sapwood

/ˈsæpˌwʊd/
noun
  1. The soft, living outer layers of wood in a tree, through which water and nutrients flow.
    • When cutting firewood, you can see the pale ring of sapwood just under the bark.
    • Insects often attack the sapwood of a tree first.
    • The carpenter explained that sapwood is lighter in color than heartwood.
Antonyms