Leucaena leucocephala is a small fast-growing Mimosoideae tree native to southern Mexico and northern Central America (Belize and Guatemala).
Common names include white leadtree,
Leucaena leucocephala is used for a variety of purposes, such as fencing, soil fertility, firewood, Fiber crop, and livestock fodder.
Description
Leucaena leucocephala is a small tree, growing up to . Its bark is grey and cracked. The branches have no thorns, each branch has 6–8 pairs of leaf stalks that bear 11–23 pairs of leaflets, each leaflet is 8–17 mm long with a pale green surface and whitish underneath.
Its inflorescence is a cream-coloured puff with many stamens. They produce flat and straight seed pods measuring long that matures from a green colour to a brown; one pod contains between 15 and 30 seeds.
File:Leucaena leucocephala NP.JPG| L. leucocephala pods in the month of May, Nepal
File:Leucaena leucocephala MHNT.BOT.2011.3.71.jpg|Dried L. leucocephala pod and seeds - MHNT
Ecology
Leucaena leucocephala is susceptible to insect infestations. In the 1980s, a widespread loss in
Southeast Asia was due to pest attack by psyllids.
In India, this tree was initially promoted for afforestation due to its fast-growing nature. However, it is now considered unsuitable for urban planting because of its tendency to get uprooted in rain and wind. Eight of every ten trees uprooted by wind in Pune are L. leucocephala.
Invasive properties
Leucaena leucocephala is considered one of the 100 worst invasive species by the Invasive Species Specialist Group of the IUCN Species Survival Commission.
It is a highly invasive species in the arid parts of Taiwan, The Bahamas, the Hawaiian Islands, Fiji, Puerto Rico, Hong Kong, South Africa,
The plant is also found in parts of the U.S., including California, Arizona, Texas, Hawaii, and Florida.
It grows quickly and forms dense thickets that crowd out all native vegetation.[Kuo, Yau-Lun. "Ecological Characteristics of Three Invasive Plants (Leucaena Leucocephala, Mikania Micrantha, and Stachytarpheta Urticaefolia) in Southern Taiwan." 12 1 2003.http://www.agnet.org/library/eb/541/ (accessed 3 24 2008).]
In urban areas, it is an especially unwanted species, growing along arid roadsides, in carparks, and on abandoned land.[ Tree Preservation]
Toxicity
The
of
Leucaena leucocephala contain
mimosine, an
amino acid known to be
Toxin to non
ruminant .
Uses
During the 1970s and 1980s,
Leucaena leucocephala was promoted as a "miracle tree" for its multiple uses.
It has also been described as a "conflict tree" because it is used for forage production but spreads like a weed in some places.
The legume is promoted in several countries of Southeast Asia (at least Burma, Cambodia, Indonesia, Laos,
Culinary
The young pods are edible and occasionally eaten in
Pecel, and
Buntil in Indonesia, and in papaya salad in
Laos and Thailand, where they are known as phak krathin ().
In Mexico it is eaten in soups and also inside tacos, it is known as
guaje. Cooking is thought to remove most of the poison.
Forage and fodder
The legume provides an excellent source of high-protein cattle fodder.
However, the fodder contains
mimosine, a toxic amino acid. Horses and donkeys which are fed it lose their hair.
In many cases this acid is metabolized by ruminants to goitrogenic DHP 3-hydroxy-4(1H) in the rumen,[Hammond, A. C. 1995. Leucaena toxicosis and its control in ruminants. J. Animal Sci. 73: 1487–1492.][Allison, M. J., A. C. Hammond, and R. J. Jones. 1990. Detection of ruminal bacteria that degrade toxic dihydroxypyridine compounds produced from mimosine. Appl. Environ. Microbiol. 56: 590–594.] but in some geographical areas, ruminants lack the organisms (such as Synergistes jonesii) that can degrade DHP.
In such cases, toxicity problems from ingestion of Leucaena have sometimes been overcome by infusing susceptible animals with rumen fluid from ruminants that possess such organisms,[Allison, M. J., W. R. Mayberry, C. S. Mcsweeney, and D. A. Stahl. 1992. Synergistes jonesii, gen. nov., sp. nov.: a rumen bacterium that degrades toxic pyridinediols. Syst. Appl. Microbiol. 15: 522–529.] and more recently by inoculating cattle rumen with such organisms cultured in vitro.[Graham, S. R., S. A. Dalzell, Nguyen Trong Ngu, C. K. Davis, D. Greenway, C. S. McSweeney, and H. M. Shelton. 2013. Efficacy, persistence and presence of Synergistes jonesii in cattle grazing leucaena in Queensland: on-farm observations pre-and post-inoculation. Animal Prod. Sci. 53: 1065–1074.]
Such measures have facilitated Leucaena use for fodder in Australia and elsewhere.
Green manure and biomass production
Leucaena leucocephala has been considered for
biomass production because its reported yield of foliage corresponds to a dried mass of kg/ha/year, and that of wood 30–40 m
3/ha/year, with up to twice those amounts in favorable climates. In India it is being promoted for both fodder and energy.
[ Subabul Reloaded: How One Tree Could Be the Answer to India’s Fodder, Fuel Needs; Published in The Better India, 11 February 2019]
It is also efficient in nitrogen fixation, at more than 500 kg/ha/year.
It has a very fast growth rate: young trees reach a height of more than in two to three years.
Pulpwood for paper industry
The wood of
Leucaena leucocephala is used for making pulp in the pulp and paper industry. In the southern and central states of India, it is the most important pulpwood species for making pulp. It has huge positive socio-economic impact on the livelihood of the small farmers where
Leucaena leucocephala is grown as an industrial crop. This provides an alternative crop to the farmers of
Andhra Pradesh and
Telangana, where they are also growing cotton and chillies.
Potential as bioherbicidal agent
Leucaena leucocephala is an
allelopathic tree. Phytotoxic allelochemicals, such as
mimosine and certain phenolic compounds, including p-hydroxycinnamic acid, protocatechuic acid, and
gallic acid, have been identified in the leaves of the species.
Bioherbicidal activity of
L. leucocephala on terrestrial plants
[Hong NH, Xuan TD, Eiji T, Hiroyuki T, Mitsuhiro M, Khanh TD (2003) Screening for allelopathic potential of higher plants from Southeast Asia. Crop Protection 22:829–836][John J, Narwal SS (2003) Allelopathic plants. 9. Leucaena leucocephala (Lam.) de Wit. Allelopath J 12:13–36 OpenURL] and aquatic weed
water hyacinth[Chai TT, Ooh KF, Ooi PW, Chue PS, Wong FC (2013) Leucaena leucocephala leachate compromised membrane integrity, respiration and antioxidative defence of water hyacinth leaf tissues. Botanical Studies 54: 8.] were reported.
In culture
The state of
Oaxaca in Mexico derives its name from the
Nahuatl word huaxyacac, the name for
Leucaena leucocephala trees that are found around
Oaxaca City.
==Gallery==
External links
