AKD ITS DIFFEKEXT KINDS. 9? 



and branching off horizontally, and throwing out 

 fibres as it goes. This kind of root is cKtrcmelv te- 

 nacious of life, for any portion of it will grow. Hence 

 weeds furnished with it are among the most trouble- 

 some, as the different sorts of Couch-grass, Triticum 

 repens, Engl. Bot. t. 909, Bolctis mollis, t, 1170, Sec; 

 while, on the other hand, many sea-side grasses, hav- 

 ing such a root, prove of the most important service 

 in binding down loose blowing sand, and so resisting 

 the encroachments of the ocean. These are princi- 

 pally Carex arenaria, Engl. Bot. t. 928, Arundo are^ 

 nana, t. 520, and Elymus arenar'ms, t. 1672, 



3. Radix fusiformis, / 7. A Spindle-shaped or Ta- 

 pering Root. Of this the Carrot, Parsncp and Rad- 

 ish are familiar examples. Such a root is formed, on 

 the principle of a wedge, for penetrating perpendicu- 

 larly into the ground. It is common in biennial 

 plants, but not peculiar to them. The caiidex, which 

 is the spindle shaped part, abounds with the proper 

 secreted juices of the plant, and throws out numerous 

 fibres or radicles, which are in fact the real roots, as 

 they alone imbibe nourishment. 



4. Radix pramorsa,/. 8. An Abrupt Root, is natu- 

 rally inclined to the last- mentioned form, but from 

 some decay or interruption in its descending point, it 

 becomes abrupt, or as it were bitten off. Scahiosa 

 succisa, Devil's-bit, Scabious, Engl, Bot. t. 878, 

 Hedypnois hirta, t. 555, and some other Hawk weeds, 

 have this kind of root, the old opinion concerning 



