Asiatic dayflower | |
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Commelina communis flowers | |
Scientific classification ![]() | |
Kingdom: | Plantae |
Clade: | Tracheophytes |
Clade: | Angiosperms |
Clade: | Monocots |
Clade: | Commelinids |
Order: | Commelinales |
Family: | Commelinaceae |
Genus: | Commelina |
Species: | C. communis |
Binomial name | |
Commelina communis | |
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Green = native, Red = introduced |
Commelina communis, commonly known as the Asiatic dayflower, is an herbaceous annual plant in the dayflower family. It gets its name because the blooms last for only one day. [1] It is native throughout much of East Asia and northern parts of Southeast Asia. In China, the plant is known as yazhicao (simplified Chinese : 鸭 跖 草 ; traditional Chinese :鴨跖草; pinyin :yāzhīcǎo), [2] roughly translating to "duckfoot herb", while in Japan it is known as tsuyukusa ( 露 草 , tsuyukusa), [3] 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 small 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. [4] [5] The diffusely branched stems tend to root at the basal nodes. [5] 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. [2] [4] 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. [4] 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. [2] [4] 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+1⁄4–4+3⁄4 in) by 1–4 cm (1⁄2–1+1⁄2 in) wide. [2] [5] The blades range from glabrous to puberulent and have scabrescent, or slightly rough, margins. [2] [4] 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. [4] [5]
The flowers are arranged on inflorescences 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 (1⁄2–1+1⁄4 in) long, but some may be up to 3.5 cm (1+1⁄2 in) in length, while they are 0.8–1.3 cm (1⁄4–1⁄2 in) tall, but sometimes up to 1.8 cm (3⁄4 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. [2] [5] The spathes are borne on peduncles, or stalks, that measure 0.8–3.5 cm (1⁄4–1+1⁄2 in) and sometimes up to 5 cm (2.0 in) long. [5]
There are often two cincinni present, though the upper, or distal, cincinnus may be vestigial. [5] 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 (0.31 in) long. [2] [4] The individual flowers are subtended by bracteoles that fall off early in development. The pedicels supporting single flowers, and later the fruits, are erect initially but curve when in fruit. They measure about 3–4 mm (0.12–0.16 in). [4] The 3 concave, membranous sepals are inconspicuous, but persist after the fruit develops; the lateral pair are fused basally, measure only 4.5–5 mm (0.18–0.20 in) long by 3–3.7 mm (0.12–0.15 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 (0.087 in) wide. [4] The 2 upper petals 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 (0.20–0.24 in) long by about 6 mm (0.24 in) wide. [2] [4] The 2 upper petals are composed of a claw about 3 mm (0.12 in) long and a broadly ovate limb with an acute apex and a cuneate-cordate base. [4]
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 staminodes. The fertile stamens are dimorphic: the lateral pair have maroon to indigo anthers that measure about 2 mm (0.079 in) long and are elliptic with a base that is sagittate or arrowhead-shaped. Their filaments 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 (0.098 in) long while its filament is about 5–6 mm (0.20–0.24 in) long. [4] The three staminodes are all alike with yellow, cruciform, or cross-shaped, antherodes that are about 2 mm (0.079 in) long on filaments about 3 mm (0.12 in) long. [4] [5] Sometimes the antherodes will have a central maroon spot. [5] Each antherode has two abortive lateral pollen sacks. The ovary is ellipsoid, about 2 mm (0.079 in) long and has a style that is about 1.3 cm (0.51 in) long. [4]
The fruit is a dehiscent, ellipsoid capsule with two locules 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. [4] [5] The seeds are brown or brownish yellow in colour and deltoid, or roughly triangular in outline. [2] [4] 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 (0.098–0.165 in), but seeds as short as 2 mm (0.079 in) can occur, while they are 2.2–3 mm (0.087–0.118 in) across. The surfaces are rugose pitted-reticulate and are densely covered with smaller farinose granules with sparse larger farinose granules. [4] [5]
Commelina communis was first described in 1753 by Carl Linnaeus in the first edition of his Species Plantarum , along with eight other species in the genus. [5] [6] 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. [5] 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. [4] [7] 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. [7] Karl Sigismund Kunth created the synonym Commelina willdenowii in 1841. [7] Finally, Korean populations of the species were named under the synonym Commelina coreana in 1910 by Augustin Abel Hector Léveillé. [7]
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 it was placed by Friedrich Anton Wilhelm Miquel in 1861. [5] [7] 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. [5] Jisaburo Ohwi's Flora of Japan also treats the variety as geographically distinct, stating that it is restricted to mountainous areas. [8] This variety is still accepted by some workers, but others, such Robert B. Faden, consider it impossible to consistently separate from the type variety. [5] 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. [9] It differs in having larger showy flowers which are used to produce a dye (see "Uses" section below). [8] 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. [5]
The plant's native distribution includes much of East Asia and Southeast Asia. Country by country, it is found in China, Taiwan, Japan, Korea, the Russian Far East, Cambodia, Laos, Malaysia, Thailand, India, Iran and Vietnam. Within China it is found in all provinces except Qinghai, Hainan, Xinjiang, and Tibet. [2] 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. [8]
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. [4] 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 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. [10] 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 state in the northeast, west to Minnesota and south through the Great Plains to Texas and east to Florida in the United States. [5]
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. [2] [4] [11] In Taiwan, it can be found from 350 to 2,400 m (1,150 to 7,870 ft) elevation. [4] 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. [5]
The Asiatic dayflower is considered an invasive weed 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. [12] 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. [13]
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. [14]
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, the highest in the 48 species tested. Commelina communis had sequestered some 361 mg/kg of copper, while the plant with the next highest concentration, Polygonum macrathum, had 286 mg/kg. 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. [15]
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 beetles, 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 . [13] Important pollinators include the Asian honeybee, Apis cerana , syrphid fly, Episyrphus balteatus , and the bumble bee species Bombus diversus. [14]
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. [2] [7] 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. [16] In China and India the plant is also used as a vegetable and fodder crop. [7]
In Japan 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 aigami ( 藍 紙 ), [3] which is the famous product of the Yamada village in the Shiga prefecture. [9] The paper is usually resoaked, allowing the pigment to be reabsorbed in water for use as a dye. [3] The dye, also referred to as aigami, but also as aobanagami ( 青 花 紙 ) or tsuyukusairo (露草色 ), [3] 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. [17] [18] The colorant is known to have been used by several famous Ukiyo-e artists such as Torii Kiyonaga. [19] 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. [20] The plant is also grown for its dye in northern China. [7] Additional uses of the colourant include making preparatory designs on cloth before dyeing with other pigments. [3]
Commelinin, the blue pigment from the flowers of C. communis, is a metalloanthocyanin. It is a complex of 4 Mg 2+ ions chelating six anthocyanin molecules. [21]
Commelina communis is also used as a model organism in plant physiology and plant development to a limited extent, especially in relation to stomatal physiology and the biology of pigmentation development. [22] For example, the blue pigmentation of Asiatic dayflower petals was shown to consist of a large complex of six anthocyanins, six flavones, and two associated magnesium ions, demonstrating that supramolecular complexes of several copigments and chelated metals often determine colour. [23] 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, [22] [24] abscisic acid perception and its role in cell signaling, particularly concerning the chemical's role in stomatal function, [22] [25] [26] the role of vanadates in inhibiting stomatal opening, [27] and the necessity of calcium in stomatal closure, [28] 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. [29]
The stamen is the pollen-producing reproductive organ of a flower. Collectively the stamens form the androecium.
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 usually different from foliage leaves. They may be smaller, larger, or of a different color, shape, or texture. Typically, they also look different from the parts of the flower, such as the petals or sepals. A plant having bracts is referred to as bracteate or bracteolate, while one that lacks them is referred to as ebracteate and ebracteolate, without bracts.
Commelina is a genus of approximately 170 species commonly called dayflowers due to the short lives of their flowers. They are less often known as widow's tears. It is by far the largest genus of its family, Commelinaceae. The Swedish taxonomist Carl Linnaeus of the 18th century named the genus after the two Dutch botanists Jan Commelijn and his nephew Caspar, each representing one of the showy petals of Commelina communis.
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 about 731 known species in 41 genera. Well known genera include Commelina (dayflowers) and Tradescantia (spiderworts). The family is diverse in both the Old World tropics and the New World tropics, with some genera present in both. The variation in morphology, especially that of the flower and inflorescence, is considered to be exceptionally high amongst the angiosperms.
Cornus canadensis is a species of flowering plant in the dogwood family Cornaceae, native to eastern Asia and North America. Common names include Canadian dwarf cornel, Canadian bunchberry, quatre-temps, crackerberry, and creeping dogwood. Unlike its relatives, which are for the most part substantial trees and shrubs, C. canadensis is a creeping, rhizomatous perennial growing to about 20 centimetres tall.
Dicentra cucullaria, Dutchman's britches, or Dutchman's breeches, is a perennial herbaceous plant, native to rich woods of eastern North America, with a disjunct population in the Columbia Basin.
Commelina tuberosa is an herbaceous perennial plant in the dayflower family which is native to Mexico but grown worldwide as an ornamental plant. It is characterized by its purple-splotched spathes with free margins, its bright blue petals of equal size, its tuberous roots, and its four to ten flowered lower cymes. In the wild, it is encountered in moist fields, open forests, or pine-oak forests. The species is sometimes considered to include the species Commelina coelestis, Commelina dianthifolia, and Commelina elliptica, such as in the Flora Mesoamericana. When these are treated as separate, they are often referred to as the "Commelina tuberosa complex". Horticulturally, the species are often treated as separate entities because of their differing habits and leaf shapes. In this sense, Commelina tuberosa is a low-growing plant with long narrow leaves.
Commelina diffusa, sometimes known as the climbing dayflower or spreading dayflower, is a pantropical herbaceous plant in the dayflower family. It has been introduced to the southeastern United States where it is most common in wet disturbed soils. There are two recognised varieties, one being the type and the other being C. diffusa var. gigas, which is native to Asia and has been introduced to Florida. It flowers from spring to fall and is most common in disturbed situations, moist places and forests. In China the plant is used medicinally as a febrifuge and a diuretic. A blue dye is also extracted from the flower for paints. In the Hawaiian Islands, it is known as "honohono grass", although it is technically not a grass. "Honohono" refers to the alternating structure of the leaves. At least one publication lists it as an edible plant in New Guinea.
Commelina caroliniana, sometimes known as the Carolina dayflower, is an herbaceous plant in the dayflower family native to India and Bangladesh. Both the scientific name and the common name are misleading as the plant was described based on specimens found in the southeastern United States before it was known that the plant had in fact been introduced from India. It was most likely introduced to South Carolina in the late 17th century along with rice seed from India. The plant has also been recently reported from South Korea. Its flowers emerge from summer to fall and rarely into the winter.
Commelina benghalensis, commonly known as the Benghal dayflower, tropical spiderwort, or wandering Jew, kanshira in Bengali, is a perennial herb native to tropical Asia and Africa. It has been widely introduced to areas outside its native range, including to the neotropics, Hawaii, the West Indies and to both coasts of North America. It has a long flowering period, from spring to fall in subtropical areas, and throughout the year closer to the equator. It is often associated with disturbed soils.
Commelina cyanea, commonly known as scurvy weed, is a perennial prostrate herb of the family Commelinaceae native to moist forests and woodlands of eastern Australia, Lord Howe Island and Norfolk Island. The blue flowers appear over the warmer months and are pollinated by bees and flies.
Commelina lukei is a monocotyledonous, herbaceous plant in the dayflower family from East Africa. This blue-flowered herb has been recorded in lowland areas of Kenya, Tanzania, and Madagascar, where it is found in a variety of habitats ranging from forests to grasslands to roadsides. Described in 2008, the species was previously confused with Commelina mascarenica and Commelina imberbis. Despite this misinterpretation, a third similar species, Commelina kotschyi, is actually most closely related to C. lukei. The plant's distinctive features include a scrambling habit, capsules with a rounded extension at the apex, appendaged seeds, clasping leaf bases throughout, and solely needle-like hairs along the upper side of the leaf's midrib. The species was named in honour of the botanist W. Q. R. Luke, whose collection of the plant served as the type specimen and allowed for a complete illustration and description.
Commelina sphaerorrhizoma is a monocotyledonous, herbaceous plant in the dayflower family from south-central Africa. This blue-flowered herb has been recorded from western Zambia, central Angola, and the southern portion of the Democratic Republic of the Congo, although at the time of its description it was known only from 11 collections and may be more broadly distributed. It is found in a variety of habitats ranging from woodlands to grasslands to roadsides. The plant's most distinctive feature and the source of its scientific name is its moniliform rhizome composed of spherical segments that can form a bead-like chain. Other distinguishing characteristics include glaucous leaves with clasping bases, unfused and virtually hairless spathes, capsules composed of three, one-seeded locules, and very large seeds with a hairy surface.
Commelina grossa is an herbaceous plant in the dayflower family found in the East and Southern African countries of Tanzania, Malawi, and Zambia. The species is easily recognised by its mainly basal leaves which are long and linear, and its spathes, which lack hairs and are quite large. The petals are mauve-blue with the lower petal being highly reduced and the sepals fused into a cup. These features suggest it may be related to Commelina schweinfurthii and its allies, which share many of the same floral characters. The species' typical habitat is in woodland on sandy soil or soils that become seasonally waterlogged. Flowering occurs in April and June.
Commelina acutispatha is an herbaceous plant in the dayflower family found primarily in East and Central Africa, including limited distribution in the African Great Lakes country of Uganda. In addition to that country, it is known from Sierra Leone, Liberia, Ghana, Togo, Nigeria, Cameroon, Gabon, and the Democratic Republic of the Congo. It is a common species in regions of West Africa with significant forest cover, where it is often weedy. It is most common in disturbed, moist soils, in which it scrambles over other plants. The name Commelina thomasii was often used for West African plants until it was realized that Commelina acutispatha, an older name originally applied to plants from the Democratic Republic of the Congo, was the same species. The petals range in color from white to pale lilac to violet; the lower petal is about half as large as the upper paired petals. The central anther is reported to have a blue patch on the connective. It has solitary spathes borne on a peduncle covered in hook-hairs.
Commelina fluviatilis is an herbaceous plant in the dayflower family found primarily in Central Africa. It is known from Tanzania, the Democratic Republic of the Congo, Zambia, and the Caprivi Strip region of Namibia.
Commelina maculata is an herbaceous plant in the dayflower family found in India, Burma, Bhutan, and southern China. It is most often encountered along forest margins, in grasslands, along roadsides, or in moist ditches. The species is characterized by its short-stalked spathes with fused margins that usually occur in clusters of two or three, bearing flowers that barely stick out from the mouth of the spathe. The species is very similar to Commelina paludosa, and further study is needed to recognize the boundary between the two. The two are typically differentiated on the basis of C. paludosa having larger and more numerous spathes that occur in clusters of four to ten, forming a sort of head. C. paludosa is also reported to have larger leaves, a more erect habit, less branching, and thicker stems. On the other hand, C. maculata is supposed to have heads of only two to three spathes, low-growing stems, numerous branches, slender stems that root at the nodes, and leaves less than ten cm long by two and a half cm wide.
Commelina hockii is an herbaceous plant in the dayflower family found primarily in Central Africa, from southwestern Tanzania in the east, west through the Democratic Republic of the Congo and Zambia, and possibly extending further west to Angola. The species' distinctive features include its long, tapering spathes with unfused margins, its white flowers, and its many-flowered lower cymes. It can be found in grasslands and Brachystegia-dominated woodland. It is fairly unusual among Commelina species in having variation in the color of the antherodes, with some individuals having entirely yellow antherodes, while others contain a dark spot in the center. Also, it is one of the only Commelina species known to leave a papery residue of dried fluid inside its spathes; normally only fused-spathe species are known to produce this substance. Only one specimen from Angola resembles this species, but it has blue flowers, suggesting it may be a poorly understood and as-yet undescribed separate species. Commelina hockii is probably closely related to Commelina kituloensis, which shares a similar fruit type, the same tufted perennial habit, similar large spathes with dried fluid substance, and equally numerously flowered inflorescences. That species differs in having purplish flowers, hairy leaves, shorter spathes, and a preference for high altitude grassland.
Iris sanguinea is a rhizomatous flowering plant in the genus Iris and in the series Sibiricae. It is cultivated as an ornamental plant in temperate regions. It is one of the species considered a Japanese iris. It is from Asia, found between Russia, Mongolia, China, Japan and Korea. It has grey green leaves, an unbranched flowering stem and flowers in reddish-purple shades, from blue to blue-purple, red-violet, with a rare white variant.
Cyanothamnus subsessilis is a species of plant in the citrus family, Rutaceae and is endemic to the south-west of Western Australia. It is a woody, mostly glabrous shrub with simple leaves and flowers with four petals that are white on the front and green to blue on the back.
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