Since the flowers were white, it's possible that it's a different datura. Jimson weed flowers don't open all the way. Other datura flowers do open all the way (at night), and smell lovely. They're all poisonous, if you didn't read that already.

That mystery plant is Mullein! http://kswildflower.org/flower_details.php?flowerID=46 http://www.altnature.com/gallery/mullien.htm Grows all over the rolling hills, they make are real neat ground cover the first year, soft leaves covering the ground. Flowers smell sweet and delicate. I would suggest cutting the seed head off when it starts to brown out and die, transfer to a location where you would not mind lots of these growing and they will self seed where you place or plant seed. It is a wonderful lung herb and also works well in a pinch as an emergency toilet paper! .... so I've been told.......

Thanks! I goolged it and it looks like ti will keep evil spirits away, can be use for congestion and has a narcotic effect. "Properties Great Mullein has been used as an alternative medicine for centuries, and in many countries throughout the world, the value of Great Mullein as a proven medicinal herb is now backed by scientific evidence. Some valuable constituents contained in Mullein are Coumarin and Hesperidin, they exhibit many healing abilities. Research indicates some of the uses as analgesic, antihistaminic, anti-inflammatory, anticancer, antioxidant, antiviral, bacteristat, cardio-depressant, estrogenic, fungicide, hypnotic, sedative and pesticide are valid." http://www.altnature.com/gallery/mullien.htm

Probably Aspidistra, cast iron plant. http://www.clemson.edu/extension/hgic/graphics/1717/aspidistra_1050_bhs_16.jpg