Jack-in-the-pulpit (Arisaema triphyllum) 三葉天南星
Flower image see: https://en.wikipedia.org/wiki/Arisaema_triphyllum#/media/File:Jack-in-the-pulpit.JPG
Jack-in-the-pulpit (Arisaema triphyllum) 三葉天南星
Cold and shade tolerant perennial. Very hardy and easy to grow. Best in partial shade but also tolerant full shade location. Unusual flowers in spring. USDA Zones:5-9. Mature size:1.5′-2′(H) X 1′-1.5′(W). Propagate by seeds/rhizomes/corms/ bulbs/offsets. Whole plant is toxic if ingested.
天南星屬的多年生球根類耐蔭植物. 極其強健易栽培. 最好是種在半日照處,全蔭處亦可生長. 春天開花,花形相當奇特. 耐寒也耐熱. 成熟株高1.5-2呎高,寬幅為1-1.5呎. 繁殖方式以種子/地下根莖/球根. 全株有毒勿食.
Reference links:
https://en.wikipedia.org/wiki/Arisaema_triphyllum
http://www.finegardening.com/jack-pulpit-arisaema-triphyllum
My Food And Flowers 
I Have a ton of these in my gardens. They self-seed enthusiastically.
Do you have extra seeds for exchange? It is a native plant here in woods. But living in the city is hard to get them, normally in spring some garden centres and nurseries will only carry few. 😦 The plant in the picture is not mine.
I would like to but all of mine are infested with the rust fungus and I would not like to spread it.
Agreed!