Verbena

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 usually included in the Verbenaceae until the 1990s.[2] Intergeneric chloroplast gene transfer by an undetermined mechanism – though probably not hybridization – has occurred at least twice from vervains to Glandularia, 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.[3]
==Species==
:See also Aloysia, Glandularia and Junellia for species formerly placed here.
* Verbena alata Cham.
* Verbena andalgalensis Moldenke
* Verbena atacamensis Reiche
* Verbena australis Moldenke
* Verbena balansae Briq.
* Verbena bangiana Moldenke
* Verbena berterii (Meisn.) Schauer
** Verbena berterii f. albiflora Moldenke
** Verbena berterii f. berterii
* Verbena bonariensis L. – Purpletop Vervain, Clustertop Vervain, Tall Verbena, Pretty Verbena, "South American vervain", "purpletop"
* Verbena bracteata Lag. & Rodr. – Large-bracted Vervain
* Verbena brasiliensis – Brazilian Verbena, Brazilian Vervain
* Verbena californica – California Vervain, Red Hills Vervain
* Verbena canescens Kunth
* Verbena caniuensis Moldenke
* Verbena carnea Medik.
* Verbena carolina L.
* Verbena carollata Briq.
* Verbena catamarcensis Moldenke
* Verbena chacensis Moldenke
* Verbena clavata Ruiz & Pav.
* Verbena cloverae Moldenke
* Verbena cochabambensis Moldenke
* Verbena concepcionis Moldenke
* Verbena cumingii Moldenke
* Verbena cuneifolia Ruiz & Pav.
* Verbena × deamii
* Verbena delicatula Mart. & Zucc.
* Verbena demissa
* Verbena ehrenbergiana Schauer
* Verbena × engelmannii
* Verbena ephedroides Cham.
** Verbena ephedroides var. entreriensis Tronc.
** Verbena ephedroides var. ephedroides
* Verbena fasciculata Benth.
* Verbena ferreyrae Moldenke
* Verbena filicaulis Schauer
* Verbena gentryi Moldenke
* Verbena glabrata Kunth
* Verbena glutinosa Kuntze
* Verbena goyazensis Moldenke
* Verbena gracilescens (Cham.) Herter
* Verbena gracilis Desf.
* Verbena grisea B.L.Rob. & Greenm.
* Verbena halei – Texas Vervain Small Munir (sometimes included in V. officinalis)
* Verbena hastata – Swamp Verbena, Blue Vervain
* Verbena hayekii Moldenke
* Verbena hintonii Moldenke
* Verbena hirta Spreng.
* Verbena hispida Ruiz & Pav.
* Verbena imbricata Wooton & Standl.
* Verbena inamoena Briq.
* Verbena intermedia Gillies & Hook.
** Verbena intermedia f. albiflora Moldenke
** Verbena intermedia f. intermedia
** Verbena intermedia var. intermedia
** Verbena intermedia var. lanuginosa Moldenke
* Verbena johnstonii (Moldenke) G. L. Nesom
* Verbena kuhlmannii Moldenke
* Verbena landbeckii Phil.
* Verbena lasiostachys Link
* Verbena lindbergi Moldenke
* Verbena lindmanii Briq.
* Verbena litoralis Kunth
* Verbena lobata Vell.
* Verbena longifolia M.Martens & Galeotti
* Verbena lucanensis Moldenke
* Verbena macdougalii A.Heller
* Verbena macrodonta L.M.Perry
* Verbena malmii Moldenke
* Verbena menthifolia Benth.
* Verbena minutiflora Briq.
* Verbena montevidensis Spreng.
* Verbena monticola Moldenke
* Verbena multiglandulosa Moldenke
* Verbena neomexicana (A.Gray) Small
** Verbena neomexicana var. hirtella L.M.Perry
** Verbena neomexicana var. neomexicana
** Verbena neomexicana var. xylopoda L.M.Perry
* Verbena nivea Moldenke
* Verbena occulta Moldenke
* Verbena officinalis – Common Vervain, Simpler's Joy, Holy Herb, "mosquito plant", "wild hyssop"
* Verbena orcuttiana L.M.Perry
* Verbena ovata Cham.
* Verbena paraguariensis Moldenke
* Verbena paranensis Moldenke
* Verbena parvula Hayek
* Verbena paulensis Moldenke
* Verbena paulsenii Phil.
* Verbena pedicellata Moldenke
* Verbena perennis Wooton
* Verbena × perriana
* Verbena pinetorum Moldenke
* Verbena plicata Greene
* Verbena polycephala Turcz.
* Verbena porrigens Phil.
* Verbena pseudojuncea Gay
* Verbena ramboi Moldenke
* Verbena ramulosa Phil.
* Verbena recta Kunth
* Verbena rectiloba Moldenke
* Verbena regnelliana Moldenke
* Verbena reineckii Moldenke
* Verbena reitzii Moldenke
* Verbena ribifolia Walp.
* Verbena rigida Spreng.
** Verbena rigida var. obovata (Hayek) Moldenke
** Verbena rigida var. rigida
* Verbena riparia Raf. ex Small & A. Heller
* Verbena robusta Greene
* Verbena runyonii Moldenke
* Verbena russellii Moldenke
* Verbena × rydbergii
* Verbena scabra Vahl
* Verbena scabrella Sessé & Moc.
* Verbena sedula Moldenke
* Verbena simplex Lehm. – Narrow-leaved Vervain
* Verbena spartioides Turcz.
* Verbena speciosa 
* Verbena sphaerocarpa L.M.Perry
* Verbena storeoclada Briq.
* Verbena stricta Vent. – Hoary Vervain
* Verbena strigosa Cham.
* Verbena subuligera Greene
* Verbena supina L.
* Verbena swiftiana Moldenke
* Verbena tecticaulis Tronc.
* Verbena tessmannii Moldenke
* Verbena teucroides 
* Verbena thymoides Cham.
* Verbena tomophylla Briq.
* Verbena townsendii Svenson
* Verbena trachea Phil.
* Verbena trifida Kunth
* Verbena triphylla L.{ 
* Verbena triternata Phil.
* Verbena urticifolia – White Vervain
* Verbena valerianoides Kunth
* Verbena variabilis Moldenke
* Verbena villifolia Hayek
* Verbena weberbaueri Hayek
* Verbena xutha Lehm.