Phlox pilosa var. ozarkana
Missouri Botanic Garden says: [Phlox Pilosa] "Subsp. ozarkana is a stoloniferous, Missouri-native wildflower which typically forms a low ground cover with stems growing 15-20" tall. It occurs in open woods, thickets, meadows, glades and prairies in the Ozark region of the State. Loose clusters of slightly fragrant, tubular, dark rose-lavender flowers with five, flat, petal-like lobes appear at the stem ends in spring. Stems, inflorescences and leaves are hairy (thus giving rise to the sometimes common name of downy phlox for this plant). Narrow, lance-shaped to linear leaves (to 3" long). Spreads somewhat rapidly by stolons and can form large colonies over time.
USDA Hardiness Zone 5-9