Auricularia auricula-judae, oreille de Judas is the wood ear, jelly ear or Judas’s ear in English; in French another name for it is oreille du diable. It grows mostly on dead trees, especially elders (according to legend, the tree Judas used to hang himself).
They are the kind of dried mushrooms you can buy in big bags in Asian shops to using in your Chinese recipes.
Image by Dominicus Johannes Bergsma