某些伞菌类子实体菌柄上由内菌幕的残留部分形成的膜质环状结构。子实体形成的幼期，在菌盖与菌柄之间有膜相连，此膜即内菌幕。当菌柄开始伸长，菌盖逐渐张开时，内菌幕即被拉破，残留在菌柄上的内菌幕形成菌环。菌环多呈膜质，少数呈蛛网状，如丝膜菌，多单层，少数为双层，如
双环林地菇等；有的菌环生于菌柄上部，有的生于菌柄中部或下部，有的菌环可在菌柄上上下移动，如高环柄菇。常见具菌环的种类如蘑菇属、环锈伞属、环柄菇属、蜜环菌等。
Someagaricfruiting stipe class by the residual part of the screen within the bacteria formed membranaceous ring. Fruiting body formation of young period, between the membrane cap and the stipeconnectedscreen in this film that the bacteria inside the . elongation started when the stipe, cap gradually opened, the curtain that is pulled inside the bacteria break, left in the stipe on the formation of bacteria within the fungus-screen ring. bacterium Duocheng membranaceous ring, a few showed cobweb-like, such assilkfilm bacteria, multi-single-layer, a small number of two-layer, such as the double loop woodland mushroom, etc.; some bacteria, Central, was born in the upper part of stipe, and some born in the middle or lower part of stipe, and some bacteria on the ring can be moved up and down the stipe, such as high-ring mushroom stem. common with the types of bacteria, such as mushrooms is a ring, ring rust umbrella genus Lepiota mushroom genus, Armillaria bacteria.