Inocybe praetervisa

Inocybe praetervisa was first described by Lucien Quélet in the first volume of Giacomo Bresadola's 1883 publication Fungi tridentini.[1] The species was moved to the genus Astrosporina by Joseph Schröter in 1889,[2] but this was rejected, and the name Astrosporina praetervisa is now considered an obligate synonym.[3] Astrosporina praetervisa was the type species of the no longer recognised genus.[4] The specific epithet praetervisa comes from the Latin word meaning "overlooked".[5]

Within the genus Inocybe, I. praetervisa has been placed in the subgenus Inocybe. Mycologist Rolf Singer places the species in the section Marginatae; mycologist Thom Kuyper considers Marginatae a supersection, and includes I. praetervisa along with I. abietis, I. calospora and I. godeyi. Phylogenetics has shown that, in addition to the large clade of subgenus Inocybe, I. praetervisa forms a clade with I. calospora, I. lanuginosa and I. leptophylla. The species are similar in that all four have basidiospores with small nodules; it was this feature that defined the genus Astrosporina, with then A. praetervisa as its type species. However, when phylogenetic analysis later concluded that nodulose-spored Inocybe species do not form a monophyletic group, the name Astrosporina was deemed inappropriate at a generic level. But it may be considered useful at a lower level to refer to the clade of the four Inocybe species. Of those four, I. praetervisa is most closely related to I. calospora, with which it forms a smaller and closer clade.[6] A different study also found the close relationship between I. praetervisa and I. calospora; it also named I. teraturgus as a part of the clade containing I. praetervisa, I. calospora, I. lanuginosa and I. leptophylla.[7]

Inocybe praetervisa has a bell-shaped (later expanding) cap of 3 to 5 centimetres (1.2 to 2.0 in) in diameter, which is a yellowish-brown colour. It is fibrous, and splits from the margin (which curves inwards[8]) to the centre. The stem is from 5 to 6 centimetres (2.0 to 2.4 in) in height, and from 3 to 8 millimetres (0.12 to 0.31 in) thick. It is white, maturing to a pale straw-yellow, and the whole stem is farinaceous, meaning it is covered in particles resembling meal.[9] The stem has a distinct bulb at the base, which is moderately marginate,[8][9] and lacks a ring.[10] The flesh is white, and discolours to yellowish in the stem. The gills are initially whitish, but later become a clay-brown with toothed, white edges.[8][9] They are adnexed, meaning they connect to the stem by only part of their depth, and are crowded closely together.[8]

Inocybe praetervisa is an ectomycorrhizal species,[13] and is found on the ground in mixed, deciduous or even coniferous woodland. It typically favours beech.[8][9][14] Mushrooms grow solitarily or in "trooping groups"[10] in late summer and throughout autumn, though it is not commonly encountered species.[9] It is found in Europe, Asia and North America.[15]

The species has a mild, indistinct taste, and a faint smell of flour.[9][10] Mycologist Roger Phillips describes its edibility as "suspect", recommending that it be avoided,[9] and notes that it is possible that the species is poisonous; most species of Inocybe have been shown to contain poisonous chemicals.[14] Mycologist Ian Robert Hall lists the mushroom as containing the poisonous compound muscarine. Consumption of muscarine could lead to a number of physiological effects, including: excess salivation, lacrimation, uncontrollable urination and defecation, gastrointestinal problems and emesis (vomiting); this array of symptoms is also known by the acronym SLUDGE.[16] Other potential effects include a drop in blood pressure, sweating and death due to respiratory failure.[16]

• List of Inocybe species