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MANUAL OF POISONOUS PLANTS 



Many of the Ericaceae contain the glucoside ericolin C 34 H 58 O 21 ; this in 

 turn contains ericinol C 10 H ie O, a peculiarly fragrant oil; ericolin occurs in the 

 leaves of Ledum, Erica, Calluna, Rhododendron, Gaultheria and Epigaea. Rho- 

 dodendron C 16 H 22 O 7 , is found in the leaves of Rhododendron chrysanthum; 

 it is converted by hydrolysis into rhododcndrol, C 10 H 12 O 2 . Oxycoccin occurs 

 in V actinium Oxycoccus. 



Andromedotoxin or acetoto.vin, found in the leaves of Andromeda Polifolia 

 and A. japonica, and also in many other Ericaceae, as Azalea, Rhododendron 

 Japonicum, A. javanicum, and Kalmia is one of the most toxic substances known. 



Asebotin, C 24 H 2g O 12 , derived from andromedotoxin, and asebogenin, 

 C 18 H lg O 7 , are found in Andromeda Japonica. Arbutin C 12 H 16 O r occurring 

 in the leaves of many of the Ericaceae was flrst detected in Arctostaphylos 

 Uva-ursi; quercetrin is found in Calluna, as is also calluna tannic acid. 



In Lehmann's work on the poisonous plants commonly found in Germany 

 only one species of this family is listed as poisonous, namely the Labrador tea 

 (Ledum palustre) of the Arctic region. This pretty shrub, growing in swamps, 

 has alternate entire leaves with rusty wool underneath; revolute margins; white 

 flowers in umbel like clusters; followed by a many seeded capsule. The L. 

 groenlandicum related to it and also occurring in swamps, thickets and on 

 mountain slopes but further southward has wider leaves and is a larger plant. 



Fig. 378. Great laurel (Rhododendron max- 

 imum): a, flowering branch; b, fruiting cap- 

 sules both one-third natural size. Very poi- 

 ponous. (U. S. Dept. Agr.) 



