Alburnum

·noun The white and softer part of wood, between the inner bark and the hard wood or duramen; sapwood.

alburnum
alburnum, i, n. [albus], the soft , thin , white layer between the bark and wood of trees , sap-w...

A New Latin Dictionary by Charlton T. Lewis Ph.D. and Charles Short, LL. D.
alburnum
The sap-wood of timber, commonly termed the slab-cuts. ...

The Sailor's Word-Book