BiologyWise
Biology Wise: Structure and Function of a Casparian Strip
The Casparian strip is found in the endodermis layer of a plant's roots and it assists the plant in absorbing water and nutrients from the soil. The structure of a plant root is described and the process by which the Casparian strip...
Estrella Mountain Community College
Estrella Mountain Community College: Roots
This excellent site on plant structure contains information and diagrams under the first section, "General Plant Organization", about roots.