sapwood
noun
- the part of living wood where sap flows, as distinct from the heartwood, where it doesn't
Wiktionary
Pronunciation: /ˈsapwʊd/
noun
Etymology: From sap + wood.
- The wood just under the bark of a stem or branch; it differs from the heartwood in color and in physiologic activity (flow of sap).
“A popular myth is that sapwood is not as strong as heartwood.”