Tamarix aphylla (PROTA)

Plant Resources of Tropical Africa Introduction

List of species

General importance
Geographic coverage Africa
Geographic coverage World
Dye / tannin
Medicinal
Timber
Fuel
Ornamental
Forage / feed
Auxiliary plant
Fibre
Climate change

Tamarix aphylla (Jusl.) H.Karst.

Protologue: Deut. Fl.: 641 (1882).

Family: Tamaricaceae

Chromosome number: 2n = 24

Synonyms

Tamarix articulata Vahl (1791).

Vernacular names

Athel tree, leafless tamarisk, athel tamarisk, tlaie of Morocco (En). Tamaris aphylle, tamaris à galles (Fr).

Origin and geographic distribution

In tropical Africa Tamarix aphylla occurs in dry regions from Mauritania and Senegal east to Somalia. It is also found in North Africa and the Middle East, and extends east into India. It has been introduced in South Africa, Madagascar, Mexico, the United States, Canada and Australia.

Uses

In West Africa the wood is used for carpentry and turnery. In Ethiopia it is used for construction, as firewood and for charcoal production. It is suitable for furniture, agricultural implements, fence posts and boxes.

The shoots are used in Ethiopia as fodder, and to cure scabies in camels. In India the bark is used as an astringent and to treat skin disorders such as eczema. As an auxiliary plant Tamarix aphylla is well suited for dune fixation, soil conservation and stabilization, and as shelterbelt and windbreak. Planted in rows or strips it is effective to stop fires as the leaves excrete salt that suppresses undergrowth while the litter does not burn because of the high salt content. Galls are formed when flowers and branches are attacked by a gall midge (Eriophyes tlaie). These galls are powdered and mixed with oil for tanning sheep and goat skins. The bark is sometimes also used in leather production and as a mordant in dyeing. Tamarix aphylla is widely planted for shade and as an ornamental, often along roads. The twigs are sometimes used for making baskets.

Properties

The heartwood of Tamarix aphylla is creamy white and indistinctly demarcated from the sapwood. The grain is often interlocked. The wood shows a silver-grain figure or a mottled to wavy appearance on quarter-sawn surfaces. The wood is medium-weight, with a density of about 680 kg/m³ at 12% moisture content, and fairly hard. The wood often splits during cutting. Flat-sawn boards tend to cup and warp during drying, and quarter-sawing is recommended. The rates of shrinkage from green to oven dry are about 2.7% radial and 12.4% tangential. The wood is somewhat difficult to machine, but it polishes and turns well with a lustrous surface. It is generally durable for indoor uses, but susceptible to termites. The wood is easy to treat with preservatives for outdoor uses. It is less suitable for pulping as the cellulose content is too low, but it is suitable for the manufacture of particle board.

Galls contain up to 55% tannin, twigs about 16% and bark about 8.5%; wood also contains tannin. The polyphenol tamarixellagic acid is found in the galls, as well as dehydrodigallic acid and dehydrotrigallic acid.

Description

Evergreen, small tree up to 15(–20) m tall; bole usually straight, up to 80(–90) cm in diameter; bark surface becoming fissured, reddish brown to grey; twigs drooping. Leaves alternate, reduced to sheathing scales 1.5–4 mm long and 1 mm in diameter on twigs, abruptly truncate and with minute point, with salt-excreting glands, larger branchlets with persistent scale-like leaves. Inflorescence a spike up to 6(–8) cm long, inserted towards the end of twigs. Flowers bisexual, regular, 5-merous, nearly sessile; sepals free, almost circular, c. 1.5 mm long, green or pinkish; petals free, oblong, c. 2 mm long, white; stamens c. 2 mm long; disk irregularly lobed between insertion of stamens; ovary superior, obovoid, c. 1.5 mm long, glabrous, style conical, stigmas 3. Fruit an ovoid capsule 4–5 mm long, 3-valved, many-seeded. Seeds c. 0.5 mm long, with an apical tuft of hairs c. 3 mm long.

Other botanical information

Tamarix comprises about 50 species of xerophytic and halophytic shrubs and trees. It is restricted to the Old World, but some species have become naturalized in arid regions of the Americas and Australia. About 7 species occur naturally in tropical Africa, and several others have been introduced from Asia and Europe into tropical Africa. The value of the flower disk characteristics, considered important in distinguishing between species, is in doubt. A revision of the genus will probably lead to a reduction of the number of species.

Other Tamarix spp. have many uses in common with Tamarix aphylla, especially as a source of firewood and in land management.

Tamarix nilotica

Tamarix nilotica (Ehrenb.) Bunge is a small tree found in Sudan, Eritrea, Ethiopia, Djibouti, Somalia, Kenya and Tanzania, as well as in Egypt, Israel and Lebanon. In Kenya the wood is used for house construction and firewood. In Sudan the bark and galls are used to treat fever and colds and methanolic extracts of both were shown to have moderate antiplasmodial activity.

Tamarix senegalensis

Tamarix senegalensis DC. is recorded from Cape Verde, Mauritania and Senegal. In Mauritania the wood is used for house building. The wood is also used for tent-pegs and tool handles. Camels eat the twigs. An exudate is collected from the tree and used as a sweetener. In Senegal a decoction made of the twigs is applied as an eyewash to cure conjunctivitis and a fruit macerate is used to treat rhinitis.

Tamarix usneoides

Tamarix usneoides E.Mey. ex Bunge is distributed in Angola, Namibia and South Africa. In Namibia it is popular as a source of firewood and the leafy branches are eaten by livestock. A decoction of the roots is drunk to cure diarrhoea and indigestion, and to overcome stomach pains.

Anatomy

Wood-anatomical description (IAWA hardwood codes):

• Growth rings: 1: growth ring boundaries distinct.
• Vessels: (4: wood semi-ring-porous); 5: wood diffuse-porous; (11: vessel clusters common); 13: simple perforation plates; 22: intervessel pits alternate; 23: shape of alternate pits polygonal; 24: intervessel pits minute (≤ 4 μm); 25: intervessel pits small (4–7 μm); 30: vessel-ray pits with distinct borders; similar to intervessel pits in size and shape throughout the ray cell; 41: mean tangential diameter of vessel lumina 50–100 μm; 42: mean tangential diameter of vessel lumina 100–200 μm; (45: vessels of two distinct diameter classes, wood not ring-porous); 47: 5–20 vessels per square millimetre; 58: gums and other deposits in heartwood vessels.
• Tracheids and fibres: 61: fibres with simple to minutely bordered pits; 66: non-septate fibres present; 69: fibres thin- to thick-walled.
• Axial parenchyma: 79: axial parenchyma vasicentric; 83: axial parenchyma confluent; 90: fusiform parenchyma cells; 91: two cells per parenchyma strand; (92: four (3–4) cells per parenchyma strand).
• Rays: 99: larger rays commonly > 10-seriate; 102: ray height > 1 mm; 106: body ray cells procumbent with one row of upright and/or square marginal cells; 107: body ray cells procumbent with mostly 2–4 rows of upright and/or square marginal cells; (110: sheath cells present); 114: ≤ 4 rays per mm.
• Storied structure: 120: axial parenchyma and/or vessel elements storied.
• Mineral inclusions: 136: prismatic crystals present; 137: prismatic crystals in upright and/or square ray cells.

(P. Ng’andwe, H. Beeckman & P.E. Gasson)

Growth and development

Under favourable conditions when groundwater is accessible, growth is rapid. On sand hills in Somalia, the survival rate 7 years after planting was 68%, mean height 4.9 m and mean bole diameter 8.5 cm. In Sudan cuttings planted into irrigated fields showed a survival rate of 55–80% after 2 years, with an average height of 3 m. The root system of Tamarix aphylla extends up to 35 m horizontally and 20 m vertically, tapping deep water reserves.

Ecology

Tamarix aphylla is found in deciduous woodland and thickets on sandy soils, on dunes, canal and river banks, and in salty deserts up to 1700 m altitude. When established, it tolerates drought and high salt concentrations, is tolerant of high temperatures and withstands temperatures as low as –6°C. It grows in areas with a rainfall of (100–)250–500(–1200) mm/year.

Propagation and planting

One kg contains 100,000–300,000 seeds. The seeds of Tamarix aphylla loose viability quickly. For natural regeneration seed dispersal and flooding have to coincide. Propagation is often done with cuttings of 10 cm long taken from shoots developed during the last growing season, and planted in moist sand. Cuttings of 30–40 cm long and 0.5–1 cm in diameter are also used for planting in the nursery; they are ready for transplanting into the field after about 5 months. Protection of young plants against grazing animals is necessary.

Management

Large-scale planting has been done in Israel, Kuwait, the United States and Australia. In Israel drip-irrigation using saline water is practised. In both the United States and Australia the species has become naturalized and in the latter it is considered an invasive weed. In the United States eradication attempts for several of the introduced Tamarix spp. tried to spare Tamarix aphylla because this species is considered useful.

Spacing plants too closely will lead to water stress, whereas planting too widely may result in damage to young plants caused by the wind. Planting close and thinning after 2 years are suggested as good options. Recommended plant densities are 30–80 plants/ha. A row spacing of 4.5 m has been recommended in Arizona (United States).

For production of firewood coppicing is practised. The first harvest of firewood can be done 4 years after planting. For timber production, pruning to a single bole is essential. Under favourable conditions, poles for fence posts can be harvested after 5–8 years and logs for sawn timber after 20 years. Larger trees produce 20–30 kg of galls per year that need to be collected after the rainy season, and need to be dried carefully to avoid fermentation.

Genetic resources

Tamarix aphylla is widespread and not intensively used, and therefore no threats of genetic erosion are foreseen.

Breeding

Some selection work has been done in Israel on Tamarix aphylla and an improved cultivar ‘Erecta’ has been released. Interspecific hybridization in the genus offers opportunities for breeding.

Prospects

Tamarix aphylla is a useful species for timber production, control of bush fires, windbreaks and erosion control. When considering the introduction of a Tamarix species, Tamarix aphylla is often the best choice as it is less invasive than other species. As the plant uses water from deep reservoirs and exudes salt from the leaves, the risk of salinization of the top soil should be considered wherever considering to introduce the plant. More research is needed on wood properties, which may lead to a better use in dry regions, and on the value as a forage, providing salt and other minerals to livestock. The taxonomy of the genus needs to be clarified.

Major references

• Baum, B.R., 1978. The genus Tamarix. Israel Academy of Sciences and Humanities, Jeruzalem, Israel. 209 pp.

• Bekele-Tesemma, A., Birnie, A. & Tengnäs, B., 1993. Useful trees and shrubs for Ethiopia: identification, propagation and management for agricultural and pastoral communities. Technical Handbook No 5. Regional Soil Conservation Unit/SIDA, Nairobi, Kenya. 474 pp.

• Booth, F.E.M. & Wickens, G.E., 1988. Non-timber uses of selected arid zone trees and shrubs in Africa. FAO Conservation Guide No 19. FAO, Rome, Italy. 176 pp.

• Burkill, H.M., 2000. The useful plants of West Tropical Africa. 2nd Edition. Volume 5, Families S–Z, Addenda. Royal Botanic Gardens, Kew, Richmond, United Kingdom. 686 pp.

• Orwa, C., Mutua, A., Kindt, R., Jamnadass, R. & Simons, A., 2009. Agroforestree database: a tree reference and selection guide. Version 4.0. [Internet] World Agroforestry Centre (ICRAF), Nairobi, Kenya. http://www.worldagroforestry.org/ resources/databases/ agroforestree. May 2010.

Other references

• Ali, H., König, G.M., Khalid, S.A., Wright, A.D. & Kaminsky, R., 2002. Evaluation of selected Sudanese medicinal plants for their in vitro activity against hemoflagellates, selected bacteria, HIV-1 RT and tyrosine kinase inhibitory, and for cytotoxicity. Journal of Ethnopharmacology 83: 219–228.

• Arbonnier, M., 2004. Trees, shrubs and lianas of West African dry zones. CIRAD, Margraf Publishers Gmbh, MNHN, Paris, France. 573 pp.

• Canadell. J., Jackson, R.B., J.R. Ehleringer, J.R., Mooney, H.A., Sala, O.E. & Schulze, E.-D., 1996. Maximum rooting depth of vegetation types at the global scale. Oecologia 108: 583–595.

• Choukr-Allah, R., Malcolm, C.V. & Hamdy, A. (Editors), 1995. Halophytes and biosaline agriculture. CRC Press, Boca Raton, Florida, United States. 424 pp.

• Hunt, D.R., 1966. Tamaricaceae. In: Milne-Redhead, E. & Polhill, R.M. (Editors). Flora of Tropical East Africa. Crown Agents for Oversea Governments and Administrations, London, United Kingdom. 4 pp.

• Jansen, P.C.M., 1981. Spices, condiments and medicinal plants in Ethiopia, their taxonomy and agricultural significance. Agricultural Research Reports 906. Centre for Agricultural Publishing and Documentation, Wageningen, Netherlands. 327 pp.

• Mesfin Tadesse, 1993. Tamaricaceae. In: Thulin, M. (Editor). Flora of Somalia. Volume 1. Pteridophyta; Gymnospermae; Angiospermae (Annonaceae-Fabaceae). Royal Botanic Gardens, Kew, Richmond, United Kingdom. pp. 208–209.

• Milbrath, L.R. & Deloach, C.J., 2006. Acceptability and suitability of athel, Tamarix aphylla, to the leaf beetle Diorhabda elongata (Coleoptera: Chrysomelidae), a biological control agent of saltcedar (Tamarix spp.). Environmental Entomology 35(5): 1379–1389.

• Nawwar, M.A.M., Hussein, S.A.M., Buddrus, J. & Linscheid, M., 1994. Tamarixellagic acid, an ellagitannin from the galls of Tamarix aphylla. Phytochemistry 35(5): 1349–1354.

• Van den Eynden, V., Vernemmen, P. & Van Damme, P., 1992. The ethnobotany of the Topnaar. University of Gent, Belgium. 145 pp.

Sources of illustration

• Baum, B.R., 1978. The genus Tamarix. Israel Academy of Sciences and Humanities, Jeruzalem, Israel. 209 pp.

• Bekele-Tesemma, A., Birnie, A. & Tengnäs, B., 1993. Useful trees and shrubs for Ethiopia: identification, propagation and management for agricultural and pastoral communities. Technical Handbook No 5. Regional Soil Conservation Unit/SIDA, Nairobi, Kenya. 474 pp.

Author(s)

• C.H. Bosch, PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands

• D. Louppe, CIRAD, Département Environnements et Sociétés, Cirad es-dir, Campus international de Baillarguet, TA C-DIR / B (Bât. C, Bur. 113), 34398 Montpellier Cedex 5, France

Correct citation of this article

Bosch, C.H. & Louppe, D., 2011. Tamarix aphylla (L.) H.Karst. In: Lemmens, R.H.M.J., Louppe, D. & Oteng-Amoako, A.A. (Editors). PROTA (Plant Resources of Tropical Africa / Ressources végétales de l’Afrique tropicale), Wageningen, Netherlands. Accessed 19 December 2024.

• See the Prota4U database.