Common name: African cedar

African cedar is a timber and essential-oil yielding conifer with a native range that extends from the Arabian Peninsula to the highlands of East Africa. 

It may reach heights of up to 30 m (98 ft) in its natural habitat, though is slow-growing, averaging only around 0.5 m (1.6 ft) per year. The trunk is usually straight, often fluted at the base in older trees, with vertically fissured and peeling brown to reddish-brown bark. Branching is low on young trees, forming a pyramid-shaped crown that gradually becomes rounded as the tree ages and sheds its lower branches. 

The leaves are evergreen, needle-like on young trees changing on adult trees to tiny scale-like leaves typical of junipers.

The flowers are cones, with female and male cones borne on separate trees. Flowering is infrequent, usually only once every several years, at which time the fertilised female cones develop into a small fleshy, berry-like fruit, turning blue-black when ripe with one to four seed inside.

Use

African Cedar yields a light-weight wood, with a density of about 480 kgs per cubic meter (30 lbs per cubic ft) and with good natural resistance to decay. This classes it as a durable softwood suitable for both indoor and outdoor construction.

The sawn timber is used for roofing shingles, joinery work, furniture and cabinets, as well as for small speciality items such as pencils. The small-diameter roundwood is cut for poles and posts, including fence posts and in particular transmission poles that carry electricity and communication cables high above the ground.

The essential oil distilled from the sawdust is known as 'Cedar oil' or 'Cedarwood oil' in the trade. It has a long history of use as a fragrance in toiletry and cosmetic products, including high-end perfumes.

The tree's natural habitat is under threat and it is recorded, by the International Union for Conservation of Nature (IUCN), as a species in need of conservation attention.

Climate

It grows naturally in sub-humid subtropical and high-elevation tropical climates, generally areas with annual lows of 7 to 16°C, annual highs of 18 to 30°C, annual rainfall of 600 to 1300 mm and a dry season of 6 months or less, extending to 10 months with irrigation or groundwater.

Growing

New plants are usually grown from seed, which are extracted by crushing and sieving the dried female cones. Performance is best on free-draining, loam and sand soils of a slightly acid to alkaline nature, generally with a pH of 6.0 to 8.5, and on sites with full to partial sun exposure. It is intolerant of shade conditions.

Problem features

Birds eat the fruit and carry the seed afar. However, there does not appear to be any records of it escaping cultivation and naturalising anywhere, which may be due in part to its infrequent flowering and fruiting habit, and the inability of seedling plants to establish in shade.

Pollen released by male cones is carried on the wind and contributes to a high pollen count, which may cause hay fever in some people.

Books

• C.A.B. International 2013, The CABI encyclopedia of forest trees, CABI Publishing, Wallingford, Oxfordshire

• Chudnoff, M. 1984, Tropical timbers of the world, Forest Service, U.S. Department of Agriculture (USDA), Washington, D.C.

• Coppen J.J.W. 1995, Flavours and fragrances of plant origin, Non-wood forest products (Volume 1), Food and Agriculture Organization of the United Nations (FAO), Rome

• Food and Agriculture Organization of the United Nations (FAO) 1986, Databook on endangered tree and shrub species and provenances, FAO Forestry Paper 77, Forest Resources Division, Rome

• Guenther, E. & Althausen, D. 1948 to 1952, The essential oils (6 volumes), Van Nostrand Publishing, New York

• Hines, D. A., & Eckman, K. 1993, Indigenous multipurpose trees of Tanzania: uses and economic benefits for people, Cultural Survival Canada

• Jelks, Mary 1986, Allergy plants : that cause sneezing and wheezing, 1st ed., World-Wide Publications, Tampa, Florida

• Lemmens, R.H.M.J., Louppe, D. & Oteng-Amoako, A.A. (eds). PROTA, Plant Resources of Tropical Africa, Volume 7(1) : Timbers 1, PROTA Foundation, Backhuys Publishers, Leiden

• Scheffer, T. C & Morrell, J. J. 1998, Natural durability of wood : a worldwide checklist of species, Forest Research Laboratory, Oregon State University, Corvallis, Oregon