 The toxicity of Narcissus varies with species, N. poeticus being more toxic than N. pseudonarcissus, for instance. The distribution of toxins within the plant also varies, for instance there is a five times higher concentration of alkaloid in the stem of N. papyraceus than in the bulb, making it dangerous to herbivores more likely to consume the stem than the bulb, and is part of the plant's defence mechanisms. The distribution of alkaloids within tissues may also reflect defence against parasites. The bulbs can also be toxic to other nearby plants, including roses, rice, and cabbages, inhibiting growth. For instance placing cut flowers in a vase alongside other flowers shortens the life of the latter.
