CHAP. II.] PAPILIONACEOUS FLOWERS. 37 



t 

 wliicli (c) stands erect, and is called the vex- 

 illum or standard; below this are. two smaller 

 petals (d), which are called the algae or wings ; 

 and below these are two petals, joined together 

 so as to form a kind of boat (e), which are called 

 the carina or keel, and which serve as a cradle 

 for the stamens and pistil. There are ten 

 stamens, nine of which have the lower half of 

 their filaments growing together, so as to form 

 a fleshy substance at the base, as shown in Ji.^. 

 14 at/i and the other ((/) is free. 

 The ovary is oblong, terminating 

 in a filiform style, with a pointed 

 stigma, as shown at q in Jlc/. 13 ; 

 and it is one-celled and many- 

 seeded ; the seeds being what we 

 call the peas. When the petals p,^ u.-stamens 

 fall, the pod still retains the calyx oftheSweet-pea. 

 (b), and the style (g) ; and these remain on till 

 the seeds are ripe, when the pod divides natu- 

 rally into two parts, or valves as they are 

 called, which curl back so as to discharge the 

 seeds. If the pod be examined before it bursts, 

 it will be found that the valves are composed 

 of a fleshy substance, lined with a strong mem- 

 brane or skin, and that they are united by two 

 seams, called the dorsal and ventral sutures. 

 Along the ^'^€t«-tFal -suture (A)l there runs a kind 

 of nerve, called the placenta, to which the peas 



