Ruhnu flora. The development of flora and vegetation on Ruhnu has been greatly influenced by the sea that makes the winters here mild. As the island is located at a quite a distance from the mainland, plants have made their way here mainly with birds, winds and water but perhaps also with the help of humans. Many plants have come from the west side. Compared to Kihnu Island, flora on Ruhnu is rather rich in species.

614 species of vascular plants (from 85 families) have been found. At the end of 20^th century, there were many species of Poaceae – 63, Asteraceae – 61, Cyperaceae – 42, Rosaceae – 35 and Brassicaceae – 26 species.

The dominant tree species is pine (Pinus silvestris), there are also a lot of black alders (Alnus glutinosa), moor birches (Betula pubescens) and Swedish whitebeams (Sorbus intermedia). There are almost no grey alders (Alnus incana).

7 species of vascular plants are on the II conservation class list and 15 species are on the III conservation class list. A few of the once common species on the island have probably disappeared, such as Low Hop Clover (Trifolium campestre; II conservation class; vulnerable), Juncus bulbosus (near threatened) and Creeping Lady Tresses (Goodyera repens; III conservation class). Twinflower (Linnaea borealis; near threatened) is very common in temperate needle leaf forests.

A total of 135 species of Bryophyte have been found – 103 of Bryophyta and 32 species of Marchantiophyta. Ruhnu is rich in Dicranaceae, Mniaceae,Brachytheciaceae, Plagiotheciaceae and Grimmiaceae species. Some mosses that are rare elsewhere in Estonia can be found in massive amounts on Ruhnu, for instance Leucobryum can even form sods in different types of forest. The extremely rare Buxbaumia viridis (I conservation class; vulnerable) has not been found on Ruhnu anymore.

Created in 2014