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 aucuparia at elevations of up to 2000 m. "S. aucuparia" appears north of the boreal forest at the arctic tree line; in Norway, it is found up to the 71st parallel north. It has naturalized in America from Washington to Alaska and eastward in Canada and the northeast of the US very successfully. "Sorbus aucuparia" is an undemanding species and can withstand shade. It is frost hardy and can tolerate winter dryness and a brief growing season. The plant is also resistant to air pollution, wind, and snow pressure. "S. aucuparia" mostly grows on soil that is moderately dry to moderately