Mycena is a genus of about 500 species of fungi.

Rarely more than a few centimeters in width, the mushrooms are characterized by a small conical or bell-shaped cap and a thin fragile stem. Most are grey or brown, but a few species have brighter colours. Most have a translucent and striate cap, which rarely has an incurved margin. The gills are attached and usually have cystidia. Some species, like M. haematopus, exude a latex when the stem is broken, and many species have a chlorine or radish-like odour. They produce a white spore print.

The species are saprotrophic. Their edibility varies, with some members containing toxins.

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