42 



ORGANOGRAPHY. 



spike is similar to a crowded raceme, with the flowers ses- 

 sile (Fig. 91). Two special forms of the spike have peculiar 

 uames, namely, the spadix (Fig. 86), 

 which is fleshy (and commonly sur- 

 rounded by a spathe) ; and 

 the catkin, or ament, 

 which is scaly (Fig. 92). 

 The head difiers from a 

 spike in that the axis is re- 

 duced, crowding the flowers 

 into a head-like cluster (Fig. 

 92 93). A panicle is an open 

 and more or less compounded raceme 

 or corymb (Fig. 94). 



50. The cyme is a determinate or 83 



definite flower-cluster, with a flat or convex top. It resem- 

 bles the corymb somewhat, except that in the latter the flow- 

 ering is centripetal, while in the cyme it is centrifugal (Fig. 

 95). A crowded cyme is called a fascicle. Many of the 

 clusters are often compound, as compound umbels, compound 

 q9 cymes, etc. The two 



) , / n classes of inflores- 



I r In cence may be repre- 

 sented in one and 

 the same plant; thus 

 the Mint Family 

 ■V n >^ has cymes or fasci- 

 W'^1^-^ J cles, which are eew- 

 trifugal in their flow- 

 ering, but these are 



F!g. 92. Catkin of the American Hazel. Fig. 93. Head of Clover-flowere. Fig. 

 94. Diagram of a Panicle. Fig. 95. Diagram of a Cyme. 



