Blue Vervain, Verbena Hastata, is an attractive native wildflower that grows naturally in moist to wet areas in full sun. The plant forms a clump roughly 2 to 4 feet high topped with narrow spikes of blue to purple flowers. Butterflies are attracted to the small flowers. Blue Vervain can reproduce through rhizomes or by self-seeding under the right conditions. Plant with other moisture-loving plants such as swamp sunflowers or swamp tickseed. Blue Vervain is a larval host plant for the Common Buckeye butterfly. The plant also has a history of medicinal use.