American barberry Berberidaceae Berberis
Leaf: Alternate, simple, slightly thickened, finely spinose margin, narrowly obovate to elliptical, 1/2 to 1 1/2 inches long, bright green above, paler and somewhat glaucous below.
Flower: Pale yellow, 1/3 inch across, usually in small racemes, appearing in April to May.
Fruit: Shiny red, egg-shaped berry, 1/3 inch long, ripening in the fall and persisting into the next spring.
Twig: Slender, angled or grooved and slightly zigzagged, reddish brown, buds small, (usually) three thorns at each node, yellow inner bark.
Bark: Gray-brown, may become finely shreddy.
Form: Small loosely branched shrub, reaching several feet tall.
Looks like: Japanese barberry