Is chusquea gigantia truly clumping?

I have a screening emergency as a house being built just over my back fence has added a 2nd storey which entirely overlooks my garden and bedroom windows. I have large cedar arbours and smargd cedars along the fence which will help once they're at full height, but there's a space I need to fill with something that will grow tall quickly. I went to the local Sunshine Coast nurseries and discussed my options and eventually came away with a chusquea gigantea as the nursery person said it was a clumper and my quick google on my phone seemed to indicate it would do what I wanted. However, I've spent more time researching extensively today before I put the plant in the ground as I do not want problems with spread. (Clumpers I already have in another location, one of the fargesias have stayed very tight over 5 years, but also didn't get much height). But as I read through various sites on bamboos, most say chusquea gigantia is a lovely plant, easy to control, but a few others have said it runs and can be a real problem. Now I'm scared to commit. Does anyone on this site have experience with the variety?

 

My resources suggest it stays in a tight clump. However, I wonder if there is some question about proper identification--it seems like this has been somewhat confused taxonomically, so maybe therein lies the problem with other people's accounts.

What are the chances that the nursery knows where some of its plants have been sold and you can go have a look? Shouldn't be a problem if any of them have been planted commercially...

 

Thanks for your response. I think it used to be called something else and in France in 1999 or thereabouts, the current name was fixed. I'll phone the nursery tomorrow and see if I can find out more about the variety and perhaps other purchasers. In the meantime, I've bought a big pot as an interim measure though almost all sources say the roots grow so fast, they don't last long in a pot. But I'll get a chance to see how it behaves. The space I've got for it is quite small, about 8' horizontally and 4' from the fence to the front of the bed. I can't seem to find out if the root structure grows and spreads infinitely even though slowly, or has a maximum spread built in to its genetics. If I knew that it had a reasonable limit, I could lift some grass and widen the bed if necessary. I'm quite keen on having a stand of tall bamboo (apart from the need to screen) as it would be a nice variation in the texture and colour of the cedars which line the rest of the fence line.