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 
postertor side, that furthest away the anterzor. 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. 












| | 
Nawg NuUMBer Union  Posttron | 
ee ee ON REMARKS. | 
| Leaves, LEAvES. RECEPTACLE. | 
Sar ee | eae er ere hater oan | 
Calyx fee! Free Inferior The sepals project 
~~ (sepals) beyond the point 
Pee - of attachment ; 
| the two anterior 
ee sepals allow the 
spur to protrude | 
Corolla 5 Free Hypogynous The anterior petal 
(petals) | forms a spur 
Andreecium, = 9 Free Hypogynous 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 : 
