I believe that the link below is for a plant that will survive your conditions. Note that the plant will die down once flowering is done but will regrow from creeping rootstocks. I have some planted in a pile of soil, concrete pieces, and branches that I dumped on top of a driveway. You would not know it. Can provide photo if you wish to see. Let me know.
From what I have seen of understory in pine forests or under pine trees (in California) , it tends to be rather sparse or just pine needles.
You may need to provide some water when the new growths begin to emerge but it depends on your weather. You can tell if it wilts back that it needs it.

Here is a link that might be useful: Ceratostigma plumbaginoides