Many factors determine whether animals are poisoned by plants including the quantity and rate of the plant eaten; the stage of growth of the plant; the growing conditions of the plant; and whether or not the plants have been fertilized or treated with herbicides. The species of the animal, age, sex and general body condition of the animal also determine the outcome of plant poisoning. Lastly th...

Aposematic coloration, a well-known phenomenon in animals, has been given little attention in plants. Here I discuss two types of conspicuousness of thorns which are typical of many plant species: (1) colorful thorns, and (2) white spots, or white and colorful stripes, associated with thorns in leaves and stems. Both types of aposematic coloration predominate the spine system of taxa rich with ...