|'Jackmanii' is a larger potentilla, up to 4 feet in height, with dark green foliage. The flowers are bright yellow, 1 1/2 inches in diameter. Flowers end before 'Goldfinger' and 'Coronation Triumph'. Bushy, compact, deciduous shrub with pinnate leaves. Flowers are saucer shaped and come in a variety of colors, yellow being most common. Native to the Rocky, Cascade and Olympic mountains, these hardy plants flower continuously from June through October with little preference to soil or water conditions.