THE AMERICAN BOTANIST. 53 



Two othef familiar forms of corolla deserve mention. 

 One is the bi-lahiate or two-lipped in which the corolla is 

 unequally divided wath three petals forming one lip, and 

 the remaining two, the other. Illustrations of this are at 

 once called to mind by the snapdragon, toad flax, catalpa, 

 bladder-wort, fig-wort, turtle-head, beard-tongue, mon- 

 kej'-flower and fox-glove. The second form is called pa- 

 pilionaceous or butterfij^-shaped and is most common in 

 the great bean family. The sweet pea is a typical flower 

 of this kind. In such flowers the petals have different 

 names. The broad upper petal is the standard, the two 

 side petals are the wings and the tw^o lower petals, usual- 

 ly form the keel. 



POISON IVY AND ITS EXTERMINATION. 



BY CHARLES FRANCIS SAUNDERS. 



IN view of the great numlDcr of people who are subject to 

 rhus poisoning and who are annually made sufferers 

 from it, does it not seem strange that no systematic effort 

 is made to rid the country of this pest ? It is a plant that 

 serves no good purpose in the world and is distinctly a 

 menace to human comfort. Why then is its existence tol- 

 erated ? There would appear to be no physical obstacle 

 to its eradication, if a determined and intelligent move- 

 ment were started to that end. Of course, it would take 

 work, but it grows and spreads most luxuriantly near the 

 abodes of men where effort is most readily expended upon 

 it. Anj^land owner whose propertynow harbors itcould, 

 at the cost of a comparatively small amount of time and 

 labor, have it torn down from his trees and fences and up- 

 rooted in his fields ; then as the new shoots put up they 

 might be cut off at once, and on subsequent reappearing 

 nipped down close again. A plant that is not allowed 

 leaves to breath with and digest with, must eventually die 

 of suffocation and mal-nutrition, and poison ivy is no ex- 

 ception to the rule. 



Again it is possible to do something by making use of 

 the aid of other and more vigorous plants that will 



