The role of the Cactus Working Group is to:
- Co-ordinate cactus research and management nationally in order to know what is been done and by which organisation or stakeholder.
- Ensure that the correct methods of control are being used.
- Improve coordination and communication between the Department of Agriculture, Working for Water and SANBI’s Early Detection Rapid Response (EDRR) teams.
- Compile a list of undesirable cacti.
- Liaise with cactus nurseries.
- Co-ordinate communications related to cacti.
- Develop a database of invasive cacti.
The Cactus Working Group held its second meeting at SANBI in Pretoria on 13 November 2012. Topics under discussion included the drafting of the National Strategy for Invasive Cacti and a review of the trade in cacti in South Africa.
How can you help?
Where possible, try to provide an accurate locality, including GPS coordinates as well as information on the size of the invasion. You can also get species identified by submitting photographs to the iSpot website at http://www.ispot.org.za/ or search the plant database at http://invasives.org.za/plants
Avoid transplanting cactus or randomly dumping cactus parts like cladodes onto dumping sites, as these can take root and form a dense colony in a short space of time.
Several cactus species have been identified as serious invaders in parts of South Africa, especially the Northern and Eastern Cape. Some cactus species have invaded large tracts of land to the detriment of indigenous plants. They are also a threat to livestock due to the spines which cause injury to animals. Of particular concern are the following cactus species:
- Pine-cone cactus (Tephrocactus articulatus) – proposed category 1
- Pink-flowered cholla (Cylindropuntia pallida) – proposed category 1
- Yellow-flowered cholla (Cylindropuntia tunicata) – proposed category 1
- Jointed cactus (Opuntia aurantiaca) – CARA category 1
- Bur cactus (Opuntia salmiana)
- Creeping prickly pear (Opuntia humifusa) – CARA category 1
- Teddy-bear cactus (Opuntia microdasys) – proposed category 1
- Barbados gooseberry (Pereskia aculeata) – CARA category 1
- Night-blooming cereus (Hylocereus undtatus) – proposed category 1
- Climbing harrisia (Harrisia balansae)
- Midnight lady (Harrisia pomanensis)
- Harrisia cactus (Harrisia martinii) – CARA category 1
- Pencil cactus (Cylindropuntia leptocaulis)
- Long-spine cactus (Austrocylindropuntia subulata) (=Opuntia exaltata) – CARA category 1
- Austrocylindropuntia cylindrica (=Opuntia cylindrica)
- Chain-fruit cholla (Cylindropuntia fulgida var. fulgida) – CARA category 1
- Cylindropuntia fulgida var. fulgida – CARA category 1
- Imbricate cactus (Cylindropuntia imbricata) – CARA category 1
- Cane cholla (Cylindropuntia spinosior)
- Serpent cactus (Peniocereus serpentinus)
- Torch cactus (Echinopsis schickendantzii) – CARA category 1
- Bilberry cactus (Myrtillocactus geometrizans)
- Queen of the night (Cereus hildmannianus subsp. uruguayanus) – proposed category 1
- Queen of the night (Cereus jamacaru subsp. jamacaru) – CARA category 1
- Spiny sweet prickly pear (Opuntia ficus-indica) – CARA category 1
- Drooping prickly pear (Opuntia monocantha) – CARA category 1
- Blue-leaf cactus (Opuntia robusta) – proposed category 1
- Aaron’s beard prickly pear (Opuntia leucotricha)
- Saucepan cactus (Opuntia spinulifera) – CARA category 1
- Small round-leaved prickly pear (Opuntia engelmannii) – CARA category 1
- Australian pest pear (Opuntia stricta) – CARA category 1
- Orange tuna (Opuntia elata)