In my area, Mullein seems to favor dry waste areas...not sure if wetland creeks will be a successful hunt. HOWEVER, you should also keep a lookout for Swamp Rose Mallow--also hugely useful, and a lover of wet places! https://altnature.com/gallery/mallows.htm
Have you ever checked out Rosemary Gladstar's Medicinal Herbs for Beginners? It has been a great introduction for me on some useful (and safe!) medicinal herbs, and its still one of my favorites. ( http://amzn.to/2xPiBXK )
Thanks for the book recommendation!! Definitely going to check with my library for this one.
Just got the book from my library- they actually had one on the shelves. Super excited to check it out later today
Nice! I do enjoy it, for the most part. It's very accessible--though Gladstar definitely sometimes wends far too "magical" for my tastes, she keeps it in check for her beginner's guide. It's the only book of hers I would wholeheartedly recommend. But it is the first book I reach for when it comes to learning herbal medicine! I just made my first tinctures this week...it's exciting!