Small tree to 8 m, with spreading branches, much resembling M. × floribunda. Leaf margins slightly wavy. Dark red buds opening pink (darker outside), ageing white, to 5 cm diameter on reddish pedicels to 5 cm. Calyx almost hairless. Fruit yellow, sometimes blushed pink or dull red; 1–1.5 cm diameter. (Fiala 1994; Bean 1981).
USDA Hardiness Zone 4-8
RHS Hardiness Rating H6
Similar to the familiar M. × floribunda, the Arnold Crabapple has rather larger flowers and leaves, and long, arching young shoots, redder than those of M. × floribunda. It too is at its most attractive when only some of the copious flowers are open, showing the contrast between intensely coloured buds and pale open flowers to best effect (Bean 1981). It arose as a chance seedling at the Arnold Arboretum around 1883; it was described and named in rather piecemeal fashion, mentioned in a series of papers by Rehder and Sargent (see Rehder 1920). It was taken to represent the backcross between M. × floribunda and that hybrid’s presumed parent M. baccata. In effect this is simply an old cultivar, named as a nothospecies following the practice of those times.
At one time it was common and popular in North America, but is now more or less commercially extinct, probably because it is weaker and more disease-prone than M. × floribunda (Jacobson 1996). Historically important in breeding ornamental crabs, specialist collections still find room for this ‘venerable matriarch’ (Fiala 1994), for example the Morton and Arnold Arboreta (Morton Arboretum 2020; Arnold Arboretum 2020).
Very uncommon in Europe, the Tree Register of Britain and Ireland records just two rather stunted old specimens of 2.5 m tall, growing at Holker Hall, Cumbria, and Bute Park, Cardiff (The Tree Register 2020).