It comes under several tradenames, but I suspect the best-known is "Roundup". It will systemically kill the whole plant of whatever leaves you spray or paint. It becomes inactive on contact with the soil. As long as you don't get "drift" on a breezy day, other plants won't be affected. I am using it currently to clear ground, though, as you suggested, because we have a really bad infestation of bindweed, and it's difficult to extricate the roots without snapping them off below the surface. I have dug all my precious perennials out and moved them for the season, will let the weeds grow merrily, and then I shall zap them a few times to make sure I have killed every last bit before re-planting. A bit of a nasty job, but it shouldn't have to be done again for a very long time.

One can also paint it on leaves so it will not harm nearby plants. and if you do get some spray on a leaf, then you merely remove that leaf as soon as possible. It does take a while to translocate down the plant to the roots.

You can buy a generic glyphosate though - stores like Wilkinsons usually have their own version. This is better for the environment than Round Up, which contains other surfactants and ingredients which cause problems (Round Up used to have the words 'biodegradable' as a banner on its products - they have been legally obliged to remove that word, because it's not true. They also made claims that it was 'harmless and inactive' once it hit the soil - also not true). The combination of ingredients in Round Up appears to be the problem - glyphosate was sold for some years under the name Tumbleweed, not sure if its still available, but that doesn't contain all the other ingredients in Round Up either.
Glyphosate works 'through the green', in other words, it needs to be applied directly to the leaves and stems of an actively growing plant to work.

I didn,t know that Bamboo, thanks for the info