Verbena (verbenas or vervains) is a genus in the family Verbenaceae. It contains about 250 species of annual and perennial herbaceous or semi-woody flowering plants. The majority of the species are native to the New World from Canada south to southern Chile, but some are also native in the Old World, mainly in Europe. These include Common Vervain (V. officinalis) and V. supina.
The leaves are usually opposite, simple, and in many species hairy, often densely so. The flowers are small, with five petals, and borne in dense spikes. Typically some shade of blue, they may also be white, pink, or purple, especially in cultivars.
The genus can be divided into a diploid North American and a polyploid South American lineage, both with a base chromosome number of 7. The European species derived from the North American lineage. It seems that Verbena as well as the related mock vervains (Glandularia) evolved from the assemblage provisionally treated under the genus name Junellia; both other genera were usally included in the Verbenaceae until the 1990s. Intergeneric chloroplast gene transfer by an undetermined mechanism – though probably not hybridization – has occurred at least twice from vervains to Glandularia, once between the ancestors of the present-day South American lineages and once more recently, between V. orcuttiana or Swamp Verbena (V. hastata) and G. bipinnatifida. In addition, several species of Verbena are of natural hybrid origin; the well-known Garden Vervain has an entirely muddy history. The relationships of this close-knit group are therefore hard to resolve with standard methods of computational phylogenetics.
Some species, hybrids and cultivars of vervain are used as ornamental plants. They are valued in butterfly gardening in suitable climates, attracting Lepidoptera such as the Hummingbird Hawk-moth (Macroglossum stellatarum), Chocolate Albatross (Appias lyncida), or the Pipevine Swallowtail (Battus philenor), and also hummingbirds. Especially Common Vervain (V. officinalis) is also grown as a honey plant.
Vervain has longstanding use in herbalism and folk medicine, usually as a herbal tea. Nicholas Culpeper's 1652 The English Physitian discusses folk uses. Among others effects, it may act as a galactagogue and possibly sex steroid analogue. It is one of the original 38 Bach flower remedies, prescribed against "over-enthusiasm". The plants are also sometimes used as abortifacient.
The essential oil of various species - mainly Common Vervain - is traded as Spanish Verbena oil. Considered inferior to oil of Lemon Verbena (Aloysia citrodora) in perfumery, it is of some commercial importance for herbalism and it seems to be a promising source of medical compounds. Verveine, the famous green liqueur from the region of Le Puy-en-Velay (France) is flavored with vervains.
Verbena has long been associated with divine and other supernatural forces. It was called "tears of Isis" in Ancient Egypt, and later on "Juno's tears". In Ancient Greece, it was dedicated to Eos Erigineia. In the early Christian era, folk legend stated that Common Vervain (V. officinalis) was used to staunch Jesus' wounds after his removal from the cross. It was consequently called "Holy Herb" or (e.g. in Wales) "Devil's bane".
Other legends held it that vervain protects people from vampires, by mixing it in a herbal tea, keeping it near you, or using oil extracted from it in a bath. Vervain flowers are engraved on cimaruta, Italian anti-stregheria charms. In the 1870 The History and Practice of Magic by "Paul Christian" (Jean Baptiste Pitois) it is employed in the preparation of a mandragora charm.
While Common Vervain is not native to North America, it has been introduced there and for example the Pawnee have adopted it as an entheogen enhancer and in oneiromancy, much like Calea zacatechichi is used in Mexico.
The generic name is the Ancient Roman term for sacrificial herbs considered very powerful. Pliny the Elder describes verbena presented on Jupiter altars; it is not entirely clear if this referred to a Verbena rather than the general term for prime sacrificial herbs.
The common names of Common Vervain in many Central and Eastern Europes languages often associate it with iron. These include for example the Dutch IJzerhard ("iron-hardener"), Danish Læge-Jernurt ("medical ironwort"), German Echtes Eisenkraut ("true ironherb"), and Slovenian Železník lekársky ("medical ironherb").
According to the William Faulkner short story "An Odor of Verbena", vervain is the only scent that can be smelled above the scent of horses and courage.