This is a beautiful native woodland plant with large, bright yellow flowers from spring into early summer; they are followed by fuzzy capsules. It will form a clump with blue-green foliage that resembles the greater celandine (Chelidonium majus). With enough moisture it remains green the whole season, otherwise it may go dormant. It thrives in any woodland conditions, in dappled shade and rich, moist soil; very good for naturalized areas and it will self-seed if it likes the place, but not in an invasive way. The whole plant contains a yellow sap, which was used as a dye by Native Americans.
In Ontario, the only known wild population of S. diphyllum apparently resides on a private property in London. Perhaps there are more populations but nobody has stumbled on them yet. The disappearance of this species from Ontario is blamed on the habitat destruction and there has also been the speculation that it may have reached the limit of its hardiness. However, the latter cause is invalidated by its ability to thrive in gardens from Ontario and Quebec.
Whatever the real reason may be, it would help to cultivate it more!
Germination: best sown right away, or any time till spring but with seeds kept moist and allowed a warm-cold cycle. They are equipped with ‘mohawk-crest’ elaiosomes and dispersed by ants. Seeds kept in moist vermiculite will start to germinate somewhere March (last date for safe shipping). This is a species with a true 100% germination if done from moist stored seeds.
Very easy to grow from seeds and you can obtain almost a flowering size plant in the first year! (gallery image)