Lesser celandine (Ranunculus ficaria)

 

Collins, 72; Readers Digest, 26

This is an extremely pretty low growing perennial with fleshy dark green leaves which inhabits shady areas.  The flowers are out between March and May and are bright yellow with eight to twelve petals.  The plant enjoys woods especially those with bare dank ground.  It is one of the earliest flowers to bloom under the woodland canopy and it is even mentioned by William Wordsworth:

There is a flower, the Lesser Celandine

   That shrinks, like many more, from cold and rain "

Sometimes the dark green leaves bear light and dark markings like a puzzle.

 

 

See also: http://www.botanical.com/botanical/mgmh/c/celles44.html