vervain vs verbena

vervain and verbena both are nouns.

Word	Noun	Adjective	Verb	Adverb
vervain	Yes	No	No	No
verbena	Yes	No	No	No

As nouns, vervain and verbena are synonyms defined as:

vervain and verbena: any of numerous tropical or subtropical American plants of the genus Verbena grown for their showy spikes of variously colored flowers

vervain (noun)	verbena (noun)
any of numerous tropical or subtropical American plants of the genus Verbena grown for their showy spikes of variously colored flowers	any of numerous tropical or subtropical American plants of the genus Verbena grown for their showy spikes of variously colored flowers