This is widely grown as an ornamental plant, and it has occasionally escaped across northern states and adjacent Canada (K). There is only one verified Ky. coll., from a population with 100s of plants in KENT (KNK) that may have been persistant from a planting. Perhaps also belonging here is a coll. of B from KENT (US) that she referred to S. nemerosa L. or the hybrid of nemerosa with pratensis (= X sylvestris L. pro sp.). The two coll. localities are about 3 miles apart, and they appear to be morphologically distinct. Plants known as sylvestris or nemorosa have been developed into many cultivars, which are widely grown. They do not appear to spread from seed in Ky. but escapes have been reported from across northern states and southern Canada (K). S. nemorosa sensu stricto may be unknown as a naturalized plant in North America, but it has often been combined into sylvestris (K, W). Compared to pratensis (Cr), its leaves are more cauline, and its flowers are smaller; 2n = 12 or 14, versus 18.