84

CHAPTER XII.

OF 'HIE ROOT, AND ITS DIFFERENT KINDS.

w e begin the description of the completely formedvegetable by its root, being the basis of all the rest,as well as the first part produced from the seed. Itsuse in general is two-fold ; to fix the plant in a com-modious situation, and to derive nourishment for itssupport. This part is therefore commonly plungeddeeply into the ground, having, as we have alreadyshown, a natural tendency to grow downwards. Insome cases however, when plants grow on the stemsor branches of others, as the Dodder or Cuscuta, se-veral Ferns , and a portion of the Orchis tribe, theroot is closely attached to the bark, from which itdraws nourishment, by the under side only, theupper being bare.

The root consists of two parts, Caudex the bodyof the root, and Radicula the fibre. The latter only isessential, being the part which imbibes nourishment.

Roots are either of annual, biennial or perennialduration. The first belong to plants which live onlyone year, or rather one summer, as Barley ; the se-cond to such as are produced one season, and, livingthrough the ensuing winter, produce flowers andfruit the following summer, as Foxglove , and several