CHAPTER XXIX. 



ROSACEJS. 



I. General characters of the Order. — Flowers regular, and 

 usually perigynous. Calyx gamosepalous, five sepals; in some 

 genera an epicalyx is present. (See strawberry below.) Corolla 

 polypetalous, five petals. Androecium, usually of many stamens. 

 Gynsecium, apocarpous, sometimes more or less syncarpous, one 

 or many carpels. Fruit various. Seeds endosperraous. 



The Order Rosacese comprises about looo species of herbs, 

 shrubs, and trees. The leaves are generally compound, and 

 possess stipules. 



There is no plant of the Order of much importance to the 

 farmer as a fodder crop, but all our most valuable edible fruits 

 of the orchard and garden belong to it. The genera, the struc- 

 ture of whose fruits it is important to notice, are mentioned 

 below. 



2. Genus Prunus. Plums and Cherries. — The plants of this 

 genus are shrubs or trees with simple leaves. The flowers are 

 perigynous ; the receptacle has the form of a hollow cup, around 

 the edge of which are arranged five sepals, five petals, and fifteen 

 to twenty stamens (Fig. 124.). The single carpel, which pos- 

 sesses a long terminal style and two ovules, is placed at the 

 bottom of the hollow receptacle. After fertilisation the latter 

 divides by a circular cut near its base at f, Fig. 124, and soon 

 withers and falls off, carrying the calyx, corolla, and androecium 

 with it. Sometimes the withered receptacle and its appendages 

 remain for a time surrounding the growing carpel. 



397 



