A plant developmentalist's guide to paedomorphosis: reintroducing a classic concept to a new generation.

Paedomorphosis is an evolutionary change in morphology through an alteration in the rate or timing of a developmental pathway, resulting in more derived species appearing juvenilised in comparison to their ancestors. This concept has long been the subject of extensive, often intimidating, discussion in the animal literature, but is less frequently considered by only a few plant developmentalists. We define the main types of paedomorphosis and explain how they can be applied to plants, considering the differences between plant and animal lifecycles. We provide examples of plant paedomorphoses and point out their likely significance in the evolution of floral diversity. 2010 Elsevier Ltd. All rights reserved.