Thyme-leaved buchu (Agathosma thymifolia)

Kingdom	Plantae
Phylum	Tracheophyta
Class	Magnoliopsida
Order	Sapindales
Family	Rutaceae
Genus	Agathosma (1)
Size	Height: to over 1 m (2)

Classified as Near Threatened (NT) on the Interim Red Data List of South African Plant Taxa (3).

The thyme-leaved buchu belongs to Rutaceae family, a group of aromatic trees and shrubs, sometimes known as the citrus family (1). The thyme-leaved buchu is a single-stemmed shrub that branches near ground level, and grows to form a rounded bush. The leaves are narrow ovals (2), and when crushed, produce a mild aroma from the oil glands that can be seen as small, translucent, black dots on the leaves (1). The small pink or mauve flowers (eight millimetres wide), grow in loose clusters at the tips of the branches (4), and the fruits are small berries (2).

Endemic to the Cape Floristic Region, a ‘hot-spot’ of plant diversity in south-western South Africa; from Vredenburg to Yzerfontein (2).

The thyme-leaved buchu has fairly specialised habitat requirements (5), growing only on coastal sand and dunes on limestone (2).

The thyme-leaved buchu flowers from August until October (2), and like other species of the Rutaceae family, it is likely to be pollinated by insects (1).

This aromatic plant is threatened by the encroachment of agriculture into its habitat, and habitat degradation (3). Cultivation for agriculture has transformed almost 26 percent of the Cape Floristic Region and 1.6 percent is now covered by urban areas (6). The spread of invasive alien plants also threatens to alter the unique, natural habitat of the Cape Floristic Region (7), to the detriment of many plant species. The thyme-leaved buchu may be more vulnerable to such threats than some other species, due to its specific habitat requirements.

The Cape Floristic Region contains nearly 9,000 plant species, most of which are found no where else in the world. This unique area is valued for its incredible diversity in plants, and thus there are a number of protected areas (8), and a number of conservation organisations are working to conserve this botanically rich habitat. Conservation actions include purchasing land to protect it from the threats of encroaching agriculture and urban development (9), the removal of alien plants, and the establishment of new protected areas (7); measures which should help ensure a thriving future for the thyme-leaved buchu.

For further information on the Cape Floristic Region and its conservation see:

• Conservation International: Biodiversity Hotspots (February 2008)
  www.biodiversityhotspots.org/xp/hotspots/cape_floristic

This information is awaiting authentication by a species expert, and will be updated as soon as possible. If you are able to help please contact: arkive@wildscreen.org.uk

• Cape Floristic Region: an area occupying about 90,000 square kilometres in South Africa that contains an incredibly high diversity of plant species (around 8,700 species), of which 68 percent are found no where else.
• Endemic: a species or taxonomic group that is only found in one particular country or geographic area.
• Pollinated: the transfer of pollen grains from the anther (male part of a flower) to the stigma (female part of a flower) of a flowering plant. This usually leads to fertilisation, the development of seeds and, eventually, a new plant.

1. Heywood, V.H. (1978) Flowering Plants of the World. Oxford University Press, Oxford.
2. Goldblatt, P. and Manning, J. (2000) Cape Plants: A Conspectus of the Cape Flora of South Africa. National Botanical Institute of South Africa, Pretoria .
3. Threatened Species Programme. (2007) Interim Red Data List of South African Plant Taxa. South African National Biodiversity Institute, Pretoria, South Africa. Available at:
   http://www.sanbi.org/biodiversity/reddata.htm
4. Paterson-Jones, C. and Manning, J. (2007) Ecoguide Fynbos. Briza Publications, Pretoria, South Africa.
5. Golding, J.S. (2002) Southern African Plant Red Data Lists. Southern African Botanical Diversity Network Report No. 14. SABONET, Pretoria.
6. Rouget, M., Richardson, D.M., Cowling, R.M., Lloyd, J.W. and Lombard, A.T. (2003) Current patterns of habitat transformation and future threats to biodiversity in terrestrial ecosystems of the Cape Floristic Region, South Africa. Biological Conservation, 112: 63 - 85.
7. Conservation International: Biodiversity Hotspots (February, 2008)
   http://www.biodiversityhotspots.org/xp/hotspots/cape_floristic/Pages/default.aspx
8. UNEP-WCMC: Cape Floral Protected Areas of South Africa (February, 2008)
   http://www.unep-wcmc.org/sites/wh/pdf/CAPE%20FLORAL%20REGION.pdf
9. Fauna and Flora International (February, 2008)
   http://www.fauna-flora.org/fynbos.php