Common name: Kassod tree

Kassod is a fast-growing timber and landscape tree native to forested areas in Southeast Asia, its natural range extending across Cambodia, Laos, Malaysia, Myanmar (Burma) and Thailand.

In closely spaced forests, it reaches heights of up to 24 m (79 ft) with a tall, slim trunk and a narrow crown, though on open sites is more typically 10 to 15 m (30 to 50 ft) tall with a wide-spreading crown. The bark is light grey or brown, smooth in young trees, becoming slightly cracked and rough with age.

The leaves are up to 35 cm (14 in) long and feather-like, consisting of twelve to twenty-four dark green, oval leaflets arranged in pairs along the length. Their dense arrangement casts a deep shade beneath the tree.

It produces large, showy clusters of pale yellow flowers at the tips of the branches, mainly in summer and on and off throughout the rest of the year, particularly in the wetter parts of its range. They are followed by long, narrow, flat seedpods in large numbers, each with up to twenty-five small seed inside. Green when young, they become dark brown when mature, then split open to release their seed, which fall to the ground.

Use

Kassod is widely planted as a street tree in its native range to beautify streetscapes and for the shade it provides. It is also grown in plantations to shade crops, particularly coffee (Coffea arabica) and Cacao (Theobroma cacao).

The wood is medium-weight to heavy, in the 600 to 800 kg per cubic meter (37 to 50 lbs per cubic ft) range, and has high natural resistance to rot and decay. This puts it in the durable hardwood class. The heartwood is dark brown to near black and is attractively marked by light and dark streaks. However, most of the logs come in diameters too small for sawing into planks or lumber, with the occasional large diameter log reserved for making fine furniture.

Most of the wood is used for fuelwood, for which the tree has long been cultivated. However, its use as a fuel is best restricted to charcoal production, as it produces much smoke when burnt as firewood. It is also cut into wood-turning lengths and is suitable for posts and poles used in fencing and other construction.

New or young stems and leaf growth have a reported crude protein content of around 17% of dry matter and are actively browsed by livestock, such as cattle, goats and sheep, but are toxic to non-ruminant animals, including pigs and poultry.

It is reported as a major honey plant in Venezuela. The flowers bloom over a long period and produce sufficient nectar of good quality, making it a honey plant. Still, there is little to no information about the honey produced, the yield per colony, colour, taste, or other properties.

Climate

Grows naturally in sub-humid to moderately humid tropical lowland climates, generally areas with annual lows of 17 to 25°C, annual highs of 26 to 35°C, annual rainfall of 700 to 2500 mm and a dry season of 3 to 8 months. However, it reaches its best development as a timber tree in areas with 1200 mm or more annual rainfall.

Growing

New plants are usually grown from seed, which remain viable for several years under cool, dry storage conditions. Seedlings can be planted out when around 30 cm tall. They perform best on deep, rich, free-draining clay and loam soils of a moderately acid to neutral nature, generally with a pH of 5.5 to 7.5 and on sites with full to partial sun exposure.

Problem features

The leaves are reportedly poisonous to humans and other non-ruminant animals due to the presence of an alkaloid with a strong purgative effect.

It produces a significant quantity of seed that fall to the ground and germinate readily but may remain viable in the soil for months or even years. It is listed as a weed in more than one reference publication and is recorded as a serious weed in Australia, and has been assessed as a high weed risk species for Hawaii by the Hawaii Pacific Weed Risk Assessment (HPWRA) project.

Books

• Allen, O. N. & Allen, E. K. 1981, The Leguminosae : a source book of characteristics, uses, and nodulation, University of Wisconsin Press, Madison, Wisconsin

• Bradbear, N. 2009, Bees and their role in forest livelihoods : a guide to the services provided by bees and the sustainable harvesting, processing and marketing of their products, Food and Agriculture Organization of the United Nations (FAO), Rome

• Colfer, C. J. et. al 2006, Forests and human health : assessing the evidence, Center for International Forestry Research (CIFOR), Bogor Barat, Indonesia

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

• Do, D. S. & Nguyen, H. N. 2003, Use of indigenous tree species in reforestation in Vietnam, Agricultural Publishing House, Hanoi

• Francis, J. K. 1998, Tree species for planting in forest, rural, and urban areas of Puerto Rico, U.S. Department of Agriculture, Forest Service, International Institute of Tropical Forestry, Río Piedras, Puerto Rico

• Francis, J. K. and Liogier, H. A. 1991, Naturalized exotic tree species in Puerto Rico, General technical report SO-82, USDA Forest Service, Southern Forest Experiment Station, New Orleans

• Francis, J. K. et al. 2000, Silvics of Native and Exotic Trees of Puerto Rico and the Caribbean Islands, Technical Report IITF-15, USDA Forest Service, Rio Piedras, Puerto Rico

• Gohl, B. 1981, Tropical Feeds : feed information summaries and nutritive values (Revised edition), Food and Agriculture Organization of the United Nations (FAO), Rome

• Hocking, D. 1993, Trees for drylands, International Science Publisher, New York

• Holttum, R. E. & Enoch, I. C. 2010, Gardening in the tropics : the definitive guide for gardeners, Marshall Cavendish Editions, Singapore

• Jensen, M. 1999, Trees commonly cultivated in Southeast Asia : an illustrated field guide, 2nd ed., Food and Agricultural Organisation of the United Nations (FAO) Regional Office for Asia and the Pacific (RAP), Bangkok

• Jim, C.Y. 1990, Trees in Hong Kong: Species for Landscape Planting, Hong Kong University Press, Hong Kong

• Krishen, P. 2006, Trees of Delhi : a field guide, Dorling Kindersley Publishers, Delhi

• Letourneux, C. 1957, Tree planting practices in tropical Asia, Food and Agriculture Organization of the United Nations (FAO), Rome

• Liegel, L. H. 1987. A technical guide for forest nursery management in the Caribbean and Latin America, U.S. Dept. of Agriculture, Forest Service, Southern Forest Experiment Station, New Orleans

• Little, E. L. & Skolmen, R. G. 1989, Common forest trees of Hawaii (native and introduced), Agricultuural Handbook No. 679, Forest Service, U.S. Department of Agriculture, Washington, D.C.

• Little, E.L. Jr. 1983, Common fuelwood crops: a handbook for their identification, McClain Printing Company, Parsons, West Virginia

• Luna, R. K 1996, Plantation trees, International Book Distributors, Dehradun, Uttarakhand

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

• Martin, F. W & Ruberte, R. M. 1975, Edible leaves of the tropics, U.S. Agency for International Development (USAID), and the Agricultural Research Service, U.S. Department of Agriculture (USDA), Mayaguez, Puerto Rico

• Nair, P. K. R. 1993, An introduction to agroforestry, International Centre for Research in Agroforestry (ICRAF), Kluwer Academic Publishers, Dordrecht

• 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.

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

• Perkins, K. D. & Payne, W. 1981, Guide to the poisonous and irritant plants of Florida, Florida Cooperative Extension Service, Gainesville, Florida

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

• Tatken, R. L., & C. A. Browning 1987, Health effects of exposure to wood dust: A summary of the literature. No. PB-87-218251/XAB, National Institute for Occupational Safety and Health, Cincinnati, Ohio

• Webb, D. B. 1984, A Guide to species selection for tropical and sub-tropical plantations, 2nd ed., Unit of Tropical Silviculture, Commonwealth Forestry Institute, University of Oxford, Oxfordshire

Articles, Journals, Reports and Working Papers

• Walkar, Tad, et al. Dispersal modes of woody species from the northern Western Ghats, India. Tropical Ecology 53.1 (2012).