Tall Verbena

Verbena bonariensis

Tall Verbena

Family: Verbenaceae

Other Common Names: clustertop vervain, purpletop vervain, Argentinian vervain, pretty verbena
Weed class: monitor list
Year Listed: 2012
Native to: South America
Is this Weed Toxic?:

not known to be

Why Is It a Noxious Weed?

This plant is on the monitor list. Please contact the Noxious Weed Control Board to report locations or for more information.

How would I identify it?

General Description

This herbaceous perennial can grow up to 6ft tall and can spread 3ft wide, in clumps. Older and larger plants will have a slightly woody base.

Flower Description

Umbrella to flat topped clusters of light purple flowers grow in small clumps at the tops of stems. Each flower has five petals, growing up from a red purple calyx that is covered in sticky hairs.

Leaf description

A clump of lance-shaped leaves with serrated edges forms before the stems bolt up. Similar leaves grow opposite each other along the stems, with their bases connected. The upper side of the leaves feel bristly with short, coarse hair.

Stem description

The stems are square. Older plants have a slightly woody base, otherwise they are entirely herbaceous. They lightly branch along the stems, with more frequent branching towards the flowering ends.

Fruit Seed Description

4 very small nutlets form per flower.

Where does it grow?

Can grow in sun and partial shade, preferably with soil moisture, but is drought tolerant.

How Does it Reproduce?

Seed and rhizome

How Do I Control It?

Hand pulling and digging works on smaller populations, while herbicide is recommended for large populations

Additional Photos