166 INFLORESCENCE. 



The term Spikelet, is applied exclusively to grasses 

 that have many florets in one calyx, and the filiform 

 receptacle to which these florets are attached is de- 

 nominated the Rachis. 



6. RACEME. Fig. 66. A Raceme or cluster differs 

 from the spike only in the length of its individual flower- 

 stalks which are also in this case attached to the sides oi 

 a common stem. The Currant is a fine example of a 

 cluster^ which more frequently than any other falls 

 within our observation. It is unilateral in the Scull- 

 cap Scutellaria lateriflora ; terminal in the Cohush Ae- 

 tata Americana ; lateral in the Currant, and compound 

 in the Woody Nightshade. 



7. HEAD. Fig. 67. — This is an assemblage of flow 

 ers upon the extremity of the branch or stem, and ar- 

 ranged in a globular, oval or cylindrical form. It oc- 

 curs in the Globe Amaranth, and in several species of 

 the Trifolium or Clover. 



. 8. WHORL. Fig. 68. — An assemblage of flowers sur- 

 rounding the stem or its branches constitutes the whorl. 

 It occurs in the Mint, and in many of the Labiate plants. 

 9. PANICLE. Fig. 69. — When the flowers are ar- 

 ranged on a stalk variously and repeatedly subdivided, 

 as in the Oat, their inflorescence constitutes the Pani- 

 cle. In the grasses the branches of the panicle are some- 

 what verticillate, being diffuse or loosely spreading, or 

 dense and crowded ; sometimes nodding and sometimes 

 erect. 



10. THYRSE.— The flowers of the Thyrse are ar- 

 ranged like those of the panicle, the branches of the 

 pedincle being short and the flowers more compact, as 

 in the Lilac and Prim. 



11. AMENT or CATKIN. Fig. 71.— Like the Spike, 

 fhe flowers of the Catkin are arranged along the side 



