Amphycribral Vascular Bundle of a Fern Rhizome-Pterídium aquilinum Big cells with red cell wall are tracheids. They serve in the transport of water.
Around the xylem there are xylem parenchyma and phloem cells. A single row layer of small cells (with red content) located circumferentially is endoderm.

Anatoly Mikhaltsov

Mederic Ap