My neighbor has one of these he started from seed - he was told that someone from India passed along the seeds, but we can not find any info on this plant, but it is gorgeous. Its growing in central Florida.
It might not be hardy in MD z7a but I've grown it for many years in NC z7b. Maybe if you planted it close to your house on the south side you might be able to get a sufficiently warm micro-climate with some winter protection?
These grow like weeds and re just about as invasive. I have to mow some of them or they would take over my back yard. Needless to say, they grow great in zone 9A and they love the sun. Even 100 degree days don't bother it.