Bulgaria inquinans (Pers.) Fr. - Black Bulgar

Class: Leotiomycetes - Order: Helotiales - Family:  Bulgariaceae - Phylum: Ascomycota

Bulgaria inquinans - Black Bulgar

Bulgaria inquinans, sometimes referred to as the Black Bulgar, Bachelor's Buttons or Rubber Buttons, grows in groups most commonly on felled oak trunks and fallen branches, and occasionally on other dead hardwoods including Ash.

Despite its texture this is not one of the hererobasidiomycetes 'Jelly Fungi' which belong to the class Basidiomycota. Bulgaria inquinans belongs to the Ascomycota.

Bulgaria inquinans - Black Bulgar on a wind-thrown Ash trunk

Because of the current Ash Dieback disease, many more trees are falling or having to be felled for safety reasons, and so Bulgaria inquinans is probably in for a feast; we can expect to see these already fairly common little button-like fungi even more frequently in years to come.

They may look like liquorice or black gumdrops (and indeed in the USA they are sometimes referred to a Black Jelly Drops or Poor Man's Licorice), but Black Bulgars are not considered to be edible fungi and they may possibly contain toxins.

Distribution

A fairly common and widespread woodland species in Britain and Ireland, Bulgaria inquinans is found also throughout mainland Europe and in many other regions of the world including parts of North America, where it is commonly referred to as Black Jelly Drops.

Bulgaria inquinans - Black Bulgar, Scotland

Toxicity

Generally considered as inedible in western countries, and according to some researchers even reported to be poisonous and to cause food-sensitised solar dermatitis, in northeastern China Bulgaria inquinans is treated as a delicacy. We strongly advise against easting these liquorice gum drop lookalikes.

Taxonomic history

The basionym of this species was proposed by Christiaan Hendrik Persoon and subsequently ratified by the great Swedish mycologist Elias Magnus Fries in his 1822 publication Systema Mycologicum.

Synonyms of Bulgaria inquinans include Bulgaria polymorpha (Oeder) Wettst., Tremella turbinata Huds., Peziza turbinata (Huds.) Relhan, Peziza polymorpha Oeder, Peziza inquinans Pers., and Phaeobulgaria inquinans (Pers.) Nannf.

Bulgaria inquinans is the type species of its genus and the only Bulgaria species known to occur in Britain.

Etymology

Bulgaria, the genus name, may be a reference to leathery skin - a leather pounch within which wine was carried. Any other suggestions would be most welcome! Rather more straightforward, the specific epithet inquinans means polluting or staining - a reference to the dark brown stain that comes from handling Black Bulgar fruitbodies.

Identification guide

Closeup picture, Bulgaria inquinans, young fruitbodies

Fruitbody

Flat-topped at first but becoming slightly cup shaped, Bulgaria inquinans is easily overlooked because it is almost black. Its fertile surface is shiny, and the sides (the outsides of the cup) are felty and dark brown.

The flesh of the fruitbody is dark ochre-brown. It is soft and rubbery in wet weather but in dry conditions it becomes tougher and more like elastic.

Often growing in dense masses, the individual fruit bodies are between 0.5 and 4cm across and typically 1cm tall.

Ascus of Bulgaria inquinans

Asci

Typically 200 x 9µm, with eight spores per ascus.

Brown spores of Bulgaria inquinans

Spores

The top four spores in each ascus are dark brown, ellipsoidal to kidney shaped, smooth, 11-14 x 6-7µm. The lower four spores are hyaline (colourless), kidney shaped and much smaller at 5-7 x 2-4µm.

Show larger image

Spore print

Very dark brown, almost black.

Odour/taste

Not distinctive.

Habitat & Ecological role

Saprobic, on felled oaks, Sweet Chestnut and Beech; less frequently on Ash.

Season

September to March in Britain and Ireland.

Similar species

Neobulgaria pura is similar in shape and size but creamy white.

Witches' Butter Exidia glandulosa is much softer black fungus and belongs to the Jelly Fungus group.

Reference Sources

Fascinated by Fungi, Pat O'Reilly 2016.

Mao, X.L (1980). Toxic mushrooms and poisoning. Journal of Preventative Medical Science of China 14: 188-192 [NB: this paper is published in Chinese].

Dennis, R.W.G. (1981). British Ascomycetes; Lubrecht & Cramer; ISBN: 3768205525.

Dictionary of the Fungi; Paul M. Kirk, Paul F. Cannon, David W. Minter and J. A. Stalpers; CABI, 2008

Taxonomic history and synonym information on these pages is drawn from many sources but in particular from the British Mycological Society's GB Checklist of Fungi and (for basidiomycetes) on Kew's Checklist of the British & Irish Basidiomycota.

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