PAPILIONACEOUS FLOWERS. 
179 
understanding a science, thinking, very erroneously, that the knowl- 
edge of the one is as important as that of the other. If a clear con- 
ception of general rules be established in the mind, the exceptions 
will be easily learned. Irregular corollas differ so widely from the 
regular ones, that you will be in little danger of mistaking them for 
exceptions to the general rule ; they constitute, indeed, a different 
natural family, though, according to the artificial method of classifi- 
cation, they may often be placed near to regular corollas. Irregular 
corollas are various in their forms ; the papilionaceous, which we 
are now considering, seem, as they stand upon their stem, to con- 
sist of an upper and under part. In examining a natural flower of 
this kind, a pea for example, you should first observe the calyx ; this 
is monosepalous, that is, consisting of one sepal, ending in five dis- 
tinct leafy points, (see Fig. 142, a ;) the two upper ones wider than 
the three under ones. The peduncle is slender and flexible, (see Fig. 
142, g ;) thus the flower readily avoids a current of air by turning its 
back to the wind and rain. 
In examining the corolla you will see that it is polypetalous. The 
first piece, or large petal, covering the others and occupying the up- 
per part of the corolla, is called the standard or banner. This petal 
is evidently designed to protect the stamens and other parts of the 
flower from injuries by the weather. Upon taking off the banner, 
you will find that it is inserted by a little process or projecting part 
into the side-pieces, so that it cannot be easily separated by winds. 
The banner being taken off, the two side-pieces, or wings, are ex- 
posed to view ; they are strongly inserted into the remaining part 
of the corolla, and their use appears to be that of protecting the sides 
of the flower. Upon taking off the wings, you will discover the last 
piece of the corolla, called, on account of its form, the keel, {carina^) 
or boat. This covers and protects the stamens and pistils. Upon 
drawing the keel downward, you will find the ten stamens, double 
in number to the petals; these stamens are joined together by the 
sides of their filaments, forming a cylinder which surrounds the 
pistil. One of the stamens, however, does not adhere to the rest ; but 
as the flower fades and the fruit increases, it separates and leaves 
an opening at the upper side, through which the germ can extend 
itself by gradually opening the cylinder. In the early stage of the 
flower, this stamen will seem not to be separated ; but by carefullj^ 
moving it with a pin or needle, its filament will be found unconnect- 
ed with the other nine. 
The germ of the papilionaceous plant extends itself into that kind 
of pod called a legume. It is distinguished from the silique of the 
cruciform family, by having no partition in the legume. Besides, the 
seeds grow to one side only 5 but in the silique pod they are alter- 
nately attached to both edges of the partition. The legume opens 
'engthwise and rolls backwards ; in the silique, the valves separate 
and diverge from the base upward. The seeds of this family have 
a marked scar, black spot or line, called the Mlum, by which they 
adhere to the pod. Near this scar there is a minute opening into the 
body of the seed, through which moisture is imbibed at the period 
of its first growth or germination. The proper germ, or that part 
of the seed which is to be the future plant, continues to swell, and 
at length bursts through the coats of the seed, presenting between 
the divided halves, or cotyledons, the first true leaves, and the root. 
Irregular corollas— In what manner should you proceed to examine a papilionaceous 
flower 'J— Distinction between the legume and silique — What is said of the seeds of ihr 
leguminous tribe 7 
