214 



LUSSONS WITS PLANTS 



246. We have now seen flowers in which the 

 parts are arranged in threes, fours, fives and sixes. 

 This numerical order is very important in deter- 

 mining the kinships of plants. It is most apparent 

 in the floral envelopes and in the androecium, but 

 it is very apt to appear in the pistil in the number 

 of locules or placentae, or in the styles or stigmas. 



246o. To indicate the numerical plan, the number is prefixed 

 to the Greek word "merous," denoting member : as 2-merous, 

 3-merous, 4-merous, 5-merous, 6-merous, and the like,— written in 

 full respectively, dimerous, trimerous, tetramerous, pentamerous, hexa- 

 merous. 



2466. The pupil will now see that ("except in the 6-merous 

 plan) the crape myrtle is really very suggestive of the plum flower 

 (Fig. 144), for each is apparently perigy- 

 nous, polypetalous and unipistillate. 



247. The bleeding-heart of 

 the garden is familiar. It has 

 a characteristic pattern of flower. 

 The squirrel -corn and dutch- 

 man's breeches of the spring 

 copses are close of kin. So 

 is the Alleghany vine or smoke 

 vine (or adlumia) of moist 

 woods, flowers of which are 

 shown in Fig. 207. The ovary is superior and 

 has two placentae ; stigmas two. The sepals are 

 two, minute and scale -like— well shown in the pic- 

 ture. The petals are four, and united into a 



F:g. 207. 

 Alleghany vine, or adlumia. 



