Lilies tweek their fruit and seeds to ensure their propagation

AFRICAN BUSH lilies are demanding plants. To thrive, they need dappled shade—for they are sensitive to full sunlight—and well-drained soil. They are therefore patchily distributed, growing only in microclimates where these conditions pertain. That means their seeds are likely to do best if they germinate near the plant that bore them. Too near, though, and they will compete with that parent for resources. Somehow, a way needs to be arranged for seeds to be carried the optimum distance from their parental plants. And Ian Kiepiel and Steven Johnson at the University of KwaZulu-Natal, in South Africa, think they know how it happens.Plants are masters at manipulating animals into assisting their reproduction. One way this happens is that the seeds of many species are just the right size and shape to endure passage through the alimentary canals of the animals that swallow them. When they eventually end up as part of a dung pile, they are thus far from home. The bush lily’s predicament, however, suggested to Mr Kiepiel and Dr Johnson that it was not in the plant’s best interest for animals to swallow its seeds in the first place.