Commelina diffusa
Encyclopedia
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.
blades are relatively variable, ranging from lanceolate to ovate, with proximal leaves tending to be more oblong. They measure 3 to 12 cm in length by 0.8 to 3 cm in width. North American populations tend to have smaller leaf size, typically measuring 1.5 to 5 cm, by 0.5 by 1.8 cm. The leaf apex is acute to acuminate. The leaf surface can be either glabrous (i.e. hairless) or hispid (i.e. bristly). The leaves are subsessile (i.e. having a very small petiole
) with a leaf sheath striped with red and covered with hispid pubescence.
The flower
s are arranged into cincinni (singular: cincinnus), or scorpioid cymes. This is a form of a monochasium where the lateral branches arise alternately on opposite sides of the false axis. There are typically two cincinni present, with the lower cincinnus bearing 2 to 4 flowers, while the upper cincinnus has one to several flowers. The upper cincinnus is generally exerted on specimens with larger spathes, but it may be included in specimens with smaller spathes. The upper cincinnus bears only male flowers and has a longer peduncle, while the lower cincinnus bears bisexual flowers on a shorter peduncle. The pedicel
s supporting single flowers, and later the fruits, are thick and curved and measure about 3 to 5 mm. The membranous sepal
s are inconspicuous at only 3 to 4 mm in length. The petal
s are blue, though may be lavender in rare cases. The upper two petals measure 4.2 to 6 mm. The anther connective (i.e. the tissue connecting the two halves of the anther) of the centre-most stamen
has a broad transverse band of violet. The spathes are solitary, borne on a peduncle
and typically falcate (i.e. sickle-shaped) with a cordate (i.e. heart-shaped) to rounded base, acuminate apices and can be either glabrous or hispidulous (i.e. minutely hispid) beneath. They usually measure 0.8 to 2.5 cm long, but may be as short as 0.5 cm and as long as 4 cm. They are typically 0.4 by 1.2 cm wide, but may be up to 1.4 cm long. Their peduncles are usually 0.5 to 2 cm long and rarely up to 2.9 cm. Flowering occurs from May to November.
The fruit is a capsule
which has three locules and 2 valves. It measures 4 to 6.3 mm long by 3 to 4 mm wide, though it may be as narrow as 2.1 mm. They contain five brown seeds that are 2 to 2.8, rarely up to 3.2 mm long, by 1.4 to 1.8 mm wide. They are deeply reticulate (i.e. net-like). The chromosome
number is 2n = 30.
, specifically in the provinces of Guangdong
, southwestern Guangxi
, southwestern Guizhou
, Hainan
, southeasten Xizang and southeastern Yunnan
. In Japan
the plant has been reported from Yakushima
off Kyūshū
and is also present in the Ryukyu Islands
from Amami Ōshima
southwards.
It is native in parts of the West Indies, including much of Puerto Rico
and several of the Virgin Islands
such as Saint Croix
, Saint Thomas
and Tortola
. It has also been introduced to the southeastern United States
where it is present from Maryland
in the north, west to Missouri
and south to Texas
and Florida
. It has also been introduced to Hawaii
, where it is a common and quickly spreading weed. The variety C. diffusa var. gigas has been introduced to Florida
.
In China it can be found from sea level up to 2100 metres, and is typically associated with forests, thickets, stream banks and other open and humid habitats. In the West Indies it is a common weed
that is especially associated with roadsides, moist ditches and waste places and it can be found from sea level to 1050 metres. In the United States it is also typical of disturbed locations, such as gardens, cultivated areas and lawns, but can also be found in woods and other moist situations.
Within Hawaii, "honohono grass" was used as medicine to aid with deep cuts. While other hawaiian herbs just get superficial cuts, honohono grass is an herb to aid with deeper troubling issues.
According to a work by Bruce French published on papuaweb.org, the young leaf tips are cooked and eaten in New Guinea. (See page 80.)
Pantropical
In biogeography, a pantropical distribution one which covers tropical regions of all of the major continents, i.e. in Africa, in Asia and in the Americas. Examples include the plant genera Acacia and Bacopa....
herbaceous plant 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 has been introduced to the southeastern United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
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
Asia
Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...
and has been introduced to 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...
. It flowers from spring to fall and is most common in disturbed situations, moist places and forests. 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...
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.
Description
Commelina diffusa is typically an annual herb, though it may be perennial in the tropics. It spreads diffusely, creeping along the ground, branching heavily and rooting at the nodes, obtaining stem lengths up to 1 metre. Pubescence on the stem is variable and ranges from glabrous to hispidulous, which can occur either in a line or throughout. The leafLeaf
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....
blades are relatively variable, ranging from lanceolate to ovate, with proximal leaves tending to be more oblong. They measure 3 to 12 cm in length by 0.8 to 3 cm in width. North American populations tend to have smaller leaf size, typically measuring 1.5 to 5 cm, by 0.5 by 1.8 cm. The leaf apex is acute to acuminate. The leaf surface can be either glabrous (i.e. hairless) or hispid (i.e. bristly). The leaves are subsessile (i.e. having a very small 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...
) with a leaf sheath striped with red and covered with hispid pubescence.
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 into cincinni (singular: cincinnus), or scorpioid cymes. This is a form of a monochasium where the lateral branches arise alternately on opposite sides of the false axis. There are typically two cincinni present, with the lower cincinnus bearing 2 to 4 flowers, while the upper cincinnus has one to several flowers. The upper cincinnus is generally exerted on specimens with larger spathes, but it may be included in specimens with smaller spathes. The upper cincinnus bears only male flowers and has a longer peduncle, while the lower cincinnus bears bisexual flowers on a shorter peduncle. 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 thick and curved and measure about 3 to 5 mm. The 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 at only 3 to 4 mm in length. The 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, though may be lavender in rare cases. The upper two petals measure 4.2 to 6 mm. The anther connective (i.e. the tissue connecting the two halves of the anther) of the centre-most stamen
Stamen
The stamen is the pollen producing reproductive organ of a flower...
has a broad transverse band of violet. The spathes are solitary, borne on a 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...
and typically falcate (i.e. sickle-shaped) with a cordate (i.e. heart-shaped) to rounded base, acuminate apices and can be either glabrous or hispidulous (i.e. minutely hispid) beneath. They usually measure 0.8 to 2.5 cm long, but may be as short as 0.5 cm and as long as 4 cm. They are typically 0.4 by 1.2 cm wide, but may be up to 1.4 cm long. Their peduncles are usually 0.5 to 2 cm long and rarely up to 2.9 cm. Flowering occurs from May to November.
The fruit is a 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...
which has three locules and 2 valves. It measures 4 to 6.3 mm long by 3 to 4 mm wide, though it may be as narrow as 2.1 mm. They contain five brown seeds that are 2 to 2.8, rarely up to 3.2 mm long, by 1.4 to 1.8 mm wide. They are deeply reticulate (i.e. net-like). The chromosome
Chromosome
A chromosome is an organized structure of DNA and protein found in cells. It is a single piece of coiled DNA containing many genes, regulatory elements and other nucleotide sequences. Chromosomes also contain DNA-bound proteins, which serve to package the DNA and control its functions.Chromosomes...
number is 2n = 30.
Distribution and habitat
The plant is present in tropical and subtropical locations worldwide. It can be found throughout much of southern ChinaChina
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...
, specifically in the provinces of Guangdong
Guangdong
Guangdong is a province on the South China Sea coast of the People's Republic of China. The province was previously often written with the alternative English name Kwangtung Province...
, southwestern Guangxi
Guangxi
Guangxi, formerly romanized Kwangsi, is a province of southern China along its border with Vietnam. In 1958, it became the Guangxi Zhuang Autonomous Region of the People's Republic of China, a region with special privileges created specifically for the Zhuang people.Guangxi's location, in...
, southwestern Guizhou
Guizhou
' is a province of the People's Republic of China located in the southwestern part of the country. Its provincial capital city is Guiyang.- History :...
, 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...
, southeasten Xizang and southeastern Yunnan
Yunnan
Yunnan is a province of the People's Republic of China, located in the far southwest of the country spanning approximately and with a population of 45.7 million . The capital of the province is Kunming. The province borders Burma, Laos, and Vietnam.Yunnan is situated in a mountainous area, with...
. In 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...
the plant has been reported from Yakushima
Yakushima
, one of the Ōsumi Islands, is an island of about 500 km² and roughly 15,000 islanders to the south of Kyūshū in Kagoshima Prefecture, Japan. The Vincennes Strait separates it from Tanegashima. The highest point on the island is Miyanoura-dake at 1,935 metres...
off 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....
and is also present in the Ryukyu Islands
Ryukyu Islands
The , also known as the , is a chain of islands in the western Pacific, on the eastern limit of the East China Sea and to the southwest of the island of Kyushu in Japan. From about 1829 until the mid 20th century, they were alternately called Luchu, Loochoo, or Lewchew, akin to the Mandarin...
from Amami Ōshima
Amami Oshima
is a semi-tropical island in the Amami Islands, which is part of the larger Nansei Islands in Japan. Ōshima literally means big island, and it is the largest of the Amami Islands. It lies roughly halfway between the islands of Okinawa and Kyūshū. Briefly part of the Ryūkyū Kingdom, in 1624 it was...
southwards.
It is native in parts of the West Indies, including much of Puerto Rico
Puerto Rico
Puerto Rico , officially the Commonwealth of Puerto Rico , is an unincorporated territory of the United States, located in the northeastern Caribbean, east of the Dominican Republic and west of both the United States Virgin Islands and the British Virgin Islands.Puerto Rico comprises an...
and several of the Virgin Islands
Virgin Islands
The Virgin Islands are the western island group of the Leeward Islands, which are the northern part of the Lesser Antilles, which form the border between the Caribbean Sea and the Atlantic Ocean...
such as Saint Croix
Saint Croix, U.S. Virgin Islands
Saint Croix is an island in the Caribbean Sea, and a county and constituent district of the United States Virgin Islands , an unincorporated territory of the United States. Formerly the Danish West Indies, they were sold to the United States by Denmark in the Treaty of the Danish West Indies of...
, Saint Thomas
Saint Thomas, U.S. Virgin Islands
Saint Thomas is an island in the Caribbean Sea and with the islands of Saint John, Saint Croix, and Water Island a county and constituent district of the United States Virgin Islands , an unincorporated territory of the United States. Located on the island is the territorial capital and port of...
and Tortola
Tortola
Tortola is the largest and most populated of the British Virgin Islands, a group of islands that form part of the archipelago of the Virgin Islands. Local tradition recounts that Christopher Columbus named it Tortola, meaning "land of the Turtle Dove". Columbus named the island Santa Ana...
. It has also been introduced to the southeastern United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
where it is present from Maryland
Maryland
Maryland is a U.S. state located in the Mid Atlantic region of the United States, bordering Virginia, West Virginia, and the District of Columbia to its south and west; Pennsylvania to its north; and Delaware to its east...
in the north, west to Missouri
Missouri
Missouri is a US state located in the Midwestern United States, bordered by Iowa, Illinois, Kentucky, Tennessee, Arkansas, Oklahoma, Kansas and Nebraska. With a 2010 population of 5,988,927, Missouri is the 18th most populous state in the nation and the fifth most populous in the Midwest. It...
and south 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 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...
. It has also been introduced to Hawaii
Hawaii
Hawaii is the newest of the 50 U.S. states , and is the only U.S. state made up entirely of islands. It is the northernmost island group in Polynesia, occupying most of an archipelago in the central Pacific Ocean, southwest of the continental United States, southeast of Japan, and northeast of...
, where it is a common and quickly spreading weed. The variety C. diffusa var. gigas has been introduced to 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 China it can be found from sea level up to 2100 metres, and is typically associated with forests, thickets, stream banks and other open and humid habitats. In the West Indies it is a common weed
Weed
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...
that is especially associated with roadsides, moist ditches and waste places and it can be found from sea level to 1050 metres. In the United States it is also typical of disturbed locations, such as gardens, cultivated areas and lawns, but can also be found in woods and other moist situations.
Uses
Within China, Commelina diffusa is used as a medicinal herb with febrifugal and diuretic effects. A dye is also obtained from the juice of the petals for use in painting.Within Hawaii, "honohono grass" was used as medicine to aid with deep cuts. While other hawaiian herbs just get superficial cuts, honohono grass is an herb to aid with deeper troubling issues.
According to a work by Bruce French published on papuaweb.org, the young leaf tips are cooked and eaten in New Guinea. (See page 80.)