Weed or Wildflower?

Soon after digging up the "lawn", seedlings of what was later identified as greater celandine started to sprout up. The leaves were an interesting shape and colour, and the plants filled in the bare spots. When the yellow flowers appeared, adding some colour contrast to the already delicately textured foliage, these plants became much welcomed additions to the landscape. I was delighted that "wildflowers" had established themselves in my garden so quickly.

It soon became apparent, however, that greater celandine was very good at self-propagating. Seedlings began appearing in huge numbers all through the yard and the four-letter "w"-word ("weed") began coming to mind. Luckily, they're not too difficult to pull. I started dead-heading the plants. Not only did this reduce the number of seeds which were given the chance to sprout, as with other seed-producing plants, it encouraged further flowering -- a total bonus! Last summer, there were flowers well into September.
Several years after establishing themselves, there are now a few plants which have reliably appeared in the same spots each year.

The one thing to watch out for when dead-heading (or pulling) this plant is the bright orange sap that oozes from the stems. It is apparently toxic and an irritant.