Leucocortinarius bulbiger

Leucocortinarius bulbiger

White Webcap (Leucocortinarius bulbiger (Alb. & Schwein.) Singer 1945) is a mushroom belonging to the Tricholomataceae family.

Systematics –
Domain Eukaryota,
Kingdom Fungi,
Division Basidiomycota,
Class Agaricomycetes,
Order Agaricales,
Family Tricholomataceae,
Genus Leucocortinarius,
Species L. bulbiger.
The following terms are a basionym:
– Agaricus bulbiger Alb. & Schwein.
The following terms are synonymous:
– Armillaria bulbigera (Alb. & Schwein.) P.Kumm.;
– Armillaria bulbigera Alb. & Schwein.;
– Armillariella bulbigera (Alb. & Schwein.) Parrot;
– Cortinarius bulbiger (Alb. & Schwein.) J.E.Lange;
– Cortinellus bulbiger (Alb. & Schwein.) Pat.;
– Gyrophila bulbigera (Alb. & Schwein.) Quél.;
– Mastoleucomyces bulbiger (Alb. & Schwein.) Kuntze;
– Tricholoma bulbigerum (Alb. & Schwein.) Ricken.

Etymology –
The genus name Leucocortinarius comes from the Ancient Greek “λευκός” (leucós), meaning white, combined with the genus Cortinarius. This is a white Cortinarius.
The specific epithet bulbiger derives from the Latin “bulbus,” meaning bulb, and from “gero,” meaning “to carry,” “I carry,” and therefore “bulb-bearer,” clearly referring to the enlarged base.

Geographic Distribution and Habitat –
The genus Leucocortinarius is monotypic, containing the single species Leucocortinarius bulbiger, which is widespread throughout Europe.
Its European habitat is mountainous, in sparse coniferous forests but also mixed with beech, during the summer and autumn.

Identification –
Leucocortinarius bulbiger is a mushroom characterized by a white, filamentous-membranous partial veil, a mostly reddish-brown cap, and a large, margined bulb, as its species name suggests.
The cap averages 5-10 cm, initially hemispherical, then convex, then flat-convex, and finally spiny, with or without a blunt umbo. The margin is long, involuted, then more or less straight, sometimes wavy. The surface is smooth, glabrous, sometimes slightly scaly, finely fibrillose, more or less slimy in humid weather. Its color ranges from brownish-ochre, ochre-tawny, flesh-beige, to reddish-brown, often with remnants of the general veil, especially at the edge, which is covered with whitish flakes.
The gills are dense, broad, adnate, without margins, sometimes decurrent with a small tooth, white, whitish, then cream, with an entire thread.
The stipe, 5.0-9.0 × 1.0-1.7 cm, is cylindrical, full, robust, longitudinally fibrillose, initially pure white, then light brownish, with a large, rounded or margined basal bulb 2.0-3.2 cm wide. The cortina is white and rather persistent.
The flesh is fragile, soft, thin at the margin, thick in the center of the cap, fibrous on the stipe, and white; it has a faint celery-like odor and a mild flavor. It is edible, but due to its rarity, collection is recommended only for study purposes.
Under a microscope, smooth, ellipsoidal, thick-walled, and single-guttulate spores are visible; Average spore size 7.5 × 4.5 µm, spore size range (6.7) 6.8-8.6(9.2) × 4.2-4.8(5.0) µm, Qm = 1.7 (1.4-2.0), Vm = 81 (62-114) µm. Basidia clavate, with basal clamp joints, tetrasporic, 36.2-40.2 × 7.5-8.4 µm. Parallel lamellar network, fertile lamellar thread. Pileipellis: an ixocutis formed by loosely intertwined, gel-like hyphae, with intracellular pigment, but on some hyphae also encrusting, yellow-ochre in color. Cortinoid veil formed by cylindrical, thin, more or less parallel hyphae, with clamp joints on all septa.

Cultivation –
There are no known experiences of commercial cultivation of Leucocortinarius bulbiger (it is reported as a rare species collected in the wild). The few naturalistic and taxonomic sources describe its habitat in coniferous/mixed forests, sporadic in Europe, but do not describe cultivation protocols.

Uses and Traditions –
The genus Leucocortinarius (J.E. Lange) Singer 1945 has only one species, Leucocortinarius bulbiger (Alb. & Schwein.) Singer 1945, which has white spores (hyaline under the light microscope) and is smooth despite its cortinary-like silhouette. Therefore, the genus is considered monospecific, and the genus description corresponds to the species description.
This mushroom is easily recognized in the field by the fact that it appears like a Cortinariaceae mushroom but has white gills, even when mature. It is an uncommon but not rare species that grows in beech and fir forests, but also in beech and pine forests. Its appearance could be confused with Cortinarius allutus Fr., which, however, prefers mountain spruce forests. Its gills are initially white, then clay-colored, and its spores are slightly warty.
Leucocortinarius bulbiger was first described, under the name Agaricus bulbbiger, by Albertini & Schweintz in 1805 as a red-tinged mushroom with torn veil remnants on the cuticle, a whitish ring, and a “bulb slightly depressed at the margin, which grows in September between the leaves.”
In the following years, this species migrated to different genera depending on the interpretations of different authors.
Kummer (1881) placed the species in the genus Armillaria (Fr.) Staude, due to its white gills and the remnants of the partial veil on the stipe, which form bracelets.
Quélet (1886) created the genus Gyrophila to include those fungi with convex to flat caps with an involute margin, adnate or sinuous gills, a fleshy stipe, a fibrillose or pruinose ring, and small ovoid spores, and included this species there as well.
In 1891, Kuntze stated that this species, whose genus is highly questionable, could be placed among Lepiota P. Browne, or among Tricholoma (Fr.) Staude, due to its smooth, white spores. However, he adopted the genus Mastoleucomyces Battarra ex Kuntze and transferred to it all the species that Saccardo listed in the genus Armillaria in volume 5 of Sylloge Fungorum.
Ricken (1915) placed this species in the genus Tricholoma due to the attachment of the gills around the stipe, the non-hygrophanous cap, and its single or gregarious growth.
Lange (1935), due to its strong resemblance to species ascribed to the Section Sauri Fr. of the subgenus Phlegmacium (Fr.) Trog, moved it to the genus Cortinarius (Pers.) Gray, subgenus Leucocortinarius Lange.
This mushroom, although edible, should absolutely not be collected due to its rarity and, therefore, the particular ecological role it plays.

Preparation Instructions –
Although Leucocortinarius bulbiger is edible, as mentioned, due to its rarity, it is advisable not to collect it, or at least only for study and research.

Guido Bissanti

Sources
– Wikipedia, the free encyclopedia.
– GBIF, the Global Biodiversity Information Facility.
– Cetto B., 2008. I funghi dal vero, Saturnia, Trento.
– Pignatti S., 1982. Flora d’Italia, Edagricole, Bologna.
– Conti F., Abbate G., Alessandrini A., Blasi C. (eds.), 2005. An annotated checklist of the Italian vascular flora, Palombi Editore.

Photo Source:
– https://www.funghiitaliani.it/topic/19851-leucocortinarius-bulbiger-alb-schwein-fr-singer-1945/

Warning: The pharmaceutical applications and dietary uses are provided for informational purposes only and do not in any way constitute medical prescriptions. We therefore decline any responsibility for their use for curative, aesthetic, or nutritional purposes.