It is seeds and is more like a bush. Very easy to start. Plant in the ground or in a large pot. Freeze will kill them but it will give you many seeds to start again.
I have many Angel's Trumpets and a few Datura (sometimes called Devils Trumpet) The Angels face down, the Datura (while a similar flower) faces up. In Florida they die back every winter and come up again from the same plant and produce seed pods too. These are beautiful plants and can get very tall. The only caution would be if you have small children or animals that are prone to messing about in your flower beds, you will have to be careful as the sap can be harmful to them.