Invader Fact Sheets


Just when you thought it was safe to go into the mountains again...

And it's true: our pristine, Biosphere-protected plateau is being invaded, mainly from the south, by a determined force of ruthless exploitative aliens from other lands or their allies from elsewhere in the country.

And on this occasion, I'm not referring to humans with strange-sounding accents or GP-plated SUVs (although some of them too, could use a pesticide or two). No, the reference here is to an ever-increasing group of plant species that would like to make our plateau their home "preferably, or inevitably, at the expense of those species whose home this has been since time immemorial and whose presence is what caused the area to be declared a biosphere reserve in the first place.

There are already many names in this group, some posing more of an immediate threat than others. Several, like the ubiquitous gum (Eucalyptus spp) or the garden syringa (Melia azedarach), or the jacaranda (Jacaranda mimosifolia) are so well-established "and sadly, so well-loved by some "that they are hardly considered to be aliens any more. But aliens they remain; and if you watch them carefully, you might see them shedding skin or changing colour, or smiling cruelly to themselves as they suck the moisture from the ground or crowd out some indigenous species struggling to survive under their toxic shade.

In the coming summer, the Conservancy will once again run a campaign to rid our region of one of the most pernicious and aggressive of these aliens: the Pom Pom weed (Campuloclinium macrocephalum). Details will be communicated in due course, but we hope to build on last summer's small but successful pilot project to launch an all out attack on this deceptively attractive roadside floozie, hopefully with the assistance of Working for Water, ARC, SANBI, the Biosphere, local schools and game reserves.

In the meanwhile, we will be putting together a series of information sheets, each of which will describe a particular species of obnoxious alien / invader, together with details on how you, the conservation-oriented reader, can go about identifying the species and taking steps to eliminate it from your property. These sheets, which will start to appear within the next month or so, will be produced both electronically and in hard copy. Initially, they will be written in English, but we would like to produce them in Afrikaans and North Sotho too, provided we can find people with the requisite skill and patience to make the translations. Volunteers for this task are sought urgently.

Most of the information to be included in the sheets will not be new: it will be obtained from one of the several excellent existing publications about alien, invasive and problem plants, as well as lifted from the outstanding material published online by the Agricultural Research Council on its very accessible website . In particular, the highly informative SAPIA News series compiled by Lesley Henderson of the Plant Protection Research Institute of ARC (go to"News Articles" on the above website) will be raided for anything that can be used (SAPIA stands for South African Plant Invaders Atlas). Our thanks in advance go to Lesley and the ARC team.

The list of offenders is long, but initially, the intention is to focus on the following hardened individuals:

  • Gums (Eucalyptus spp) of every description "not just because they're Australian, but also because they are robbing our land of its scarce water resources
  • Bankrupt bush (Seriphium plumosum = Stoebe vulgaris) "the invader from the Cape fynbos that is crowding out the already limited edible grassland
  • Lantana (Lantana camara) "a poisonous plant that reduces pasturage and creates impenetrable thickets
  • Queen of the Night (Cereus jamacaru) "the naboom-like cactus that displaces grazing - and only flowers when everyone is asleep
  • Prickly pears (Opuntia spp) - introduced from Central America and widely cultivated for their fruit, as a fodder and as a hedge, they are rapacious invaders
  • Wattles (Acacia spp) "not only because they are also Australian and have now succeeded in stealing the name Acacia (which means thorned) for their exclusive use despite having no thorns, but because like their cousins the gums, they are voraciously thirsty (i.e. Australian)
  • Fluff bush or pluisbos (Lopholaena coriifolia) "another indigenous invader, which grows in alliance with bankrupt bush to destroy grazing
  • Pom Pom weed (Campuloclinium macrocephalum) "the pink lady described above.

We will add to the list as we go along "names of additional suspects will be welcomed.