I've blogged about this amazing Sanseveria before, but I just found the pics which show the flowers in full bloom in the evening. They fade during the day, and a new ring of flowers opens up the next evening above the faded ring from the night before. The huge inflorescence is about a foot wide. These pics were taken a few years ago when I summered the plant outside, but for at least two years since I've left it in my classroom through the summer, since it is so now big that it is difficult to fit in in my car to drag it home. The one disadvantage of this is that I am not there when the flowers look their best, by the time I come in to check on the summer residents and my school gardens, the flowers are past their prime.
Its an enormous species with impressive foliage and massive rhizomes, even it its huge pot it is pushing on one side, so I will have to find something new to put it in this coming year--a bushel basket, perhaps?!
My source said he thought he collected the plant in Kenya many years ago, and he has it growing in the ground in his greenhouse for a long time. Sanseverias are great collector plants, they live forever, are hard to kill, very accomodating of less than perfect conditions (except cold and overwatering in combination, especially), and easy to prop (leaf sections). No one ever seems to admire their fragrant white flowers, but in this species they are a star attraction, easily rivaling any other flowering plant for bold effect and interest.