Sorbus pseudomeinichii Sorbus pseudomeinichii Sorbus pseudomeinichii, known as false rowan and Catacol whitebeam, is a rare tree endemic to the Isle of Arran in south west Scotland. It is believed to have arisen as a hybrid of the native rowan ("Sorbus aucuparia") and the cut-leaved whitebeam ("Sorbus pseudofennica") which is in turn a rowan/Arran whitebeam ("Sorbus arranensis") hybrid. Only two specimens of the Catacol whitebeam are known, making it the rarest tree in Scotland and also the United Kingdom. A third was recorded as a sapling but is believed to have been destroyed by deer. A seedling has also been grown in
Sorbus mougeotii which differs only in slightly broader leaves. It is also closely related to "Sorbus intermedia" (Swedish whitebeam), which differs in having the leaves grey-white below and more deeply lobed, with the lobes spreading rather than forward-pointing, the fruit oval and less bright red, and in forming a stouter tree with a single trunk and more horizontal branching. All are tetraploid apomictic species which breed true without pollination, and ultimately of hybrid origin between "Sorbus aria" and "Sorbus aucuparia". It is widely grown as an ornamental tree in northern Europe, though usually unrecognised, misidentified as "Sorbus intermedia". Although described in 1858,