PLANT FAMILIES : ROSIFLORjK. 



275 



ROSIFLORj*. 



530. Lesson XI. — The rose-like flowers are an interesting and 

 important group. In all the members the receptacle (the end of 

 the stem which bears the parts of the flower) is an important part 

 of the flower. It is most often widened, and either cup-shaped or 

 urn-shaped, or the center is elevated. The carpels are borne in the 

 center in the depression, or on the elevated central part where 

 the receptacle takes on this form. The calyx, corolla, and the 

 stamens are usually borne on the margin of the widened recep- 

 tacle, and where this is on the margin of a cup-shaped or urn- 

 shaped receptacle they 

 are said to be perigynous , 

 that is, around the gyn- 

 cecium. The calyx and 

 corolla are usually in 

 fives. There are three 

 families, as follows. 



531. The rose fam- 

 ily (rosaceae). — In this 

 family there are five 

 types, represented by the following plants and illustrations : 

 1st. In spiraea (fig. 362) the receptacle is cup-shaped. There 



are five carpels, united at the 

 base, but free at the ends. 

 2d. In the strawberry the re- 

 ceptacle is conic and bears the 

 carpels (fig. 363). The conic 

 receptacle becomes the fleshy 

 fruit, with the seeds in little pits 

 over the surface. 3d. The rasp- 

 berries, blackberries, etc., represented here by the flowering 

 raspberry (Rubus odoratus), fig. 364. 4th. This is represented 

 by the roses. The receptacle is urn-shaped and constricted 



Fig. 362. 

 Perigynous flower of spiraea (S. lanceolatal. 

 Warming.) 



(From 



Fig. 3°3- 



Flower of Fragaria vesca with columnar 



receptacle l From Warming.) 



