Ikea is planning to use packaging made with mushrooms as an eco-friendly replacement for polystyrene. The American company Ecovative developed the product, which it calls Mushroom Packaging, by letting the mycelium grow around clean agricultural waste, such as corn stalks or husks. Over a few days, the fungus fibres bind the waste together, forming a solid shape, which is then dried to stop it growing any further. Mycelium is the part of a fungus that effectively acts as its roots. It grows in a mass of branched fibres, attaching itself to the soil or whatever surface it is growing on.