220 ON COMPOUND FLOWERS. 



Mrs. B. The florets, being so close together, protect 

 each other : the use of the tuft is to assist the fruit to dis- 

 engage itself from the involucrum, and then to transport 

 it to a distance ; for the pappus remains upon the fruit 

 after the blossom has fallen. There are some few com- 

 pound flowers, the calyx of which is not at all elongated, 

 and which, consequently, have no pappus. 



Emily. How, then, does the fruit or seed disengage 

 itself from the involucrum ? 



Mrs. B. When the tuft is wanting, the fruit is fur- 

 nished with other means of separating itself from the pa- 

 rent-plant. Sometimes the recepticle rises up after the 

 blossom is over, to force out the fruit ; at others, the 

 weight of the head, when it is mature, bends the pedun- 

 culus, and the seeds fall to the ground. Thus you see 

 that every difficulty is foreseen and obviated in the ad- 

 mirable structure of which I am endeavoring to give you 

 a mere outline. 



Caroline. You speak sometimes of the fruit, and some- 

 times of the seed, which the tuft wafts away: do you 

 mean to use these terms indifferently, or have they each 

 of them a distinct meaning? 



Mrs. B. I was not quite correct in so expressing my- 

 self; but the error was very trifling, as you will perceive, 

 when I have explained the difference to you. I said that 

 the small body, to which the tuft was attached, was com- 

 posed of the ovary and the calyx. The ovary contains a 

 single seed, which has its own particular covering, call- 

 ed Spermoderme. Thus the single seed of each little 

 flower is enveloped in three integuments, adhering to 

 each other the calyx, the ovary, and the spermoderm. 

 In some compound flowers, these three integuments are 

 distinctly seen ; but in others they are only supposed to 

 exist by analogy, without being actually visible. These 

 three integuments, soldered together, form a peculiar spe- 

 cies of fruit, which was formerly called a naked seed, but 

 is now distinguished by the name ofJlchenium. In some 

 families (such for instance, as the Epilobiums and the Apo~ 

 cinums,) small feathery tufts grow within the germen, and 



1204. What is the use of the tuft! 1205. What flowers have no 

 pappus 1 ? 1206. If they have no pappus, how does the fruit or seed 

 disengage itself from the involucrum! 1207. With what is the single 

 seed of each little flower enveloped! 1208. What was formerly call- 

 ed the naked seed! 



