pericambium

from The Collaborative International Dictionary of English v.0.48

Pericambium \Per`i*cam"bi*um\, n. [NL. See {Peri-}, and
   {Cambium}.] (Biol.)
   A layer of thin-walled young cells in a growing stem, in
   which layer certain new vessels originate.
   [1913 Webster] Pericardiac