Tree of the year 2009 Searsia lancea Karee Photos: top, and bottom left - C. Mannheimer; bottom middle - G. Boois; bottom right - P. Horn. Poster and booklet design: Alice Jarvis. National Arbor Day 9th October 2009 PLANT TREES FOR ENVIRONMENTAL STABILITY Searsia lancea (=Rhus lancea) DESCRIPTION Searsia was named after An evergreen, untidy shrub or single- Paul Sears (1891-1990) stemmed tree with spreading crown and drooping branches, up to 6 m high, often who was head of the with a bright green appearance. The bark is Yale School of Botany; grey to grey-black, rough and deeply fissured to form fragments that flake off to expose lancea (Latin) refers to the a pale brown, reddish underbark. Young lance-shaped leaflets. branchlets are slightly reddish. The leaves are trifoliolate and spirally arranged; the leaflets are sessile, linear-lanceolate, straight or slightly sickle-shaped, hairless, shiny green above and dull olive- green below. The inflorescence is an axillary COMMON NAMES or terminal spray up to 6 cm long; male and female flowers are on separate plants. • Karee; Willow rhus (English) Flowers are small and greenish-yellow. Flowering is between June and January, • Soetkaree (Afrikaans) mostly August to October. The fruit are almost round, 4-5 mm in diameter, dull grey • Afrikanische Rivierweide (German) to shiny brown with a single seed. • !areb (Khoe-khoegowab) The genus Searsia is easy to recognise as the • Oruso (Otjiherero) leaves are all trifoliolate and have a resinous smell when crushed. The Karee is probably the best known of the 13 Searsia species BACKGROUND occurring in Namibia. The wood is pale red to pink when freshly sawn, becoming deep Searsia lancea is commonly known as red when dry. It generally dries well though Karee, which means ‘mead’ in the Khoi occasionally develops cracks. The timber is language. It flourishes in the most arid parts hard and cross-fibred with a fine grain, but of the country and is normally found along often has defects like knots and heartwood- seasonal drainage lines, rivers and streams rotting. or on pan edges. It occurs naturally in Acacia woodland and is often found growing Karee is said to indicate the presence of on lime-rich substrates. underground water. It is drought- and frost- tolerant, relatively fast-growing and thrives Karee has a widespread distribution from on a variety of soils. It is susceptible to Zambia in the north to the Western Cape aphid attack when planted in gardens and Province of South Africa in the south. It is as a result the whole tree is often covered common in central Namibia mostly along with ‘balls’ of malformed leaves, which rivers, plains, hill slopes and pans in the compromises growth. This can partly be central-east. prevented by effective ant control. Karee trees growing in the wild seldom develop Karee is a highly versatile and useful tree, this problem. recommended for shade and windbreaks. It provides natural soil stabilisation and USES increases the infiltration of rainwater into the soil, thus reducing erosion and raising Karee is an easy to grow, highly adaptable the groundwater table. It is protected by tree that can be used very successfully for Forestry legislation in Namibia. both urban and estate-type landscapes. It Tree of the year 2009 is an excellent shade tree especially in hot CULTIVATION regions since it is evergreen and drought- tolerant. Whether planted as a single tree Karee can be propagated easily from seed, or grouped, the Karee creates a lovely soft cuttings or layers. Ripe seed should be sown garden feature. in seedling trays and transplanted into bigger containers when the seedlings reach the The root system is not aggressive, making two leaf stage. Cuttings can be taken using the species suitable for planting near paved young growth from September to October. and tarred surfaces. Because Karee is The tree can grow up to 80 cm a year and hardy, tolerant and evergreen, it is ideal for is thus fairly fast growing. Because the tree establishing a protective canopy for frost- is hardy it does not require any special sensitive and shade-loving plants. It could be attention once its roots are established. utilised as a pioneer plant when establishing a new forest in an area that receives frost. Karee is suitable for use as a large hedge TAXONOMIC ASPECTS along the boundaries of properties such as farms because of its dense growth habit. It Following taxonomic revision, most of the can also be effectively used as a screen or species belonging to the genus Rhus in barrier against wind, noise, objectionable southern Africa have now been placed in the views or to provide privacy. Karee can adapt genus Searsia. In southern Africa there are well to different soils including those that about 111 species of Searsia. Karee belongs are poorly drained and is therefore ideally to the family Anacardiaceae (the Mango suited for use as a street tree. Aesthetically, family) which is the fourth largest tree family the Karee is a graceful tree with a willow-like in southern Africa. Common edible fruit and appearance due to its drooping habit; this seeds that belong to this family include the makes it suitable for use near water such as mango, pistachio nut and cashew nut. garden water features, dams or rivers. REFERENCES The fruit is eaten by birds including bulbuls, guineafowl and francolins. Game animals Coates-Palgrave, K. 1983. Trees of Southern Africa. Struik: Cape including kudu, roan and sable browse the Town. leaves, which can be an important food Curtis, B.A & Mannheimer, C.A. 2005. Tree Atlas of Namibia. source in times of drought. The fragrant Windhoek: National Botanical Research Institute. flowers attract bees and other insects. Jackson, W. 1990. Origins and Meanings of Names of South African Plant Genera. Rondebosch: University of Cape Town. Joffe, P. 1993. The Gardener’s Guide to South African Plants. 1st The leaves provide valuable fodder for edition, Cape Town: Tafelberg Publishers Limited. livestock but can taint the flavour of milk if Mannheimer, C.A. & Curtis, B.A. (Eds.) In prep. Le Roux and eaten in large quantities by dairy cattle. The Müller’s Field Guide to Trees and Shrubs of Namibia. tree can provide valuable shade for livestock, Windhoek: MacMillan Education Namibia. especially when planted in groups. Moffett, R.O. 2007. Name changes in the Old World Rhus and recognition of Searsia (Anacardiaceae). Bothalia 37(2):165- 175. The timber processes easily and polishes National Herbarium of Namibia (WIND). 2009. SPMNDB Database. well. The wood makes excellent fence posts National Herbarium of Namibia (WIND), National Botanical and, in the past, was used for tool handles, Research Institute, MAWF, Windhoek, Namibia. Neethling, R. & L. 2009. TreeCo-Wholesale Big Tree Nursery, wagon parts, bowls, tobacco pipes and Wellington. bows. The fruit is edible with a pleasant, but SEPASAL Database: National Botanical Research Institute. sour, taste; it is eaten after it turns yellow Thomas, V. & Grant, R. 1998. Sappi Tree Spotting: Highveld and but before it dries. It is used as an important the Drakensberg. Tree and Shrub Identification Made Easy. ingredient of mead and beer. Tannin from 1st edition, Johannesburg: Jacana. the bark, twigs and leaves has been used Van Wyk, B. & van Wyk, P. 1997. Field Guide to Trees of Southern for dyeing, and the roots have been used Africa. 1st edition, Cape Town: Struik Publishers. medicinally for stomach disorders. Venter, F. & Venter J. 1996. Making the Most of Indigenous Trees. 1st edition, Pretoria: Briza Publications. Distribution of Searsia lancea in Namibia PUBLISHED BY: DIRECTORATE OF FORESTRY MINISTRY OF AGRICULTURE, WATER AND FORESTRY PRIVATE BAG 13184 WINDHOEK NAMIBIA Text compiled by Gerhardt Boois, Directorate of Forestry. 061 2087671.