After giving my container a bit of water, I couldn't help but poke around in the soil. Sure enough, I saw one of the seeds has sprouted! I think it was one of the ones from the first batch, which I had all but written off as lost; but I suppose it is also possible that one of the seeds I planted two days ago already sprouted. That means that either P. incarnata is much more tolerant of radical temperature changes than I anticipated, or that the seeds can sprout very quickly under optimal temperature (75 F/24 C). I suspect the latter is the case, so I would keep a close eye on your first batch of seeds Triloba Tracker!
I will keep you guys posted as other seeds come up and try to have a success ratio within the next week. Otherwise, I'm chalking this one up as a success. Those of you who were interested in these seeds, I'll reach out to you again and arrange sending a few out to you.