554 A TEXT-BOOK OF BOTANY. 



Neslia paniculata of Europe and the Orient ; and Lepidium ozvai- 

 hiense of the Hawaiian Islands. Shepherd's purse {Capsella 

 Bursa-pastoris) contains an alkaloid (bursine) and tannin. The 

 leaves and roots of many of the Cruciferse are used as garden 

 vegetables, and some are cultivated as ornamental plants. The 

 seeds of Limaria biennis (or "honesty") contain an orange-red 

 crystalline alkaloid, or possibly a mixture of alkaloids. 



c. There are several other' families of the Rhoeadales which 

 yield economic products. The Resedace.Ti include the migno- 

 nette {Reseda odorata), the flowers of which yield a fragrant vola- 

 tile oil ; and R. Luteola of Europe, which contains a yellow coloring 

 principle and also an anthelmintic principle. The Moringace.e 

 comprise a single genus, Moringa. The root of M. oleifera of 

 tropical and sub-tropical countries contains a volatile oil resem- 

 bling the volatile oil of mustard, and the stem yields an astringent 

 gum resembling that of Bomhax inalabaricum (Bombaceae). 



XIV. ORDER SARRACEXIALES. 



This order Includes several families which are of special inter- 

 est because of the fact that the leaves are of peculiar construction 

 and adapted to the catching and digestion of insects (Fig. 208). 



Probably all of the plants of this order produce proteolytic 

 ferments resembling those in the pine-apple and are capable of 

 acting upon and digesting animal substance. Some writers have 

 supposed that the properties of these plants might be due to bac- 

 teria present in the liquid contained in the pitchers of the leaves, 

 but there seems to be no question that a distinct enzyme resem- 

 bling trypsin is formed in those plants which have been studied. 



(a) The genus Sarracenia of the family Sarraceniace.e or 

 pitcher-plant family, is represented in the United States by a 

 number of species. The rhizome of Sarracenia purpurea (Fig. 

 311) contains several alkaloids, one of which, sarracenine, seems 

 to have some resemblance to veratrine. (&) The Droserace^ or 

 sundew family includes the Droseras or sundew plants and Diona^a 

 muscipula, the Venus's flytrap of North Carolina (Fig. 209). A 

 number of species of Drosera contain a red coloring principle 

 similar to that isolated from the rhizomes of D. Whittakerii of 

 Australia and is a derivative of methylnaphthoquinone. Citric 



