Prunus ร cistena, commonly called purple-leaf sand cherry, is an upright deciduous shrub that typically grows 6-10โ tall and 5-8โ wide. It also may be trained as a small tree. It is most noted for its reddish purple foliage that retains good color throughout the summer. Prunus ร cistena, commonly called purple-leaf sand cherry, is an upright deciduous shrub that typically grows 6-10โ tall and 5-8โ wide. It also may be trained as a small tree. It is most noted for its reddish purple foliage that retains good color throughout the summer.