Appearing in late summer and autumn, fruit bodies are found in deciduous woodlands on clay or chalky soils, or nearby parklands, sometimes in the form of fairy rings.

[5] The saga of this species' name begins in 1788 with the publication of part 8 of Jean Baptiste Bulliard's Herbier de la France.

He had in 1886 proposed a new, broader genus that included all pink-gilled fungi with adnate or sinuate gills and angular spores: Rhodophyllus.

[14] However, most other authorities have tended to favor Entoloma,[15] and Singer conceded the name was far more widely used and adopted it for his Agaricales in Modern Taxonomy text in 1986.

1[note 3] E. sordidulum E. politum E. rhodopolium E. caccabus E. sericatum E. myrmecophilum The specific epithet sinuatum is the Latin for "wavy", referring to the shape of the cap, while the generic name is derived from the Ancient Greek words entos/ἐντός "inner" and lóma/λῶμα "fringe" or "hem" from the inrolled margin.

[26] In the Dijon region of France it was known as le grand empoisonneur de la Côte-d'Or ("the great poisoner of Côte d'Or").

[16] A 2009 study analyzing DNA sequences and spore morphology found it to lie in a rhodopolioid clade with (among other species) E. sordidulum, E. politum and E. rhodopolium, and most closely related to E. sp. 1.

[30] It is convex to flat, often with a blunt umbo in its centre and wavy margins, ivory white to light grey-brown in color, and darkening with age.

The distant gills are sinuate (notched at their point of attachment to the stipe) to almost free, generally (but not always) yellowish white before darkening to pink and then red.

[33] Confusion with the highly regarded miller or sweetbread mushroom (Clitopilus prunulus) is a common cause of poisoning in France; the latter fungus has a greyish -white downy cap and whitish decurrent gills which turn pink with maturity.

[35] The rare and edible all-white dovelike tricholoma (T. columbetta) has a satiny cap and stem and a faint, not mealy, odor.

[28] E. sinuatum may be confused with Clitocybe multiceps in the Pacific Northwest of North America, although the latter has white spores and generally grows in clumps.

[35] A casual observer may mistake it for an edible field mushroom (Agaricus campestris),[27] but this species has a ring on the stipe, pink gills that become chocolate-brown in maturity, and a dark brown spore print.

[33] In Asia, it has been recorded in the Black Sea region,[39] the Adıyaman Province in Turkey,[40] Iran,[41] and northern Yunnan in China.

[33] They are found in deciduous woodlands under oak, beech, and less commonly birch, often on clay or calcareous (chalky) soils,[33] but they may spread to in parks, fields and grassy areas nearby.

[49] Hospital treatment of poisoning by this mushroom is usually supportive; antispasmodic medicines may lessen colicky abdominal cramps and activated charcoal may be administered early on to bind residual toxin.

[52] A study of trace elements in mushrooms in the eastern Black Sea Region of Turkey found E. sinuatum to have the highest levels of copper (64.8 ± 5.9 μg/g dried material—insufficient to be toxic) and zinc (198 μg/g) recorded.