FOUR INGENIOUS FLORAL MECHANISMS 



35 



Four Ingenious Floral Mechanisms. 



BY IIKRBIJRT VV. lUULKNIiR, WASHINGTON, 

 CONNECTICUT. 



Nature, in her efforts to procure the 

 cross-fertilization of flowers, offers in 

 July many examples to that end. We 

 may disregard flowers with stamens 

 and pistils in separate blossoms on the 



or surprising methods and are there- 

 fore more interesting. 



The spotted touch-me-not {Impatiens 

 biHora) bears its stamens in a compact 

 mass, with five prongs that cover and 

 clasp the pistil but are easily detached 

 by the touch of an insect. The stigma 

 is not exposed until the pollen has been 



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same plant (monoecious) and with the 

 two kinds of flowers on separate plants 

 (dioecious). We may likewise disre- 

 gard those whose cross-fertilization de- 

 pends upon the maturing of stamens and 

 pistils at different times, and investi- 

 gate a few of those that have unusual 



removed. Self-fertilization is thus pre- 

 vented. 



In Oswego tea (Moiiarda didyma) 

 the two stamens grow with their an- 

 thers pressed together like two hands, 

 palm to palm. Thus they form a lasso 

 which catches the bumblebee as he 



