DISTRIBUTION:
Originally from Central and South America, it is now a serious invading plant. More commonly found in the moist eastern parts of the country. Often cultivated as a garden subject.
BOTANICAL DESCRIPTION:
General: A bushy shrub or untidy scrambler. The branches are ridged or four-
angled and generally covered with short stiff hairs and recurved prickles.
Leaves: The dark green leaves have toothed margins, are rough to the touch on
the upper surface and slightly hairy beneath. They smell strongly when crushed.
Flowers: Compact flower heads with tubular flowers coloured from red, orange,
mauve to white. Usually a mixture of 2 or more of these colours.
September - April.
Fruit: Round, black berries in a cluster, ±5 mm in diameter, containing a stone
with two seeds.
TOXIC PRINCIPLE:
• Very similar to that of Lippia rehmannii
• Pentacyclic, triterpene acids such as lantadene.
Mechanism of action:
• Alters permeability of liver cell membranes and leads to intrahepatic
cholestasis with relatively little damage to liver cells.
• Also paralyses smooth muscle of gall bladder - can’t contract - bile
accumulation may cause erosion.
• Phylloerythrin concentration increases in circulation.
SYNDROMES:
Hepatogenous photosensitivity primarily due to liver parenchymal damage.
SYSTEMS AFFECTED:
Liver.
CLINICAL SIGNS:
• Mainly a cattle problem.
• Goats may eat it.
• Sheep are also susceptible, but seldom eat it.
• Secondary photosensitivity - unpigmented areas, hairless areas, i.e. muzzle, and
perineal area.
• Marked icterus.• Rumen stasis, constipation - may have diarrhea.
NECROPSY:
Macroscopical findings:
• Secondary photosensitivity skin lesions• Yellow to orange brown liver with enormously enlarged gall bladder with oedematous wall containing straw-coloured to dark green bile.
• Nephrosis
• Impaction of caecum and colon.
HISTOPATHOLOGY:
Cellular degeneration and necrosis in liver and kidney.
TREATMENT:
• Can try choleretics, i.e. clanobutin.
• Antihistamines
• Antibiotics
• Place in shade
• Dose activated charcoal
• Diet low in chlorophyll (good quality hay)
• Skin protectant creams.
PREVENTION AND ERADICATION:
• Avoid infected veld at danger periods.
• Eradication difficult - spread by birds.
• Herbicides: “Round-up” (glyphosate), “Tordon” (picloram) effective, but expensive.
