Why do some insect-eating plants like sundews keep their flowers so far away from their traps?
Sex can be complicated at the best of times, but plants have an extra difficulty. If you’re a plant who relies on insects to pollinate your flowers and reproduce, you will want your flowerstalks to be long. That way your flowers are on display to insects above the crowd. But if your stalk is too long, you’ll stand out to herbivores, and you flower will end up as someone’s lunch. It used to be thought that carnivorous plants like Sundews had the opposite problem. They reproduce better if they avoid eating insects that pollinate them, so a long stalk prevents an unfortunate meal. Simply looking at a plant, it’s impossible to tell if the stalks evolved for sex or safety, but Bruce Anderson at the University of Stellenbosch has now found an answer to be published in the October issue of the Annals of Botany. He examined two Sundews, Drosera cistiflora, which has a long stalk above its rosette of traps and Drosera pauciflora, which is more upright and has a shorter flower stalk. Both plants
