The cells of the phellogen towards outside differentiate as phellem,and towards inside as phelloderm or secon- dary cortex.
The cells of the phellogen towards outside differentiate as phellem,and towards inside as phelloderm or secon- dary cortex.
木栓形成层不断向内分裂分化成栓内层,此时可称次生皮层。