Originally Posted by echinosum

Seems to be Fargesia nitida, like everyone else's.

It will probably die. So what's best - well what do you want? Quickest way to get a new mature plant is to buy a new one. Post-flowering F nitida is readily available, and make sure it is that you buy. Else there are lots of other lovely Fargesias.

Otherwise, you can collect the seed (has to be well-timed, it will fall off when ready, and the birds love it, so you probably need to wrap some heads after they are pollinated) and grow it. But that is slow, and what grows back is a bit random in terms of form. You may get some adventitious seedlings anyway. They do sometimes appear to survive, reverting to juvenile form, but this may be misinterpretation of adventitious seedlings.