Looking for good biomass producing plants that work well in the SE

I'm in the Atlanta area and am looking for perrenial plants that will grow very fast and can be chopped down (partially) for mulch. I'm hoping to find something woody/shrubby that gets a little large (10' to 20') so I can harvest a lot of biomass from it continuously. I have some areas that get 8 hours of direct sun, and a lot of other areas that are either full shade, or partial shade.

I've done some searching on this but can't find anything specific to my area and a lot of what I find is geared to more northern areas. I also find a lot of suggestions for smaller non-woody plants likee Comfrey and other low cover grops, which I do intend to use, but I'm hoping to find more woody perrenials to add even more biomass to my soil.

Thanks in advance!

Vetiver grass?

Forms clumps/hedges that make good natural terraces. You can cut the clumps regularly with something like a hedge trimmer and let the grass lie as a mulch. Really deep rooted and once established can tolerate drought and flood. Vetiver can serve a similar purpose to swales - slowing and holding back surface water to increase infiltration.

Thanks for the reply. I looked it up and it looks like it would be a good option though apparently it is only suited to zone 9-11 and I'm in 7b.

Willow? It has been used for a long time in England as a biomass plant. The real vigorous growth doesn't come until the second and third years, so it is often on a 3-5 year coppice cycle. There is even a Willow Biomass Project at this link if you want more info. It does particularly well in wet spots in our thick Georgia clay.

Willow tree.... interesting. I never would have thought of that. My yard does stay pretty damp in a few places so maybe a willow would work nicely. Thanks for the tip!