This is largely restricted to siliceous soils from s. Ala. and n. Fla. to s. Ky. and w. N.C. In Ky. it is a somewhat conservative remnant of more open woodland and grassland. It remains locally common on the Cumberland Plateau and adjacent hills to the west, especially along rights-of-way. But it has become rare further west in the former Big Barrens region, where most colls. date from before 1950. There are also 1840s colls. named "pilosa" by C.W. Short (GH, NY) from "barrens of Ky.", some stating "abundant"; these may be from CHRI. For "pilosa" Short (1840) noted: "It occurs in great abundance in early spring in the barrens; and it is a very handsome, low species, with dark purple flowers." Compared to pilloa, amoena has distinctively compact cymes (with longest pedicels branches ca. 2-5 mm versus 5-15 mm), and deeper red-purple corollas with glabrous to thin-hairy tubes (versus usually dense-hairy). Also, its mid-cauline leaves are usually shorter (ca. 1.5-3 cm versus 3-4.5 cm), more or less oblanceolate (versus lanceolate to a sharp tip), with l/w ca. 4-6 (versus 9-12). Plants are generally shorter (ca. 15-30 cm versus 30-60 cm) and somewhat decumbent (versus more or less erect). Pubescence is strictly non-glandular (versus non-glandular or glandular). P. amoena tends to occur on more acid, infertile soils than pilosa, and does not usually persist in eutrophic gardens without special care (Wherry 1955; confirmed by personal experience of JC). Goulet-Scott et al. (2023) found evidence of local adaptation using reciprocal transplants; In amoena habitat (versus pilosa), transplants tended to be less vigorous, especially in fruit production of pilosa; and transplants tended to experience more herbivory, especially on pilosa.