Ruhnu mycoflora. 601 species of fungi (as of 2005) have been found on Ruhnu. The mycoflora is rich in rarities and many new species for Estonia have been discovered here. Fungi growing on fallen trees that break down wood have played a significant role because after the 1969 November storm, a lot of wood was left lying around in the forests and as a result, this type of species thrived in numbers both species-wise and specimen-wise. Although the island has been struck by storms after that one as well, they have not been as devastating, less forest has been destroyed and that is why such fungi are decreasing.

On a good year, Ruhnu is rich in such edible mushrooms as Boletales (especially Bolatus), chanterelle, Russula, milk caps and Hydnum. Lung oysters (Pleurotus pulmonarius) are also well-known edible mushrooms; they grow on broad-leaved trees.

Out of fungi that grows on trees, the most species grow on black alder (Alnus glutinosa) – 67 species. 30 species have been found on Sorbus. (An overview of Ruhnu mycoflora, including a list of mushrooms according to host tree species, can be found in the 7th edition of Estonia Maritima.)

Endangered fungi species. The following Ruhnu fungi are on the Estonian Red List as vulnerable species: Bankera fuligineoalba (III conservation class; grows in temperate needleleaf and moor forests) and Rigidoporus crocatus (grows in forests that in the process of becoming mires). Near threatened species are Cordyceps capitata (grows on the ground) and

Leucoagaricus nympharum (II conservation class; grows in deciduous needleleaf forests). Erastia salmonicolor that is critically endangered in Estonia has not been found on Ruhnu anymore and is probably extinct on the island.

Created in 2014