"Ectopic Cambia: Connections Between Natural and Experimental Vascular Mutants".

One of the most remarkable innovations in the evolution of vascular plants is secondary growth: the developmental process by which plants grow thicker. The textbook illustration of secondary growth--a core of secondary xylem surrounded by a sheath of secondary phloem--is generated through a cylindrical meristem called the vascular cambium (Fig. 1A). This modality is conserved across thousands of species, providing mechanical support for ever-elongating shoots, and a regenerative source of vascular tissues to feed the ever-expanding crown of branches and leaves This article is protected by copyright. All rights reserved.