Polyporus umbellatus (Umbrella Polypore, Zhu Ling)
The umbrella polypore thrives in warm deciduous forests on the stumps and roots of oak and birch trees. This rare but esteemed edible mushroom forms dense bundles of dozens to hundreds of tall, narrow caps. These bundles can grow to sizes of up to 50cm across and weigh several kilos. The light brown and rounded appearance of these bundles at the foot of oak trees has earned the polypore the nickname "oak rabbit" (Eichhase) in German, because at first glance one might mistake it for a wild rabbit.
The individual caps grow from a shared stump that emerges from the mushroom's blackish-brown sclerotium, which is a type of hardened mycelium that grows underground or inside a tree trunk and which can survive harsh temperatures in winter. The polypore can allegedly live for up to 30 years. While the fruiting body is typically used in cooking, the sclerotium is more often used in medicine.