Cedrela odorata (Cedarwood)

Scientific name

Cedrela odorataL.

Synonyms

Cedrela dugesii S. Watson; Cedrela guianensis A. Juss; Cedrela  mexicana M. Roem; Cedrela  occidentalis C. DC.; Cedrela sintenissii C. DC

Common names

Cedarwood, cedar, cigar box cedar, Spanish cedar, West Indian cedar, Barbados cedar

Family

Meliaceae

Origin

Cedrela odorata is native to the tropical America from Mexico through Central America to Argentina including the Caribbean.

Naturalised distribution (global)

Locations within which Cedrela odorata is naturalised include Several Pacific Islands, South African and western and eastern Africa.

Introduced, naturalised or invasive in East Africa

Cedrela odorata is invasive in parts of Tanzania (Tropical Biology Association 2010) (Global Invasive Species Database). It has been introduced to Kenya and Uganda. It has been listed as an invasive species in the Amani Nature Reserve, in the East Usambara Mountains in northeast Tanzania.

Habitat

In the introduced range, Cedrela odorata occurs in tropical and subtropical forests and forest edges, especially those with well drained soils and some disturbance. It prefers fertile, free-draining weakly acidic soils.

Description

Cedrela odorata is a deciduous tree up to 35 m tall, sometimes with small buttresses. The young bark is smooth, grey and becomes deeply fissured with age.

Leaves are compound; leaflets (pinnules) are divided to second order and are arranged on secondary axis (paripinnate). Leaflets oval to lanceolate (lance-shaped), 6 to 15 cm long, 3 to 5 cm wide, hairless (glabrous) to densely pubescent.

Flowers are borne on large branched inflorescences. Male and female flowers are borne on the same inflorescences. Female flowers open first. Flowers are white or yellowish, 5 mm long, fragrant. Annual flowering is regular from about 10 years of age.

The fruit consists of a woody capsule, about 2 to 4 com long, which is borne near branch tips. The capsule splits when ripe, usually still attached to the parent tree. Each fruit contains between 40 to 50 winged seeds, each about 20 to 25 mm in length. Fruit maturation takes about 6 to 10 months.

Reproduction and dispersal

Winged seeds are wind dispersed and can be blown over several kilometres.

Similar species

C. occidentalis C.DC.; C. rotunda S.F. Blake; C. ciliolata Blake; C. longipesBlake

Economic and other uses

The timber of Cedrela odorata is famous for use in making cigar boxes, musical instruments, light construction, veneer, and plywood. The insect repellent smell makes it suitable for wardrobes. In cocoa and coffee plantations, it is planted for shade and as a windbreak.

Environmental and other impacts

Cedrela odorata displaces native plants by blocking out sunlight with its large leaves. It spreads very quickly due to prolific seed production and wind dispersal. C. odorata quickly invades the disturbed areas, blocking natural succession processes. Dense growths of the plant are likely to increase the frequency and intensity of fires. the increase risk may disrupt settlements and affect economic benefits of forests such as timber.

C. odorata has been included in the Global Invasive Species Database (GISD 2006).

Management

The precise management measures adopted for any plant invasion will depend upon factors such as the terrain, the cost and availability of labour, the severity of the infestation and the presence of other invasive species. Some components of an integrated management approach are introduced below.

The best form of invasive species management is prevention. If prevention is no longer possible, it is best to treat the weed infestations when they are small to prevent them from establishing (early detection and rapid response). Controlling the weed before it seeds will reduce future problems. Control is generally best applied to the least infested areas before dense infestations are tackled. Consistent follow-up work is required for sustainable management.

In invaded habitats, Cedrela odorata plants can be controlled by mechanical methods; seedlings and saplings can be dug out; large trees can be killed by cutting down at ground level.

Chemical control can be undertaken on larger plants by the application of a suitable herbicide to cut stumps. When using any herbicide always read the label first and follow all instructions and safety requirements. If in doubt consult an expert.

The editors are not aware of any biological control programmes for C. odorata.

Legislation

Not listed as a noxious weed by the state or governments in Kenya, Tanzania and Uganda.

References

GISD (2006). Global Invasive Species Database online data sheet. Cedrela odorata (tree, shrub). www.issg.org/database. Accessed March 2011.

Pennington, T.D. and Muellner, A.N. (2010). A monograph of Cedrela (Meliaceae). DH Books. The Manse, Milborne Port, England.

Tropical Biology Association (2010). Usambara Invasive Plants - Amani Nature Reserve - www.tropical-biology.org/research/dip/species.htm.

Editors

Agnes Lusweti, National Museums of Kenya; Emily Wabuyele, National Museums of Kenya, Paul Ssegawa, Makerere University; John Mauremootoo, BioNET-INTERNATIONAL Secretariat - UK.

Acknowledgments

This fact sheet is adapted from The Environmental Weeds of Australia by Sheldon Navie and Steve Adkins, Centre for Biological Information Technology, University of Queensland. We recognise the support from the National Museums of Kenya, Tropical Pesticides Research Institute (TPRI) - Tanzania and Makerere University, Uganda. This activity was undertaken as part of the BioNET-EAFRINET UVIMA Project (Taxonomy for Development in East Africa).

Contact

BioNET-EAFRINET Regional Coordinator: eafrinet@africaonline.co.ke