9* DESCRIPTIVE BOTANY. ' PART I. 



corresponds to the limb of that organ. By the cohesion 

 of the claws, a tube is frequently formed, whilst the 

 limbs continue more or less free, and appear as a border 

 round the top of it. In some cases, the petals adhere 

 at the base and apex, but are free in the middle, as in 

 Phyteuma. An irregularity in the cohesion, produces a. 

 lipped corolla, as in the case of the calyx. We will 

 here enumerate a few of the most important forms 

 which the corolla assumes, the most remarkable of 

 which are among such as are monopetalous. 



1. Regular monopetalous Corolla. Where the 

 several parts are symmetrically arranged round the 

 axis, the forms are named after certain appearances 

 which they are supposed to resemble ; as the bell-shaped 

 (fiy- 92. u), funnel-shaped (6), salver-shaped (c), 

 rotate (d). 



2. Irregular monopetalous Corollte. Where the 

 petals cohere, but one part of the corolla is differently 

 modified from another; as in the "lipped" or "labiate" 

 flower (fig. 93.), which has two 

 lobes forming the limb; and the " per- 

 sonate" flower (fig. 131. a), formed 

 on somewhat the same plan, but where 

 the mouth of the tube is closed. In 

 these, and in other cases of irregular 

 monopetalous corollse, it is not always 

 easy to distinguish the precise number 

 of petals which cohere together, al- 

 though we may generally do so by 

 examining the venation, or by observing the apices of 



