MUSTARD FAMILY. 



103 



The seeds are either olive brown or greenish yellow, 

 slightly roughened, oblong, angular, and about one- 

 twenty-fifth of an inch long. The radicle shows up prom- 

 inently through the thin seed coat, the grooves on each 

 side being darkened. The palisade cells of this seed, like 

 those of Wild Mustard, form a cherry red compound 

 with chloral hydrate and hydrochloric acid. 



1 



* 



' 



Fig. 23. Seeds of Tumbling Mustard Sisymbrium altissimum. 

 Five times natural size. 



FIELD PENNYCRESS Thlaspi arvense L. 



Other Common Names: French weed, Stinkweed. 

 The seeds of this plant are pungently bitter, and sick- 

 ening to taste, owing to a peculiar oil. For this reason 

 they are seldom eaten by pigs, on which such 

 Effect of see d s have the strongest effects. Samples with 

 accompanying complaints indicate that consid- 

 erable quantities of shorts and bran have been 

 made unfit for use as feed for pigs owing to the unpal- 

 atableness of the Field Pennycress seeds. If eaten, the 

 plant and seeds have the same poisonous effect as 

 the other plants of the mustard family. On some ani- 

 mals this effect is less apparent than on others. It would 

 seem, for example, that rabbits can eat the seeds with 



Seeds in 

 Feed 



