The term is likely derived from the Greek λεπις, "scale". The basionym is Agaricus sect. Lepiota Pers. 1797, devalidated by later starting date, so the citation is (Pers.) per S.F.Gray. It was only described, without species, and covered an earlier mentioned, but unnamed group of ringed, non-volvate species, regardless of spore color. The Swedish mycologist Elias Magnus Fries restricted the genus to white-spored species, and made into a tribe, which was, like Amanita, repeatedly raised to genus rank.
The type species is unclear. L. procera is considered the type by Earle in 1909. Agaricus columbrinus (L. clypeolaria) was also suggested (by Singer, 1946) to avoid the many combination involved otherwise in splitting Macrolepiota, which include L. procera. Since both species had been placed into different genera prior to their selection (in Leucocoprinus and Mastocephalus respectively), Donk observes that a conservation will probably be needed, expressing support for Singer's emendation.
With respect to mushrooming, this is a genus to be avoided as several species contain amanitins and are highly toxic. Those known to have caused death (or would have caused death except for intensive medical therapy) include L. josserandi in upstate New York in 1986, , L. brunneoincarnata in Spain, and L. helveola.
Previously, the most familiar species were the larger species, such as the parasol mushroom and the shaggy parasol. However, these have now been placed in the different genera Macrolepiota and Chlorophyllum. However the status of the genera is not unanimous as some current books still leave the members of Macrolepiota in Lepiota.