162 LESSONS WITH PLANTS 



are pushing out, the young shoot is growing 

 rapidly, and it makes a little cluster of pistillate 

 flowers at its end (S) ; and these pistillate flowers 

 appear in season to receive the benefits of the 

 pollen. In the hickory, then, the fruit -buds are 

 both terminal and co- terminal (55). 



181a. Is not the birch catkin, Fig. 156, co-terminal ? The pupil 

 may now revert to the discussion of Pig. 55, and to an examina- 

 tion of the fruit-bearing of hickories and walnuts. 



1816. We have seen, then, that those flowers which are borne 

 in catkins or aments are diclinous ( 132c) ; and this is usually 

 the case. The true catkin -bearers or amentaceous plants, in fact, 

 are always diclinous. These comprise all the oaks, chestnuts, hazels, 

 willows, poplars, birches, alders, beeches, hornbeams, walnuts and 

 hickories; and these are for the most part very early-flowering trees 

 or bushes. The fruits of many of them are nut-like. 



182. It is evident that the catkin is only one 

 kind of a flower -cluster; and as we shall so often 

 need a comprehensive term to designate the mode 

 of flower arrangement, we shall hereafter use the 

 word inflorescence. (See Obs. xxxv. and xxxvi.) 



183. Since flower -clusters often branch, we 

 cannot use the word peduncle (or flower- stalk) 

 indiscriminately. We use it for the flower -stem, 

 when the cluster is simple or unbranched; but 

 when the cluster is branched, we use it for the 

 stem of the entire cluster, while the particular 

 stalklet upon which the flower is borne is called 

 the pedicel. 



