Please help me identify this common triangle shrub. I believe this plant
most often takes the form of a dense, six foot high or so shrub, but it can
also grow to tree height. I've only seen it as a multiple, twisted-trunked
plant, but it may take other forms as well. Its leaves don't fall off
during winter, and are about three inches long, smooth edged and sharp
tipped, and dark glossy green on top and dull light green beneath. They are
folded slightly upward along their central spines and grow from their stems
in pairs from a single node. This plant gives small purple berries that
grow in clusters at the ends of the stems. The birds eat them. The bark is
freckled with small bumps, but otherwise smooth. It grows along with
mulberry trees and pecan trees. I especially like this tree becasue it's
pretty, stays green all year, and seems to thrive in my yard. I hope to
plant some more of them. Any ideas of what it is? Can I propigate it from
its berries?

Tom