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.
Aneilema is a genus of monocotyledonous plants of approximately 60 species. The vast majority of the species are native to sub-Saharan Africa, but a few are found in Oceania and one, Aneilema brasiliense, is from South America. It is the third largest genus in the family Commelinaceae after Commelina and Tradescantia, and it is one of only six genera in the family to occur in both the Eastern Hemisphere and the Western Hemisphere.
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 virginica, commonly known as the Virginia dayflower, is a perennial herbaceous plant in the dayflower family. It is native to the mideastern and southeastern United States, where it is typical of wet soils. While most members of the genus have thin, fibrous roots, the Virginia dayflower is relatively unique for its genus in having a perennial rhizome. The plant was first described by Carl Linnaeus in his 1762 publication of the second edition of Species Plantarum. A phylogenetic study based on the nuclear ribosomal DNA region 5S NTS and the chloroplast region trnL-trnF, two commonly used gene regions for determining relationships, suggested that Commelina virginica is most closely related to two African species, namely Commelina capitata and Commelina congesta. However, the statistical support for this result was low. Morphologically speaking the supposedly related species do share some unique traits. C. virginica and C. capitata have red hairs at the top of their leaf sheaths, an unusual character in the genus, while C. virginica and C. congesta both have clustered inflorescences on very short stalks.
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 mascarenica is a monocotyledonous, herbaceous plant in the dayflower family from East Africa. This pale blue-flowered herb is found in a variety of open habitats from open bush to roadsides. Although the species was originally thought to be restricted to Madagascar and the Comoro Islands, further study revealed that the species is also widely distributed along the East African coast from Somalia south to Mozambique. It had formerly been confused with the closely related species Commelina imberbis and Commelina lukei, the latter occurring alongside C. mascarenica throughout much of its range.
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 orchidophylla is a monocotyledonous, herbaceous plant in the dayflower family from south-central Africa. This blue-flowered herb has been recorded only from the Haut-Katanga District of the Democratic Republic of the Congo, although at the time of its description it was known only from 3 collections. It is found in woodlands, especially in rocky areas, and on sandstone. The plant's most distinctive feature and the source of its scientific name is its orchid-like pair of broad basal leaves. Other distinctive characteristics include hairy tuberous roots, solitary spathes on long stalks that arise directly from the basal leaves before the development of elongated flowering shoots, dimorphic seeds, and unfused spathes lacking hairs which contain an upper cincinnus that barely emerges. The flowers have never been observed directly and are only partially known from bud dissections.
Commelina forskaolii, sometimes known as rat's ear, is an herbaceous plant in the dayflower family native to much of Africa, Arabia, and India. It has also been introduced to Florida in the United States. It is considered a common species in most of its range. It can be easily recognized by its bright blue flowers with winged stamen filaments. The seeds are also distinctive with distinctive irregular ridges on their sides. It often forms dense mats, and can be found most commonly in sandy soils in at least somewhat sunny situations. The species is considered a weed in many areas because of its hardiness and ability to produce cleistogamous flowers.
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 welwitschii is an herbaceous plant in the dayflower family found in Southern Africa from Zimbabwe to Angola. A phylogenetic study based on the nuclear ribosomal DNA region 5S NTS and the chloroplast region trnL-trnF, two commonly used gene regions for determining relationships, revealed that Commelina welwitschii forms a clade with Commelina purpurea and Commelina fluviatilis. Both of these relatives are African, share an unusual leaf anatomy, and have linear leaves that are often folded. Although it has yellow flowers, this study did not find a close relationship with Commelina capitata or Commelina africana, the two other African yellow-flowered species. Robert Faden, an expert on the Commelinaceae, points out that Commelina welwitschii is one of only three species in the genus to have bead-like rhizomes along with Commelina crassicaulis and Commelina sphaerorrhizoma. While it is clear that the former species is most likely a close relative given its many other similarities, the latter species is unlikely closely related given major differences in other characters.
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.
Commelina eckloniana is an herbaceous plant in the dayflower family with a broad distribution in Central and East Africa. It ranges from Ethiopia, Kenya, and Tanzania in the east, west through Uganda, Burundi, Rwanda, and Malawi, into the Democratic Republic of the Congo and Zambia. It is considered one of the most diverse species in Africa. Its distinctive characteristics include a fused spathe with sparse hairs, blue flowers with bilocular ovaries, and nearly square fruits containing four seeds that are roughly spherical. It currently contains five subspecies, and at times has been split into five separate species that mostly correspond to the currently recognised subspecies. However, some of the subspecies may be functioning as species, and further study is needed to resolve the question of species limits in this group.
- Commelina eckloniana subsp. claessensii(De Wild.) Faden - Zaïre, Uganda
- Commelina eckloniana subsp. critica(De Wild.) Faden - Zaïre, Tanzania, Zambia, Malawi
- Commelina eckloniana subsp. echinosperma(K.Schum.) Faden - Zaïre, Tanzania, Zambia, Rwanda, Burundi, Kenya, Uganda, Ethiopia
- Commelina eckloniana subsp. eckloniana - Zimbabwe, South Africa, Swaziland
- Commelina eckloniana subsp. nairobiensis(Faden) Faden - Kenya
- Commelina eckloniana subsp. thikaensisFaden - Kenya
Commelina polhillii is a plant species native to Tanzania, known only from the Iriniga and Mpanda Districts. It occurs in open woodlands and in disturbed sites.
Commelina zenkeri is a plant species native to tropical Africa. It is known from Uganda and Cameroon. Unconfirmed reports place it in Democratic Republic of the Congo as well. It grows on rocky hillsides in evergreen tropical forests at elevations up to 1300 m.
