ver·be·na 
(vər-bēnə)
(vər-bēnə)n.
1. Any of various plants of the genus Verbena, chiefly of the Americas, that have opposite leaves and flowers with five-lobed corollas and are used medicinally or cultivated for their showy spikes of variously colored flowers. Also called vervain.
2. Any of several similar plants, such as the lemon verbena.
[Latin verbēna, sacred foliage; see wer-2 in the Appendix of Indo-European roots.]
verbenapurpletop verbena
Verbena bonariensis