44 _ ELEMENTARY BOTANY 
The terms posterior and anterior are used by botanists to 
denote the exact position of the floral leaves with regard to 
the stem; the side of the flower nearest the stem is the 
posterior acs that furthest away the anterior. In the dead- 
nettle, the two large petals forming the upper lip are on the 
posterior side of the flower ; the spur of the violet is on the 
anterior side, for it is furthest away from the main stem ; 
the large overlapping petal of the sweet pea is posterior. 
- DESCRIPTION OF FLOWER OF VIOLET. 













Name (NUMBER) Unton | Position 
Be eee a OF AON REMARKS. 
| Leaves. | LEAVES.) RECEPTACLE. 
Calyx 5 .| Free [Inferior The sepals project 
(sepals) beyond the point 
| | of attachment ; 
| | the two anterior 
| sepals allow the 
spur to protrude 
Corolla 5 Free Hypogynous The anterior petal 
(petals) forms a spur 
Andreecium) = 9 Free HY pogynous The two anterior 
_ (stamens) : stamens have 
| appendages or 
| | nectaries, which 
| fit into: the spur 
Gynecium 3 |Joined Superior — Placentation parie- 
| (carpels) tal, stigma hooked 



The floral diagrams representing the median, vertical section 
of a flower show whether it is hypogynous, perigynous, or 
epigynous. (See Fig. 34.) 
Floral Instead of writing out a technical description 
Formulas. of a flower, the union or non-union of parts, and 
the position of the floral leaves on the receptacle may be 
expressed by means of formulas as follows: 
