486 MANUAL OF POISONOUS PLANTS 



dehiscent, separating into joints; seeds without endosperm; seed coat frequently 

 mucilaginous; embryo large. About 1500 species of wide distribution. 



The cabbage (Brassica oleracea), native to Europe, has long been culti- 

 vated; cauliflower, brocoli, and brussels sprouts also belong to the same species. 

 Rape, a well known forage plant, the turnip, the Swedish turnip, and ruta- 

 baga {B. campestris) are native to Europe. The Chinese cabbage (S. Pe- 

 Tsai) is commonly cultivated in China. Black mustard (5. nigra) and white 

 mustard (B. alba) are extensively cultivated for their seeds, which when ground 

 make the commercial mustard. The radish (Raphanus sativus), cultivated for 

 the root, is native to Europe. Water cress {Radicula nasturtium-aquatkum) is 

 much used as a salad plant in colder regions. Horse radish (i?. Armoracia) 

 the well known condiment is native to Europe. European pepper grass {Lepidi- 

 uin sativum) is cultivated as a salad plant, while the seeds of our pepper 

 grasses (Lepidium apetalum and L. virginicum) are used as bird food. Sea- 

 kale (,Crambe maritima), native to Europe, has also been introduced into this 

 country as a vegetable. The Pringlea antiscorbutica of Kuerguelen's Land 

 resembles the common cabbage and is used by sailors as a vegetable when they 

 touch that country. The Rose of Jericho {Anastatica hierochuntica) of North 

 America and Syria is regarded as sacred by the natives. Many plants of this 

 family are cultivated for ornamental purposes; among the most familiar are 

 the candytuft {Iberis), stock (Matthiola incana), sweet alyssum {Alyssum mari- 

 timum), and wall-flower {Erysimum asperum). Dyer's woad (Isatis tinctoria) 

 of China was formerly cultivated for a dye obtained from the leaves. The 

 characteristic odor of plants of this order when crushed or when mustard 

 seed is ground in water is due to an enzyme myrosin, discovered by Bussey 

 in 1839. This same ferment occurs in the families Cruciferae, Capparidaceae, 

 Resedaceae, Tropaeolaceae, Limnanthaceae, Papaveraceae. 



It occurs in special cells known as myrosin cells which give a marked pro- 

 tein reaction. The contents are finely granular, free from starch, chlorophyll, 

 fatty matter, and aleurone grains. These cells become red with Millon's 

 reagent, and when heated become orange red, and a violet red color when treated 

 with copper sulphate and caustic potash. The subjcet is treated fully by Rey- 

 nolds Green in his work on "The Soluble Ferments and Fermentation," and in 

 Effront and Prescott's "Enzymes and their Applications." 



Some of the European plants of the family like (Erysimum crepidijolium) 

 cause staggering in animals. The Cheiranthus Cheiri contains a glucoside which 

 acts on the heart. Rape under some conditions is poisonous. Several corres- 

 pondents in Breeders' Gazette (Chicago) have ascribed poisoning where rape 

 was frozen, or when the plants were wet with dew. 



Genera of Cruciferae 



Pod terete or turgid or 4-angled. 



Pod obovoid ; flowers yellow •. S. Camelina 



Pod linear or oblong. 



Cotyledons accumbent. 



Pod short ; flowers yellow or white 3. Radicula 



Cotyledons incumbent. 



Pod angled or terete; flowers yellow or white 1. Sisymbrium 



Cotyledons conduplicate ; flowers yellow or white 2. Brassica 



