''Inocybe rimosa'' (formerly known as ''Inocybe fastigiata''), commonly known as straw-colored fiber head, is a poisonous mushroom native to Europe. Its toxic ingredient is

muscarine Muscarine, L-(+)-muscarine, or muscarin is a Secondary metabolite, natural product found in certain mushrooms, particularly in ''Inocybe'' and ''Clitocybe'' species, such as the deadly ''Clitocybe dealbata, C. dealbata''. Mushrooms in the g ...

, discovered during the 1930s. Serious poisoning can result from consuming any quantity of the mushroom. German naturalist

Jacob Christian Schäffer Jacob Christian Schäffer, alternatively Jakob, (31 May 1718 – 5 January 1790) was a German Dean (Christianity), dean, professor of theology, botanist, mycology, mycologist, entomology, entomologist, ornithology, ornithologist and inventor. He ...

described this species in 1774.

Lucien Quélet Lucien Quélet (; 14 July 1832 – 25 August 1899) was a French natural history, naturalist and mycologist. Quélet discovered several species of fungi and was the founder of the Société mycologique de France, a society devoted to mycological ...

transferred it to the genus ''

Inocybe ''Inocybe'' is a genus of mushroom-forming fungi, with over 1,000 species. Its members are mycorrhizal, and some evidence shows that the high degree of speciation is due to adaptation to different trees and possibly also local habitats. Taxonomy ...

'' in 1872. The tan (or rarely whitish) cap is cone-shaped then expands, generally retaining an umbo and a darker center. Its surface is fibrous. The gills are light grayish and brown with age. The stalk is whitish, semi-fibrillose, and slightly clavate. The odour tends to be spermatic. In Israel, the species grows under Palestine oak (''

Quercus calliprinos ''Quercus coccifera'', the kermes oak or commonly known as Palestine oak, is an oak shrub or tree in section (botany), section ''List of Quercus species#Section Ilex, Ilex'' of the genus. It has many Synonym (taxonomy), synonyms, including ''Quer ...

'') and pines, with mushrooms still appearing in periods of little or no rain as they are mycorrhizal. In Israel, it is confused with edible mushrooms of the genus ''

Tricholoma ''Tricholoma'' is a genus of fungus A fungus (: fungi , , , or ; or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and mold (fungus), molds, as well as the more familiar mushrooms ...

'', particularly ''

Tricholoma terreum ''Tricholoma terreum'', commonly known as the grey knight or dirty tricholoma, is a grey-capped mushroom of the large genus ''Tricholoma''. It is found in coniferous woodlands in Europe and North America, and has also been encountered under intr ...

'', and '' Suillus granulatus'', all of which grow in similar habitats. ''I. sororia'' is another similar species.

References

{{Taxonbar, from=Q1737818 rimosa Poisonous fungi Fungi described in 1774 Fungi of Europe Taxa named by Jean Baptiste François Pierre Bulliard Fungus species