Dendrophthoe falcata
Encyclopedia
Dendrophthoe falcata (L.f) Ettingsh is one of the hemiparasitic plants that belong to the Loranthaceae
family of mistletoe
s. It is the most common of all the mistletoes that occur in India
. At the moment reports say that it has around 401 plant hosts. The genus Dendrophthoe comprises about 31 species spread across tropical Africa
, Asia
, and Australia
(Flora of China, 2003) among which 7 species are found in India.
D.falcata bears grey barks, thick coriaceous leaves variable in shape with stout flowers (Wealth of India. 2002). The flowering inflorescence
s in D.falcata was previously referred to as axillary or as one developing on the scars of fallen leaves, but Y.P.S Pundir (1996) verified it to be of strictly cauliflorous
nature and also notified that it shares fundamental similarity to that of Ficus glomerata, F. pomifera and F. hispida. Two of its varieties are widespread in India namely, var. falcata (Honey Suckled Mistletoe) and var. Coccinea (Red Honey Suckled Mistletoe) distinguished by occurrence of white and red flowering, respectively (Flowers of India). Till date, D.falcata represents the only known mistletoe with the largest global host range (Calvin and Wilson, 2009) which is continuously and rapidly widening.
linkages is known to be widespread (Wilson and Calvin, 2006). In general, haustorial connections among 72 (of the 75) ariel parasitic genera may belong to either of the four types viz., epicortical roots (ERs), clasping unions, wood rose
s, and bark strands (Calvin and Wilson, 1998). ERs may run along the host branches in either direction forming haustorial structures at variable intervals while “unions” occur as single points of attachment of individual parasites hence pronounced as solitary. In D.falcata on different hosts two of the haustorial kinds have been observed viz., solitary unions as on Sugar apple (Annona squamosa
), and epicortical roots as on Sapota (Achras zapota), guava (Psidium guajava
), pomegranate (Punica granatum) have been known. It is unknown about what factors decide formation of different haustorial types by the leafy mistletoe on different hosts.
The host branches infected with D.falcata show a gradual reduction in growth and diameter as compared to other healthy uninfected branches (Karunaichamy et al., 1999). This mistletoe does not have an indigenous rooting system and is dependent on the host for water and minerals. Nutrient
dynamics have shown that a higher titre of N, P , K, Mg and Na in the leaves of mistletoe than the leaves of uninfected and infected hosts which may be due to differential translocation of elements within the host phloem
(Surya Prakash et al., 1967; Karunaichamy et al., 1999). The haustorial connections of the parasite with the plant are devoid of any efficient retranslocation system (Smith and Stewart, 1990).
is usually mediated by the birds that thrive on fruits from the parasite and/or host. Particularly in southern India, Tickel’s Flowerpecker (also called the Pale-billed Flowerpecker) is reported to facilitate seed dispersal of D. falcata among Neem
through fecal excretions or regurgitation
s (Karunaichamy et al., 1999; Hambali, 1977 and references therein). Studies conducted at the higher altitudes of the Western Ghats
(where both the mistletoes and the flowerpeckers occur predominantly), which parallel the western coast of India infer that the flowerpecker pollinated mistletoes have particularly developed feature specialized to attract a unique vector both to facilitate pollination and seed dispersal: the fruit and flowers have similar resemblance and more significantly, the fruiting time overlap with the next flowering season (Davidar, 1983). The Hair-crested Drongo
(sometimes called the Spangled Drongo) and sunbird
s are also known to feed on the nectar from the D.falcata flowers adding to the list of pollinators to this mistletoe (Kunwar et al., 2005).
, anti-microbial, anti-oxidant, antinociceptive properties of its ethanol
ic extracts (Pattanayak and Sunita, 2008, Shihab et al., 2006). Medicinal properties of this hemiparasite may vary in effects respective to different hosts it establishes a relation with (Mallavadhani et al., 2006).
The whole plant is used in indigenous system of medicine as cooling, bitter, astringent
, aphrodisiac
, narcotic
and diuretic
(Alekutty e al., 1993) and is useful in treating pulmonary tuberculosis, asthma
, menstrual disorder
s, swelling wounds, ulcer
s, renal
and vesical calculi and vitiated conditions of kapha and pitta
(Anarthe et al., 2008; Sastry, 1952; Pattanayak et al., 2008 ). Also, the decoction of plant used by women as an anti-fertility agent has been evidenced to possess anticancer activity (Nadkarni, 1993). The leaf ethanolic extract significantly and dose dependently inhibits the acetic acid
induced writhing in mice (Shihab et al., 2006) and has indicated a low level toxicity
in the brine shrimp
lethality assays. Besides, a more recent work by Pattanayak et al. (2008) shows significant tumor reduction in induced mammary carcinogenesis
in Wistar female rats when fed with hydroalcoholic extracts of D. falcata.
stage of Glomerella cingulata
(Mohamed Ali and Florence, 1987).
From a conservation biologists’
viewpoint mistletoes are considered as a keystone resource of biodiversity
(Watson, 2001) and from that of an ethnobiologist’s
and/or pharmacologist’s
(Pattanayak et al., 2008), they possess numerous ethnomedicinal
assets with prospects extending to promises even for use as an anti-tumor agent. Besides, a farmer’s perspective entails that they are notorious and devastating parasitic plants. Being backed by easy seed dispersal mediated by frugivorous
birds, they continue to pose serious losses to economically valuable fruit trees, flowering plants and those with medicinal properties whether growing in forests, orchards or gardens (Sridhar and Rao, 1978).
Loranthaceae
Loranthaceae is a family of flowering plants, which has been universally recognized by taxonomists. It consists of about 75 genera and 1,000 species of woody plants, many of them hemi-parasites, all of them except three having the mistletoe habit...
family of mistletoe
Mistletoe
Mistletoe is the common name for obligate hemi-parasitic plants in several families in the order Santalales. The plants in question grow attached to and within the branches of a tree or shrub.-Mistletoe in the genus Viscum:...
s. It is the most common of all the mistletoes that occur in India
India
India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...
. At the moment reports say that it has around 401 plant hosts. The genus Dendrophthoe comprises about 31 species spread across tropical Africa
Africa
Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...
, 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 Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
(Flora of China, 2003) among which 7 species are found in India.
D.falcata bears grey barks, thick coriaceous leaves variable in shape with stout flowers (Wealth of India. 2002). The flowering 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 in D.falcata was previously referred to as axillary or as one developing on the scars of fallen leaves, but Y.P.S Pundir (1996) verified it to be of strictly cauliflorous
Cauliflory
Cauliflory is a botanical term referring to plants which flower and fruit from their main stems or woody trunks rather than from new growth and shoots. This can allow trees to be pollinated or have their seeds dispersed by animals which cannot climb or fly...
nature and also notified that it shares fundamental similarity to that of Ficus glomerata, F. pomifera and F. hispida. Two of its varieties are widespread in India namely, var. falcata (Honey Suckled Mistletoe) and var. Coccinea (Red Honey Suckled Mistletoe) distinguished by occurrence of white and red flowering, respectively (Flowers of India). Till date, D.falcata represents the only known mistletoe with the largest global host range (Calvin and Wilson, 2009) which is continuously and rapidly widening.
Host-parasite interface
Among angiosperms, parasitic relationship through the formation of haustorialHaustorium
In botany, a haustorium is the appendage or portion of a parasitic fungus or of the root of a parasitic plant that penetrates the host's tissue and draws nutrients from it. Haustoria do not penetrate the host's cell membranes.Fungi in all major divisions form haustoria...
linkages is known to be widespread (Wilson and Calvin, 2006). In general, haustorial connections among 72 (of the 75) ariel parasitic genera may belong to either of the four types viz., epicortical roots (ERs), clasping unions, wood rose
Wood rose
Wood rose may refer to:* Wood rose a parasitic plant endemic to New Zealand* Hawaiian baby woodrose * Rosa gymnocarpa* Merremia tuberosa...
s, and bark strands (Calvin and Wilson, 1998). ERs may run along the host branches in either direction forming haustorial structures at variable intervals while “unions” occur as single points of attachment of individual parasites hence pronounced as solitary. In D.falcata on different hosts two of the haustorial kinds have been observed viz., solitary unions as on Sugar apple (Annona squamosa
Annona squamosa
Annona squamosa a small well-branched tree or shrub that bears edible fruits called sugar-apple, species of the genus Annona and member of the family Annonaceae more willing to grow at lower altitudes than its relatives Annona reticulata and Annona cherimola making it the most widely cultivated of...
), and epicortical roots as on Sapota (Achras zapota), guava (Psidium guajava
Psidium guajava
The apple guava or common guava is an evergreen shrub or small tree native to Mexico, the Caribbean, and Central and South America...
), pomegranate (Punica granatum) have been known. It is unknown about what factors decide formation of different haustorial types by the leafy mistletoe on different hosts.
The host branches infected with D.falcata show a gradual reduction in growth and diameter as compared to other healthy uninfected branches (Karunaichamy et al., 1999). This mistletoe does not have an indigenous rooting system and is dependent on the host for water and minerals. Nutrient
Nutrient
A nutrient is a chemical that an organism needs to live and grow or a substance used in an organism's metabolism which must be taken in from its environment. They are used to build and repair tissues, regulate body processes and are converted to and used as energy...
dynamics have shown that a higher titre of N, P , K, Mg and Na in the leaves of mistletoe than the leaves of uninfected and infected hosts which may be due to differential translocation of elements within the host phloem
Phloem
In vascular plants, phloem is the living tissue that carries organic nutrients , in particular, glucose, a sugar, to all parts of the plant where needed. In trees, the phloem is the innermost layer of the bark, hence the name, derived from the Greek word "bark"...
(Surya Prakash et al., 1967; Karunaichamy et al., 1999). The haustorial connections of the parasite with the plant are devoid of any efficient retranslocation system (Smith and Stewart, 1990).
Seed dispersal and pollination
Seed dispersal and pollinationPollination
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...
is usually mediated by the birds that thrive on fruits from the parasite and/or host. Particularly in southern India, Tickel’s Flowerpecker (also called the Pale-billed Flowerpecker) is reported to facilitate seed dispersal of D. falcata among Neem
Neem
Azadirachta indica is a tree in the mahogany family Meliaceae. It is one of two species in the genus Azadirachta, and is native to India growing in tropical and semi-tropical regions. Its fruits and seeds are the source of neem oil...
through fecal excretions or regurgitation
Regurgitation (digestion)
Regurgitation is the expulsion of material from the mouth, pharynx, or esophagus, usually characterized by the presence of undigested food or blood.Regurgitation is used by a number of species to feed their young...
s (Karunaichamy et al., 1999; Hambali, 1977 and references therein). Studies conducted at the higher altitudes of the Western Ghats
Western Ghats
The Western Ghats, Western Ghauts or the Sahyādri is a mountain range along the western side of India. It runs north to south along the western edge of the Deccan Plateau, and separates the plateau from a narrow coastal plain along the Arabian Sea. The Western Ghats block rainfall to the Deccan...
(where both the mistletoes and the flowerpeckers occur predominantly), which parallel the western coast of India infer that the flowerpecker pollinated mistletoes have particularly developed feature specialized to attract a unique vector both to facilitate pollination and seed dispersal: the fruit and flowers have similar resemblance and more significantly, the fruiting time overlap with the next flowering season (Davidar, 1983). The Hair-crested Drongo
Hair-crested Drongo
The Hair-crested Drongo is an Asian bird of the family Dicruridae. This species was formerly considered conspecific with Dicrurus bracteatus, for which the name "Spangled Drongo" – formerly used for both – is now usually reserved. Some authorities include the Sumatran Drongo in D...
(sometimes called the Spangled Drongo) and sunbird
Sunbird
The sunbirds and spiderhunters are a family, Nectariniidae, of very small passerine birds. There are 132 species in 15 genera. The family is distributed throughout Africa, southern Asia and just reaches northern Australia. Most sunbirds feed largely on nectar, but also take insects and spiders,...
s are also known to feed on the nectar from the D.falcata flowers adding to the list of pollinators to this mistletoe (Kunwar et al., 2005).
Medicinal uses
Dendrophthoe falcata possesses remarkable potentials as a medicinal plant evident from the wound healingWound healing
Wound healing, or cicatrisation, is an intricate process in which the skin repairs itself after injury. In normal skin, the epidermis and dermis exists in a steady-state equilibrium, forming a protective barrier against the external environment...
, anti-microbial, anti-oxidant, antinociceptive properties of its ethanol
Ethanol
Ethanol, also called ethyl alcohol, pure alcohol, grain alcohol, or drinking alcohol, is a volatile, flammable, colorless liquid. It is a psychoactive drug and one of the oldest recreational drugs. Best known as the type of alcohol found in alcoholic beverages, it is also used in thermometers, as a...
ic extracts (Pattanayak and Sunita, 2008, Shihab et al., 2006). Medicinal properties of this hemiparasite may vary in effects respective to different hosts it establishes a relation with (Mallavadhani et al., 2006).
The whole plant is used in indigenous system of medicine as cooling, bitter, astringent
Astringent
An astringent substance is a chemical compound that tends to shrink or constrict body tissues, usually locally after topical medicinal application. The word "astringent" derives from Latin adstringere, meaning "to bind fast"...
, aphrodisiac
Aphrodisiac
An aphrodisiac is a substance that increases sexual desire. The name comes from Aphrodite, the Greek goddess of sexuality and love. Throughout history, many foods, drinks, and behaviors have had a reputation for making sex more attainable and/or pleasurable...
, narcotic
Narcotic
The term narcotic originally referred medically to any psychoactive compound with any sleep-inducing properties. In the United States of America it has since become associated with opioids, commonly morphine and heroin and their derivatives, such as hydrocodone. The term is, today, imprecisely...
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 :...
(Alekutty e al., 1993) and is useful in treating pulmonary tuberculosis, asthma
Asthma
Asthma is the common chronic inflammatory disease of the airways characterized by variable and recurring symptoms, reversible airflow obstruction, and bronchospasm. Symptoms include wheezing, coughing, chest tightness, and shortness of breath...
, menstrual disorder
Menstrual disorder
-Disorders of ovulation:Infrequent or irregular ovulation -Disorders of ovulation:Infrequent or irregular ovulation -Disorders of ovulation:Infrequent or irregular ovulation (usually defined as cycles of ≥36 days or -Disorders of ovulation:Infrequent or irregular ovulation (usually defined as...
s, swelling wounds, ulcer
Ulcer
An ulcer is a sore on the skin or a mucous membrane, accompanied by the disintegration of tissue. Ulcers can result in complete loss of the epidermis and often portions of the dermis and even subcutaneous fat. Ulcers are most common on the skin of the lower extremities and in the gastrointestinal...
s, renal
Kidney stone
A kidney stone, also known as a renal calculus is a solid concretion or crystal aggregation formed in the kidneys from dietary minerals in the urine...
and vesical calculi and vitiated conditions of kapha and pitta
Ayurveda
Ayurveda or ayurvedic medicine is a system of traditional medicine native to India and a form of alternative medicine. In Sanskrit, words , meaning "longevity", and , meaning "knowledge" or "science". The earliest literature on Indian medical practice appeared during the Vedic period in India,...
(Anarthe et al., 2008; Sastry, 1952; Pattanayak et al., 2008 ). Also, the decoction of plant used by women as an anti-fertility agent has been evidenced to possess anticancer activity (Nadkarni, 1993). The leaf ethanolic extract significantly and dose dependently inhibits the acetic acid
Acetic acid
Acetic acid is an organic compound with the chemical formula CH3CO2H . It is a colourless liquid that when undiluted is also called glacial acetic acid. Acetic acid is the main component of vinegar , and has a distinctive sour taste and pungent smell...
induced writhing in mice (Shihab et al., 2006) and has indicated a low level toxicity
Toxicity
Toxicity is the degree to which a substance can damage a living or non-living organisms. Toxicity can refer to the effect on a whole organism, such as an animal, bacterium, or plant, as well as the effect on a substructure of the organism, such as a cell or an organ , such as the liver...
in the brine shrimp
Brine shrimp
Artemia is a genus of aquatic crustaceans known as brine shrimp. Artemia, the only genus in the family Artemiidae, has changed little externally since the Triassic period...
lethality assays. Besides, a more recent work by Pattanayak et al. (2008) shows significant tumor reduction in induced mammary carcinogenesis
Carcinogenesis
Carcinogenesis or oncogenesis is literally the creation of cancer. It is a process by which normal cells are transformed into cancer cells...
in Wistar female rats when fed with hydroalcoholic extracts of D. falcata.
Diseases
Dendrophthoe falcata is susceptible to diseases such as leaf blight caused by ColletotrichumColletotrichum
Colletotrichum is a genus of fungi that are obligate symbionts to plants in the form of endophytes. Many of the species in this genus are plant pathogens, although some species may express a mutualistic life-style in non-disease hosts....
stage of Glomerella cingulata
Glomerella cingulata
Glomerella cingulata is a plant pathogenic fungus that causes disease on many different hosts including quince and apple bitter rot and anthracnose on many fruit and vegetable species. Glomerella cingulata is the sexual stage while the asexual stage is called Colletotrichum gloeosporioides.-...
(Mohamed Ali and Florence, 1987).
Hyper-parasitism
D.falcata can be parasitised by Scurrula cordifolia (another mistletoe) (Pundir, 1979). Similarly, Viscum orientale has also been reported to grow on D.falcata (Saxena, 1971). In another instance Cuscuta reflexa has been shown to act as a rival to the leafy mistletoe (Nath and Indira, 1975).From a conservation biologists’
Conservation biology
Conservation biology is the scientific study of the nature and status of Earth's biodiversity with the aim of protecting species, their habitats, and ecosystems from excessive rates of extinction...
viewpoint mistletoes are considered as a keystone resource of biodiversity
Biodiversity
Biodiversity is the degree of variation of life forms within a given ecosystem, biome, or an entire planet. Biodiversity is a measure of the health of ecosystems. Biodiversity is in part a function of climate. In terrestrial habitats, tropical regions are typically rich whereas polar regions...
(Watson, 2001) and from that of an ethnobiologist’s
Ethnobiology
]Ethnobiology is the scientific study of dynamic relationships between peoples, biota, and environments, from the distant past to the immediate present....
and/or pharmacologist’s
Pharmacology
Pharmacology is the branch of medicine and biology concerned with the study of drug action. More specifically, it is the study of the interactions that occur between a living organism and chemicals that affect normal or abnormal biochemical function...
(Pattanayak et al., 2008), they possess numerous ethnomedicinal
Ethnomedicine
Ethnomedicine is a sub-field of ethnobotany or medical anthropology that deals with the study of traditional medicines: not only those that have relevant written sources Ethnomedicine is a sub-field of ethnobotany or medical anthropology that deals with the study of traditional medicines: not only...
assets with prospects extending to promises even for use as an anti-tumor agent. Besides, a farmer’s perspective entails that they are notorious and devastating parasitic plants. Being backed by easy seed dispersal mediated by frugivorous
Frugivore
A frugivore is a fruit eater. It can be any type of herbivore or omnivore where fruit is a preferred food type. Because approximately 20% of all mammalian herbivores also eat fruit, frugivory is considered to be common among mammals. Since frugivores eat a lot of fruit they are highly dependent...
birds, they continue to pose serious losses to economically valuable fruit trees, flowering plants and those with medicinal properties whether growing in forests, orchards or gardens (Sridhar and Rao, 1978).