THE STUDY OF TREES. 267 



linear forms to mere brown specks. They are also fre- 

 quently unequal in size (Fig. 149). 



The leaf -stalk is slender and has a median groove on its 

 upper surface. The blade is cuneate and is lobed, three 

 and five lobes being the usual number, but seven is also 

 common. Gradations may, however, be traced from the 

 undivided blade (Fig. 150). 



There are a few soft hairs on the under side of the blade ; 

 the upper surface is smooth. 



The flower clusters are of the type described by botanists 

 as a corymb. Those flowers in the centre of the cluster 

 are furthest advanced, and those on the outside least so. 

 The flower stalks are short and their tops are expanded 

 into a cup on the edges of which are the five small tooth- 

 like sepals. 



Fig. 150. 

 Outline of blade of leaf of Hawthorn, showing gradations of lobing. 



There are five free white petals, imbricate in the bud, 

 arising on the edge of the aforenamed cup. They are 

 roundish in form with an irregular margin. There are 

 about twenty stamens with pink anthers turning brown as 

 they ripen. Within the cup are the seed vessels, one or 

 more in number. The stigma on the ,top is slightly ex- 

 panded and is sticky. The cup is hairy around the base of 

 the style, and the whole inner surface seems modified as a 

 nectary. The anthers split inwardly and tend to curl 

 inwardly when ripe. The stigma is ripe before the anthers. 

 The flowers have a pleasant odour. 



