|'William Purdom' has bright, canary-yellow flowers with darker centers, over 1 inch wide. The foliage is bright green and finely textured, on a large, rounded shrub which can reach 4 to 6 feet in height. Bushy, compact, deciduous shrub with pinnate leaves. Flowers are saucer shaped and come in a variety of colors, yellow being most common. These hardy plants flower continuously from June through October with little preference to soil or water conditions.