156 ESSENTIALS OF BOTANY 
When the receptacle is 
concave, so that the pistil is 
inserted on the same level with the stamens or lower, but 
I It Il 
Fic. 114. Insertion of the 
Floral Organs. 
I, hypogynous, all the other parts on 
the receptacle, beneath the pistil ; 
II, perigynous, petals and stamens 
apparently growing out of the 
calyx, around the pistil; ITI, co- 
rola hypogynous, stamens 
epipetalous. 
not at all united with the 
receptacle, the flower is said 
to be perigynous (around the 
pistil) and the ovary is half- 
inferior (Fig. 114, II). When 
the ovary is united with the 
receptacle, the flower is said to 
be epigynous (upon the pistil) or 
the ovary is inferior (Fig. 99). 
186. Floral Diagrams. — 
Sections (real or imaginary) 
through the flower lengthwise, 
like those of Fig. 114, help 
greatly in giving an accurate 
idea of the relative position of the floral organs. Still 
more important in this way 
are cross-sections, which may 
be recorded in diagrams like 
those of Fig. 116.1 
In constructing such dia- 
grams it will often be neces- 
sary to suppose some of the 
parts of the flower to be raised 
or lowered from their true 
position, so as to bring them 
into such relations that all 
could be cut by a single sec- 
Fie. 115. White Water-Lily. 
The inner petals and the stamens 
growing from the ovary. 
tion. This would, for instance, be necessary in making 
1¥or floral diagrams see Le Maout and Decaisne’s Traité Général de 
Botanique or Eichler’s Blithendiagrumme. 
