Common name: Malabar Nut

Malabar Nut, or Vasaka Nut, is an ornamental and medicinal shrub native to Pakistan, India, and Southeast Asia.

It is a fast-growing shrub that may reach up to 5 m (16 ft) under favourable conditions, though it is more typically 2 to 3 m (7 to 10 ft) tall, with multiple stems supporting a wide-spreading crown often as wide as the plant is tall.

The leaves are elongated oval, up to 25 cm (10 in) long, on top bright green and prominently ribbed, underneath pale green. They remain on the plant year-round and give off an unpleasant odour when crushed.

The flowers are unusually shaped, with two large white lips and purple veining. They bloom in the dry winter season in their native range, tightly packed on erect flower spikes and are soon followed by club-shaped seed capsules up to 2.5 cm (1 in) long. When mature, the light-brown seedpods pop open and expel their seed some distance from the parent plant.

Environmental uses

Livestock browsing resistant - The leaves and young twigs are unpalatable and even poisonous to livestock because of their high potassium nitrate content.

Green manure - The same high potassium nitrate content helps make the leaves valuable green manure. They are harvested and used in southern India to fertilise rice, tea (Camellia sinensis) and tobacco crops.

Hedge plant - Because the leaves are unpalatable to livestock, the plant has been cultivated as a hedge in areas where free-roaming, browsing livestock can be a problem for gardeners.

Seaside garden plant - Its tolerance to salt spray makes it suitable for seaside gardens.

Bee forage - It is reported as a major honey plant in Pakistan. Still, there is little to no reliable information on the honey, its colour, flavour, or the plant's value as bee forage more generally.

Material uses

Firewood - The wood is a valued firewood that burns cleanly for a long time, with little to no odour or spark.

Charcoal - The wood is also reported to have been used in the past for making charcoal for gunpowder.

Natural insecticide - An infusion of the leaves is used as an insecticide in its native range against mosquitoes, flies and termites. The active ingredient is an alkaloid known as vasicine. Vasicine is toxic to insects and cold-blooded animals like fish and frogs, but not to mammals.

Health uses

Vasicine, the alkaloid in the leaves responsible for their insecticidal action, is effective against coughs, asthma, bronchitis, excessive phlegm and similar respiratory ailments. In traditional Indian, or Ayurvedic, medicine, it is prescribed to treat such conditions.

Climate

Grows naturally in sub-humid to moderately humid subtropical and tropical lowland to mid-elevation climates, generally in frost-free areas with annual lows of 14 to 23°C, annual highs of 26 to 35°C, annual rainfall of 600 to 1700 mm and a dry season of 3 to 8 months.

Growing

New plants are usually grown from seed. Its showy foliage is at its best display when there is some protection from the mid-day sun, generally on sites with partial sun exposure to light shade.

It performs best on loam, sand and limestone soils of a neutral to alkaline nature, generally with a pH of 7.0 to 8.0. It has a high tolerance to salt, with growth reportedly unaffected by slight to moderate salinity conditions of up to 6 grams of dissolved salt per litre of water. Although also drought tolerant, plants need regular watering until established.

Problem features

It has been introduced to many countries outside its native range and is reported to have become naturalised in most, so it is listed as a serious weed in more than one reference publication. It can quickly escape cultivation, and escapees are typically found on shaded sites where they form dense thickets.

The whole plant gives off an unpleasant odour when brushed against.

Books

• Adams, C. D. 1972, Flowering plants of Jamaica, University of the West Indies, Mona, Greater Kingston

• Champion, H. G. & Seth, S. K. 1968, A revised survey of the forest types of India, Natraj Publishers, Dehradun, India

• Chevallier, A. 2000, Encyclopedia of herbal medicine, 2nd American ed., Dorling Kindersley, New York

• Crane, E., Walker, P. & Day, R. 1984, Directory of important world honey sources, International Bee Research Association, London, United Kingdom

• Dastur, J. F. 1964, Useful plants of India and Pakistan : a popular handbook of trees and plants of industrial, economic, and commercial utility, 2nd ed., D. B. Taraporevala Sons, Bombay

• Jacobson, M. 1958, Insecticides from plants : a review of the literature, United States Department of Agriculture (USDA), Washington D.C.

• Khan, I. A. & Abourashed, E. A. 2010, Leung's encyclopedia of common natural ingredients : used in food, drugs and cosmetics, 3rd edition, Wiley Publishing, Hoboken, New Jersey

• Macmillan, H. F. 1943, Tropical planting and gardening : with special reference to Ceylon, 5th ed, Macmillan Publishing, London

• National Research Council (Board on Science and Technology for International Development) 1980, Firewood crops : shrub and tree species for energy production (Volume 1), The National Academies Press, Washington D. C.

• Oakman, H. 1995, Harry Oakman's what flowers when : the complete guide to flowering times in tropical and subtropical gardens, University of Queensland Press, St. Lucia, Queensland

• Parrotta, J. A. 2001, Healing plants of peninsular India, CABI Publishing, Wallingford, Oxfordshire

• Randall, R. P. 2002, A global compendium of weeds, R.G. and F.J. Richardson Press, Melbourne

• Randall, R. P. 2007, The introduced flora of Australia and its weed status, Cooperative Research Centre for Australian Weed Management, Glen Osmond, South Australia

Articles, Journals, Reports and Working Papers

• Dagar, J. C. & Singh, G. 2007, Biodiversity of Saline and Waterlogged Environments: Documentation, Utilization and Management, NBA Scientific Bulletin, (9), 78.

• National Research Council (Board on Science and Technology for International Development) 1990, Saline agriculture : salt-tolerant plants for developing countries, The National Academies Press, Washington D. C.