92 
THE FIRST BOOK OF BOTANY, 
of these styles varies very much in nature. You will 
find umbels, panicles, corymbs, etc., very unlike each 
other. Great differences among the clusters of a va- 
Fig. 145. Fig. 146. 
riety may be occasioned by the presence or absence 
of bracts, by their forms and colors, by the length, 
stiffness, and ever-varying positions of peduncles and 
Fig. 147. 
pedicels, as well as by differences in the form of re¬ 
ceptacles. The various sorts sometimes run together 
in many different ways. You may find a flower- 
cluster resembling two different varieties so much 
