Sweet woodruff (Galium odoratum) is a commonplace herbaceous plant that's known for its fragrant flowers and foliage, but this is almost certainly the...
Maiwein uses wine and is much less commercially available. At 20% abv. and no mention of wine, it is certainly more similar to Waldmeisterlikör. Based on my experiences with many provincial French distilleries, that the inspiration to make it came from an entry in a creative contest that they hosted, (and Simon's statement above), I believe there is a very good chance that they were not even aware of Waldmeisterlikör. It would be most interesting to do a comparative tasting.