Coefficient of Conservatism:
Coefficient of Wetness:
A. A. Reznicek
Sandy or gravelly shores, dunes, and old beach ridges around the Great Lakes; inland, on sandy plains and fields, often with jack pine and/or oak, in both Upper Peninsula and Lower Peninsula; also on rocky ledges, pavements, and summits.
Catling, McKay-Kuja, & Mitrow (1999) and Rohrer (2000) provide much new information about our sand cherries. Rohrer recognizes three varieties in Michigan. Variety susquehanae (Willd.) Jaeger, broad-leaved, with oblong-elliptic or obovate leaf blades quite obtuse or rounded, and pale beneath and first year twigs finely pubescent, is found on jack pine plains and other dry open or lightly forested areas throughout Michigan, but apparently in somewhat acidic soils and usually not on the Great Lakes shores. In var. pumila the leaves are more narrowly oblanceolate, more acute, and less pale beneath and the twigs are glabrous. This is confined to beaches and dunes of the Great Lakes. A few collections from the western Upper Peninsula and northernmost Lower Peninsula appear to be P. pumila var. besseyi (L. H. Bailey) Waugh, a western plant, also with glabrous twigs but with broader, shinier leaves that are more acutely toothed. This also occurs in northern Indiana, very close to Michigan. An additional variety, the prostrate and creeping var. depressa (Pursh) Bean occurs on Manitoulin Island, Ontario and should be sought on rocky or sandy shores in the eastern Upper Peninsula, especially Drummond Island.
Of the three Michigan varieties, var. susquehanae is the most distinctive with its pubescent twigs, and Catling, McKay-Kuja, & Mitrow (1999) recognize it at the rank of species, as P. susquehanae.