Interesting locality of Physcomitrium eurystomum (Funariaceae) on a thermally active coal-waste heap (Silesian Upland, S Poland)

Physcomitrium eurystomum Sendtn. is a rare species in Poland, known from scattered sites, primarily in lowland areas. It occurs ephemerally, primarily in communities of small therophytes associated with moist mineral substrates of the class Isoëto-Nanojuncetea . In Europe, P. eurystomum is regarded as a threatened species, classified as vulnerable to extinction (category VU).

In the Silesian Upland, it is very rare and has so far been known from only two localities. In 2025, the species was discovered in an unusual habitat, on a thermally active coal-waste heap. The paper provides a detailed description of the locality, including selected physicochemical parameters of the substrate.

The discovery of P. eurystomum under such unfavourable habitat conditions is an interesting contribution to understanding the biology of this threatened species and the diversity of the bryoflora of coal-waste heaps.