It's a type of bamboo but I couldn't tell you the variety. They can be horribly invasive, so keep an eye on it and don't let it get out of hand!

Probably phyllostachys aurea by the look of it, clump-forming, and well-behaved unless conditions are consistently wet and warm when it will take off to 14ft and think about sending out rhizomes and spreading. It is not one of the worst, I promise. That title belongs with pseudosasa japonica which has much bigger leaves and a much bigger appetite for the ground around it.

Thanks to you both.

I think this is the variety of Bamboo that I have,and it has been in the same large pot for years now..the label got lost along the way... clump forming ,which as Worthy says,is the best type..it prefers partial shade,not full sun..and keep well watered..you will soon know if it dries out,as the leaves curl up..