Sorbus pseudomeinichii of the location. The species is named after Glen Catacol where it was found and one of the two surviving plants is thought to be more than fifty years old. 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
Sorbus chamaemespilus in corymbs 3–4 cm diameter. The fruit is an oval red pome 10–13 mm diameter. It is the sole species in a group that has been called genus "Chamaemespilus" or "Sorbus" subgenus "Chamaemespilus", distinguished from other subgenera of "Sorbus" by the pink (not white) flowers with forward-pointing petals (not opening flat). More recently, it has become clear that the simple-leafed species traditionally included in "Sorbus" form a monophyletic group, and this species could be included in a clade called "Aria" (genus "Aria" or "Sorbus" subgenus "Aria"). Sorbus chamaemespilus Sorbus chamaemespilus, the false medlar or dwarf whitebeam, is a species of