Occurs in grassland and bushveld in sandy, well-drained spots.
General: This is a succulent perennial plant, which grows between 50cm and 1 metre high when in flower. It has thick stems that root everywhere where they touch the soil.
Leaves: The fleshy leaves vary greatly in size and shape, from broadly ovate to oblong to lanceolate. They are covered with a thin waxy bloom and usually pale blue-green with red-rimmed margins.
Flowers: The waxy tubular flowers, carried in a terminal inflorescence, vary in colour from light orange to pink, but are usually coral-red, and pendulous. All flower parts in fives.
• Contains four extremely cumulative bufadienolides, namely:
- Orbicuside A, B, C, D.
• The flowers are more toxic than the leaves and the toxicity of plants differ both
within and between localities.
• Soil-type may influence toxicity - e.g. C. orbiculata growing on black clay is less toxic than those plants growing on sandy soils.
Cumulative bufadienolides (Krimpsiekte)
Cotyledon orbiculata can cause both acute intoxication and krimpsiekte
under natural conditions. Krimpsiekte is a disease of small stock (sheep and goats).
• Krimpsiekte is basically a paretic syndrome.
• Affected animals lag behind the flock.
• When forced to move, they tire easily and lie down or stand trembling, typically
with the feet together, the back arched and the head low.
• The neck may be twisted and the head may dangle loosely as the animal walks.
Thalamic vacuolisation has been reported with krimpsiekte.
• Acute intoxication: dose 2g/kg activated charcoal.
• Large dose is essential.
• Adsorption and fixation of excess in rumen.
• Even retro-diffusion back from plasma.
• Minimize stress to prevent catecholamine release.
With krimpsiekte treatment is symptomatic and supportive.
Colour photos. Final web-ready size: JPEG. Photo 1: 7.7 kb, 72 ppi; Photo 2: 19.3 kb, 72 ppi; Photo 3: 43.1 kb, 96 ppi. Original TIFF file housed at the Dept. of Paraclinical Sciences, Section Pharmacology and Toxicology, University of Pretoria.