Japenese "suge"... have seen it spelled about anyway you can imagine and a bunch I cannot! Carefully singe the wood until quite black. A hot fire with minimal flame and quite a bit of smoke will make it easier.
Like some kids with marshmallows that get them perfectly golden brown... The idea then is to polish the wood to take the less cooked long-grain back to a lighter color and the deeper black on the more end-grain sections stays dark.
It takes some practice to get it right, but that is the traditional way. Some poplars do very wierd things with commercial stains, so if you take the easy way out and go with stain do a test piece before hand or it might come out butt-ugly green...
If you decide to stain, I prefer oil-based stains, thinned a lot with the proper thinner (usually mineral spirits) and done in thin layers until it is exactly what you want...
art
