verbena bonariensis; purpletop vervain.

Description:

Verbena bonariensis (Purpletop vervain, Tall verbena, Clustertop vervain, or Pretty verbena) is a member of the verbena family cultivated as a flowering annual or herbaceous perennial plant. In USA horticulture, it is also known by the ambiguous names "purpletop" (also used for the grass Tridens flavus) and "South American vervain" (which can mean any of the numerous species in the genus Verbena occurring in that continent)

Habitat:

Verbena bonariensis is a tall and slender-stemmed perennial. It can grow to 6 ft (120 cm) tall and can spread to 3 ft (90 cm) wide. At maturity, it will develop a woody base. Fragrant lavender to rose-purple flowers are in tight clusters located on terminal and axillary stems, blooming from mid-summer until fall frost. The stem is square with very long internodes. Leaves are ovate to ovate-lanceolate with a toothed margin and grow up to 4 in (10 cm) long