136 ELEMENTS OF BOTANY. 
The student should construct such diagrams for some rather com- 
plicated flower-clusters like those of the grape, horse-chestnut or buck- 
eye, hardhack, vervain, or many grasses. 
-170. Terminal Flowers. Determinate Inflorescence. — The 
terminal bud of a stem may be a flower-bud. In this case 
the direct growth of the stem is stopped or determined by the 
appearance of the flower, hence such plants are said to have 
a determinate inflorescence. The simplest possible case of this 
kind is that in which the stem bears but one flower at its 
summit. 
‘171. The Cyme.—Very often 
flowers appear from lateral (axil- 
lary) buds, below the terminal 
flower, and thus give rise to a 
flower-cluster called a cyme. This 
may have only three flowers, and 
in that case would look very much 
like a three-flowered umbel. But 
in the raceme, corymb, and umbel 
the order of flowering is from 
below upward, or from the out- 
side of the cluster inward, because 
the lowest, or the outermost 
flowers, are the oldest, while in 
* Fig. 114.—Compound Cyme of determinate forms of inflorescence 
Mouse-Ear Chickweed. 
the central flower is the oldest, 
and therefore the order of blossom- 
ing is from the centre outwards. Cymes are very commonly 
compound, like those of the elder and of many plants of 
the pink family, such as the Sweet William and the mouse-ear 
chickweed (Fig. 114). They may also, as already mentioned, 
be panicled, thus making a cluster much like Fig. 113 A. 
é, the terminal (oldest) flower. 
