POISONOUS PLANTS 283 



The yellow flowers open between May and August, are 

 nearly i inch in diameter, and occur " in loose few- 

 flowered umbels " on slender stalks ; the petals are four 

 in number. The seed capsules are about ij inch long. 

 The plant exhales an unpleasant odour, and contains a 

 yellowish acrid juice. 



C. majus is a vegetable irritant, producing nausea and 

 dysentery, and is a drastic purgative. The toxic 

 principle is Chelidonine, an alkaloid, and neither drying 

 nor boiling eliminates the poisonous property. It has 

 been used by country people as an emetic and purga- 

 tive, but should be avoided owing to its harmful nature. 

 Animals refuse the plant. 



CRUCIFER^: 



Charlock (Sinapis arvensis), which is more fully dealt 

 with at p. 58, must also be included among poisonous 

 plants, since the whole plant is an irritant when in 

 bloom, and the seeds are of a dangerous character, 

 causing inflammation of the intestine. Cornevin states 

 that when used in admixture in the manufacture of a 

 poor quality oil-cake and fed to cattle the cake caused 

 intestinal inflammation, severe diarrhoea, and great 

 thirst. The effects are probably due to Oil of 

 Mustard. 



CARYOPHYLLACE^E 



Corn Cockle (Agrostemma Githago L.) is a common 

 plant of cornfields, covered with white hairs, and 

 attaining 3 or 4 feet in height. It is tall and erect, 

 with straight, narrow lanceolate leaves up to 5 inches 

 long placed opposite one another on the stem in pairs. 

 The flowers (Fig. 78) are borne singly on long stalks 

 which spring from the axils of the leaves. They are 



