Gliricidia sepium, often simply referred to as gliricidia or by its Spanish common name madre de cacao (also anglicized as mother of cocoa),[2] is a medium size leguminous tree belonging to the family Fabaceae. It is an important multi-purpose legume tree,[3] with a native range from Mexico to Colombia, but now widely introduced to other tropical zones.[4]
Description
Gliricidia sepium is a medium-sized tree that grows 10–12 m (33–39 ft) high. The bark is smooth, and its color can range from a whitish gray to deep red-brown. The flowers are located on the end of branches that have no leaves. These flowers have a bright pink to lilac color that is tinged with white. A pale yellow spot is usually at the flower’s base. The tree’s fruit is a pod about 10–15 cm (4–6 in) long. It is green when unripe and becomes yellow-brown when it reaches maturity. The pod produces four to ten round brown seeds.
Distribution and spread
G. sepium has been cultivated extensively by indigenous American cultures in North, Central, and South America since the pre-Columbian era, which makes it difficult to ascertain its original native distribution. Genetic studies have identified the center of genetic diversity of G. sepium as the dry zones of southern Mexico and northern Central America, which is now generally regarded as its true native range.[6][7]
G. sepium was first introduced to the Philippines from Mexico via the Manila galleons along with 200 other tropical American plant species from as early as the early 1600s. Their use as a shade tree for cacao, coffee, and tea plantations led to their further spread. These later introductions include the Caribbean before 1850; Sri Lanka in the 1800s; India and Indonesia at around 1900; and West Africa, Uganda, and Kenya in the early 1900s. Other introductions followed in the 20th century and G. sepium now has a pantropical distribution.[6]
G. sepium grows well in acidic soils with a pH of 4.5-6.2. The tree is found on volcanic soils in its native range in Central America and Mexico. However, it can also grow on sandy, clay, and limestone soils.[8][9]
Uses
G. sepium was spread from its native range throughout the tropics to shade plantation crops such as coffee.[10] Today it is used for many other purposes including live fencing, fodder, firewood,[11] green manure, intercropping, and rat poison.[12] Its use expanded following the widespread defoliation of Leucaena by psyllid in the 1980s.[10] In the charsutri method of paddy cultivation, leaves of glyricidia are incorporated in soil during ploughing.
Salinity tolerance & Nitrogen fixation
The tree possesses high level of Nitrogen fixation[2] and tolerance to salinity[3].
Fodder
G. sepium is used as cut and carry forage for cattle, sheep, and goats. Its high protein content allows it to complement low-quality tropical forages. G. sepium can tolerate repeated cutting, every 2 to 4 months depending on the climate. Cutting G. sepium causes it to retain its leaves during the dry season when many forage crops have lost their leaves. In some cases it is the only source of feed during the dry season.[10]
Intercropping
G. sepium trees are used for intercropping in part because they fix nitrogen in the soil and tolerate low soil fertility, so when they are interplanted with crops they can boost crop yields significantly, without the need of chemical fertilizers.
G. Sepium tolerates being cut back to crop height, and can even be coppiced, year after year. When the trees are cut back, they enter a temporary dormant state during which their root systems do not compete for nutrients needed by the crops, so the crops can establish themselves.[13]
These properties also enable G. Sepium to be used as green manure.[10]
Soil stabilization
G. sepium is a fast-growing ruderal species that takes advantage of slash and burn practices in its native range.[8] Because it is easily propagated and grows quickly, it is also planted to prevent topsoil erosion in the initial stages of reforesting denuded areas, and as an intermediate step to be taken before introducing species that take longer to grow.[13]
Shade trees
The common name madre de cacao (literally “mother of cacao” in Spanish) used in Central America and the Philippines is in reference to its traditional use as shade trees for cocoa tree plantations.[14]
Other
G. sepium is widely used in the form of poles for live fencing in Cuba,[15] other islands and India. This is one of the best plants used for traditional live fencing to protect agriculture and fruit bearing plantations from animals such as goats, cow, and buffalo. As a Caribbean native, G. sepium has traditionally been used for live fencing in Cuba.
As in India, during the recent past one could see many living fences around mango and cashew orchards and agricultural properties in Goa, Maharashtra and Karnataka, erected with G. sepium and tied with bamboo rafters.
G. sepium is also used for its insect repellent properties. Farmers in Latin America often wash their livestock with a paste made of crushed G. sepium leaves to ward off torsalos (botflies). In the Philippines, the extract obtained from its leaves is made into anti-mange dog shampoo.[8]
Health benefits
Medicinal plants have been used in traditional medicine practices since prehistoric times. Humans learned to seek therapy in the barks, leaves, fruits, flowers, and other parts of plants as a result of many years of struggles against illnesses. Gliricidia sepium (Jacq.) Kunth. ex. Walp., is one of the most important plants in pharmacognosy and medical fields because it serves as a reservoir for potent bioactive compounds such as saponins, flavonoids, volatile oils, and other bioactive compounds that have been extracted from various parts of it. Gliricidia sepium is the topic of much research due to its numerous traditional applications, which include treating coughs, asthma, curing urticaria, rash, burns, scabies, dermatitis, acting as an antipruritic on the skin, and treating bacterial and protozoal infections. Many medicinal uses for Gliricidia sepium have been discovered over time, including cytotoxic activity, anti-microbial activity, anti-bacterial activity, anti-inflammatory activity, antioxidant activity, thrombolytic, anti-sickling activity, wound healing, mosquitocidal activity, and anthelmintic activity.
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