Known as Toloache by the Aztecs (and probably used by most Mesoamerican cultures before them), this beautiful representative of the Datura genus just recently began opening its flowers in my garden. It blooms in the evening, pollinated by night-flying moths, with huge (8"+) flowers and a sweet aroma that sets it apart from its cousin, the Jimson weed (D. stramonium).
Many members of the Solanaceae (Nightshade family, perhaps my favorite plant family though the Araliae are right up there) possess alkaloids like scopolamine and hyoscyamine which have the ability to limit the action of the parasympathetic nervous system (they are so-called parasympatholytics). This yin-like side of our nerve networks promotes rest, digestion, and reproduction, and actively counterbalances the more yang-like sympathetics continuously.