DR KEITH WHEELER / SCIENCE PHOTO LIBRARY DR KEITH WHEELER / SCIENCE PHOTO LIBRARY
Walnut bark. Cross section through the trunk of a walnut tree (Juglans regia) revealing the pattern in its bark. This pattern is known as a rhytidome. The rhytidome is composed of alternate layers of cork cells and dead cortical cells. Cork cells are produced in the stem by a layer of meristemetic cells (phellogen). Trees usually have one layer of phellogen, but in walnut there are several, which causes the pattern seen here.
Model release not required. Property release not required.