alburnum (albernum)

[L., sap-wood, prop. neut. of albur -d nus, which appears in ML. in the sense of 'whitish': see au burn.] The lighter-colored and softer part of the wood of exogenous plants, between the inner bark and the heart-wood. It is frequently called sap - wood, and is gradually transformed into heart-wood wood; c, pith; đả, or duramen. Another form is alburn. IMG:content-0470.png:[ocr errors] Alburnum. aa, alburnum, or sap-wood; bb, heart bark.