From Seed to Seed:
Plant Science for K-8 Educators

The contents of the cell: exudates and extracts

In this section, we'll explore products and materials extracted from the contents of living cells. The function of these materials, called exudates or extracts, varies, and in some cases can only be speculated upon. Some likely function in wound healing or protection from predators or climate; others may simply be waste products that are exuded from the protoplasm.

A surprising number of common substances are extracted from the living contents of plant cells. In general, the quantity of these extracts is small compared to the volume of the overall plant body, and this relative scarcity has made many types very valuable. Essential oils, spices, dyes, and resins have been traded for centuries, and wars have been fought over land on which certain valuable plants were found. Let's look at a few examples, some of which were important historically and some of which continue to be used today.