36 



ROOTS. 



[SECTION 5. 



Spindle-shaped, or Fusiform, when thickest in the middle and tapering to 

 both ends ; as the common Radish (Fig. 85). 



76. These examples are of primary roots. It will be seen that turnips, 

 carrots, and the like, are not pure root throughout ; for the caulicle, from 

 the lower end of which the root grew, partakes of the thickening, perhaps 

 also some joints of stem above : so the bud-bearing and growing top is 

 stem. 



77. A fine example of secondary roots (67), some of which remain fibrous 

 for absorption, while a few thicken and store up food for the next season's 

 growth, is furnished by the Sweet Potato (Fig. 86). As stated above, 

 these are used for propagation by cuttings; for any part will produce ad- 

 ventitious buds and shoots. The Dahlia produces fascicled (i. e. clustered) 

 fusiform roots of the same kind, at the base of the stem (Fig. 87) : but 

 these, like most roots, do not produce adventitious buds. The buds by 

 which Dahlias are propagated belong to the surviving base of the stem 

 above. 



78. Anomalous Roots, as they may be called, are those which subserve 

 other uses than absorption, food-storing, and fixing the plant to the soil. 



Aerial Roots, i. e. those that strike from stems in the open air, are 

 common in moist and warm 

 climates, as in the Mangrove 

 which i - eaches the coast of 

 Florida, the Banyan, and, less 

 strikingly, in some herbace- 

 ous plants, sucli as Sugar 

 Cane, and even in Indian 

 Corn. Such roots reacli the 

 ground at length, or tend to 

 do so. 



Aerial Rootlets are abun- 

 dantly produced by many 

 climbing plants, such as the 

 Ivy, Poison Ivy, Trumpet 

 Creeper, etc., springing from 

 the side of stems, which they 

 fasten to trunks of trees, 

 walls, or other supports. 

 These are used by the plant 

 for climbing. 



79. Epiphytes, or Air- 

 Plants (Fig. S8), are called by the former name because commonly growing 



Fig. 88. Epiphytes of Florida and Georgia, viz., Epidendrnm conopseum, a 

 small Orchid, and Tillandsia usneoides, the so-called Long Moss or Black Moss, 

 which is no moss, but a flowering plant, also T. recurvata ; on a bough of Live Oak 



