Plum pox show no symptoms on leaves or fruit. Not all infection in "Prunus" are characterized by a ring symptom on leaves. Several cultivars show yellowing line patterns and blotches, or necrotic ring symptoms on expanded leaves. Leaf distortion has also been observed. Infected fruit can develop yellow rings or blotches, or brown rings, and some plum and apricot fruit can be severely deformed and bumpy. The seed of many infected apricots and some plums show rings. Many non-"Prunus" species, in at least nine plant families, have been infected artificially with one or more strains of the plum pox virus, and in
Plum jerkum Plum jerkum Plum jerkum is an alcoholic drink produced from plums. It has been variously described as made in the same way as cider and as a fruit wine, although the terminology implies slightly different methods. The drink is native to the north Cotswolds and particularly to the county of Worcestershire, where plum cultivation was once centred on Pershore and the Vale of Evesham; it was also found around Chipping Campden in Gloucestershire. Jerkum was known as a traditional product of Worcester along with potted lamperns and curd cheesecakes. A 19th century reference, again from Worcester, suggests that it was