1. Phlox amplifolia Britton (broadleaf phlox, largeleaf phlox)

Pl. 493 i, j; Map 2252

Plants perennial herbs with short, thick rhizomes. Vegetative stems not produced or, if present, then similar to the flowering ones. Stems typically 1–3, 45–100 cm tall, erect, with 8–14 nodes, glabrous toward the base, hairy above the midpoint, with the hairs becoming shorter and glandular toward the inflorescence, sometimes with red streaks. Leaves all opposite, the blade elliptic toward the stem base, grading to oval or ovate toward the stem tip, those of the largest leaves 9.0–11.5 cm long and 35–65 mm wide, angled or more commonly tapered to a sharply pointed tip, mostly tapered at the base, the surfaces sparsely pubescent with soft or bristly hairs, the margins short-hairy, the secondary veins forming closed loops. Inflorescences with 25–150 flowers, consisting of clusters, the aggregate of clusters often appearing as domed panicles. Flower stalks 2–8 mm. Calyces 6–9 mm long, the lobes slender, tapered evenly to sharply pointed tips, glandular-hairy. Corollas bright pink to pinkish purple, the tube 15–30 mm long, glabrous externally, lacking a basal constriction, the lobes 8–11 mm long and 5–8 mm wide, obovate, rounded at the tips. Stamens with the filaments 12–27 mm long, the anthers positioned from below to at or above the stigma near the mouth of the tube (not exserted). Style 13–23 mm long, the stigmas 0.7–1.0 mm long. 2n=14. June–August.

Uncommon in the Ozark Natural Division north locally to St. Louis County (eastern U.S. west to Missouri and Arkansas). Mesic upland forests; rarely also roadsides.