These two plants, both called by the popular name "celadine," are confused by many people. The Celandine-poppy (Stylophorum diphyllum) is a valued wild-flower filling the spring woodland with its bright yellow.  The other Chelidonium majus)an alien invader. 

Wood-poppy, Celandine-poppy (Native)
Stylophorum diphyllum

Large Photo of Stylophorum diphyllum

A native that spreads in rich moist woods.   Will not tolerate sun.  Coefficient of conservatism = 10.

Can be distinguished from the alien celandine (Chelidonium majus) by a more golden yellow in the flower.  Leaves have a deeper lobed.  Seed pods are rounder.

Celandine (Alien)
Chelidonium majus

Greater Celandine

An alien that spreads.  Will tolerate sun, but not deep shade.

Can be distinguished form the native celandine-poppy (Stylophorum diphyllum) by a paler and narrower yellow pedal.  Leaves are shallower in lobbing.  Seed pods are cigar shaped.