Verbena bonariensis (purpletop vervain, clustertop vervain, Argentinian vervain, tall verbena, 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).
It is native to tropical South America where it grows throughout most of the warm regions, from Colombia and Brazil to Argentina and Chile.
It can be grown as an annual in areas where it is not winter hardy and will bloom in the first year when grown from seed. Its long internodes give it a sparse appearance but allow it to intermingle and coexist with other plants. The flowers which appear in mid- to late summer, are very attractive to butterflies, and provide nectar for native bees and many beneficial garden insects.
This species grows best in a well-drained soil. It prefers full sun to partial shade and needs regular moisture. It has a reputation of rarely being attacked by insect pests, but may be susceptible to powdery mildew. V. bonariensis is commonly grown from seed which germinates readily without pre-treatment, but can also be propagated from herbaceous stem cuttings.
This plant is not on Dragonfly Lake