210 



THE FLOWER 



298. Dissection of an Irregular Flower. Irregularity 

 is more noticeable in the corolla than in the other parts, 

 and when we speak of an irregular flower the reference is 

 generally to that organ. 



Sketch a blossom of any kind of pea or vetch as it 

 appears on the outside. Are the sepals all of the same 

 length and shape ? If not, which are the shorter, the 

 upper or lower ? 



Turn the flower over and examine its inner face. 

 Notice the large, round, and usually upright petal at the 

 back, the two smaller ones on each side, and the boat- 



408-412. Dissection of papilionaceous flowers (after GRAY) : 408, front view 

 of a corolla. 409, the petals displayed : v, vexillum, or standard ; w, wings; k, keel. 

 410, side view with nil except one of the lower petals removed, showing the essential 

 organs protected in the keel: /, loose stamen; st, stamen tube. 411, side view, 

 showing how the anthers protrude when the keel is depressed. 412, ground plan. 



shaped body between them, formed of two small petals 

 more or less united at the apex. Press the side petals 

 gently down with the thumb and -forefinger and notice 

 how the essential organs are forced out from the little boat 

 in which they are concealed. Observe how the end of the 

 style is bent over so as to bring the stigma uppermost 

 when the petals are depressed. Imagine the legs of a 

 bee or a butterfly probing for honey ; with what organ 

 would his body first come in contact when he alighted ? 

 If his thorax and abdomen had previously become dusted 

 with pollen when visiting another flower, where would the 

 pollen be likely to be deposited ? 



Remove the sepals and petals from one side and sketch 



