Physiological Functions

Abstract

Leaf margins of many plant species belonging to the floras of several continents feature a conspicuous band of red/purple color around their periphery. Despite the widespread distribution of this leaf trait, very few studies have proposed or tested hypotheses to explain its significance (if any). Common explanations for leaf coloration, such as photoprotection, plant camouflage, attraction of seed dispersers, or undermining herbivorous insect camouflage do not seem, at first glance, to be applicable to this color pattern. Could pigments localized at the leaf margin still function in these traditional ecological or physiological roles? Or should new hypotheses be devised that are more specific to coloration at the leaf margin? The purpose of this paper is to review and explore potential ecological and physiological functions of pigmented leaf margins, in hopes of inspiring further inquiry into this topic.