Prunus × cistena
Prunus × cistena, the purple leaf sand cherry or dwarf red-leaf plum, is a hybrid species of prune-cherry, the result of a cross between Prunus cerasifera (cherry plum or myrobalan plum) and Prunus pumila (sand cherry). A leggy bush or shrubby tree, it typically reaches a height of 1.5–2.5 meters and has a useful life of 10–20 years. The fruit are edible, if strong-tasting. Some people make jams or preserves from them. It is not advisable to eat the pits. 

Frost-tolerant, purple leaf sand cherries can be grown up to USDA Hardiness Zone 2. Commercial specimens are typically grafted to a rootstock from any of a number of other species, which will influence their growth form and final height. There are also a limited selection of cultivars available.  

Prunus × cistena was developed by Niels Ebbesen Hansen in 1910. In 1993 it won the Royal Horticultural Society's Award of Garden Merit.