162 RELATIONSHIPS OF THE INDEFINITE INFLORESCENCES. 
a minimum of energy, is, provided the plant tends to branch mono- 
podally, the solitary axillary flower. It is generally agreed that 
this is the simplest possible type of indefinite inflorescence.* 
Next we may consider the case of a (monopodal) plant which ir 
& 
c 
production of floral shoots. In the first place, a series of sessile 
rs might be produced on the primary axis. If the internodes 
the primary axis continued to develop normally, but the axes of 
the floral shoots remained undeveloped, the resulting inflorescence 
would be a spike. It is, however, important to remember that, to 
produce such a form, energy must be expended in two distinct 
ways, viz. the production of a certain number of floral shoots, and 
the elongation of the primary internode 
But there is a second method, which would be even simpler. 
If a series of sessile flower-buds were produced on a primary axis 
without at the same time elongating the internodes of that axis, the 
resulting inflorescence would be a capitulum. A capitulum differs 
from a spike in that the whole of the energy is expended in the 
production of flower-buds, and none of it is devoted to the internodal 
elongation of the primary or secondary axes. It is obvious that with 
the same supply of energy in each case more flowers can be produced 
and t 
ther, the umbellate type, in which certain internodes remain 
have acquired an additional supply of energy available for flower 
Such energy might be spent in several ways, each 
to 
All these forms belong to one or other of the two original 
ypes. ‘The Racemose, in which all the internodes are normally 
developed :—the spike, raceme, and panicle. The Umbellate, in 
which certain internodes remain undeveloped throughout :—the 
capitulum, umbel, and compound umbel. 
* J. H. Balfour, Class Book of Botany, 3rd ed., p. 169.* 
