Agaricus ectypus Fr. (1821)
Armillariella ectypa (Fr.) Singer (1943)
Camarophyllus ectypus (Fr.) P. Karst. (1879)
Clitocybe ectypa (Fr.) Gillet (1874) 
Omphalia ectypa (Fr.) Quél. (1886)
Marsh Honey Fungus is a characteristic and also very rare Eurasian species. It is confined to the specific types of fens with low nitrogen availability and at least localized base-rich micro-habitats (or alkaline fens). Despite of sufficient number of wetlands there are only small amount of types ones appropriate to the successful existence of Armillaria ectypa. Even insignificant changes of hydrological regime inside and around fens can lead to extinction of this species. It’s recorded in 13 countries, redlisted in 11 ones (including the Red Data Books of regional level in Russia).
Armillaria ectypa is an Eurasian species, but the most finds (~60) are known from the European part and only a few (4) localities are found in the Western Siberia. It’s recorded also in Japan.
Dahlberg & Cronebirg (2003) reported 57 known localities in Europe in 2003, Otto reported about 50 in 2011 (Otto, 2011). In addition in Russia 6 localities are known (despite of intensive special investigation in some regions). 7 sites (very small and considered as fragile habitats) are known in Japan.
In Denmark, Finland, France, Germany, Czech Republic, and Netherlands decreasing of habitats has been noticed for the last 50 years. Declining and strong treath was registered in redlisting in some of European countries: Switzerland - Ex (last record 1935), Germany -Cr; Latvia - Cr (A3), Austria (1 (Cr); Denmark - En and declining (total 9 records, but only 2 after 1990 http://svampe.dk/soeg/rapportside.php?DKIndex=10523), Finland - Vu (A1c, B1+2c). Only in UK the number of locality increased due to very intensive special investigation, however despite this fact this species is estimated as En because of rareness and fragile type of habitats.
Trends in Russia are not known, but a threat to successful existence of localities is actual because of very small area of suitable habitats (for example in Tula region the bogs with Armillaria ectypa are about 700 m2 - 2000m2, and even the light damage of the bog can lead to change of hydrological mode and habitat in general.
Total number of known localities in Europe and Russia can be about 60, the number of unknown localities may be 10 times higher, so 600 . We estimated 2 functional individuals per locality and number of mature individuals 2x10 per locality (due to mycelium fragmentation). 600x2x10 - 12000
Declining more then 20% due to habitat loss and degradation (draining, peat extraction)
Applicable criteria A2c+3+4; C1 - NT, close to Vu.
Population Trend: Decreasing
Marsh Honey Fungus looks rather like to the other species of Armillaria, but it’s easily distinguished from related species by the lack of a ring, and typically growing solitary or in small groups. However the habitat is strongly different since A.ectypa is confined to various types of wetlands including mesotrophic mires (karst ones, alkaline fens), ombrogenic peat bogs, sometimes reeds at paludified pond shores, and other paludous habitats near calcareous springs. Important specific details of habitats probably are: low or rather low nitrogen contents and the presence at least localized base-rich micro-habitats (local calcareous flushes of ground water). A. ectypa is a saprotroph associated mainly with plant communities consisting of Sphagnum spp., Carex spp (mainly oligo- and mesothrophic spp.), Drosera spp. ,Rhynchospora alba, Scheuchzeria palustris etc.
The all kinds of actions leading to changing of hydrological regime in and around mires such as peat and moss extraction, drainage ditch digging, extensive forestry plantations, eutrophication of groundwater, agricultural toxic discharges and the intensive cattle grazing nearby the habitats, etc.
The maintenance of appropriate hydrological regime, prevention of actions leading to drying, eutrophication and changing of water composition.
We need to know preferable habitats and plant communities, the exact sizes of individuals and populations (detected with molecular methods) and their dependence from the nature conditions, breeding system, the ability of maintenance in cultures etc.
Ainsworth A. M. Report on the marsh honey fungus Armillaria ectypa, a UK BAP species. — L., 2003. — 22 p. — (English Nature Research Reports, No. 540).
Dahlberg A., Croneborg H. 33 threatened fungi in Europe: Complementary and revised information on candidates for listing in Appendix I of the Bern Convention. Uppsala: Swedish Species Information Centre, 2003. 82 p.
Mitchel D. Armillaria ectypa – marsh honey fungus http://www.habitas.org.uk/priority/species.asp?item=665
Otto P, 2011. Ecology and chorology of 51 selected fungal species. Draft, Leipzig (unpublished)
Red Data Book of Tula Region: plants and fungi. Official edition / Edited by A.V.Shcherbakov. - Tula: Grif et K, 2010. 393 p. (in Russian)
Red Data Book of of the Khanty-Mansiysk Autonomous Okrug - Ugra: animals, plants, fungi. Ed. 2nd / Edited by AM Vasin, AL Vasina. - Ekaterinburg: Publishing Basco, 2013. 460 p/
Termorshuizen, A.J. in Bas, C. et al. 1995. Flora Agaricina Neerlandica 3: 38-39. Rotterdam, Brookfield.