THE AXGIOSPERMAE 



1 103 



is that which we have described as typical, namely, sepals, petals, stamens, 

 and carpels, the latter occupying the highest position, around the summit 

 of the receptacle. Such flowers are called hypogynous (Fig. 1073), because 

 the other parts stand below the gynoecium. In a number of cases, however, 



A B 



Fig. 1073. — Longitudinal sections of hypogynous flowers. A, Adonis. B, Heliantlieiiiuni. 



the receptacle appears to be expanded laterally, so that a floral disc is 

 formed, sometimes, as in the Strawberry, surrounding a normal conical 

 receptacle, sometimes replacing this entirely, so that the whole receptacle 

 is saucer-shaped or even cup-shaped. This disc has sometimes been given 

 the status of a distinct organ, under the name of the torus, but this 

 involves the idea that in hypogynous flowers it is present in a suppressed 

 condition as a special zone or layer of the receptacle, for which there is no 



B 



Fig. 1074. — Longitudinal sections of perigynous flowers. A, Pviiniis. B, Rhainiitis. 



direct evidence. The surface of the disc is sterile and the perianth and 

 stamens, being attached to its rim, are thereby elevated to a level with the 

 carpels. This is the perigynous condition (Fig. 1074). The cup may in 

 some cases, as in the Rose, become, in fact, a flask within which the carpels 



c 



