506 



MANUAL OF POISONOUS PLANTS 



poisonously by dissolving the blood corpuscles. Cholesterin contained in the 

 body acts as a natural antidote against them. 



Several plants of the order produce members of the terpene group ; rose oil, 

 contains rhodinol C^^Hj^O, supposed to be identical with geranium oil; and a 

 second terpene, roseol, Cj^H^^Oj. Many fruits of the order, especially Pomeae, 

 contain mannite and sorbite. The arhutin, Cj^Hj^^O^ obtained in many plants 

 also occurs in some plants of this order; the glucoside hydrochinon, C H O, 

 occurs in the buds of pears. Quercetrin C^^'R^^O.^, derived from a glucoside, 

 is found in the flowers of haw {Crataegus), the bark of apple trees and of 

 Prunus insiititia. Amygdalin C,|jH,^NOjj^, occurs in the seeds of many plants 

 of the family, especially in Pomeae and Pruneae; also in the bark of Prunus 

 Padus, P. serotina, etc., and in the seeds of Pyrus Aucuparia. 



J'ig- 266- Kooso (Bray era anthelminUca) . Flowering branch. Contains a muscle poison. 

 (After Faguet). Fig. 266a. Common Wild Plum (.Prunus americana). (C. M. King). 



Genera of Rosaceae 



Ovary inferior or enclosed in the calyx tube. 



Carpels numerous ; fruit an achene 3. Rosa. 



Carpels few, fruit not an achene. 



Carpels cartilaginous ; fruit a pome. 4. Pyrus. 



Carpels bony, drupe-like 6. Crataegus. 



Ovary superior not enclosed in calyx tube. 



Calyx deciduous; fruit a drupe 5. Prunus. 



