I just did a quick google search and it looks like Canning Perennials may have it. They look to have a lot of neat stuff, I think they were located in Ontario, but their plants are offered mail order. Good luck!

Here is a link that might be useful: Canning Perennials

Well, I finally got the Spigelia marilandica. It was in the Dominion Seed catalogue late last year. I bought 3 plants via mail order. They were very small (less than 6" tall) but healthy.

I plunked 2 into the ground and left 1 in the pot, exposed to the elements in our zone 8 environment. The one in the pot didn't survive the -10 c winter. But the two little ones in the ground survived, grew to nearly twice the size this year and actually flowered in late summer and fall. I didn't know that they would flower while the plant was so small. Couldn't see any seeds though.

Can't wait to see what the plants look like next year.