138 REPRODUCTIVE ORGANS. CHAP. III. 



the lower whirls of Mentha viridis. In some they 

 are interspersed with a number of small leaves, as 

 in Ajuga reptans ; and in others they are naked 

 or without leaves. The number of individual 

 flowers composing the whirl is different in different 

 species, varying from six or eight, to ten or more, 

 in which case the whirl is said to be many-flowered, 

 as Leonurus. 



SUBSECTION III. 



Descrip- The Spike. The spike (PI. V. Fig. 3.) is an as- 

 modi a fica- sem blage of flowers arranged in close succession 

 tions. upon a common and longitudinal axis, which is a 

 vertical prolongation of the stem, or on a common 

 peduncle, which is generally erect. The term seems 

 to have been originally confined to an assemblage 

 of sessile flowers arranged in the foregoing order, as 

 in the ear of Wheat or Barley ; but it is now ex- 

 tended by the common consent of botanists, to such 

 also as are supported on short pedicles, if otherwise 

 corresponding to the definition, as in common La- 

 vender ; and even to such as are arranged in whirls, 

 particularly if the whirls are closely crowded 

 together, as in some of the Mints. A spike ge- 

 nerally begins flowering at the base, as in Lythrum 

 Salicaria, and continues to protrude its blossoms in 

 gradual succession up to the top ; so that the lower 

 flowers are oftentimes quite decayed before the up- 

 per ones have begun to expand. But in Sang\ 

 sorba afficinalis the flowering begins at the toj 



