SECT. IV. THE INFLORESCENCE. ] 37 



flowers are either sessile, as in Trifolium suffocatum ; 

 or pedicled, as in Thymus Serpyllum. 



The head is also either sessile, as in Trifolium 

 glower at -urn ; or supported upon a peduncle, as in 

 Trifolium ochroleucum ; or it is axillary, as in Tri- 

 folium scabrum; or terminal, as in Gomphrena 

 globosa. Sometimes it is interspersed with a num- 

 ber of small leaves, as in Thymus Serpyllum ; at 

 other times it is naked, that is without leaves, as in 

 Trifolium. 



SUBSECTION II. 



The tVhirl.The whirl (PI. V. Fig. 2.) is a group Descrip- 

 or assemblage of flowers surrounding the stem or mo difica- 

 branch as a common axis, and in the form of a ring. dons> 

 The Verticillate flowers of Tournefort, or Labiate 

 flowers of Linnaeus, afford the best examples. If 

 the individual flowers composing the whirl are ses- 

 sile, as in Marubium> the whirl is said to be sessile ; 

 and if they are pedicled, as in Thymus Calamintha, 

 the whirl is said to be pedicled. But sometimes 

 the whirl extends only halfway round the stem ; and 

 in this case it is said to be dimidiate, as in Melissa 

 offtcinalis. Plants affecting this mode of inflores- 

 cence produce generally a succession of whirls, 

 which are arranged at regular intervals upon the 

 upper part of the stem or branch. In some plants 

 the whirls stand close to one another, the intervals 

 between them being very small, as in the Mentha 

 acutifolia ; in others they stand wide apart, as in 



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