She Who Must Be Obeyed has seen a plant that she wants us to grow - its called moon flower or queen of the night and is a climber with thick leaves similar to cereus and the flower starts off in a pipe shape before opening up. The flower only lasts one night.
Any ideas of the latin name(I know - more plants called moon flower)
I believe Ipomea alba (Calonyction aculeatum) is the scientific name for Moonvine...the plant with large white and very fragrant flowers that only blooms in the evening. The vine has heart shaped leaves and is easy to grow. Another wonderful tropical plant with a deliciously scented flower that blooms only at night is Brunfelsia americana or Lady of the Night. It grows like a small bush (to 5') with heavenly fragrant white flowers that later turn to pale yellow. Both would be perfect for your Moon Garden.