A friend upon looking at my holly plants with the yellow flowers...ventured the opinion that what I thought was holly... was actually Oregon grape. Wikipedia seems to verify that opinion. The Oregon-grape is not closely related to grapes, but gets its name from the purple clusters of berries whose color and slightly dusted appearance are reminiscent of grapes. Its leathery leaves resemble holly and the stems and twigs have a thickened, corky appearance. The flowers, borne in late spring, are an attractive yellow. As the leaves of Oregon-grape are holly-like and resist wilting, the foliage is sometimes used by florists. Now I'm waiting to see the grape-like berries in the fall.