Palmer pigweed (Amaranthus palmeri) is not a weed to trifle with. It can reach more than 2.5 metres tall, grow more than 6 centimetres a day, produce 600,000 seeds and has a tough, woody stem that can wreck farm equipment that tries to uproot it.
It is also becoming more and more resistant to the popular herbicide glyphosate. The first such resistant population was confirmed in 2005 in a cotton field in Georgia, and the plant now plagues farmers in at least 23 US states. It is just one of many resistant weeds marching through the world.
Read more of the ‘Nature’ news story here