Cork cells form a periderm that replaces rhizodermis

Phloem rays dilate at periphery of root as diameter increases

Enlarged image of the previous picture showing a peripheral zone. The periderm shows uniform stacking of flat thin-walled cork cells that have replaced the rhizodermis and cortex of the root in its primary state of growth. Note patches of secondary phloem fibers (seen in red) dispersed throughout the phloem.

Identify wood, vessels, vascular cambium, cork and raysùof which one dilates in the secondary phloem to accommodate an increase in circumference of the root.