64 



FORMS OF ROOTS. 



125. When the descending axis is very short, and at once divides 

 into thin, nearly equal fibrils, the root is called fibrous, as in many 

 grasses; when the fibrils become short and succulent, the root is fasci- 

 culated, as in Ranunculus Ficaria and Asphodelus luteus (fig. 120); when 

 the succulent fibrils are of uniform size, and arranged like coral, the 

 root is coralline, as in Corallorhiza innata; when some of the fibrils 

 are developed in the form of tubercules containing starchy matter, as 

 in Orchis, the root is tubercular (fig. 121); when the fibrils enlarge in 

 certain parts only, the root is nodulose, as in Spiraea Filipendula (fig. 

 122), or moniliform, as in Pelargonium triste (fig. 123), or annulated, as 

 in Ipecacuanha. 



120 



126. Root of Dicotyledonous or Exogenous Plants. In these plants 



the root in its early state, or the radicle as it is then called, is a pro- 

 longation of the stem, and elongates directly by its extremity. It then 

 continues to grow in a simple or branched state (fig. 119). From this 

 mode of root development, these plants have been called Exorhizal 

 (lg<a, outwards, and pict, a root), by Eichard. In their after progress, 

 these roots follow the arrangement seen in the woody part of the stem. 

 In some cases, as in the Walnut and Horse-chestnut, there is a pro- 

 longation of the pith into the root to a certain extent. 



127. Root of Monocotyledonons or Endogenous Plants. In these 



Fig. 120. Fasciculated root of Asphodelus luteus. 



Fig. 121. Tubercular root of Orchis. Several of the radical fibres retain their cylindrical form, 

 while two are tubercules containing starchy matter. 

 Fig. 122. Nodulose root of Spiraea Filipendula. 

 Fig. 123. Moniliform root of Pelargonium triste. 



