260 KHIZOMES AND ROOTS. 



(125) Vera Cruz Sarsaparilla. 



The root of Smilax sp. (N.O. Liliacese). 



The root presents the following structure : 



(1) Exodermis, composed of several rows of cells, which exhibit 

 in transverse section very strong thickening on the lateral and 

 outer tangential wall, the cavity being small and situated near 

 the inner tangential wall. In longitudinal sections these cells 

 are strongly elongated axially and pitted. 



Exterior to the exodermis the broken remains of root hairs 

 may sometimes be found. 



(2) Cortex, the cells of which are also axially elongated, and 

 contain either starch or bundles of acicular crystals of calcium 

 oxalate. The starch is in either simple or compound grains ; 

 the former are ovoid or rounded ; the latter contain three, four, 

 or five component grains which, when isolated, exhibit one 

 rounded and one or more flat surfaces. 



(3) Endodermis, which is rather conspicuous ; the cells are 

 radially elongated, and their lateral and inner tangential walls 

 rather strongly thickened, so that they exhibit a horse-shoe 

 thickening in transverse section. In longitudinal section they 

 are seen to be strongly axially elongated, and one of the 

 longitudinal walls is somewhat conspicuou&ly thickened. 



(4) Stele, composed of numerous, closely approximated fibro- 

 vascular bundles, which are surrounded by a lignified pericycle ; 

 the pith in the centre is also lignified. The vessels arn mostly 

 pitted, and are surrounded by fibres with thickened walls. 

 The pericyclic cells exhibit a similar structure. The cells of the 

 pith are rounded in section, and ihair .walls are slightly thick- 

 ened ; they contain starch. 



Jamaica Sarsaparilla closely resembles Vera Cruz in structure, 

 but may be distinguished by the cells of the exodermis and 

 endodermis, which are nearly square in tranverse section and 

 less strongly but almost uniformly thickened. 



The diagnostic characters of powdered Vera Cruz Sarsaparilla 

 are : 



(a) The very remarkable cells of the exodermis and 



endodermis. 



(b) The bundles of acicular crystals of calcium oxalate. 



(c) 7 he starch grains. 



