Siberian Crab apple is a cross between two species, Malus baccata and Malus prunifoila. It is unclear how long they have been in cultivation. The variety Red Sentinel is good in that it holds its fruit well into winter provided that the birds leave it alone.
Crab apples, like their domestic relatives which derive from them, are surrounded in the same mythology. For instance, in the Baroque period, death is often shown holding a crab apple, a reference to Psyche the goddess of the soul. Folklore traditions within living memory predicted that an apple tree producing blossom in the autumn was a harbinger of death within the family.
Crab apple fruit
Crab apple blossom