WILD FLOWERS OF \ I \\ YORK J 5 



of united stamens. In this form of arrangement there may be a union of 

 the filaments of all the stamens except one, which is a common diadelphous 

 arrangement of stamens in many of the species of the Bean family. When 

 there are several sets of united stamens, the arrangement is said to be 

 polydelphous. 



Adnation or union of the stamens with other parts of the flower is of 

 frequent occurrence, and the terms employed depend upon the degree <>\ 

 adnation, or the absence of it, namely, hypogynous (meaning beneath the 

 pistil), applied to parts, including stamens, which are inserted or borne 

 on the receptacle of the flower (figure 56). This is the absence of adnation 

 and indicates an unmodified type. Perigynous (around the pistil) implies 

 an adnation which carries up the apparent origin or place of insertion of 

 the parts of the flower to some distance above or away from the receptacle 

 and thus placing the insertion around instead of beneath the pistil ( figure 57 . 

 Epigynous (on the pistil), where the adnation is complete to the very top 

 of the ovary (figure 58). 



When the stamens are borne upon the corolla, or upon the tube of 

 the corolla, they are said to be epipetalous (figure 69), and when they are 

 borne upon the pistil, as in the Orchid family, they are said to be gynandrous. 



The most important part of a stamen is the anther (figure 44D), which 

 contains the pollen. It normally consists of two lobes or sacs ; but as each 

 sac is often, and in most of our common flowers, divided into two cavities, 

 it appears to possess in such instances four pollen sacs. For the discharge 

 of the pollen, the cells of a normal anther open along a definite line, usually 

 extending from top to bottom. This suture or line of dehiscence may be 

 lateral or marginal, or centrally located. 



In the genus Solanum, to which the Potato belongs, in most members 

 of the Heath family (Ericaceae), in Polygala, and certain other species, the 

 anther cells open only by a hole or pore (figure 71). In the Blueberry, 

 Cranberry etc. the pore-bearing tip of the anther cell is prolonged con- 

 siderably, often into a slender tube. In the Barberry, and in most other 

 members of that family, and in the Lauraceae, the whole face of each anther 



