152 BOTANY. [chap. iv. 



during the bud stage by the calyx. This arrangement 

 is met with in the inflorescence of the laburnum, red 

 currantj lupin, etc. Now, if we imagine all the naked 

 portions of flower-stalk between the flowers and their 

 floral-bracts to be removed or not developed, and at the 

 same time have the flowers sessile or without stalks, then 

 we get the crowded inflorescence characteristic of com- 

 posite plants as already described, which consists of a 

 dense cluster of sessile or stalkless small flowers crowded 

 at the top of a much swollen and flattened out flower- 

 stalk, each floret accompanied by its floral-bract, the 

 latter collectively forming the involucre, or outer row of 

 green leaves seen on the under side of the daisy, sun- 

 flower, etc., and which might at first be mistaken for a 

 calyx ; the involucre incloses and protects the entire 

 inflorescence during its early stage of development, hence 

 the calyx of each individual flower is not required to 

 perform its original function of protection, and in some 

 species, as the dog-daisy and nipplewort, has become 

 quite rudimentary, whereas in other species possessing 

 more aptness in turning things to account, have found 

 out a new use for the calyx, and utilize it as a dispersive 

 organ for the purpose of carrying away from the neigh- 

 bourhood of the parent plant the mature fruits. Under 

 this new form the modified calyx, which has given up its 

 cell-contents and become light and feathery for the pur- 

 pose of floating away its attached fruit, is known botani- 

 cally as the pappus, popularly as " clocks " in the 

 dandelion ; thistle-down is also a forni of pappus, but it 

 is important to remember that every form of down or 

 dispersive arrangement for the purpose of scattering 

 seeds or fruits is not a pappus, that is, a modified calyx. 



