This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol3", by Nathaniel Lord Britton, Addison Brown. Also available from Amazon: An Illustrated Flora of the Northern United States, Canada and the British Possessions. 3 Volume Set..
Phlox paniculata L. Sp. Pl. 151. 1753.
Stem erect, stout or slender, simple or branched above, glabrous or puberulent, 2°-6° high. Leaves thin, sessile or short-petioled, oblong to oblong-lanceolate, acute or acuminate at the apex, narrowed at the base, or the uppermost subcordate, 2'-6' long, 1/2'-1 1/2' wide; flowers short-pedicelled in compact paniculate cymules, the inflorescence often 12' long; calyx-teeth subulate, glabrous, puberulent or glandular, more than one-half as long as the tube; corolla pink, purple or white, its lobes broadly obovate, rounded, entire, shorter than its tube; capsule oval, obtuse, slightly longer than the ruptured calyx-tube.
In woods and thickets, Pennsylvania to Florida, Illinois, Kansas and Louisiana. Freely escaped from gardens in the north and east. Consists of many races, differing in leaf-form, size and color of flowers, and in pubescence. July-Sept.
Phlox amplifolia Britton, Man. 757. 1901.
Stem villous or glandular-villous, at least above, 2°-3 1/20 high. Leaves large and broad, 2 1/2'-6' long, 1 1/2-21/2' wide, roughish above, the upper sessile, the lower ones, or some of them, narrowed, usually abruptly, into winged petioles which are sometimes one-third as long as the blade; flowers similar to those of P. pan.culata, the inflorescence often 1° long; calyx glandular-villous; corolla-tube glabrous, the lobes obovate, rounded or retuse; capsules 4"-5" long.
Woods and thickets, Indiana to Missouri, Kentucky and Tennessee. June-Aug.
Phlox maculata L. Sp. Pl. 152. 1753.
Phlox suaveolens Ait. Hort. Kew. 1: 206. 1789.
Stem slender, erect, simple or branched above, glabrous or puberulent, usually flecked with purple, 1 1/2°-3° high. Leaves lanceolate or the upper ovate-lanceolate, glabrous, rather firm, long-acuminate, sessile, rounded or subcordate at the base, 2'-$' long, widest just above the base, the lowest sometimes linear-lanceolate; flowers short-pedicelled, the compact cymules forming an elongated narrow thyrsoid panicle; calyx-teeth triangular-lanceolate, acute, or acuminate, about one-fourth the length of the tube; corolla pink or purple, rarely white, its lobes rounded, shorter than the tube; capsule similar to that of the two preceding species.
In moist woods and along streams, Connecticut to Florida, Ohio, Minnesota and Mississippi. Occasionally escaped from gardens further north. P. maculata var. Candida Michx. (P. suaveolens Ait.) is a race with white flowers and unspotted stem, occurring with the type. June-Aug.