Speaking of trilliums, as a rule they do not do well here in our excessivly humid climate with this one exception. A few years ago our MG group was invited to visit a private sea island where trilliums abound in one specific area. It is thought that the site was an old shell midden, where the Native Americans deposited their oyster and clam shells over hundreds of years. The soil is quite alkaline and sandy.
No one knows how the trilliums got there as they are certainly not native to the coast.