Plant
              
                - Annual bedding flower
 
                - 1-3' tall
 
              
            
          
         
        
          
            
            
              Stem
              
                - Opposite leaf arrangement
 
              
            
          
         
        
          
            
            
              Leaf
              
                - 1½-4" long
 
                - Linear or narrowly ovate
 
                - Opposite, simple
 
                - Sessile (do not have petioles)
 
              
            
          
         
        
          
            
            
              Flower
              
                - Clustered in heads up to 6" wide 
 
                - Small, tubular disc flowers in center, usually yellow
 
                - Larger outer showy flowers in pink, red, orange, lavender, white, bicolor