable to stochastic processes.
Conservation measures taken. The population in Balkan Range (Central) is within Central Balkan National Park and in a site of the European ecological network Natura 2000 in Bulgaria.
Conservation measures needed. To study the dynamics of numbers and area of the populations, as well as the biology and ecology of the species in Bulgaria, to elucidate the threatening factors and monitor the populations.
References. Petrov 1956b; Kuc et al. 1965.
Author: Rayna Natcheva
