58 



NOMENCLATURE. 



when it is also the fruit-stalk. When it springs immediately 

 from the root, and bears flowers only without leaves, it is 

 called the shaft (scapus)^ 



In the Mosses the fruit-stalk is called seta, in the Lichens 

 podetium. In the Gastromyci and Nematomyci, the part 

 which supplies the place of the fruit-stalk is called stroma, 

 and also subiculum {cephalophorum, Nees.) If we consider 

 the fruit-stalk of Calycium as a stroma, there is still another 

 part under the fruit, (Jiypostromd, Mart.) 



84 



The name spike or ear (spica), is given to that mode of 

 inflorescence in which stalkless flowers are arranged on a 

 common axis. The spike may be simple or compound. In a 

 simple spike, the lowermost flowers are first evdived, and then 

 follow by degrees those higher up. But when the spike is 

 compound, the evolution takes place in a reversed order. 



Spicula in the Grasses, is that mode of inflorescence in 

 which several flowers are contained within a common calyx. 



The catkin (^amentum) is a spike, which, instead of flowers, 

 contains only scales, as in Willow, Hazel, and Poplar. 



The spadix is a spike with a thick juicy axis, which con- 

 tains either very small blossoms, as in Acorus and Saururus, 

 or only sexual parts without any covering, as in Arum and 

 Calla. 



Sometimes we call the crowded spikes, whose flowers are 

 separated by coloured bracteae, strohili, as in Origanum. On 

 other occasions this word has a different meaning. 



When flowers without stalks, or with short stalks, stand in 

 descending rows around the stem, this is called a whorl (ver- 

 ticiUus). Such is the usual inflorescence of the Labiatae. 

 ^Frequently the flowers are only on one side, and form then 

 the half- whorl (verticilli dimidiati), as in Medusa officinalis. 

 The flowers of a whorl, however, are not always without 

 stalks. 



When stalkless flowers are crowded together on the end of 

 a common stalk, they form a head (capitulum) ; but when 

 the individual flowers which are thus crowded together have 



