58 



The Cruciferre named are such well known irritants as to need no 

 special discussion, although in none of the forms did any irritation arise 

 from a free and rather rough handling of the plants. 



The round leaved Sundew (Drosera rotundifolia L.) is classed as a 

 skin irritant. It is so rare in our area that it scarcelj' deserves mention. 

 Experiments were possible only with dried specimens. Of the five sub- 

 jects selected none showed any signs of skin irritation as a result of 

 either treatment. The material used was collected in August, the experi- 

 ments Avere made the following February, the plants having been sub- 

 jected to the usual drying. 



The Tree of Heaven (Ailanthus glandulosa Desf.), it is said, "should 

 be regarded with suspicion." No experiments were tried with this form 

 and a somewhat extended examination fails to reveal any instance in 

 which poisoning resulted from its handling. Personally I have handled it 

 for years, and have rather encouraged classes to handle it but have failed 

 utterly to find the form at all poisonous or even irritating. 



Of the Spurges (Euphorbias) more than one hundred species occur in 

 the United States. Loudon says of them, "Every one is so acrid as to cor- 

 rode and ulcerate the body wherever applied." This somewhat vigorous 

 arraignment of the genus does not seem fully justified by the behavior 

 of the local forms. In the experiments upon ten subjects E. maculata L., 

 E. humistrata Engelm., E. nutans Lag. and E. commutata Eugelm., pro- 

 duced no ill effects from handling. ■ Rubbing the arm vigorously with the 

 crushed plants and allowing the latex to dry produced a marked irritation 

 in five of the ten subjects and a light vesicular inflammation in another. 

 The inflammation was somewhat obstinate, in two cases requiring the 

 attention of a physician. In the case of the flowering Spurge (Euphorbia 

 coroUata L.) six out of ten subjects were distinctly poisoned by merely 

 handling the plant in its flowering condition. In this case the plant was 

 gathered in masses as for decorative purposes, thus attempting to imitate 

 the manner in which this attractive form is usually handled. Allowing 

 the latex to dy upon the arm caused evident poisoning in nine of the ten 

 cases. The experience with the other species named above led to the 

 prompt treatment of the inflammations, so that nothing can be said as to 

 the persistence or ultimate character of the irritation. The inference may 

 be drawn that the majority of our native spurges are not such virulent 

 contact poisons that they can not be handled in the ordinary way without 

 danger. Euphorbia coroUata is, however, to be regarded as dangerous^ 



