Revisie der Nederlandse soorten van het Bryum erythroearpum complex

Revision of the Dutch species of the Bryum crythrocarpum complex. A revision is given of the collections of the Brya erythrocarpa from Holland. Delimitating the species of this group the authors have followed the monograph of the European Brya erythrocarpa by Crundwell & Nyholm (1964). 5 species have been found in Holland up till now: Bryum micro-eryithrocarpum C. MÜLL. & KINDB., B. radiculosum Brid,. B. klinggraeffii Schimp., B. violaceum Crundw. & Nyholm and B. ruderale Crundw. & Nyholm. The latter three have not been collected until 1968, B. violaceum and B. ruderale being recorded here for the first time from our country. These two species were discovered in the Southern part of the province of Limburg, a hilly area with rich, calcareous soils, the western extension of the mountainous region of Central Europe in our country. Most of the recent gatherings of Dutch specimens of the Brya erythrocarpa have been from this area. Bryum microerythrocarpum appears to be relatively common and widespread in Holland. It mainly grows on calcareous or non-calcareous, sandy or peaty, sometimes clayish soils. It is a fairly variable species, and intermediate forms have been found between Bryum micro-erythrocarpum and Bryum rubens, an allied species which is not yet known from Holland. Bryum radiculosum has been gathered in Holland almost exclusively in the 19th century. It occurs mainly on old brick walls.