Sapwood
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A section of a Yew branch showing 27 annual growth rings, pale sapwood and dark heartwood, and pith (centre dark spot). The dark radial lines are small knots.

For the NATO reporting name for the R-7 Semyorka intercontinental ballistic missile, see SS-6 Sapwood.

Sapwood is the outer layer of wood in a tree, next to the bark. Sapwood will mature into Heartwood as the tree grows. See also wood#Heartwood and sapwood. The newer layers are the sapwood, and will stay sapwood for a certain number of years till they tree expands and new sapwood grows over it.

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