Virginia Tech Weed Identification Guide

Blue Phlox: Phlox divaricata

phloxdivaricata4-11b.jpg (72629 bytes) 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.

Roots: Rhizomes and fibrous roots occur.

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.

phloxdivaricata4-11.jpg (90888 bytes)
phloxdivaricata4-11c.jpg (152897 bytes) 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.