Moonflowers are nocturnal bloomers. After sunset, these huge white flowers bloom and glow all night in the moonlight. As the sun rises, they close their heavily fragrant blooms.The flowers unfold very quickly and that in itself is an event worth waiting for.
Mandrake Root with Plant and Flowers. Grow this one indoors, it is so valuable it is frequently stolen by plant thieves. Never use up the whole plant, use only what you need and the root will grow back.
Helleborus, which can cause tinnitus, vertigo, stupor, thirst, a feeling of suffocation, swelling of the tongue and throat, emesis (vomiting), and catharsis, bradycardia (slowing of the heart rate), and finally collapse and death from cardiac arrest. Pretty though.