This polyploid (2n = 35) has been widely cultivated in northeastern states and adjacent Canada, especially for its moderately large fruits. It may be occasionally naturalized in Ky. However, some identifications in Ky. remain tentative; and see notes under rubiginosa. There is also a coll. by S. Price (NY) of R. dumetorum Thuill. (M); but this supposed hybrid with R. obtusifolium Desv. is combined with canina by recent authors (FNA 9). Section Caninae is distinguishable from Section Cinnamomeae as follows (W, FNA 9): sepals disparate in size and shape (versus alike), the outer pinnatifid with leafy segments (versus all entire or with a few scarcely leafy teeth near the base); orifice of the hypanthium ca. 1 mm in diameter (versus 2-4 mm), the styles slightly exserted (versus blocking the orifice); leaflets often tomentulose or pubescent below (versus usually glabrous); stems erect, arching, or spreading (versus erect or sometimes arching); rhizomes absent or relatively short (versus relatively long).