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Whitebeam ecology and genetics

Ecology and genetics of rare, endemic whitebeam species

Wild Planet Trust carries out research into the ecology and genetics of rare whitebeams in South West UK.


Whitebeams are attractive trees, so called for the characteristic white backs to the leaves. They produce clusters of red or orange fruit in the autumn. They belong to the genus Sorbus, which comprises approximately 40 species native to Britain.

Many of these species are of conservation concern due to their small population sizes that may be restricted to just one or two sites.

Devon has 10 species of Sorbus and is one of the richest counties in Britain for whitebeams, some of which are found nowhere else in the world. They are primarily found in coastal areas where steep woodlands and rocky slopes provide varying habitats for all the local species. Some are more tolerant of shade and are found primarily in the oak woodlands along the Exmoor coast, while the open cliffs of Torbay and North Devon are home to more species.

By studying the genetic relationships among these species we have started to unravel the evolutionary process that gave rise to this great diversity. We have discovered that isolation from other whitebeam species can restrict seed production and this research will help determine the best management for these vulnerable trees.


Fay, M.F., Hamston, T.J., Barlow, G., Brown, A.P., Rich, T.C.G. (2022). 1048. Sorbus subcuneata: Rosaceae. Curtis’s Botanical Magazine 39: 727–736.

Hamston, T.J., de Vere, N., King, R.A., Pellicer, J., Fay, M.F., Cresswell, J.E., Stevens, J.R. (2018). Apomixis and hybridisation drives reticulate evolution and phyletic differentiation in Sorbus L.: Implications for conservation. Frontiers of Plant Science 9: 1796.

Hamston, T.J., Wilson, R.J., de Vere, N., Rich, T.J., Stevens, J.R., Cresswell, J.E. (2017). Breeding system and spatial isolation from congeners strongly constrain seed set in an insect-pollinated apomictic tree: Sorbus subcuneata (Rosaceae). Scientific Reports 7: 45122.

Hamston, T., Pellicer, J., Fay, M.F. (2015). Polyploid wild service tree: first record of a triploid Sorbus torminalis (Rosaceae) in Britain. New Journal of Botany 5: 34–36.