108 NUMBER OF CARPELS [CH. 



The pistil is monocarpellary in 



In the rest of the angiospermous trees and shrubs here 

 concerned the ovary is syncarpous. It is composed of two 

 carpels in 



Willows Birch Hazel 



Walnut Elms Mulberry 



Bittersweet Privet Red Currant 



Black Currant Sycamore Dogwood 



Poplars Alder Hornbeam 



Sweet Gale Fig Tea Tree 



Lilac Ash Gooseberry 



Maple Norway Maple Aucuba. 



In all but a few of these the placentation is axile : 

 the chief exceptions are the following, in which it is 

 parietal : 



Willows Gooseberry Black Currant 



Poplars Red Currant. 



The ovary is tricarpellary in the following : 



Butcher's Broom Horse-chestnut Wayfaring Tree 

 Honeysuckles Tamarisk Elder 



Guelder Rose. 



But it should be noted that the number may vary, by 

 abortion of one or more of the carpels, in all but the first 

 three of the last series. The placentation is usually axile. 



