Tuberous Vervain (Verbena rigida)

Verbena rigida is one of two Verbena species - Verbena rigida (Tuberous Vervain) and Verbena brasiliensis (Brazilian Vervain) - that grow in this area. Verbena rigida is known by the common names Tuberous Vervain and Stiff Verbena. Typically the plants are about 1 foot tall and grow in the grass beside roads. The flower head barely clear the grass. Plants may be single stems or branched. Verbena rigida grows widely in this area. I’ve seen it in Walton, Jasper, Oglethorpe, and Wilkes Counties.

Plants growing in the grass at the side of a road in Oglethorpe County.

A closer view of an individual plant in Walton County.

The leaves

Close up of the florets, straight on.

Close up of flower spikes, in profile.

These flower spikes occurred on the tallest V. rigida plant I’ve ever seen; the plant was about 30 inches tall.

Verbena rigida (Tuberous Vervain) is native to South America. In the United States. It grows in the southeast from Maryland to Texas and south to Florida. It also grows in California and North Dakota.
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Distribution Map:
- United States Department of Agriculture Plants Database: Verbena rigida (Tuberous Vervain
- University of North Carolina Herbarium: Verbena rigida

Identification resources:
- Southeastern Flora: Tuberous Vervain (Verbena rigida)
- Native & Naturalized Plants of Georgia and the Carolinas: Verbena rigida (Tuberous Vervain)
- Alabama Plants: Verbena rigida

Related posts:
- 2010: Year Of The Wildflower
- Brazilian Vervain (Verbena brasiliensis)