The New Student's Reference Work/Helotism
He′lotism (in plants). Two different kinds of plants have often learned to live together in such an intimate way, that they are usually found together. For example, a lichen is not a single plant, but it consists of an alga and a fungus living together. This general habit of living together in an intimate relationship is called symbiosis, and that form of it in which one plant is thought to enslave the other, that is to maintain it so that the former may live upon its products, is called helotism, the reference being to the Greek slaves of ancient times, who were called helots. Some think that the lichen is a case of helotism, the fungus having enslaved the alga. See Symbiosis.