This plant is fairly rare. One of the common names is Tree Lily. Its flower form is somewhat similar to Brugmansia and it shares the trait of night time fragrance. It is also known as Portlandia domingensis. It is not in the Brugmansia family, but is in the Gardenia family. Under the right conditions it will grow to about 5 feet in a pot (more in the ground), though it can start blooming at ~ 2 feet. It can happily live in pots and as an indoor plant where it can handle lower light. Blooms off and on from Spring - Fall.
Two companies where it is sometimes available: Logees (available as of this writing) (
http://www.logees.com) and Gardinos (
http://www.rareflora.com).