In some instances this distinction in color is very marked; in others, the contrast is slight, so that it is not always easy to tell where one leaves off and the other begins.

The color of fresh sapwood is always light, sometimes pure white, but more often with a decided tinge of green or brown.
Sapwood is comparatively new wood.

There is a time in the early history of every tree when its wood is all sapwood.

Its principal functions are to conduct water from the roots to the leaves and to store up and give back according to the season the food prepared in the leaves.

The more leaves a tree bears and the more thrifty its growth, the larger the volume of sapwood required, hence trees making rapid growth in the open have thicker sapwood for their size than trees of the same species growing in dense forests.