THE FLOWER. 
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compound umbel; in the plantain the flowers are ar- 
ranged along a central axis, but the pedicels are want- 
ing, and the inflorescence is known as a spike; in clover, 
Cephalanthus and the Composite, the rachis and pedi- 
cels are both more or less suppressed or wanting, and 
this form of inflorescence is known as a head. In the 
Compositse the head is in addition, subtended by an 
involucre. 
The determinate or definite inflorescence includes 
several types, the principal of which may be men- 
tioned : when a stem or branch is terminated by a 
flower, it is known as a cyme, and inflorescence of this 
character is described as cymose ; when the peduncle 
bears a number of cymes, it is known as a compound 
cyme, as in elder, hydrangea and viburnum; and a cy- 
mose head is known as a glomerule, as in the dogwood. 
When the cymes are opposite and sessile, or nearly so, 
the inflorescence is termed a verticillaster, as in the 
Labiatce. 
(e) MODIFICATIONS OF THE FLOWER. 
The parts of the same circle of the flower or even of 
different circles may be united, and a number of terms 
are used to describe these modifications. When the 
parts of the same circle are united there is said to be a 
cohesion or coalescence of the parts. When the parts 
of different circles are united, as of calyx with corolla, 
the union is spoken of as adhesion or adnation. 
In addition to pure adhesion among the different 
parts of the flower there may be developed, either 
beneath, around or upon the ovary, a somewhat fleshy 
part, which is usually a modification of the receptacle 
and is in the nature of a nectar-secreting apparatus. 
This is known as a disk. 
The arrangement of the other parts of the flower 
