172 PAPILIONACEOUS FLOWERS. 



there is a symmetry and equality in their parts. There may 

 be slight inequalities in regular corollas ; as in the lily we 

 sometimes see some petals a little longer than the others ; this 

 is an exception to the general rule. Irregular corollas are vari- 

 ous in their forms ; the papilionaceous seem as they stand upon 

 their stem to consist of an upper and under part ; the calyx is 

 monosepalous, ending in five distinct leafy points, the two 

 upper ones wider than the three under ones. The jjeduncle is 

 slender and flexible (see Fig. 14S, g) ; thus the flower readily 

 avoids a current of air by turning its back to the wind and rain. 

 Suppose we have before us a pea-blossom ; we see the corolla 

 is polypetalous. The large petal covering the others and occu- 

 pying the upper part of the corolla, is the standard or 'banner. 

 This j^etal is evidently designed to protect the stamens and 

 other parts of the flower from injuries by the weather. Upon 

 talking oft' the banner we find that it was inserted by a little 

 process or projecting j^art into the side pieces so that it could 

 not easily be separated by winds. The wings are strongly in- 

 serted into the remaining part of the corolla. Upon removing 

 the wings we discover a part of the corolla, called on account 

 of its form the keel {carina)^ or boat. Upon drawing the 

 keel downward, we find ten stamens (double in number to 

 the petals) 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 sepa^'ates and leaves an 

 opening at the upper side, through 'which the ovary can extend 

 itself by gradually opening the cylinder. In the early stage of 

 the flower, this stamen seems not to be separated ; but by 

 carefully moving it with a pin or needle, its filament will be 

 found unconnected with the other nine stamens. 



251. The ovary 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 ; but in the 

 silique pod they are alternately attached to both edges of the 

 partition. Tlie legume opens lengthwise and rolls backward ; 

 in the silique, the valves separate and diverge from the base 

 upward. The seeds of this family have a scar, or line, called 

 the Mlum^ by which they adhere to the pod. i^ear the hilum 

 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 ovule continues to swell, and at length 

 bursts through the coats of the seed, presenting between the 



!^r»0 Regiilar and irregular corollas — Analysis of llie pea-blossom. — 251. Distinction between th» 

 k>guiii(> rind silique— Seeds of tlie leguminous Uibe, 



