I'm trying to find the name of (and hence how to care for) a minature bamboo purchased last spring by my wife at a nearby garden centre. The label only says its a bamboo and the cultural advice in the form of diagrams suggests full sun to part shade, moderate water and a temperature of 20C. The watering aspect is somewhat contradicted by a diagram saying the pot should stand in a saucer filled with a minimum of 1cm and maximum of 3cm of water.

The plant flourished throughout the summer in this waterlogged state, the foliage being about 20cm high and a few flowers were produced.

However, throughout autumn the foliage has yellowed and is now apparently dead as are the culms. Is it a deciduous species, or annual, or simply been killed by my not adjusting the culture for autumn and winter?