t s scientific name refers to the mushroom's totally smooth cap. However, those tempted to try eating Lepista nuda had better be sure that they haven't got the poisonous Australian mushroom, Cortinanus archeri, in the pan.
Both mushrooms begin with a fairly swollen base and convex cap and both have solid pale lilac tinged flesh.
Being a Cortinarius, archeri's cap is initially attached to the stem via a web known as a cortina. However, as shown in this photo of a young Cortinarius archeri, the web can easily be mistaken for a ring.