This ornamental shrub is widely grown in northeastern states (as "flowering quince" or often just "Japonica"). Some horticultural literature indicates that the common cultivar was developed in Japan as a hybrid ("X superba") of speciosa, a Chinese species, with C. japonica Lindl., but there is little difference from typical speciosa (e.g. Wang et al. 2010). Based on FNA and W, true japonica differs as follows: branches scabrous, becoming warty in age (versus smooth); leaf margins crenate (versus serrate); fruit 2.3-4 cm in diameter (versus 4-6 cm). Distinction between these taxa has not been reliably reported across Ky. Although very persistent from old plantings, this plant has not generally been considered naturalized until recent decades (after F and Cr). Browne (1974) provided the first record of persistent plants in Ky., but establishment from seed has not yet been documented.