Is this a corydalis?

[Claire Cockcroft]

This plant appeared but wasn't from any seed I thought I'd planted.  The only corydalis that might be similar is C. saxicola.  Any ideas who this mystery plant is?

[MarcR]

Claire,

It certainly looks like one. If not, it is a flawless imitation.

[Véronique Macrelle]

I also have a new corydalis that has appeared in my garden that looks very similar to this one.
i have tried many species from the seeds in the exchange and i recycle the soil from my ungerminated pots.
 would it be Corydalis ophiocarpa?

[Carolyn]

Ophiocarpa was the one I thought of too - although in the garden it tends to make a more compact plant than the one in Claire’s photo.
Claire, was this growing in a very shady spot/or competing with lots of taller plants?

[Claire Cockcroft]

It is in an unheated greenhouse, stuffed in a corner against a south-facing wall.  The plant is quite robust -- so much so, I was tempted to pull it up last year when there were no flowers.  I am happy I didn't!

...Claire

[Carolyn]

I wonder if the heat in the greenhouse has stretched the plant out a bit?

If it is ophiocarpa, it’s a super plant to have in the garden. It will seed about, but is very easy to pull out. I have it filling spaces which were occupied by early spring bulbs. Come August, I rip most of it out, so that we can see our cyclamen hederifolium flowers.

[Véronique Macrelle]

if it is C. ophiocarpa, I have noticed that its stems are winged.