138 



PAETICULAR FORMS OF FLOWERS 



pollination. Observe how a bee forces his head into the 

 elosed throat of the toad-fiax. 



275. LILY FLOWERS.— In plants of the lily 

 family (Liliace^) the flowers are typically 

 3-merous, having three sepals, three petals, 

 six stamens and a 3-carpelled pistil. The 

 parts in the different series are distinct from 

 I ^^^-"^ each other (excepting the carpels,) and mostly 

 I if/^ free from other series. The sepals and petals 

 M**V^^ are so much alike that they are distinguished 

 W n^/k c^^^^fiy ^y position, and for this reason the 

 / /-^Sm^ words calyx and corolla are not used, but 

 f'miw tli^ floral envelopes are called the perianth 



and the parts are segments. Flowers of lilies 

 and trilliums (Fig. 221) answer these details. 

 Not all flowers in the lily family answer in all 

 ways to this description. The term perianth 

 1^ is used in other plants than the Liliacea?. 



■ 276. PAPILIONACEOUS FLOWERS. — In the 



pea and bean tribes the flower has a special 

 form (Fig. 222). The 

 calyx is a shallow 5 -toothed tube. 

 The corolla is composed of four 

 pieces, — the large expanded part 

 at the back, known as the stand- 

 ard or banner ; the two hooded 

 side pieces, known as the wiitg^ ; 

 the single boat -shaped part be- 

 neath the wings, known as the Ixevl. 

 The keel is supposed to represent 

 two united petals, since the calyx 

 and stamens are in 5's or multi- 

 ples of 5; moreover, it is com- 

 posed of two distinct parts in cassia (Fig. 223) and 

 some other plants of the pea family. Flowers of the 



220. 



Personate flowers 



of snapdragon. 



221. Flower of trillium. 



