(The above images are my illustration of the Catacol Whitebeam alongside the Herbarium Specimen from Royal Botanic Gardens Edinburgh)
The Catacol Whitebeam the most endangered plant species in Britain, with only one or two living specimens known, and although it is a recognised species in its own right, it is a cross between the Arran Service and Rowan trees (Coleman (2014))(1) – which gives the leaves of the Catacol Whitebeam their very distinctive shape. It’s scientific name: Sorbus pseudomeinichii refers to the other closely related, yet distinct species Sorbus x meinichii, which is found in “southern Norway”, and which also has the distinctive leaf shape; “The pinnate leaves have 4-6 pairs of robust deep green leaflets, fused towards the tip” More, D., White, J. (2003)(2), but makes the distinction between the two.
There is only one live specimen of Catacol Whitebeam on the Isle of Arran, however, it has been propagated by the RBG Edinburgh (through germinating seeds, and “graft[ing] material onto the roots of ordinary rowan” (1)), and they now have a specimen in the garden – making the population status of the tree slightly more secure.
More information can be found here on the Botanic Stories page.
References:
- Coleman, M. (2014) Arran’s Unique Trees. Available at:https://stories.rbge.org.uk/archives/13616 (Accessed: 26 November 2021)
- More, D., White, J. (2003) Cassell’s Trees of Britain & Northern Europe: Over 1800 Species and Cultivars. London: Cassell, an imprint of Weidenfeld & Nicholson
