
1) Recently formed wood in trees
Found on
https://www.crosswordclues.com/clue/alburnum

• (n.) The white and softer part of wood, between the inner bark and the hard wood or duramen; sapwood.
Found on
http://thinkexist.com/dictionary/meaning/alburnum/

See SAPWOOD
Found on
http://www.encyclo.co.uk/visitor-contributions.php
Al·bur'num noun [ Latin , from
albus white.]
(Botany) The white and softer part of wood, between the inner bark and the hard wood or duramen; sapwood.
Found on
http://www.encyclo.co.uk/webster/A/51

The sapwood or younger wood of a tree.
Found on
http://www.gardenology.org/wiki/Glossary_of_Gardening_Terms

Alburnum is the soft white substance which, in trees, is found between the liber or inner bark and the wood, and, in progress of time acquiring solidity, becomes itself the wood. A new layer of wood, or rather of alburnum, is added annually to the tree in every part just under the bark.
Found on
http://www.probertencyclopaedia.com/browse/BA.HTM
No exact match found.