I had never seen these ‘bootstraps’ or ‘bootlaces’ until my friend Mark pointed them out to me on a recent fungi foray. They are what remains of an infestation of Honey fungus (Armillaria mellea) which may sound sweet but, believe me, is anything but. Honey actually refers to its colour, not its habits, as this fungus is a parasite and a killer.

It lives on live wood and sends forth these extensive rhizomorphs, root-like filaments, between the affected tree’s inner core and its bark. When fresh, the bootstraps are a cream colour but they blacken over time. They cause the tree to rot and die so by the time the Honey fungus mushroom-like fruiting bodies emerge through holes in the bark, the tree is a goner.

This fungus will attack almost any type of tree from conifer to broad-leaf, softwood and hardwood. It can cause enormous damage to forests and woodlands because those rhizomorphs have been recorded up to nine metres long and they can extend through soil from one tree to the next, invading and killing as they spread.