CRUCIFEKJS. 



often deeply toothed or pinnatifid, the upper lanceolate, sparsely toothed. 

 Flowers small, in numerous racemes, forming a terminal panicle. 



Habitat. Introduced from Europe and cultivated chiefly as a condi- 

 ment. Escaping from cultivation, it has become, to some extent, natural- 

 ized. It grows best in deep, rich, moist soil, and when once well estab- 

 lished is difficult to eradicate. 



Two strictly indigenous species of this genus, namely, N. palustre De 

 Candolle Marsh-cress, and N. lacustre Gray Lake-cress, possess properties 



similar to those described 

 above, but as they are sel- 

 dom, if ever, employed, their 

 description is omitted. 



Parts Used. Water-cress, 

 the herb ; horseradish, the 

 leaves and root. Neither is 

 official. 



Constituents. Water-cress 

 distilled with water yields a 

 volatile oil, probably identical 

 with volatile oil of mustard ; 

 horseradish, treated in like 

 manner, yields a similar oil, 

 having the same chemical 

 composition as volatile oil of 

 mustard, but a slightly differ- 

 ent odor. This oil does not 

 pre-exist in the plant, but is 

 formed during the process of 

 distillation, as is the case with 

 many other volatile oils. It is 

 intensely acrid and irritating. 

 Preparations. None are 

 official. The expressed juice 

 of water-cress has been ad- 

 ministered. Horseradish is 

 generally employed in infusion, though there is an official (British Phar- 

 macopoeia) preparation, Spiritus armoracice compositus compound spirit of 

 .horseradish. 



Medical Properties and Uses. Water-cress, though used chiefly as a 

 stimulating salad to sharpen the appetite and aid digestion, possesses mild 

 antiscorbutic properties, and is used in domestic practice as a " blood 

 purifier " in the spring of the year. It probably acts simply as a stimulant 

 to the functions of digestion and assimilation. Externally it is sometimes 

 employed as a counterirritant. Horseradish possesses properties similar to, 



FIG. 108. Nasturtium (cochlearia) Armoracia. 



