I just learned about The Native Plant Network
including the Native Plant Journal
The Journal has some good articles. Iin my quick scan of the issue with the Trillium grandiflorum on the cover I found the articles on Trillium propagation were by two people I know, Bill Cullina and Stephanie Solt. The Articles are available electronically(for 2006 and earlier only) so I expect to finad a lot of good reading!
Native plant propagation Database
The protocols are based on large scale harvesting and cleaning but I expect to find a lot of useable information here as well.
Rhododendron (Rhododendron maximum)
15 hours ago