''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 ...

plant Plants are the eukaryotes that form the Kingdom (biology), kingdom Plantae; they are predominantly Photosynthesis, photosynthetic. This means that they obtain their energy from sunlight, using chloroplasts derived from endosymbiosis with c ...

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. T ...

). It belongs to the "true" vervains of

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

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 ...

''.

Description

White vervain has opposite, simple

leaves A leaf (: leaves) is a principal appendage of the stem of a vascular plant, usually borne laterally above ground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, stem, ...

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 (the latter name applying particularly to ''Urtica dioica, U. dioica''). The generic name ''Urtica' ...

'', 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. Using the SPIKES method for introducing and ...

; 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, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...

, excluding

Mexico Mexico, officially the United Mexican States, is a country in North America. It is the northernmost country in Latin America, and borders the United States to the north, and Guatemala and Belize to the southeast; while having maritime boundar ...

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 well-balanced or moderate supply of moisture throughout the growing season (e.g., a mesic forest, temperate hardwood forest, or dry-mesic prairie). The term derives from the Greek ''mesos'' ...

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 (''V. officinalis'') from

Europe Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and Asia to the east ...

. 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. Here ''sets of chromosomes'' refers to the number of maternal and paternal chromosome copies, ...

with a total of 14

chromosome A chromosome is a package of DNA containing part or all of the genetic material of an organism. In most chromosomes, the very long thin DNA fibers are coated with nucleosome-forming packaging proteins; in eukaryotic cells, the most import ...

s. The relationship of the

swamp verbena A swamp is a forested wetland.Keddy, P.A. 2010. Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge, UK. 497 p. Swamps are considered to be transition zones because both land and water play a role in ...

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

evolution Evolution is the change in the heritable Phenotypic trait, characteristics of biological populations over successive generations. It occurs when evolutionary processes such as natural selection and genetic drift act on genetic variation, re ...

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 diff ...

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