INDETERMINATE INFLORESCENCE 



173 



Indeterminate Inflorescence. A spike is a form in which 

 the peduncle is elongated and the flowers are sessile. A 

 compound spike is composed of several spikes formed by a 

 branching peduncle. Aments or catkins are short, very 



FIG. 106. Arrangement of Flowers. Spikes. 1, Common plantain 

 (Plantago major) ; 2, (Plantago lanceolata). Compound Spike; 3, blue vervain 

 (Verbena hastatd). Aments. 4, pistillate ament, willow (Salix sp.) ; 5, stami- 

 nate ament, willow (Salix sp.) ; 6, staminate ament, speckled alder (Alnus 

 incana) . Spadix. 7, sweet flag ( Acorus calamus) ; 8, wild calla (Calla palus- 

 tris). Heads. 9, buttonbush (Cephalanthus occidentalis) ; 10, red clover 

 (Trifolium pratense). 



compact inflorescences made up, as in the willows, of either 

 staminate or pistillate flowers, each subtended by a small 

 bract. A spadix is a thick fleshy peduncle with reduced 

 internodes bearing sessile flowers, as the inflorescence of sweet 

 The spadix is often, as in wild calla, subtended by a 



