Hi - I'm In Preston, Lancashire and it looks as though my black bamboo is starting to flower as well - http://i71.photobucket.com/albums/i1...oo/bamboo3.jpg
It's only a small clump at the moment and I have had it less than 2 years.

From what I have read on the 'net, the plant self pollenates, the seeds need to be fully ripe to give them the best chance of germinating, and they are ripe when ready to drop (shake them onto a tarpaulin)

As bamboos are mainly propagated by division, and only flower after many years (decades) there will be many clones of the same original stock out there. It seems they all carry the same biological clock and all flower at the same time.

As for saving the original plant, there seems to be two theories, neither of them are by any means certain of sucsess.
1 - feed very heavily during and after flowering with high nitrogen fertiliser - OR
2 - remove the flowering culms, dig up the rhizomes and chop into small sections and replant.

Some bamboos have resisted all attempts to rejuvinate the original plant after flowering, some will slowly recover on their own.

I think I am going to try method 1 because it's only a small plant anyway, and I want to try and catch as much seed as possible. So I've already started feeding with lawn food. We will have to see what happens.