81. Some plants are partly parasitic; while most of their roots act in the ordinary way, others make suckers at their tips which grow fast to the roots of other plants and rob them of nourishment. Some of our species of Gerardia do this (Fig. 89).

Fig. 89. Roots of Yellow Gerardia, some attached to and feeding on the root of a Blueberry-bush.

82. There are phanerogamous plants, like Monotropa or Indian Pipe, the roots of which feed mainly on decaying vegetable matter in the soil. These are Saprophytes, and they imitate Mushrooms and other Fungi in their mode of life.

83.Duration of Roots, etc. Roots are said to be either annual, biennial, or perennial. As respects the first and second, these terms may be applied either to the root or to the plant.

84.Annuals, as the name denotes, live for only one year, generally for [Pg 38]only a part of the year. They are of course herbs; they spring from the seed, blossom, mature their fruit and seed, and then die, root and all. Annuals of our temperate climates with severe winters start from the seed in spring, and perish at or before autumn. Where the winter is a moist and growing season and the summer is dry, winter annuals prevail; their seeds germinate under autumn or winter rains, grow more or less during winter, blossom, fructify, and perish in the following spring or summer. Annuals are fibrous-rooted.

85.Biennials, of which the Turnip, Be