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 when ripe red.
1-several seeds per fruit.
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.
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/