274 THE BEAN FAMILY. 



3O3. Vetch Tribe. 



In Vicia (the Vetch genus, to which the Broad Bean belongs) there 

 are usually at least 4 pairs of leaves, and there is a tuft of hairs on the 

 style, below the stigma. In Lathyrus (Vetchlingf or Pea genus, 

 including the Sweet Pea) the leaflets are few (usually 1 or 2 pairs) 

 and the style has hairs scattered over it, not in a little tuft. 



Pig. 99. Longitudinal Section of Flower of Scarlet Runner. 



304. Flower Mechanisms in Fapilionaceae. In ex- 

 amining the flowers note any differences in the calyx (lobes 

 equal or unequal in length, smooth or hairy, etc.) ; the corolla 

 (how are the wings jointed with the keel ?) ; the ten stamens 

 (is the stamen joined with the others so as to form a com- 

 plete stamen-tube, or is it free, and are the filaments equal or 

 unequal in length ?) ; the pistil (length of style, its position 

 with the keel, presence or absence of hairs). In each case 

 sketch all the parts carefully (sketch the separate parts and a 

 longitudinal section of the flower), and find out what happens 

 when the keel is pressed down ; if possible, watch bees at 



