FLOWER AND FRUIT 177 
escence, consisting of a great number 
of flowers or florets massed together. 
Relationships——The raceme is 
probably the primitive form of in- 
florescence. The panicle may be 
regarded as a branched raceme; the 
corymb as a raceme in which the 
pedicels of the lower flowers have 
FIG. 113A y 
Fruiting head of piri-piri Lengthened; a. spike as one in which 
(Acaena sanguisorbae) the pedicels have disappeared; a 
eatkin one in which, not only have the pedicels 
disappeared, but the flowers of certain inflorescences 
have lost their male, while those of others have lost 
their female organs; the spadix one in which a similar 
thing has happened but on the same inflorescence; an 
umbel one in which the internode-like intervals of the 
pendunele have disappeared, and all the flowers have 
been brought to the same level; and finally, a head 
is the same thing as an umbel in which the flowers have 
become sessile. 
A definite inflorescence (Fig. 114) is one in which 
the flower at the end of the axis opens first, the next 
flower, where present, being produced by the branching 
of the peduncle below the first, the third by a branch 
produced from the first branch below the second flower, 
and so on till the flowering capacity of the shoot is 
exhausted. This will best be understood by consulting 
the diagrams. The following are the chief definite 
inflorescences :— 
1. Solitary. This arises when the main axis 
produces at its end a single flower and there is no 
branching whatever. This is well seen in the tulip 
and tea-tree. In the latter the solitary inflorescence 
may be terminal, at the ends of short branches, or 
axillary, in the axils of the leaves. 
2. Cymose inflorescences are definite inflorescences 
that branch as indicated above. The branches may be 
M 
