Rings / Skirts

Rings, skirts, and similar ornamentation on the stem are commonly found. These features are often diagnostic, and shared amongst all species of a certain genus. In some cases, you can identify a mushroom to the genus by simply looking at the ring.

Rings, skirts, and the like are the remnants of a protective membrane from the button stage called an annulus, or partial veil. When young, the gills were protected by this membrane which connected to the edge of the cap on one end, and the stem on another. As the mushroom matures and the cap expands, this membrane tears and leaves remnants on the stem and sometimes on the cap edge.

The manner in which the partial veil connects the cap to the stem, and the method in which it tears, will determine the appearance of the ring. In some cases, the partial veil disintegrates, so is only evident in immature mushrooms. And of course, not all mushrooms have a partial veil.

Rings

A ring is the result of the partial veil being connected midway on the stem, and the veil being fairly short or mostly lost when it tears. There may or may not be evidence of the veil on the cap edge.

A good example of mushrooms with a ring is the genus Lepiota (Parasol mushrooms). This genus often has a ring that is loose and can be slid up and down the stem without damage. The photo to the right is of a closely related species, Chlorophyllum molybdites (Green gilled parasol).

Skirts

Similar to a ring, a skirt is a larger partial veil that remains mostly intact after tearing, with an attatchment point that is often at the stem-cap interface.

Skirts are most often associated with the genus Amanita, but Agaricus and several other genera also can have them. The photo to the right is of Amanita phalloides, the death angel.

It is important to know that the genus Amanita does include some members that are skirtless, such as the grisettes.

Cortina

A cortina is a unique form of partial veil that is often described as "cobwebby". When young, the cortina protects the gills in much the same way as the solid membrane does. It is often far less visible as the mushroom matures, and obvious cortinas in mature specimens such as the one featured here are uncommon.

The only family in which cortinas occur is Cortinariaceae, and only the genus Cortinarius expresses this feature prominently. If you find a mushroom with a cortina, you know exactly where to look in your field guide!