135 REPRODUCTIVE ORGANS. CHAP. Ill, 



If the flowers are solitary or in pairs they are re- 

 garded merely as being caulinary or rameal, axillary 

 or terminal, according to the distinctions instituted 

 in treating of the peduncle. But when many grow 

 together their aggregation forms a feature in the 

 habit of the plant peculiarly striking and peculiarly 

 interesting to the botanist, as forming the most 

 elegant and most invariable of all specific distinc- 

 tions, as well as being of undoubted importance in 

 Varieties, determining genera. On this account the in- 

 florescence claims our particular notice, and may be 

 regarded as consisting of the several following varie- 

 ties: the head, the whirl, the spike, the panicle, 

 the thyrse, the cluster, the corymb, the fascicle, the 

 umbel, the cyme, the catkin, the spadix. 



SUBSECTION I. 



Descrip- The Head. The head is a group or assemblage of 

 flowers distributed upon the extremity of the stem 



or branch, or upon a general peduncle as their com- 

 mon axis, upon which they are aggregated into a 

 globular form. The inflorescence of Statice Ar- 

 meria affords a very good example of a head of 

 flowers. (PL V. Fig. 1.) But though the head is 

 always somewhat globular, it is not by any means 

 strictly so ; for in Trifolium Jiliforme it is hemi- 

 pherical ; in Trifolium montanum it is conical ; and 

 in Dipsacus Jullonum it is oval, The individual 





