The one thing about corydalis is that the mother plant may be gone but if allowed to reseed it will pop up somewhere.
The seeds will find, sometimes a very odd spot, to germinate. So if it was allowed to seed you may see it next year. Just look for the feathery foliage. Blue panda is hard to keep alive same as for raspberry wine. Yellow is the hardiest in my zone.

karen, do add your zone to your moniker!

i'm z. 5 and corydalis lutea is my most heavy duty thug, as far as seeding itself EVERYWHERE. But I am not complaining, for what a joyous thing it is; longest blooming plant in our new england gardens. Like hostared before me, i bet it will pop up in lots of places next yr. I do not know why it would have croaked. Lamium doesn't kill it here, to my knowledge. I bet someone more knowledgeable than I -might say that it occasionally goes summer dormant, like bleeding heart or columbine, but returns the following spring.That's my guess, if a whole area disappeared.
Let's wait for the experts to weigh in.
best,
mindy

Corydalis lutea is a short lived perennial, but reeseeds itself, so that you would not ordinarily notice that the same plants are not returning each year.
Occasionally, there will be years when there are no plants, but in following years, seedlings will begin to emerge, often in most unlikely places!
This species does not tolerate high humidity and high temperatures during the summer months or wet soils during winter, which may account for it's absence during some years.
You might also like another yellow-flowering species, Corydalis cheilanthifolia, that produces a spike of yellow flowers in spring. Needs full sun, partial shade for best results. It, like C. lutea, is a reseeder and will form huge colonies, with proper growing conditions. It has fern-like foliage, that can be an interesting addition to a mixed planting area, even when not in bloom. In my area, planted in full sun, they go dormant during the summer,

Another one that has survived for many years in my garden, is Corydalis solida (bulbosa). A bulbous species with violet/purple flowers, that emerges in spring, flowers and then goes dormant until next spring.

Be patient with the C. lutea. It will likely pop up again next year! That has been my experience.

hello again..It did not come back this year yet:(
I hope to see it again sometime

I have killed at least a dozen of the blue corydalis but I was told at a plant sale last year that C. elata which is electric blue was really easy to grow. It lived and is in full bloom now and is wondrously fragrant. I'm in love.

IF you've killed the other blues, try it. It grows somewhat taller and mine did flop but the flowers and fragrance are worth the untidy habit. It doesn't go summer dormant either.

I had cordyalis lutea at the edge of a fir tree. It did not self seed in that area, maybe too dry. I added another near my deck last year and was surprised to see seedlings popping up under the deck this spring.