Verbena hastata
Encyclopedia
Verbena hastata is a flowering plant
in the vervain family, Verbenaceae
. It is a herb
with opposite, simple leaves
which have double-serate margins, borne on stiffly erect, branching square stems. The flowers appear in summer and are purple. This is a common plant that occurs across North America.
This species
is a member of the diploid North American vervains which have 14 chromosomes altogether. Hybridization seems to have played some role in its evolution
, presumably between some member of a group including the White Vervain (V. urticifolia), V. lasiostachys
or V. menthifolia
, and V. orcuttiana or a related species.
In the recent evolution
ary past, there has been an incident of chloroplast
transfer of one of the latter or the Swamp Verbena to the mock vervain Glandularia bipinnatifida which is a close relative of the genus
Verbena
. It is unknown by what mechanism this happened, but it is suspected that hybridization is not responsible.
Flowering plant
The flowering plants , also known as Angiospermae or Magnoliophyta, are the most diverse group of land plants. Angiosperms are seed-producing plants like the gymnosperms and can be distinguished from the gymnosperms by a series of synapomorphies...
in the vervain family, Verbenaceae
Verbenaceae
Verbenaceae, commonly known as 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.Recent phylogenetic studies have shown that...
. It is a herb
Herbaceous plant
A herbaceous plant is a plant that has leaves and stems that die down at the end of the growing season to the soil level. They have no persistent woody stem above ground...
with opposite, simple leaves
Leaf
A leaf is an organ of a vascular plant, as defined in botanical terms, and in particular in plant morphology. Foliage is a mass noun that refers to leaves as a feature of plants....
which have double-serate margins, borne on stiffly erect, branching square stems. The flowers appear in summer and are purple. This is a common plant that occurs across North America.
This species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
is a member of the diploid North American vervains which have 14 chromosomes altogether. Hybridization seems to have played some role in its evolution
Evolution
Evolution is any change across successive generations in the heritable characteristics of biological populations. Evolutionary processes give rise to diversity at every level of biological organisation, including species, individual organisms and molecules such as DNA and proteins.Life on Earth...
, presumably between some member of a group including the White Vervain (V. urticifolia), V. lasiostachys
Verbena lasiostachys
Verbena lasiostachys is a species of verbena known by the common name western vervain. It is native to western North America from Oregon to Baja California, where it is widespread and occurs in many types of habitat, including disturbed areas, where it grows as a common weed. This perennial herb...
or V. menthifolia
Verbena menthifolia
Verbena menthifolia is a species of verbena known by the common name mint vervain. It is native to the southwestern United States and northern Mexico, where it occurs in many types of open, dry habitat such as desert scrub. This perennial herb produces one or more rough-haired, erect stems up to...
, and V. orcuttiana or a related species.
In the recent evolution
Evolution
Evolution is any change across successive generations in the heritable characteristics of biological populations. Evolutionary processes give rise to diversity at every level of biological organisation, including species, individual organisms and molecules such as DNA and proteins.Life on Earth...
ary past, there has been an incident of chloroplast
Chloroplast
Chloroplasts are organelles found in plant cells and other eukaryotic organisms that conduct photosynthesis. Chloroplasts capture light energy to conserve free energy in the form of ATP and reduce NADP to NADPH through a complex set of processes called photosynthesis.Chloroplasts are green...
transfer of one of the latter or the Swamp Verbena to the mock vervain Glandularia bipinnatifida which is a close relative of the genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
Verbena
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...
. It is unknown by what mechanism this happened, but it is suspected that hybridization is not responsible.