Polytrichum longisetum
Polytrichum longisetum Brid.
Polytrichum gracile Sm.3
Polytrichaceae
Conservation status. Vulnerable [VU D2].
Morphology and biology. Perennial acrocarpous moss forming dark green cushions. Shoots erect, not branched, to 10 cm high. Leaves rigid, flexuous when dry, spreading and recurved when moist; above the sheathing, base colourless, abruptly narrowly long lanceolate acuminate, on the ventral surface with numerous longitudinal lamellae. Margin dentate, nerve excurrent in denticulate, brownish awn. Unisexual. Spore capsule initially erect, afterwards inclined, oval, indistinctly 5–6-angled, seta up to 6 cm long, twisted, reddish at base.
Habitats and populations. Grows in Sphagnum-dominated mires and wet meadows in the spruce belt and above. The populations have restricted distribution and low density.
Distribution in Bulgaria. Vitosha Region (Vitosha Mt – at the sources of River Bistrishka). Reported for Rila Mts.
General distribution. Balkan Peninsula, W and C Europe, Caucasus, Iceland, Greenland, N Asia, North America, Chile, Korea, Japan, New Zealand. Boreal species.
Threats. Major factor is habitat degradation due to pollution, drainage and climate aridisation, which leads to lowering of air humidity and overgrowing of habitats by competitive species of higher plants. The small number of populations makes the species vulnerable to stochastic processes.
Conservation measures taken. The population in Vitosha Mt is within Vitosha Nature Park and in a site of the European ecological network Natura 2000 in Bulgaria.
Conservation measures needed. To study the dynamics of numerical strength 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. Arnaudoff 1909; Podpéra 1911; Stefanoff & Petrov 1962.
Author: Rayna Natcheva
