The pale, slender enoki of the supermarket is the cultivated form of Flammulina filiformis, grown in the dark and in high CO2 to produce those long white needles. Wild, the same fungus (the velvet shank) is a stocky orange-brown cap that fruits in winter — one of the few cold-weather mushrooms. Cultivated enoki is mild and pleasantly crunchy, used at the very end of cooking so it keeps its bite in ramen, hot pot, and stir-fries. Note: enoki should be cooked, and several listeria recalls have underscored that raw or improperly stored enoki carries real food-safety risk.
Mild, faintly fruity, with a clean snappy crunch.
Cultivated year-round; the wild velvet-shank form fruits in winter.
Identification is a chain of clues that must all agree. This is a reference, not an identification authority -- confirm every wild find with an expert.
Relevant only to the WILD velvet-shank form: Galerina has a RUSTY-brown spore print and a stem ring; velvet shank has white spores and no ring. Cultivated enoki has no look-alike risk.
Cultivated form is unmistakable bundles of long white needles. The wild velvet shank has a sticky orange cap, dark velvety stem base, and winter fruiting — but beware the deadly Galerina marginata, which also fruits on wood.
Always cook thoroughly before eating, and try only a small test portion of any species new to you.