310 



SUBTERRANEAN ORGANS 



used by the Seneca Indians as a remedy for snake-bite, and was intro- 

 duced into medicine about the middle of the eighteenth century. 



Description. Senega root consists of a slender, greyish or brownish 

 yellow root surmounted by a knotty crown, to which are attached 

 the remains of numerous slender aerial stems and small shoots beset 

 with the scars or remains of purplish scaly leaves. The root is usually 

 about 3 to 6 mm. thick at its upper extremity, but it soon divides into 

 two or three spreading branches. It is frequently curved and contorted, 

 and is longitudinally and sometimes, especially near the crown, trans- 

 versely wrinkled. Very frequently, but not always, it exhibits a 

 prominent keel resembling a contracted sinew and following a 



gently spiral course ; this keel may 

 generally be found on the con- 

 cave surface of the curves of the 

 tap-root, and often extends a 

 considerable distance. 



The root breaks with a short 

 fracture, the fractured surface 

 exhibiting a whitish wood and 

 yellowish translucent bark. The 

 former frequently presents an ab- 

 normal appearance. Instead of a 

 complete circle of wood a wedge- 

 shaped portion, or sometimes two, 

 of varying extent, is replaced by 

 parenchymatous tissue, and the 

 wood therefore appears to have 

 had a segment cut out of it. This 

 appearance varies in different parts 

 of the same root, the segment that 

 is missing being sometimes narrow 



and wedge-shaped or occasionally increasing to nearly a semicircle, 

 thus reducing the wood to one-half its normal amount. If a keeled 

 root is soaked in water and the bark stripped from it, the wood will 

 be seen to have transverse cracks or a longitudinal fissure on the 

 convex surface, the latter usually extending for some distance and 

 widening from a narrow crack into a broad fissure. These cracks 

 and fissures are filled with easily removable parenchymatous tissue. 



The concave sides of the curved roots bear the keels, and these are 

 seen in the transverse sections to be due to a largely developed bast ; 

 the keels do not arise from any abnormal development of the wood. 

 The root has a distinct odour, recalling wintergreen ; the taste is 

 at first somewhat sweet, but soon becomes sour and acrid. The 

 powdered root is very irritating to the throat and nostrils when inhaled, 

 and imparts to water the property of frothing. 



FIG. 156. Senega root. 1 and 2, 

 roots, showing the keel ; 3, transverse 

 section. Natural size. (Vogl.) 



