hello, I'm new to this forum and am excited to be here. I have practiced bonsai for the past 7 years on the west coast U.S. For over 2 years now I have been the proud owner/care taker of a hearty deciduous shrub. It has tiny white flowers, small red berries (1/4 in.) a few thorns and tender oak-snaped leaves. I will attempt to give pictures. one in winter time, showing the berries, and one in spring. I have drawn a little study of the leaf shape, berries and flowers. Hope someone can help:):) Thanks!
Does well enough in this region to be a pest. You should find your specimen comparatively easy to maintain.