OARDAMINE. lOl 



XXV. THE TOOTHROOT CRESS. 



Description. — This plant frequents the rich woodlands 

 of the Northern and Western States, by the streams and 

 fountains, blooming in the spring months. It is glabrous 

 (smooth), 1 foot high, and often called Pepper-root. 



Analysis. — The ^oot-stock, by its peculiar shape, 

 suggests the former name, and by its crisp, pungent taste, 

 the latter. It is long, creeping, white and fleshy, with many 

 knobby, tooth-like projections, and is sometimes broken up 

 into a string of knobby tubers. 



The Sicm witli its two opposite trifoliolate leaves and 

 terminal raceme, presents no new features. 



The Flowers are constructed on the plan described 

 under Capsella, but are large and showy. When the 4 ob- 

 long white petals are expanded, their mimicry of the Mal- 

 tese cross justifies the term cruciform so generally applied 

 to this class of flowers. 



The Fruit affords a new field of study. But if your 

 specimens are not well matured, search for riper ones. The 

 form is outwardly a contrast with the silicles of Capsella. 

 The pod is many times longer than wide, lanceolate-linear, 

 broadest near the middle and tapering below to the pedicel 

 and above to the style. It is composed of 2 carpels and 

 opens by 2 valves. Within, it is divided lengthwise into 2 

 cells. Each cell nourishes a row of seeds attached alter- 

 nately to opposite sides of the valve or partition. 



Notwithstanding the difference in external form, this fruit 

 agrees in structure with the silicle of Capsella, and its name, 

 silique, is of similar import : Silicle being a short pod and 

 silique a long one. 



The Seed, skillfully dissected, as seen in (4, 5), shows the 

 embryo bent double, so that the radicle rests on the edge of 



