The structure isn't actually a single botanical flower. Instead it is a contains hundreds of relatively tiny and nondescript flowers along the base of the large spire, hidden inside the prominent shroud-like bract. The greenhouse staff cut a small window through the bract, so that visitors could see the inner structure (as well as get a very close sniff, for the brave).
The university staff had named the plant "Chauncy" and had posted some paper for people write their descriptions of the flower's scent. One description that caught my eye and well fit my experience of the flower's scent was, "A dead racoon 3 days old". The scent wasn't over-powering by the time I visited, but it did linger in my nose for about half an hour after I left the greenhouse.
In a neighboring pot to "Chauncy" was another specimen of A. titanum that isn't blooming this year. This plant was about 12 feet tall and appeared as a small tree with a few branches and luxuriant leaves. I use the word "appeared" because the entire above-ground structure of this plant is botanically a single leaf. It is somewhat like the leaf of a tomato plant, with stem-like structures, branches, and leaflets. Only in this case, the single leaf grows to tower overhead. After some time, the leaf will die and fall, only to be replaced by a new and larger leaf (if the plant is happily growing). The persistent body of the plant is a large tuber, securely hidden underground.