''Verbena urticifolia'', known as nettle-leaved vervain or white vervain, is a

herbaceous Herbaceous plants are vascular plants that have no persistent woody stems above ground. This broad category of plants includes many perennials, and nearly all annuals and biennials. Definitions of "herb" and "herbaceous" The fourth edition of t ...

plant Plants are predominantly photosynthetic eukaryotes of the kingdom Plantae. Historically, the plant kingdom encompassed all living things that were not animals, and included algae and fungi; however, all current definitions of Plantae exclud ...

in the vervain family (

Verbenaceae The Verbenaceae ( ), the verbena family or vervain family, is a family of mainly tropical flowering plants. It contains trees, shrubs, and herbs notable for heads, spikes, or clusters of small flowers, many of which have an aromatic smell. The ...

). It belongs to the "true" vervains of

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

Verbena ''Verbena'' (), also known as vervain or verveine, is a genus in the family Verbenaceae. It contains about 150 species of annual and perennial herbaceous or semi-woody flowering plants. The majority of the species are native to the Americas a ...

''.

Description

White vervain has opposite, simple

leaves A leaf (plural, : leaves) is any of the principal appendages of a vascular plant plant stem, stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", wh ...

on thin, rigid, green stems. The serrated leaves look similar to those of ''

Urtica ''Urtica'' is a genus of flowering plants in the family Urticaceae. Many species have stinging hairs and may be called nettles or stinging nettles, although the latter name applies particularly to ''Urtica dioica''. ''Urtica'' species are food f ...

'', which is the reason for the plant being named ''urticifolia''. The small flowers are borne in

spikes The SPIKES protocol is a method used in clinical medicine to break bad news to patients and families. As receiving bad news can cause distress and anxiety, clinicians need to deliver the news carefully. By using the SPIKES method for introducing a ...

; they open in summer and unusually for this normally bluish-flowered genus are white. The fruit is a dark-colored capsule with many brown and thin seeds. The entire plant except for the flowers and fruit is covered in stiff bristles.

Range

White vervain is native to eastern

North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...

, excluding

Mexico Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...

Habitat

White vervain is commonly found growing individually in disturbed areas with partial shade. It prefers

mesic habitat In ecology, a mesic habitat is a type of habitat with a moderate or well-balanced supply of moisture, e.g., a mesic forest, a temperate hardwood forest, or dry-mesic prairie. Mesic habitats transition to xeric shrublands in a non-linear fashion, ...

Relation to other vervains

This species may be closest to a group that might include such North American species as '' V. lasiostachys'' or '' V. menthifolia'', and the

common vervain ''Verbena officinalis'', the common vervain or common verbena, is a perennial herb native to Europe. It grows up to 70 cm high, with an upright habitus. The lobed leaves are toothed, and the delicate spikes hold clusters of two-lipped mau ...

(''V. officinalis'') from

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...

. Like these, it is

diploid Ploidy () is the number of complete sets of chromosomes in a cell, and hence the number of possible alleles for autosomal and pseudoautosomal genes. Sets of chromosomes refer to the number of maternal and paternal chromosome copies, respectively ...

with a total of 14

chromosome A chromosome is a long DNA molecule with part or all of the genetic material of an organism. In most chromosomes the very long thin DNA fibers are coated with packaging proteins; in eukaryotic cells the most important of these proteins are ...

s. The relationship of the

swamp verbena ''Verbena hastata'', commonly known as American vervain, blue vervain, simpler's joy, or swamp verbena, is a perennial flowering plant in the vervain family Verbenaceae. It grows throughout the continental United States and in much of southern Ca ...

(''V. hastata'') to these other species is more enigmatic; its

evolution Evolution is change in the heritable characteristics of biological populations over successive generations. These characteristics are the expressions of genes, which are passed on from parent to offspring during reproduction. Variation ...

might have involved

hybrid Hybrid may refer to: Science * Hybrid (biology), an offspring resulting from cross-breeding ** Hybrid grape, grape varieties produced by cross-breeding two ''Vitis'' species ** Hybridity, the property of a hybrid plant which is a union of two dif ...

ization with the white vervain or a related species in the past.Yuan & Olmstead (2008)

Footnotes

References

* Yuan, Yao-Wu & Olmstead, Richard G. (2008): A species-level phylogenetic study of the ''Verbena'' complex (Verbenaceae) indicates two independent intergeneric chloroplast transfers. ''

Molecular Phylogenetics and Evolution ''Molecular Phylogenetics and Evolution'' is a peer-reviewed scientific journal of evolutionary biology and phylogenetics. The journal is edited by E.A. Zimmer. Indexing The journal is indexed in: *EMBiology *Journal Citation Reports *Scopus ...

'' 48(1): 23–33.

External links

* urticifolia Flora of Western Canada Plants described in 1753 Taxa named by Carl Linnaeus Flora of Eastern Canada Flora of the Northeastern United States Flora of the Southeastern United States Flora of the North-Central United States Flora of Texas Flora without expected TNC conservation status {{Verbenaceae-stub