Most phlox species bloom in the spring so this species can be identified simply by its flowering season - July to September. This native perennial species is a member of the phlox family.  The stem is stouter than the other phlox species and the plant is usually upright. The plant has wide leaves and very prominent veins that stand out on the undersurface of the leaf. These ovate or lance-shaped leaves are opposite and 3-5 inches long. There usually are 15-40 pairs of leaves below the fragrant flower cluster. The plant grows 2-6 feet high.

Individual flowers are about one inch long. There are five spreading petals or lobes fusing to form a long slightly hairy corolla tube. There is some variation in the size and shape of the petals. Flowers form in a dense pyramidal cluster at the top of the smooth stem. As with other phlox species, the flower color varies from white to pink to light lavender.

The fall phlox grows on the edges of woods and in thickets. It does best in soils with moderate fertility and moisture. The species is native to interior parts of the eastern United States from northern Iowa, central New York, and south, especially in the mountains. It is documented in most Pennsylvania counties. It is a popular garden plant and thus can be a garden escapee outside of its natural range.

Extracts from this species have been used as an herbal remedy, mostly as a laxative and for treating boils. This species is sometimes called perennial phlox, garden phlox or summer phlox. A number of commercial cultivars are available.