138 



CONSERVATIVE ORGANS. 



[LECT. iv. 



stem or the herbaceous part of the plant, and are 

 ' generally above the tubers, to which they are not 

 attached. It is necessary to remark that, in 

 some instances, both in the bulb and the tuber- 

 bearing roots, the rootlets are unsupplied with 

 fibrils, performing themselves the functions of these 

 organs ; and, like them, they annually decay with 

 the foliage in the autumn, to be renewed 



with it in the spring. 

 The majority of annual 

 plants and many Grasses, 

 as, for example, the Sea 

 Canary Grass, Phalaris 

 arenaria (fig. g), have 

 fibrous roots. The fol- 

 lowing are varieties of 

 the fibrous root. 



a. The Filiform root (Radix filiformu) is com- 

 posed of distinct and separate threadlike rootlets, 

 as in Duckweed, Lemna. 



b. The Capillary root (Radix capillarls) (fig. 



h. h) consists of many very fine 



fibres, as in Sheep's Fescue- 

 grass, Festuca ovina, and many 

 other Grasses. You will find, in 

 works on Elementary Botany, 

 the Tufted root (R. comosa) de- 

 scribed as a modification of 

 the Capillary root; but it is, correctly speaking, 



