Ilex verticillata 'Winterberry Holly' 8ftIlex verticillata, or winterberry, is a deciduous shrub or small tree that grows 3 to 15 feet tall and is known for its abundant, bright red berries that persist into winter. It has a multi stemmed, oval, or rounded habit, with brownish gray bark and zigzag twigs. The simple leaves are elliptical with finely toothed edges, and its inconspicuous white flowers appear in the spring.