more or less erect shrub to 60cm or more in cultivation but often wide-spreading or prostrate in the wild. Leaves narrowly spathulate to oblanceolate, 3-5cm long, toothed towards the tips or entire, greyish-green. Flowers 1-1.2cm across, white, in clusters of two to four, spring. Fruits globose, about 1cm across, dark brownish-purple, bitter. P.p. var. depressa is always prostrate. North-eastern North America from Canada south to Pennsylvania, in moist sandy places.