Mushroom Lingo #3: Partial Veil

“Partial veil” is a rather mysterious, almost existential, name for a thin covering of the gills or pores on the underside of a mushroom’s cap. You are actually much more familiar with partial veils than you realize, because Agaricus bisporus, the supermarket button mushroom features one.

As the mushroom gets older, the partial veil disintegrates leaving a more or less pronounced ring.

A partial veil should be distinguished from a universal veil, which covers the entire mushroom, although a mushroom can have both a universal veil and a partial veil. For example, Amanita bisporigera, the deadly poisonous “Destroying Angel,” has both, so learning these features could save your life! (if you’re the type to casually snack on unidentified mushrooms)

In general, mushrooms with either a partial veil or universal veil are pretty suspect in terms of edibility (with the major exception of your supermarket button mushroom) because they tend to belong to the genera Agaricus and Amanita many of which are poisonous.