A large genus of South American plants. Generally for warmer soils the following vervains are hardy here with us. Verbena bonariensis being such a useful long flowering plant, although prone to prolific seeding for some. Verbena corymbosa (now Glandularia corymbosa) is the odd one out thriving at the waters edge where it runs amongst other stronger plants looking especially lovely with yellow trollius (globeflowers) or hemerocallis (daylilys).
Verbenas collectively (including Glandularia) are one of the most important garden plant genera for supporting nectar-feeding insects, from midsummer until the depths of autumn. All manner of pollinators are attracted, including bumblebees, a myriad of hoverflies, butterflies (especially admirals and whites) and also, when they are here, the migratory hummingbird hawk-moths, expertly sipping the nectar while hovering two or three centimetres away from the flower. In autumn, if you leave the stalks standing, they will undoubtedly attract finches and other seed-eating birds. V. bonariensis is increasingly being found away from cultivation in England, but it seems to be well-behaved, found on brownfield and urban habitats, rather than invading natural communities.