Commelina communis
Encyclopedia
Commelina communis, commonly known as the Asiatic dayflower, is an herbaceous
annual plant
in the dayflower family
. It is native throughout much of East Asia
and northern parts of Southeast Asia
. In China, the plant is known as yazhicao , roughly translating to "duckfoot herb", while in Japan it is known as , meaning "dew herb". It has also been introduced to parts of central and southeastern Europe
and much of eastern North America
, where it has spread to become a noxious weed. It is common in disturbed sites and in moist soil. The flowers emerge from summer through fall and are distinctive with two relatively large blue petals and one very reduced white petal.
The Asiatic dayflower plant serves as the type
species for its large genus. Linnaeus
picked the name Commelina in honour of the two Dutch botanists of the Commelijn family, using the two large showy petals of Commelina communis to symbolise them. Linnaeus described the species in the first edition of his landmark work, Species Plantarum
, in 1753. Long before the plant was studied in Europe, however, it had been used for generations in traditional Chinese medicine
. The flowers have also been used in Japan to produce a dye and a pigment that was used in many world-renowned Ukiyo-e
woodcuts
from the 18th and early 19th centuries. In the modern era the plant has found limited use as a model organism
in the field of plant physiology
due to its complex pigment chemistry and the ease of viewing its stomata.
The Asiatic dayflower is considered a weed both in areas where it was introduced and in certain parts of its native range. The flowers' interactions with pollinators have been well studied and have helped to support important hypotheses about pollination in the field of plant ecology
. Recent research has also revealed that the Asiatic dayflower can bioaccumulate
a number of metals, making it a candidate for revegetating and essentially cleaning spoiled copper mines. Several animals and fungi use the plant as a food source, with a few species feeding upon it exclusively.
The Asiatic dayflower is an annual herb with stems that are typically decumbent, meaning that they are prostrate at the base but become erect towards the tips, but some individuals may be simply erect. The diffusely branched stems tend to root at the basal nodes. The pubescence on the stems is variable, but common patterns include a line of hair continuous with the leaf sheath, or they may be glabrous basally, meaning hairless, and puberulent towards the extremities, that is covered with fine hairs. The leaves
are sessile: they lack a leaf stalk, also known as a petiole
; or they may be subpetiolate, meaning they have very small petioles. The leaf sheaths are cylindrical, sometimes striped with red, and typically glabrous, but usually have margins that are puberulent or pilose, meaning lined with fine, soft hairs. The leaf blades range from narrowly lanceolate, or lance-shaped, to ovate-elliptic, between egg-shaped and ellipse
-shaped. They measure 3–12 cm (1–4½ in) by 1–4 cm (½–1½ in) wide. The blades range from glabrous to puberulent and have scabrescent, or slightly rough, margins. Their tips are acute, meaning they come to a point quickly, to acuminate, meaning the point develops gradually. The leaf bases are oblique, or uneven.
The flower
s are arranged on inflorescence
s called cincinni (singular: cincinnus), which are also called scorpioid cymes. This is a form of a monochasium where the lateral branches arise alternately. The cincinni are subtended by a spathe, a modified leaf. The solitary spathes usually measure 1.2–3 cm long (½–1¼ in), but some may be up to 3.5 cm (1½ in) in length, while they are 0.8–1.3 cm (¼–½ in) tall, but sometimes up to 1.8 cm (¾ in). The uncurved spathes typically have a cordate, or heart-shaped, whitish base, which contrasts with its dark green veins. Their margins lack hairs, are somewhat scabrous, or rough, and are unfused, meaning they are distinct to the base. Their apices are acute to acuminate while the surfaces are glabrous, puberulent, or hirsute-ciliate, meaning with longer, shaggier hairs. The spathes are borne on peduncle
s, or stalks, that measure 0.8–3.5 cm (¼–1½ in) and sometimes up to 5 cm (2 in) long.
There are often two cincinni present, though the upper, or distal, cincinnus may be vestigial. The lower, or proximal, cincinnus bears 1 to 4 bisexual flowers and is nearly included in the spathe, while the upper cincinnus has 1 to 2 male flowers and is about 8 mm (0.3 in) long. The individual flowers are subtended by bract
eoles that fall off early in development. The pedicel
s supporting single flowers, and later the fruits, are erect initially but curve when in fruit. They measure about 3–4 mm (0.11–0.16 in). The 3 concave, membranous sepal
s are inconspicuous, but persist after the fruit develops; the lateral pair are fused basally, measure only 4.5–5 mm (0.18–0.2 in) long by 3–3.7 mm (0.11–0.15 in) wide, and are elliptic and glabrous. The lower sepal is lanceolate and about 4.5 mm (0.18 in) long by about 2.2 mm (0.09 in) wide. The 2 upper petal
s are blue to indigo
in colour, while the much smaller lower petal is white. The upper two petals measure 9–10 mm (0.35–0.39 in) long by 8–10 mm (0.31–0.39 in) wide, while the lower petal is 5–6 mm (0.2–0.24 in) long by about 6 mm (0.24 in) wide. The 2 upper petals are composed of a claw about 3 mm (0.11 in) long and a broadly ovate limb with an acute apex and a cuneate-cordate base.
There are three anticous fertile stamens, meaning they are on the lower part of the flower, and three posticous infertile stamens, meaning they are on the upper part of the flower. These infertile stamens are termed staminode
s. The fertile stamens are dimorphic
: the lateral pair have maroon
to indigo anther
s that measure about 2 mm (0.8 in) long and are elliptic with a base that is sagittate or arrowhead-shaped. Their filament
s are about 10–12 mm (0.39–0.47 in) long. The central fertile stamen has a yellow, elliptic anther with a maroon connective
and a base that is hastate or spearhead-shaped, but with the lobes at right angles. The anther measures about 2.5 mm (0.1 in) long while its filament is about 5–6 mm (0.2–0.24 in) long. The three staminodes are all alike with yellow, cruciform, or cross-shaped, antherodes that are about 2 mm (0.08 in) long on filaments about 3 mm (0.12 in) long. Sometimes the antherodes will have a central maroon spot. Each antherode has two abortive lateral pollen sacks. The ovary is ellipsoid, about 2 mm (0.08 in) long and has a style
that is about 1.3 cm (0.51 in) long.
The fruit
is a dehiscent, ellipsoid capsule
with two locule
s each containing two seeds. The capsule is glabrous, brown, measures 4.5–8 mm (0.18–0.31 in) long, and dehisces into two valves. The seed
s are brown or brownish yellow in colour and deltoid, or roughly triangular in outline. They are dorsiventral, meaning they have distinct upper and lower surfaces, with the ventral, or lower, surface being planar and the dorsal, or upper, surface being convex. Seeds range in length from 2.5–4.2 mm (0.1–0.16 in), but seeds as short as 2 cm (0.08 in) can occur, while they are 2.2–3 mm (0.09–0.12 in) across. The surfaces are rugose pitted-reticulate and are densely covered with smaller farinose granules with sparse larger farinose granules.
in the first edition of his Species Plantarum
, along with eight other species in the genus. The plant serves as the type
species for the genus. The scientific name Commelina was chosen based on the Asiatic dayflower. Linnaeus picked the name in honour of the Dutch botanists Jan
and Caspar Commelijn
, using the two large showy petals of Commelina communis to symbolise them. A number of names given to plants thought to be different species have fallen into synonymy
with the Asiatic dayflower. Albrecht Wilhelm Roth
created the first such synonym, Commelina polygama, in 1790. Wenceslas Bojer
described what he believed were two new species, Commelina barabata and Commelina salicifolia, in his work Hortus Mauritianus, both of which were quickly found to be identical to C. communis. Karl Sigismund Kunth created the synonym Commelina willdenowii in 1841. Finally, Korean populations of the species were named under the synonym Commelina coreana in 1910 by Augustin Abel Hector Léveillé.
Several varieties have also been named. Commelina communis var. ludens was created by C.B. Clarke after demoting it from the full species status in which is was placed by Friedrich Anton Wilhelm Miquel
in 1861. The variety is distinguished by its darker flowers, antherodes with central maroon spots, less well developed distal cymes that usually do not produce a flower, and spathes that are proportionally broader. Jisaburo Ohwi
's Flora of Japan also treats the variety as geographically distinct, stating that it is restricted to mountainous areas. This variety is still accepted by some workers, but others, such Robert B. Faden, consider it impossible to consistently separate from the type variety. Another variety, C. communis var. hortensis, which was named by Tomitaro Makino
and is apparently a cultivated variety which originated from C. communis var. ludens in Japan, is also accepted by some botanists. It differs in having larger showy flowers which are used to produce a dye (see "Uses" section below). A variegated form called C. communis var. ludens f. aureostriata named by Frank C. MacKeever in 1961 is known to occur randomly throughout much of the species' range.
and Southeast Asia
. Country by country, it is found in China
, Taiwan
, Japan
, Korea
, the Russian Far East
, Cambodia
, Laos
, Malaysia, Thailand
and Vietnam
. Within China it is found in all provinces except Qinghai
, Hainan
, Xinjiang
, and Tibet
. In Japan the plant is found throughout the bulk of the country from Hokkaido
south to Kyūshū
. In Russia the Asiatic dayflower is found naturally on Sakhalin
as well as in the Far East
in areas surrounding the Ussuri River
.
The species has been introduced to much of Europe
and eastern North America
. On the former continent it is now found from Central Europe
well into western Russia
. Specifically it is known from Italy
north to Switzerland
, east through the region encompassing the former Yugoslavia
, east into the regions around the Black Sea
including Romania
, the Moldavia Region
, and the Ukraine
but excluding Crimea
, north through the Dnieper Basin
into Belarus
and Russia
, continuing east into the regions surrounding the Don River
and the Volga River
south to their intersection at the Volga-Don Canal
and north to the regions around Lake Ladoga
and Lake Ilmen
, and farther east to the regions of the Ural River
and the Kama River
. It is also found in the Czech Republic
and Slovakia
. It is present in the provinces of Ontario
and Quebec
in Canada
, and in most of the eastern and central American
states from Massachusetts
and New York
in the northeast, west to Minnesota
and south through the Great Plains
to Texas
and east to extreme northern Florida
in the United States
.
Within its native distribution, the plant is most typical of moist, open places, including shady forest edges and wet areas of crop fields, orchards, ditches, and roadsides. In Taiwan
, it can be found from 350 to 2400 m (1000–7500 ft) elevation. In areas where the Asiatic dayflower is an introduced weed it is most common in waste places, but also along the edges of fields, woods, and marshes, and occasionally penetrating into woods.
in many areas where it has been introduced. In the United States, the Virginia Department of Conservation and Recreation
, for example, categorises the species as "occasionally invasive" in its Invasive Plant Species of Virginia. This means that the plant will "not affect ecosystem processes, but may alter plant community composition by outcompeting one or more native plant species". The species is typically limited to disturbed sites, whence it spreads relatively slowly. Within its native range in China it is also sometimes considered a pest, especially in the northeast of the country where it has caused economically significant agricultural damage in orchards.
The Asiatic dayflower has been used in pollination
studies concerning the behaviour of plants in relation to their pollinators. One important experiment tested the hypotheses that floral guides (i.e. various patterns and colours on anthers and petals) simultaneously promote pollinator visitation and prevent visits where the pollinator fails to come into contact with the stigma or anthers, termed pollen theft. As the flowers of the Asiatic dayflower lack nectar, they offer only pollen as a reward to their visitors. To attract pollinators, the plant has three types of brightly colored floral organs: the large blue petals, fertile yellow anthers, and infertile yellow antherodes that lack pollen. When the infertile antherodes were experimentally removed in natural populations, the number of total floral visitor landings was reduced, supporting the hypothesis that these infertile anthers essentially trick their pollinators into believing they offer more than they actually do. When the central, bright yellow fertile anther was removed, leaving only two brown fertile anthers, the frequency of legitimate flower landings decreased, meaning that the visitors were not pollinating the flowers, suggesting that floral signals also prevent "theft", or visits where the pollinators take pollen, but do not place any on the stigma. Thus both the fertile anthers and the infertile antherodes were shown to play an important role in both increasing visitor landings and orienting floral visitors toward a landing point appropriate for pollination.
Recent studies have shown that wild Asiatic dayflower populations found growing on copper mine spoils in eastern China exhibited very high concentrations of copper within the plants, more so than the 48 species tested. Commelina communis had sequestered some 361 mg/kg−1 of copper
, while the plant with the next highest concentration, Polygonum
macrathum, had 286 mg/kg−1. Five of the species examined, including the Asiatic dayflower, also showed high concentrations of other metals such as zinc
, lead
, and cadmium
. The results suggest that the Asiatic dayflower is a good candidate for copper mine spoil revegetation and phytoremediation.
Ten species of fungi have been found on the Asiatic dayflower, four of which can infect the plant, while 12 species of insects are known to be associated with it. Two of the fungi, Kordyana commelinae and Phyllosticta commelinicola, are thought to be host specific with the Asiatic dayflower. Of the ten fungi seven are Basidiomycota
and three are Ascomycota
. Nine of the 12 insects associated with the plant are beetle
s, seven of which are in the genus Lema, while the other two are in the families Hispidae and Pentatomidae
. The remaining three insects include one species of moth
, Pergesa acteus, and two true bugs, namely Aphis
commilinae and Aeschrocoris ceylonicus. Important pollinators include the Asian honeybee, Apis cerana
, syrphid fly, Episyrphus balteatus
, and the bumble bee species Bombus diversus.
In China
it is used as a medicinal herb with febrifugal, antipyretic
, anti-inflammatory
, and diuretic
effects. Additionally, it is also used for treating sore throats and tonsillitis
. Recent pharmacological investigations have revealed that the Asiatic dayflower contains at least five active compounds. One of these, p-hydroxycinnamic acid, shows antibacterial activity, while another, D-mannitol, has an antitussive effect. In China and India the plant is also used as a vegetable and fodder
crop.
there is a sizeable dye industry devoted to the plant. The purported variety Commelina communis var. hortensis, which is apparently a cultivated form of another putative variety, namely Commelina communis var. ludens, is grown for its larger petals which yield a blue juice used in manufacturing a paper called boshigami or , which is the famous product of the Yamada village in the Shiga prefecture
. The paper is usually resoaked, allowing the pigment to be reabsorbed in water for use as a dye. The dye, also referred to as aigami, but also as or , is composed primarily of malonyl awobanin and was used extensively as a colorant in 18th and 19th century woodblock prints in Japan, especially during the early Ukiyo-e
era. The colorant is known to have been used by several famous Ukiyo-e artists such as Torii Kiyonaga
. However, aigami fades to a greenish yellow in a matter of months when exposed to sunlight. As a result, the color was eventually replaced by imported Prussian blue
, a much more stable colour with its first commercial appearance in 1829 in the work of Keisai Eisen
. The plant is also grown for its dye in northern China. Additional uses of the colourant include making preparatory designs on cloth before dyeing with other pigments.
in plant physiology
and plant development to a limited extent, especially in relation to stomatal physiology and the biology of pigmentation development. For example, the blue pigmentation of Asiatic dayflower petals was shown to consist of a large complex of six anthocyanin
s, six flavones, and two associated magenesium ions, demonstrating that supramolecular complexes of several copigments and chelated
metals often determine colour. Other research on the plant has helped to explain photoreceptor systems in plants such as their stomatal responses to blue light versus red light spectrums, abscisic acid
perception and its role in cell signaling, particularly concerning the chemical's role in stomatal function, the role of vanadate
s in inhibiting stomatal opening, and the necessity of calcium in stomatal closure, among other topics. Its widespread use in stomatal studies is due to the fact that the leaves produce exceptional epidermal peels that are consistently one cell layer thick. This same quality makes the plant popular for use in laboratory exercises in higher education for demonstrating stomatal function and morphology. Guard cell
turgor pressure
and its regulation in the opening and closing of stomata is particularly easy to demonstrate with the Asiatic dayflower.
Herbaceous
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...
annual plant
Annual plant
An annual plant is a plant that usually germinates, flowers, and dies in a year or season. True annuals will only live longer than a year if they are prevented from setting seed...
in the dayflower family
Commelinaceae
Commelinaceae is a family of flowering plants. In less formal contexts, the group is referred to as the dayflower family or spiderwort family. It is one of five families in the order Commelinales and by far the largest of these with an estimated 650 species in 40 genera. Well known genera include...
. It is native throughout much of East Asia
East Asia
East Asia or Eastern Asia is a subregion of Asia that can be defined in either geographical or cultural terms...
and northern parts of Southeast Asia
Southeast Asia
Southeast Asia, South-East Asia, South East Asia or Southeastern Asia is a subregion of Asia, consisting of the countries that are geographically south of China, east of India, west of New Guinea and north of Australia. The region lies on the intersection of geological plates, with heavy seismic...
. In China, the plant is known as yazhicao , roughly translating to "duckfoot herb", while in Japan it is known as , meaning "dew herb". It has also been introduced to parts of central and southeastern Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
and much of eastern North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
, where it has spread to become a noxious weed. It is common in disturbed sites and in moist soil. The flowers emerge from summer through fall and are distinctive with two relatively large blue petals and one very reduced white petal.
The Asiatic dayflower plant serves as the type
Biological type
In biology, a type is one particular specimen of an organism to which the scientific name of that organism is formally attached...
species for its large genus. Linnaeus
Carolus Linnaeus
Carl Linnaeus , also known after his ennoblement as , was a Swedish botanist, physician, and zoologist, who laid the foundations for the modern scheme of binomial nomenclature. He is known as the father of modern taxonomy, and is also considered one of the fathers of modern ecology...
picked the name Commelina in honour of the two Dutch botanists of the Commelijn family, using the two large showy petals of Commelina communis to symbolise them. Linnaeus described the species in the first edition of his landmark work, Species Plantarum
Species Plantarum
Species Plantarum was first published in 1753, as a two-volume work by Carl Linnaeus. Its prime importance is perhaps that it is the primary starting point of plant nomenclature as it exists today. This means that the first names to be considered validly published in botany are those that appear...
, in 1753. Long before the plant was studied in Europe, however, it had been used for generations in traditional Chinese medicine
Traditional Chinese medicine
Traditional Chinese Medicine refers to a broad range of medicine practices sharing common theoretical concepts which have been developed in China and are based on a tradition of more than 2,000 years, including various forms of herbal medicine, acupuncture, massage , exercise , and dietary therapy...
. The flowers have also been used in Japan to produce a dye and a pigment that was used in many world-renowned Ukiyo-e
Ukiyo-e
' is a genre of Japanese woodblock prints and paintings produced between the 17th and the 20th centuries, featuring motifs of landscapes, tales from history, the theatre, and pleasure quarters...
woodcuts
Woodblock printing in Japan
Woodblock printing in Japan is a technique best known for its use in the ukiyo-e artistic genre; however, it was also used very widely for printing books in the same period. Woodblock printing had been used in China for centuries to print books, long before the advent of movable type, but was only...
from the 18th and early 19th centuries. In the modern era the plant has found limited use as a model organism
Model organism
A model organism is a non-human species that is extensively studied to understand particular biological phenomena, with the expectation that discoveries made in the organism model will provide insight into the workings of other organisms. Model organisms are in vivo models and are widely used to...
in the field of plant physiology
Plant physiology
Plant physiology is a subdiscipline of botany concerned with the functioning, or physiology, of plants. Closely related fields include plant morphology , plant ecology , phytochemistry , cell biology, and molecular biology.Fundamental processes such as photosynthesis, respiration, plant nutrition,...
due to its complex pigment chemistry and the ease of viewing its stomata.
The Asiatic dayflower is considered a weed both in areas where it was introduced and in certain parts of its native range. The flowers' interactions with pollinators have been well studied and have helped to support important hypotheses about pollination in the field of plant ecology
Ecology
Ecology is the scientific study of the relations that living organisms have with respect to each other and their natural environment. Variables of interest to ecologists include the composition, distribution, amount , number, and changing states of organisms within and among ecosystems...
. Recent research has also revealed that the Asiatic dayflower can bioaccumulate
Bioaccumulation
Bioaccumulation refers to the accumulation of substances, such as pesticides, or other organic chemicals in an organism. Bioaccumulation occurs when an organism absorbs a toxic substance at a rate greater than that at which the substance is lost...
a number of metals, making it a candidate for revegetating and essentially cleaning spoiled copper mines. Several animals and fungi use the plant as a food source, with a few species feeding upon it exclusively.
Description
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....
are sessile: they lack a leaf stalk, also known as a petiole
Petiole (botany)
In botany, the petiole is the stalk attaching the leaf blade to the stem. The petiole usually has the same internal structure as the stem. Outgrowths appearing on each side of the petiole are called stipules. Leaves lacking a petiole are called sessile, or clasping when they partly surround the...
; or they may be subpetiolate, meaning they have very small petioles. The leaf sheaths are cylindrical, sometimes striped with red, and typically glabrous, but usually have margins that are puberulent or pilose, meaning lined with fine, soft hairs. The leaf blades range from narrowly lanceolate, or lance-shaped, to ovate-elliptic, between egg-shaped and ellipse
Ellipse
In geometry, an ellipse is a plane curve that results from the intersection of a cone by a plane in a way that produces a closed curve. Circles are special cases of ellipses, obtained when the cutting plane is orthogonal to the cone's axis...
-shaped. They measure 3–12 cm (1–4½ in) by 1–4 cm (½–1½ in) wide. The blades range from glabrous to puberulent and have scabrescent, or slightly rough, margins. Their tips are acute, meaning they come to a point quickly, to acuminate, meaning the point develops gradually. The leaf bases are oblique, or uneven.
The flower
Flower
A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants . The biological function of a flower is to effect reproduction, usually by providing a mechanism for the union of sperm with eggs...
s are arranged on inflorescence
Inflorescence
An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Strictly, it is the part of the shoot of seed plants where flowers are formed and which is accordingly modified...
s called cincinni (singular: cincinnus), which are also called scorpioid cymes. This is a form of a monochasium where the lateral branches arise alternately. The cincinni are subtended by a spathe, a modified leaf. The solitary spathes usually measure 1.2–3 cm long (½–1¼ in), but some may be up to 3.5 cm (1½ in) in length, while they are 0.8–1.3 cm (¼–½ in) tall, but sometimes up to 1.8 cm (¾ in). The uncurved spathes typically have a cordate, or heart-shaped, whitish base, which contrasts with its dark green veins. Their margins lack hairs, are somewhat scabrous, or rough, and are unfused, meaning they are distinct to the base. Their apices are acute to acuminate while the surfaces are glabrous, puberulent, or hirsute-ciliate, meaning with longer, shaggier hairs. The spathes are borne on peduncle
Peduncle (botany)
In botany, a peduncle is a stem supporting an inflorescence, or after fecundation, an infructescence.The peduncle is a stem, usually green and without leaves, though sometimes colored or supporting small leaves...
s, or stalks, that measure 0.8–3.5 cm (¼–1½ in) and sometimes up to 5 cm (2 in) long.
Bract
In botany, a bract is a modified or specialized leaf, especially one associated with a reproductive structure such as a flower, inflorescence axis, or cone scale. Bracts are often different from foliage leaves. They may be smaller, larger, or of a different color, shape, or texture...
eoles that fall off early in development. The pedicel
Pedicel (botany)
A pedicel is a stem that attaches single flowers to the main stem of the inflorescence. It is the branches or stalks that hold each flower in an inflorescence that contains more than one flower....
s supporting single flowers, and later the fruits, are erect initially but curve when in fruit. They measure about 3–4 mm (0.11–0.16 in). The 3 concave, membranous sepal
Sepal
A sepal is a part of the flower of angiosperms . Collectively the sepals form the calyx, which is the outermost whorl of parts that form a flower. Usually green, sepals have the typical function of protecting the petals when the flower is in bud...
s are inconspicuous, but persist after the fruit develops; the lateral pair are fused basally, measure only 4.5–5 mm (0.18–0.2 in) long by 3–3.7 mm (0.11–0.15 in) wide, and are elliptic and glabrous. The lower sepal is lanceolate and about 4.5 mm (0.18 in) long by about 2.2 mm (0.09 in) wide. The 2 upper petal
Petal
Petals are modified leaves that surround the reproductive parts of flowers. They often are brightly colored or unusually shaped to attract pollinators. Together, all of the petals of a flower are called a corolla. Petals are usually accompanied by another set of special leaves called sepals lying...
s are blue to indigo
Indigo
Indigo is a color named after the purple dye derived from the plant Indigofera tinctoria and related species. The color is placed on the electromagnetic spectrum between about 420 and 450 nm in wavelength, placing it between blue and violet...
in colour, while the much smaller lower petal is white. The upper two petals measure 9–10 mm (0.35–0.39 in) long by 8–10 mm (0.31–0.39 in) wide, while the lower petal is 5–6 mm (0.2–0.24 in) long by about 6 mm (0.24 in) wide. The 2 upper petals are composed of a claw about 3 mm (0.11 in) long and a broadly ovate limb with an acute apex and a cuneate-cordate base.
There are three anticous fertile stamens, meaning they are on the lower part of the flower, and three posticous infertile stamens, meaning they are on the upper part of the flower. These infertile stamens are termed staminode
Staminode
In botany, a staminode is an often rudimentary, sterile or abortive stamen. This means that it does not produce pollen. Staminodes are frequently inconspicuous and stamen-like, usually occurring at the inner whorl of the flower, but are also sometimes long enough to protrude from the...
s. The fertile stamens are dimorphic
Sexual dimorphism
Sexual dimorphism is a phenotypic difference between males and females of the same species. Examples of such differences include differences in morphology, ornamentation, and behavior.-Examples:-Ornamentation / coloration:...
: the lateral pair have maroon
Maroon (color)
Maroon is a dark red color.-Etymology:Maroon is derived from French marron .The first recorded use of maroon as a color name in English was in 1789.-Maroon :...
to indigo anther
Stamen
The stamen is the pollen producing reproductive organ of a flower...
s that measure about 2 mm (0.8 in) long and are elliptic with a base that is sagittate or arrowhead-shaped. Their filament
Stamen
The stamen is the pollen producing reproductive organ of a flower...
s are about 10–12 mm (0.39–0.47 in) long. The central fertile stamen has a yellow, elliptic anther with a maroon connective
Stamen
The stamen is the pollen producing reproductive organ of a flower...
and a base that is hastate or spearhead-shaped, but with the lobes at right angles. The anther measures about 2.5 mm (0.1 in) long while its filament is about 5–6 mm (0.2–0.24 in) long. The three staminodes are all alike with yellow, cruciform, or cross-shaped, antherodes that are about 2 mm (0.08 in) long on filaments about 3 mm (0.12 in) long. Sometimes the antherodes will have a central maroon spot. Each antherode has two abortive lateral pollen sacks. The ovary is ellipsoid, about 2 mm (0.08 in) long and has a style
Gynoecium
Gynoecium is most commonly used as a collective term for all carpels in a flower. A carpel is the ovule and seed producing reproductive organ in flowering plants. Carpels are derived from ovule-bearing leaves which evolved to form a closed structure containing the ovules...
that is about 1.3 cm (0.51 in) long.
The fruit
Fruit
In broad terms, a fruit is a structure of a plant that contains its seeds.The term has different meanings dependent on context. In non-technical usage, such as food preparation, fruit normally means the fleshy seed-associated structures of certain plants that are sweet and edible in the raw state,...
is a dehiscent, ellipsoid capsule
Capsule (fruit)
In botany a capsule is a type of simple, dry fruit produced by many species of flowering plants. A capsule is a structure composed of two or more carpels that in most cases is dehiscent, i.e. at maturity, it splits apart to release the seeds within. A few capsules are indehiscent, for example...
with two locule
Locule
A locule is a small cavity or compartment within an organ or part of an organism ....
s each containing two seeds. The capsule is glabrous, brown, measures 4.5–8 mm (0.18–0.31 in) long, and dehisces into two valves. The seed
Seed
A seed is a small embryonic plant enclosed in a covering called the seed coat, usually with some stored food. It is the product of the ripened ovule of gymnosperm and angiosperm plants which occurs after fertilization and some growth within the mother plant...
s are brown or brownish yellow in colour and deltoid, or roughly triangular in outline. They are dorsiventral, meaning they have distinct upper and lower surfaces, with the ventral, or lower, surface being planar and the dorsal, or upper, surface being convex. Seeds range in length from 2.5–4.2 mm (0.1–0.16 in), but seeds as short as 2 cm (0.08 in) can occur, while they are 2.2–3 mm (0.09–0.12 in) across. The surfaces are rugose pitted-reticulate and are densely covered with smaller farinose granules with sparse larger farinose granules.
Taxonomy
Commelina communis was first described in 1753 by Carolus LinnaeusCarolus Linnaeus
Carl Linnaeus , also known after his ennoblement as , was a Swedish botanist, physician, and zoologist, who laid the foundations for the modern scheme of binomial nomenclature. He is known as the father of modern taxonomy, and is also considered one of the fathers of modern ecology...
in the first edition of his Species Plantarum
Species Plantarum
Species Plantarum was first published in 1753, as a two-volume work by Carl Linnaeus. Its prime importance is perhaps that it is the primary starting point of plant nomenclature as it exists today. This means that the first names to be considered validly published in botany are those that appear...
, along with eight other species in the genus. The plant serves as the type
Biological type
In biology, a type is one particular specimen of an organism to which the scientific name of that organism is formally attached...
species for the genus. The scientific name Commelina was chosen based on the Asiatic dayflower. Linnaeus picked the name in honour of the Dutch botanists Jan
Jan Commelin
Jan Commelin , also known as Jan Commelijn or Johannes Commelinus, was the son of Isaac Commelin a historian; his brother Casparus was a bookseller and newspaper publisher. Jan a botanist became a professor of botany when many plants were imported from the Cape and Ceylon and a new system had to be...
and Caspar Commelijn
Caspar Commelijn
Caspar Commelijn or Caspar Commelin , was a Dutch botanist. He was the son of the bookseller, historian and publisher, Casparus Commelijn and his first wife, Margrieta Heydanus...
, using the two large showy petals of Commelina communis to symbolise them. A number of names given to plants thought to be different species have fallen into synonymy
Synonym (taxonomy)
In scientific nomenclature, a synonym is a scientific name that is or was used for a taxon of organisms that also goes by a different scientific name. For example, Linnaeus was the first to give a scientific name to the Norway spruce, which he called Pinus abies...
with the Asiatic dayflower. Albrecht Wilhelm Roth
Albrecht Wilhelm Roth
Albrecht Wilhelm Roth was a physician and botanist who was a native of Dötlingen, Germany.He studied medicine at the Universities of Halle and Erlangen, where he received his doctorate in 1778....
created the first such synonym, Commelina polygama, in 1790. Wenceslas Bojer
Wenceslas Bojer
Wenceslas Bojer was a notable naturalist and botanist.He was born to Simon Bojer and Barbara Staub....
described what he believed were two new species, Commelina barabata and Commelina salicifolia, in his work Hortus Mauritianus, both of which were quickly found to be identical to C. communis. Karl Sigismund Kunth created the synonym Commelina willdenowii in 1841. Finally, Korean populations of the species were named under the synonym Commelina coreana in 1910 by Augustin Abel Hector Léveillé.
Several varieties have also been named. Commelina communis var. ludens was created by C.B. Clarke after demoting it from the full species status in which is was placed by Friedrich Anton Wilhelm Miquel
Friedrich Anton Wilhelm Miquel
Friedrich Anton Wilhelm Miquel was a Dutch botanist.He was head of the botanical gardens at Rotterdam , Amsterdam and Utrecht . He directed the Rijksherbarium at Leiden from 1862...
in 1861. The variety is distinguished by its darker flowers, antherodes with central maroon spots, less well developed distal cymes that usually do not produce a flower, and spathes that are proportionally broader. Jisaburo Ohwi
Jisaburo Ohwi
was Japanese botanist. He was a distinguished member of the Faculty of Science of Kyoto Imperial University. He is perhaps best known for his 1953 .- Species names after Ohwi :* Carex ohwii Masam.* Cyperus ohwii Kük....
's Flora of Japan also treats the variety as geographically distinct, stating that it is restricted to mountainous areas. This variety is still accepted by some workers, but others, such Robert B. Faden, consider it impossible to consistently separate from the type variety. Another variety, C. communis var. hortensis, which was named by Tomitaro Makino
Tomitaro Makino
thumb|200px|Tomitaro Makino was a pioneer Japanese botanist noted for his taxonomic work. He has been called "Father of Japanese Botany", as he was one of the first Japanese botanists to work extensively on classifying Japanese plants using the system developed by Linnaeus...
and is apparently a cultivated variety which originated from C. communis var. ludens in Japan, is also accepted by some botanists. It differs in having larger showy flowers which are used to produce a dye (see "Uses" section below). A variegated form called C. communis var. ludens f. aureostriata named by Frank C. MacKeever in 1961 is known to occur randomly throughout much of the species' range.
Distribution and habitat
The plant's native distribution includes much of East AsiaEast Asia
East Asia or Eastern Asia is a subregion of Asia that can be defined in either geographical or cultural terms...
and Southeast Asia
Southeast Asia
Southeast Asia, South-East Asia, South East Asia or Southeastern Asia is a subregion of Asia, consisting of the countries that are geographically south of China, east of India, west of New Guinea and north of Australia. The region lies on the intersection of geological plates, with heavy seismic...
. Country by country, it is found in China
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...
, Taiwan
Taiwan
Taiwan , also known, especially in the past, as Formosa , is the largest island of the same-named island group of East Asia in the western Pacific Ocean and located off the southeastern coast of mainland China. The island forms over 99% of the current territory of the Republic of China following...
, Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
, Korea
Korea
Korea ) is an East Asian geographic region that is currently divided into two separate sovereign states — North Korea and South Korea. Located on the Korean Peninsula, Korea is bordered by the People's Republic of China to the northwest, Russia to the northeast, and is separated from Japan to the...
, the Russian Far East
Russian Far East
Russian Far East is a term that refers to the Russian part of the Far East, i.e., extreme east parts of Russia, between Lake Baikal in Eastern Siberia and the Pacific Ocean...
, Cambodia
Cambodia
Cambodia , officially known as the Kingdom of Cambodia, is a country located in the southern portion of the Indochina Peninsula in Southeast Asia...
, Laos
Laos
Laos Lao: ສາທາລະນະລັດ ປະຊາທິປະໄຕ ປະຊາຊົນລາວ Sathalanalat Paxathipatai Paxaxon Lao, officially the Lao People's Democratic Republic, is a landlocked country in Southeast Asia, bordered by Burma and China to the northwest, Vietnam to the east, Cambodia to the south and Thailand to the west...
, Malaysia, Thailand
Thailand
Thailand , officially the Kingdom of Thailand , formerly known as Siam , is a country located at the centre of the Indochina peninsula and Southeast Asia. It is bordered to the north by Burma and Laos, to the east by Laos and Cambodia, to the south by the Gulf of Thailand and Malaysia, and to the...
and Vietnam
Vietnam
Vietnam – sometimes spelled Viet Nam , officially the Socialist Republic of Vietnam – is the easternmost country on the Indochina Peninsula in Southeast Asia. It is bordered by China to the north, Laos to the northwest, Cambodia to the southwest, and the South China Sea –...
. Within China it is found in all provinces except Qinghai
Qinghai
Qinghai ; Oirat Mongolian: ; ; Salar:) is a province of the People's Republic of China, named after Qinghai Lake...
, Hainan
Hainan
Hainan is the smallest province of the People's Republic of China . Although the province comprises some two hundred islands scattered among three archipelagos off the southern coast, of its land mass is Hainan Island , from which the province takes its name...
, Xinjiang
Xinjiang
Xinjiang is an autonomous region of the People's Republic of China. It is the largest Chinese administrative division and spans over 1.6 million km2...
, and Tibet
Tibet Autonomous Region
The Tibet Autonomous Region , Tibet or Xizang for short, also called the Xizang Autonomous Region is a province-level autonomous region of the People's Republic of China , created in 1965....
. In Japan the plant is found throughout the bulk of the country from Hokkaido
Hokkaido
, formerly known as Ezo, Yezo, Yeso, or Yesso, is Japan's second largest island; it is also the largest and northernmost of Japan's 47 prefectural-level subdivisions. The Tsugaru Strait separates Hokkaido from Honshu, although the two islands are connected by the underwater railway Seikan Tunnel...
south to Kyūshū
Kyushu
is the third largest island of Japan and most southwesterly of its four main islands. Its alternate ancient names include , , and . The historical regional name is referred to Kyushu and its surrounding islands....
. In Russia the Asiatic dayflower is found naturally on Sakhalin
Sakhalin
Sakhalin or Saghalien, is a large island in the North Pacific, lying between 45°50' and 54°24' N.It is part of Russia, and is Russia's largest island, and is administered as part of Sakhalin Oblast...
as well as in the Far East
Russian Far East
Russian Far East is a term that refers to the Russian part of the Far East, i.e., extreme east parts of Russia, between Lake Baikal in Eastern Siberia and the Pacific Ocean...
in areas surrounding the Ussuri River
Ussuri River
The Usuri ula is a river in the south of the Outer Manchuria and east of Inner Manchuria . It rises in the Sikhote-Alin range, flowing north, forming part of the Sino-Russian border based on the Sino-Russian Convention of Peking in 1860, until it joins the Amur River at Khabarovsk . It is...
.
The species has been introduced to much of Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
and eastern North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
. On the former continent it is now found from Central Europe
Central Europe
Central Europe or alternatively Middle Europe is a region of the European continent lying between the variously defined areas of Eastern and Western Europe...
well into western Russia
Russia
Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...
. Specifically it is known from Italy
Italy
Italy , officially the Italian Republic languages]] under the European Charter for Regional or Minority Languages. In each of these, Italy's official name is as follows:;;;;;;;;), is a unitary parliamentary republic in South-Central Europe. To the north it borders France, Switzerland, Austria and...
north to Switzerland
Switzerland
Switzerland name of one of the Swiss cantons. ; ; ; or ), in its full name the Swiss Confederation , is a federal republic consisting of 26 cantons, with Bern as the seat of the federal authorities. The country is situated in Western Europe,Or Central Europe depending on the definition....
, east through the region encompassing the former Yugoslavia
Yugoslavia
Yugoslavia refers to three political entities that existed successively on the western part of the Balkans during most of the 20th century....
, east into the regions around the Black Sea
Black Sea
The Black Sea is bounded by Europe, Anatolia and the Caucasus and is ultimately connected to the Atlantic Ocean via the Mediterranean and the Aegean seas and various straits. The Bosphorus strait connects it to the Sea of Marmara, and the strait of the Dardanelles connects that sea to the Aegean...
including Romania
Romania
Romania is a country located at the crossroads of Central and Southeastern Europe, on the Lower Danube, within and outside the Carpathian arch, bordering on the Black Sea...
, the Moldavia Region
Moldavia
Moldavia is a geographic and historical region and former principality in Eastern Europe, corresponding to the territory between the Eastern Carpathians and the Dniester river...
, and the Ukraine
Ukraine
Ukraine is a country in Eastern Europe. It has an area of 603,628 km², making it the second largest contiguous country on the European continent, after Russia...
but excluding Crimea
Crimea
Crimea , or the Autonomous Republic of Crimea , is a sub-national unit, an autonomous republic, of Ukraine. It is located on the northern coast of the Black Sea, occupying a peninsula of the same name...
, north through the Dnieper Basin
Dnieper River
The Dnieper River is one of the major rivers of Europe that flows from Russia, through Belarus and Ukraine, to the Black Sea.The total length is and has a drainage basin of .The river is noted for its dams and hydroelectric stations...
into Belarus
Belarus
Belarus , officially the Republic of Belarus, is a landlocked country in Eastern Europe, bordered clockwise by Russia to the northeast, Ukraine to the south, Poland to the west, and Lithuania and Latvia to the northwest. Its capital is Minsk; other major cities include Brest, Grodno , Gomel ,...
and Russia
Russia
Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...
, continuing east into the regions surrounding the Don River
Don River (Russia)
The Don River is one of the major rivers of Russia. It rises in the town of Novomoskovsk 60 kilometres southeast from Tula, southeast of Moscow, and flows for a distance of about 1,950 kilometres to the Sea of Azov....
and the Volga River
Volga River
The Volga is the largest river in Europe in terms of length, discharge, and watershed. It flows through central Russia, and is widely viewed as the national river of Russia. Out of the twenty largest cities of Russia, eleven, including the capital Moscow, are situated in the Volga's drainage...
south to their intersection at the Volga-Don Canal
Volga-Don Canal
Lenin Volga–Don Shipping Canal is a canal which connects the Volga River and the Don River at their closest points. The length of the waterway is 101 km ....
and north to the regions around Lake Ladoga
Lake Ladoga
Lake Ladoga is a freshwater lake located in the Republic of Karelia and Leningrad Oblast in northwestern Russia, not far from Saint Petersburg. It is the largest lake in Europe, and the 14th largest lake by area in the world.-Geography:...
and Lake Ilmen
Lake Ilmen
Ilmen is a historically important lake in the Novgorod Oblast of Russia, formerly a vital part of the Trade route from the Varangians to the Greeks. The city of Novgorod lies six kilometers below the lake's outflow....
, and farther east to the regions of the Ural River
Ural River
The Ural or Jayıq/Zhayyq , known as Yaik before 1775, is a river flowing through Russia and Kazakhstan. It arises in the southern Ural Mountains and ends at the Caspian Sea. Its total length is 1,511 mi making it the third longest river in Europe after the Volga and the Danube...
and the Kama River
Kama River
Kama is a major river in Russia, the longest left tributary of the Volga and the largest one in discharge; in fact, it is larger than the Volga before junction....
. It is also found in the Czech Republic
Czech Republic
The Czech Republic is a landlocked country in Central Europe. The country is bordered by Poland to the northeast, Slovakia to the east, Austria to the south, and Germany to the west and northwest....
and Slovakia
Slovakia
The Slovak Republic is a landlocked state in Central Europe. It has a population of over five million and an area of about . Slovakia is bordered by the Czech Republic and Austria to the west, Poland to the north, Ukraine to the east and Hungary to the south...
. It is present in the provinces of Ontario
Ontario
Ontario is a province of Canada, located in east-central Canada. It is Canada's most populous province and second largest in total area. It is home to the nation's most populous city, Toronto, and the nation's capital, Ottawa....
and Quebec
Quebec
Quebec or is a province in east-central Canada. It is the only Canadian province with a predominantly French-speaking population and the only one whose sole official language is French at the provincial level....
in Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
, and in most of the eastern and central American
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
states from Massachusetts
Massachusetts
The Commonwealth of Massachusetts is a state in the New England region of the northeastern United States of America. It is bordered by Rhode Island and Connecticut to the south, New York to the west, and Vermont and New Hampshire to the north; at its east lies the Atlantic Ocean. As of the 2010...
and New York
New York
New York is a state in the Northeastern region of the United States. It is the nation's third most populous state. New York is bordered by New Jersey and Pennsylvania to the south, and by Connecticut, Massachusetts and Vermont to the east...
in the northeast, west to Minnesota
Minnesota
Minnesota is a U.S. state located in the Midwestern United States. The twelfth largest state of the U.S., it is the twenty-first most populous, with 5.3 million residents. Minnesota was carved out of the eastern half of the Minnesota Territory and admitted to the Union as the thirty-second state...
and south through the Great Plains
Great Plains
The Great Plains are a broad expanse of flat land, much of it covered in prairie, steppe and grassland, which lies west of the Mississippi River and east of the Rocky Mountains in the United States and Canada. This area covers parts of the U.S...
to Texas
Texas
Texas is the second largest U.S. state by both area and population, and the largest state by area in the contiguous United States.The name, based on the Caddo word "Tejas" meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in...
and east to extreme northern Florida
Florida
Florida is a state in the southeastern United States, located on the nation's Atlantic and Gulf coasts. It is bordered to the west by the Gulf of Mexico, to the north by Alabama and Georgia and to the east by the Atlantic Ocean. With a population of 18,801,310 as measured by the 2010 census, it...
in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
.
Within its native distribution, the plant is most typical of moist, open places, including shady forest edges and wet areas of crop fields, orchards, ditches, and roadsides. In Taiwan
Taiwan
Taiwan , also known, especially in the past, as Formosa , is the largest island of the same-named island group of East Asia in the western Pacific Ocean and located off the southeastern coast of mainland China. The island forms over 99% of the current territory of the Republic of China following...
, it can be found from 350 to 2400 m (1000–7500 ft) elevation. In areas where the Asiatic dayflower is an introduced weed it is most common in waste places, but also along the edges of fields, woods, and marshes, and occasionally penetrating into woods.
Ecology
The Asiatic dayflower is considered an invasive weedWeed
A weed in a general sense is a plant that is considered by the user of the term to be a nuisance, and normally applied to unwanted plants in human-controlled settings, especially farm fields and gardens, but also lawns, parks, woods, and other areas. More specifically, the term is often used to...
in many areas where it has been introduced. In the United States, the Virginia Department of Conservation and Recreation
Virginia Department of Conservation and Recreation
The Virginia Department of Conservation and Recreation is a department of the government of Virginia; it oversees all Virginia state parks and Natural Area Preserves.-External links:*...
, for example, categorises the species as "occasionally invasive" in its Invasive Plant Species of Virginia. This means that the plant will "not affect ecosystem processes, but may alter plant community composition by outcompeting one or more native plant species". The species is typically limited to disturbed sites, whence it spreads relatively slowly. Within its native range in China it is also sometimes considered a pest, especially in the northeast of the country where it has caused economically significant agricultural damage in orchards.
The Asiatic dayflower has been used in pollination
Pollination
Pollination is the process by which pollen is transferred in plants, thereby enabling fertilisation and sexual reproduction. Pollen grains transport the male gametes to where the female gamete are contained within the carpel; in gymnosperms the pollen is directly applied to the ovule itself...
studies concerning the behaviour of plants in relation to their pollinators. One important experiment tested the hypotheses that floral guides (i.e. various patterns and colours on anthers and petals) simultaneously promote pollinator visitation and prevent visits where the pollinator fails to come into contact with the stigma or anthers, termed pollen theft. As the flowers of the Asiatic dayflower lack nectar, they offer only pollen as a reward to their visitors. To attract pollinators, the plant has three types of brightly colored floral organs: the large blue petals, fertile yellow anthers, and infertile yellow antherodes that lack pollen. When the infertile antherodes were experimentally removed in natural populations, the number of total floral visitor landings was reduced, supporting the hypothesis that these infertile anthers essentially trick their pollinators into believing they offer more than they actually do. When the central, bright yellow fertile anther was removed, leaving only two brown fertile anthers, the frequency of legitimate flower landings decreased, meaning that the visitors were not pollinating the flowers, suggesting that floral signals also prevent "theft", or visits where the pollinators take pollen, but do not place any on the stigma. Thus both the fertile anthers and the infertile antherodes were shown to play an important role in both increasing visitor landings and orienting floral visitors toward a landing point appropriate for pollination.
Copper
Copper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish...
, while the plant with the next highest concentration, Polygonum
Polygonum
Polygonum is a genus in the Polygonaceae family. Common names include knotweed, knotgrass, bistort, tear-thumb, mile-a-minute, and several others. In the Middle English glossary of herbs "Alphita" , it was known as ars-smerte. There have been various opinions about how broadly the genus should be...
macrathum, had 286 mg/kg−1. Five of the species examined, including the Asiatic dayflower, also showed high concentrations of other metals such as zinc
Zinc
Zinc , or spelter , is a metallic chemical element; it has the symbol Zn and atomic number 30. It is the first element in group 12 of the periodic table. Zinc is, in some respects, chemically similar to magnesium, because its ion is of similar size and its only common oxidation state is +2...
, lead
Lead
Lead is a main-group element in the carbon group with the symbol Pb and atomic number 82. Lead is a soft, malleable poor metal. It is also counted as one of the heavy metals. Metallic lead has a bluish-white color after being freshly cut, but it soon tarnishes to a dull grayish color when exposed...
, and cadmium
Cadmium
Cadmium is a chemical element with the symbol Cd and atomic number 48. This soft, bluish-white metal is chemically similar to the two other stable metals in group 12, zinc and mercury. Similar to zinc, it prefers oxidation state +2 in most of its compounds and similar to mercury it shows a low...
. The results suggest that the Asiatic dayflower is a good candidate for copper mine spoil revegetation and phytoremediation.
Ten species of fungi have been found on the Asiatic dayflower, four of which can infect the plant, while 12 species of insects are known to be associated with it. Two of the fungi, Kordyana commelinae and Phyllosticta commelinicola, are thought to be host specific with the Asiatic dayflower. Of the ten fungi seven are Basidiomycota
Basidiomycota
Basidiomycota is one of two large phyla that, together with the Ascomycota, comprise the subkingdom Dikarya within the Kingdom Fungi...
and three are Ascomycota
Ascomycota
The Ascomycota are a Division/Phylum of the kingdom Fungi, and subkingdom Dikarya. Its members are commonly known as the Sac fungi. They are the largest phylum of Fungi, with over 64,000 species...
. Nine of the 12 insects associated with the plant are beetle
Beetle
Coleoptera is an order of insects commonly called beetles. The word "coleoptera" is from the Greek , koleos, "sheath"; and , pteron, "wing", thus "sheathed wing". Coleoptera contains more species than any other order, constituting almost 25% of all known life-forms...
s, seven of which are in the genus Lema, while the other two are in the families Hispidae and Pentatomidae
Pentatomidae
Pentatomidae, Greek pente meaning five and tomos meaning section, is a family of insects belonging to order hemiptera that includes some of the stink bugs and shield bugs. Their antennae are 5-segmented, which gives the family its scientific name. Their bodies are usually shield-shaped...
. The remaining three insects include one species of moth
Moth
A moth is an insect closely related to the butterfly, both being of the order Lepidoptera. Moths form the majority of this order; there are thought to be 150,000 to 250,000 different species of moth , with thousands of species yet to be described...
, Pergesa acteus, and two true bugs, namely Aphis
Aphis
Aphis may refer to:* Aphis, a genus of aphid species* Animal and Plant Health Inspection Service , organizational unit of the USDA* HMS Aphis , Royal Navy insect class gunboat...
commilinae and Aeschrocoris ceylonicus. Important pollinators include the Asian honeybee, Apis cerana
Apis cerana
Apis cerana, or the Asiatic honey bee , is a species of honey bee found in southern and southeastern Asia, such as China, India, Japan, Malaysia, Nepal, Bangladesh and Papua New Guinea. This species is the sister species of Apis koschevnikovi, and both are in the same subgenus as the Western honey...
, syrphid fly, Episyrphus balteatus
Episyrphus balteatus
Episyrphus balteatus, sometimes called the marmalade hoverfly , is a relatively small hoverfly of the Syrphidae family, widespread throughout all continents. Like most other hoverflies it mimics a much more dangerous insect, the solitary wasp, though it is a quite harmless species. The upper...
, and the bumble bee species Bombus diversus.
Medicine and food
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...
it is used as a medicinal herb with febrifugal, antipyretic
Antipyretic
Antipyretics ; an-tee-pahy-ret-iks; from the Greek anti, against, and pyreticus, are drugs or herbs that reduce fever. Normally, they will not lower body temperature if one does not have a fever. Antipyretics cause the hypothalamus to override an interleukin-induced increase in temperature...
, anti-inflammatory
Anti-inflammatory
Anti-inflammatory refers to the property of a substance or treatment that reduces inflammation. Anti-inflammatory drugs make up about half of analgesics, remedying pain by reducing inflammation as opposed to opioids, which affect the central nervous system....
, and diuretic
Diuretic
A diuretic provides a means of forced diuresis which elevates the rate of urination. There are several categories of diuretics. All diuretics increase the excretion of water from bodies, although each class does so in a distinct way.- Medical uses :...
effects. Additionally, it is also used for treating sore throats and tonsillitis
Tonsillitis
Tonsillitis is an inflammation of the tonsils most commonly caused by viral or bacterial infection. Symptoms of tonsillitis include sore throat and fever. While no treatment has been found to shorten the duration of viral tonsillitis, bacterial causes are treatable with antibiotics...
. Recent pharmacological investigations have revealed that the Asiatic dayflower contains at least five active compounds. One of these, p-hydroxycinnamic acid, shows antibacterial activity, while another, D-mannitol, has an antitussive effect. In China and India the plant is also used as a vegetable and fodder
Fodder
Fodder or animal feed is any agricultural foodstuff used specifically to feed domesticated livestock such as cattle, goats, sheep, horses, chickens and pigs. Most animal feed is from plants but some is of animal origin...
crop.
Pigment and dye
In JapanJapan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
there is a sizeable dye industry devoted to the plant. The purported variety Commelina communis var. hortensis, which is apparently a cultivated form of another putative variety, namely Commelina communis var. ludens, is grown for its larger petals which yield a blue juice used in manufacturing a paper called boshigami or , which is the famous product of the Yamada village in the Shiga prefecture
Shiga Prefecture
is a prefecture of Japan, which forms part of the Kansai region on Honshu Island. The capital is the city of Ōtsu.- History :Shiga was known as Ōmi Province or Gōshū before the prefectural system was established...
. The paper is usually resoaked, allowing the pigment to be reabsorbed in water for use as a dye. The dye, also referred to as aigami, but also as or , is composed primarily of malonyl awobanin and was used extensively as a colorant in 18th and 19th century woodblock prints in Japan, especially during the early Ukiyo-e
Ukiyo-e
' is a genre of Japanese woodblock prints and paintings produced between the 17th and the 20th centuries, featuring motifs of landscapes, tales from history, the theatre, and pleasure quarters...
era. The colorant is known to have been used by several famous Ukiyo-e artists such as Torii Kiyonaga
Torii Kiyonaga
This article is about the ukiyo-e artist; for samurai named Kiyonaga, see Naito Kiyonaga and Koriki Kiyonaga. was a Japanese ukiyo-e printmaker and painter of the Torii school. Originally Sekiguchi Shinsuke, the son of an Edo bookseller, he took on Torii Kiyonaga as an art-name...
. However, aigami fades to a greenish yellow in a matter of months when exposed to sunlight. As a result, the color was eventually replaced by imported Prussian blue
Prussian blue
Prussian blue is a dark blue pigment with the idealized formula Fe718. Another name for the color Prussian blue is Berlin blue or, in painting, Parisian blue. Turnbull's blue is the same substance but is made from different reagents....
, a much more stable colour with its first commercial appearance in 1829 in the work of Keisai Eisen
Keisai Eisen
Keisai Eisen was a Japanese ukiyo-e artist who specialised in bijinga . His best works, including his ōkubi-e , are considered to be masterpieces of the "decadent" Bunsei Era...
. The plant is also grown for its dye in northern China. Additional uses of the colourant include making preparatory designs on cloth before dyeing with other pigments.
Plant physiology and development
Commelina communis is also used as a model organismModel organism
A model organism is a non-human species that is extensively studied to understand particular biological phenomena, with the expectation that discoveries made in the organism model will provide insight into the workings of other organisms. Model organisms are in vivo models and are widely used to...
in plant physiology
Plant physiology
Plant physiology is a subdiscipline of botany concerned with the functioning, or physiology, of plants. Closely related fields include plant morphology , plant ecology , phytochemistry , cell biology, and molecular biology.Fundamental processes such as photosynthesis, respiration, plant nutrition,...
and plant development to a limited extent, especially in relation to stomatal physiology and the biology of pigmentation development. For example, the blue pigmentation of Asiatic dayflower petals was shown to consist of a large complex of six anthocyanin
Anthocyanin
Anthocyanins are water-soluble vacuolar pigments that may appear red, purple, or blue according to pH...
s, six flavones, and two associated magenesium ions, demonstrating that supramolecular complexes of several copigments and chelated
Chelation
Chelation is the formation or presence of two or more separate coordinate bonds between apolydentate ligand and a single central atom....
metals often determine colour. Other research on the plant has helped to explain photoreceptor systems in plants such as their stomatal responses to blue light versus red light spectrums, abscisic acid
Abscisic acid
Abscisic acid , also known as abscisin II and dormin, is a plant hormone. ABA functions in many plant developmental processes, including bud dormancy. It is degraded by the enzyme -abscisic acid 8'-hydroxylase.-Function:...
perception and its role in cell signaling, particularly concerning the chemical's role in stomatal function, the role of vanadate
Vanadate
In chemistry, a vanadate is a compound containing an oxoanion of vanadium generally in its highest oxidation state of +5. The simplest vanadate ion is the tetrahedral, orthovanadate, VO43− anion, which is present in e.g. sodium orthovanadate and in solutions of V2O5 in strong base...
s in inhibiting stomatal opening, and the necessity of calcium in stomatal closure, among other topics. Its widespread use in stomatal studies is due to the fact that the leaves produce exceptional epidermal peels that are consistently one cell layer thick. This same quality makes the plant popular for use in laboratory exercises in higher education for demonstrating stomatal function and morphology. Guard cell
Guard cell
Guard cells are specialized cells located in the Leaf epidermis of plants. Pairs of guard cells surround tiny stomatal airway pores . These tiny holes in the surface of leaves are necessary for gas exchange into and out of the plant; carbon dioxide enters the plant allowing the carbon fixation...
turgor pressure
Turgor pressure
Turgor Pressure or turgidity is the main pressure of the cell contents against the cell wall in plant cells and bacteria cells, determined by the water content of the vacuole, resulting from osmotic pressure, i.e...
and its regulation in the opening and closing of stomata is particularly easy to demonstrate with the Asiatic dayflower.