APPENDIX 519 



SUMMARY OF PRINCIPAL KINDS OF FLOWER CLUSTERS 



A. Indeterminate inflorescence. Order of blossoming from below up- 

 ward, or from without inward 



1. Axillary flowers. Flowers growing in the axils of ordinary 



leaves. 



2. Raceme. Flowers with flower stalks, called pedicels, arranged 



along the peduncle or stem in the axils of special (usually 

 pretty small) leaves called tracts. 



3. Corymb. Flowers arranged as in the raceme, but with the 



lower pedicels so lengthened as to make the flower cluster 

 flat or nearly so (as in the hawthorn or the yarrow). 



4. Umbel. Flowers with pedicels of nearly equal length, all appear- 



ing to spring from a common point, like the ribs of an um- 

 brella. An involucre of bracts usually surrounds the bases 

 of the pedicels. 



5. Spike. Flowers as in the raceme, but sessile ; that is, without 



pedicels. 



6. Head. Flowers as in the spike, but the cluster nearly globular. 



7. Panicle. Flowers as in the raceme, but the cluster made com- 



pound by the branching of the peduncle. 



B. Determinate inflorescence. Order of blossoming from within 

 outward. 



1. Flower terminal. One flower borne at the summit of the stem. 



2. Cyme. Flowers much as in the umbel, but the innermost blos- 



soming first. 



