Lantana (Lantana camara
) is a perennial herbaceous plant and shrub with showy flowers that change color as they mature. In Australia, L. camara
is one of the most damaging invasive weed species due to it forming dense thickets, which kill off native species.
All parts of L. camara
are considered to be toxic, with the red-flowered forms being the most dangerous. L. camara
contains pentacyclic triterpenoids which are damaging to the liver when ingested by grazing horses. L. camara
also causes photosensitization through cholestasis, effectively preventing the elimination of phylloerythrin through the bile, and thereby causing photosensitization.
Early symptoms of poisoning by L. camara
include depression, loss of appetite, constipation and frequent urination, followed by 24–48 hours of jaundice. Photosensitivity
is usually followed by death, typically occurring 1–4 weeks after the appearance of symptoms. Death is ultimately caused by liver insufficiency, kidney failure and possibly myocardial damage and internal paralysis. It is acutely toxic at about 1% of the horse's body weight.