40 NOMENCLATURE OF THE ROOT. 



b. Biennial those that live through the winter in which they are 

 produced, and after the plant has flowered and yielded seed, die in the 

 following year; as with the carrot, teasels, and Canterbury-bell. 



c. Perennial those which live for many years, as with most trees 

 and shrubs. 



6. Substance: When their substance is a mark of 

 distinction, roots are said to be of a woody or of a fleshy 

 nature. 



a. Woody when composed of an epidermis, a bark, a vascular 

 system, woody matter, and pith ; as with the roots of trees and shrubs. 



b. Fleshy when they belong to herbaceous plants, and consist 

 chiefly of cellular and vascular textures, interspersed with slender 

 bundles of woody fibre ; as with the snow-drop, lily, hyacinth, and 

 narcissus. 



7. Form and Composition: By the form and compo- 

 sition of roots, we are to understand the figure which 

 they assume, and the parts which constitute the figure. 

 In these respects, roots are either simple, branched, or 

 articulated. 



a. Simple when they consist of a single caudex furnished with 

 fibres only, or of one or more rootlets with fibrils or small fibres, as 

 with the carrot, parsnip, horse-radish, dandelion, radish, and primrose. 



b. Branched when they consist of a caudex divided into lateral 

 branches, which are again subdivided and ultimately terminated in 

 absorbing fibres, so that the root, in its division, resembles the stem 

 and branches inverted. This form of root is the most general, being 

 that of all trees and shrubs ; and also of many herbaceous plants, as 

 the elecampane and senega. 



c. Articulated when the root is apparently formed of distinct 

 pieces united, as if one piece grew out of another, so as to form a 

 connected whole, with rootlets proceeding from each joint, as with 

 wild ginger, hedge hyssop, Solomon's seal, and bistort. 



