Arisaema dracontium                                                                      
Mature tuber produces 1 inflorescence per season.
 
Inflorescence produced from leaf stem.
 
Paradioecious (inflorescences alternate between male and female).
 
Spadix free of the spathe back wall. 
 
Fruit red when ripe.
 
1-several seeds per fruit.
 
Pinellia pedatisecta                                                           
Mature tuber produces multiple inflorescences per season.
 
Infloresence produced from a leafless (peduncle) flower stem.
 
Monoecious (inflorescences produce both male and female flowers at the same time).          
 
Spadix fused to the spathe back wall.
 
Fruit when ripe gray-white to green-gray.
 
1 seed per fruit.
 
 
Key:
1a.   Spadix unisexual, or if bisexual then male and female 
         zones contiguous or separated by sterile zone usually 
         covered with staminodes.                                                    2a.
 
1b.   Spadix bisexual, male and female zones separated 
         by naked sterile axis (interstice)                                           2b.
                                                 
2a. (1a.)  Leaves variously divided (most commonly 
                  pedate to pedatisect but not decompound), 
                  very rarely entire; berries ripening reddish.           Arisaema
 
2b. (1b.)  Female zone of spadix adnate to spathe.               Pinellia
 
 
Key adapted from Flora of China        http://www.efloras.org/