The leaves of this rare hybrid obviously combine its two parents: deep lobes (like Arran Whitebeam) with some free leaflets (like Rowan). Its deep, pinnately divided lobes are characterised as 'pinnatifid'.

Endemic to Scotland, classified as Critically Endangered. Found growing wild only in the north of the Isle of Arran, where a total of c.430 individual trees are known across six hyper-local populations in Glen Catacol (alongside Arran Whitebeam p. xxx).

Syn. *Sorbus pseudofennica*. An apomictic triploid evolved from Rowan (p. xxx) and Arran Whitebeam (p. xxx).

Small (3-4m), bush-like, often stunted and multi-stemmed. Bark grey, smooth, developing scaly ridges. Buds sharply lanceolate with white hairs. Leaves broad ovate or elliptic, 5-9cm, dark green above, grey-white downy then partly glabrous below, the apex half rounded-lobed and the basal half increasingly pinnatifid with 1-5 often 'pinched' free leaflets, with 12-18 veins, on a 9-21mm petiole. Flowers white (11-14mm) in a slightly domed 8cm corymb (May-July). Fruit a globose red pome (8-12mm), longer than wide. Arran Whitebeam differs: rarely with free basal leaflets.