3S 



GLOSSARY OF 



LONGITUDINAL SECTIONS. 



The pupil should make a constant practice of splitting flowers 

 through the centre (best done from below upwards with a 

 very shariD knife), and drawing the section thus presented. 

 Such a drawing is exceedingly useful in connection with 

 the floral diagram, as still further exhibiting the relation of 

 the parts to each other. 



Fig. 226 is a good example. Here the relations of the 

 parts can be seen at a glance. 



COMPOSITE FLOWERS. 



A full description of a Composite flower involves some par- 

 ticulars of a special kind ; for convenience, thei'efore, the 

 various terms in use are collected together here. 



Inflorescence. 



Under this heading describe the arrangement of the heads, 

 using the terms already explained — solitary, cymose, 

 racemose, corymbose, spiked, etc. 



Head. 



The assemblage of florets (few or many) on a common 

 receptacle. 



Parts of the Head. 



Florets : the small single flowers which in tlie aggregate 

 make up the head. These are 



(a) Ligulate, when the corolla is prolonged on one side 

 into a flat strap-shaped piece (Fig. 227). 



(b) Titbular, when the corolla is not thus prolonged, 

 but is regularly developed all rou t. ' (Fig. 228). 



Receptacle : the place upon which the florets stand. 



Involucre : the circle or circles of bracts which surround tlie i 

 head. 



Kinds of Head. 



LiGL'LiFLORAL : when all the florets of the head are ligulate, 

 as in Dandelion (Fig. 229). 



Tl'BULIFLORAl : when all the florets are not ligulate ; and 

 such heads are 



(a) Discoid, if all the florets are tubular as in Thistle. 



(b) Radiate, if the florets round the margin of tlie 

 head (ray-florets) are ligulate, while tlie central ones 

 (disk-florets) are tubular, as in Sunflower (Fig. 230), 



Fiff. 226. 



Fig. 227. 



Fig. 228. 



Fig. 229. 



ray-floret 



disk-floret cliaff 



involucre 



Fig. 230. 



