Some plants do not fit within the layer system of a wood
If you look around you may spot plants that are growing through multiple layers. The most obvious one in this woodland is ivy but you might also spot honeysuckle , bryony and wild clematis if you look carefully enough.
Ivy is a climbing plant. In a woodland it will grow across the ground as well as climb up trunks and branches of trees, spreading through the layers all the way to the canopy.
In areas of temperate rainforest where rainfall is high, such as the Wye Valley, you can also find epiphytes - plants that grow without soil (usually on other plants). This area is known as Celtic Rainforest (look it up, it's a thing!).
In temperate areas these include plants such as ferns growing on top of tree branches, or mosses and lichens growing on the bark.