What You Should Know
Entoloma chalybaeum grows singly or in small groups in deciduous woodland. It is most common at high altitudes but does occasionally occur in lowland woods and forests. The cap is 2 to 5 cm in diameter, convex and umbilicate; dark steel blue with a covering of fine hairs or scales. The gills are white at first, becoming dirty salmon pink; they are rather thick and moderately spaced.
Other names: Indigo Pinkgill, Závojenka ocelová (Czech Republic).
Entoloma chalybaeum Mushroom Identification
The cap of Entoloma chalybaeum is convex and umbilicate; dark steel blue; finely tomentose or finely squamulose; 2 to 5cm in diameter.
White at first, sometimes with a faint bluish tinge; becoming dirty salmon pink later; rather thick and moderately spaced.
Heterodiametrical with 5 to 9 sides; 8.5-12.5 x 6-8.5µm.
Striped with blue fibers over a white base, the cylindrical stem turns brown as the fruiting body ages.
Odor and Taste
Habitat & Ecological Role
Usually in small groups or singly in moist upland forests and occasionally in lowland areas. Sometimes occurring in short-sward unimproved grasslands.
Summer and autumn.
Rare in lowland areas; occasional in the uplands.
There are several blue mushrooms in the Entoloma genus, including Entoloma serrulatum, which is generally smaller than Entoloma chalybaeum and has black flecked serrulate (finely saw-toothed) gill edges.
Note on epithet spelling variants
Sometimes chalybaeum is written chalybeum, and chalybaea is written chalybea. We have followed Dutch Entoloma specialist Machiel Noordeloos, as well as Funga Nordica, in using the aeu and aea forms.
Entoloma chalybaeum Taxonomy and Etymology
In 1801 Christiaan Hendrik Persoon gave it the binomial name Agaricus chalybeus. Its currently accepted scientific name dates from 1982 when Dutch mycologist and Entoloma specialist Machiel Noordeloos (born 1949) transferred the species from Nolonea (where Paul Kummer had sited it in 1871) to the Entoloma genus when the now discarded Nolonea grouping was assimilated into an enlarged Entoloma genus.
The variety Entoloma chalybaeum var. lazulinum (Fr.) Noordel. is similar but has fine radial fibrils on its translucently striate cap. Its synonyms include Agaricus lazulinus Fr., Leptonia lazulina (Fr.) Quél. Rhodophyllus lazulinus (Fr.) Quél., and Entoloma lazulinum (Fr.) Noordel.
The generic name Entoloma comes from ancient Greek words entos, meaning inner, and lóma, meaning a fringe or a hem. It is a reference to the inrolled margins of many of the mushrooms in this genus.
The specific epithet chalybaeum came originally from Ancient Greek and into the Latin chalybs, meaning steel.
Gymnopus chalybeus (Pers.) Gray, 1821
Leptonia chalybaea (Pers.) P. Kumm., 1871
Rhodophyllus chalybaeus (Persoon) Quélet, 1886
Acurtis chalybaeus (Pers.) Singer, 1961
Entoloma chalybeum (Pers.) Zerova, 1979
Agaricus chalybeus Pers.
Leptonia chalybaea var. chalybaea (Pers.) P. Kumm.
Photo 1 - Author: enricotomschke (Attribution 4.0 International)
Photo 2 - Author: enricotomschke (Attribution 4.0 International)
Photo 3 - Author: enricotomschke (Attribution 4.0 International)