Found this lovely little thing blooming while hiking a local trail. Looks like a species of Corydalis to me, but I can't figure out which.

We have it blooming here too - whatever it is.

Which leaves go with the flowers?

Try using this key:
http://www.efloras.org/florata...

Agree with Leftwood..Corydalis sp.

Daisy, the gray-blue tinged, finey disected leaves go with the plant in question.

Thanks Rick!

I'm thinking it is probably this one:

Good to know.

In some photos I'm finding on line the foliage looks to be a match, but in others the leaves look more rounded at the tips. So I'm still unsure?

As you already know, Neal, variation is common in species, especially in the wild, and especially with species with such a large natural distribution range, like C. aurea. I grew a Corydalis species that I eventually identified as C. aurea, but it took a long time for me to be satisfied. From a friend who grew it for more than a decade, it seed around for her, but not for me, hardly, and I lost them in about 5 years. Anyway, I finally had to go back to my friend's to look at hers rather than just mine.


You may need to wait to see a more strongly delineating characteristic to get your answer.
From Bleeding Hearts, Corydalis, and their relatives by Tebbitt, Lidén and Zetterlund.

Another Kentucky native, Corydalis micrantha: http://www.kywildflowers.org/e...

edited to add: I don't know a thing about Corydalis, that's just one I came across when googling that reminded me of your plant. :)

edited again to add the gardne.org database link: Slender Fumeroot (Corydalis micrantha)

Excellent points Rick! Thanks

Lin, those photos also look like a match! I believe Rick is correct that other charactaristics need to be examined besides just leaves and blooms. Being I only have the 1 photo, I believe this one may remain a bit of a mystery.

Corydalis lutea?

I just took a look at the plants growing here and that is a good mach for them too. Thanks, Lin.