Blue Phlox

Phlox divaricata

Alternate names
Woodland phlox, wild blue phlox, wild sweet william

Weed Description
A perennial with rhizomes that produces many attractive blue flowers during the spring. Blue phlox primarily grows in moist, shaded areas such as the edges of woods. It is primarily viewed as an attractive wildflower rather than a detrimental weed.

Leaves
Leaves are elliptic to lanceolate in outline, reaching 3/4 to 1 1/2 inches in length and 5 to 12 mm in width. Leaves are arranged oppositely along the stem and 4 pairs of leaves typically occur on the flowering stems. All leaves are hairy.

Stems
Hairy, erect, reaching 15 inches in height.

Flowers
Many flowers occur on each plant clustered at the ends of the flowering stems. Individual flowers are tube- or funnel-shaped with 5 blue to lavender petals that are notched.

Roots
Rhizomes and fibrous roots occur.

Identifying Characteristics
The elliptic to lanceolate oppositely-arranged leaves, attractive blue to lavender flowers, and tendency of this plant to grow in moist, shady areas are all characteristics that help in the identification of blue phlox.

Office of Programs

University of Missouri

Blue Phlox

Phlox divaricata