• Proposed
  • Under Assessment
  • DDPreliminary Assessed
  • 4Assessed
  • 5Published

Hohenbuehelia culmicola Bon

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Scientific name
Hohenbuehelia culmicola
Common names
Marram Oyster
Pleurote des oyats
IUCN Specialist Group
Mushroom, Bracket and Puffball
Assessment status
Preliminary Assessed
Preliminary Category
Proposed by
Begoña Aguirre-Hudson
Martyn Ainsworth
Begoña Aguirre-Hudson, Tommy Knutsson, Thomas Læssøe
Comments etc.
Anders Dahlberg

Assessment Status Notes

Taxonomic notes

Why suggested for a Global Red List Assessment?

European endemic resembling small oyster mushroom restricted to coastal sand dunes and fruiting at the base of dead Ammophila. Dahlberg & Croneborg (2003) documented 6 countries with records since 1980 and Spain and Hungary can be added to this list (A. Fraiture in litt.). The relatively inconspicuous mushrooms are likely to have been overlooked due to small size, dark colour and restricted microhabitat. “Moreover, it seems to be an ephemeral fungus, occurring first in one place, than in another” (E.J.M. Arnolds pers. comm.).

Although there is some evidence of habitat decline at some occupied localities, mainly due to changing land usage on coastal dunes, evidence of a quantified decline is lacking, thus ruling out Criterion A. May possibly qualify for Criterion B since ca. 45 fruiting patches are known to have been recorded (equivalent to a maximum AOO of ca.180km2) but this species is generally not found as a result of deliberate and comprehensive sand dune surveys. Such survey work, as has recently been initiated in the Netherlands (E.J.M. Arnolds pers. comm.), is urgently required. Therefore there are considerable doubts remaining concerning its true distribution (whether it qualifies for “severely fragmented”) and its population size. Criterion C might also be appropriate, however an estimate of <250 or <2,500 mature individuals (required for an assessment of EN C2a(i)) seems beyond our current recording data and degree of confidence. In conclusion, the Global and European assessment is DD pending implementation of targeted surveys in in suitable habitat (mainly dynamic coastal dunes on the North Sea or at sites with more Atlantic influence).

Geographic range

Restricted to coastal Ammophila stands particularly around Atlantic and North Sea coasts (one outpost locality in inland dunes in Hungary: A. Fraiture in litt.)

Population and Trends

Dahlberg & Croneborg (2003) documented 6 countries with records since 1980 and Spain and Hungary (1 collection) can now be added to this list (A. Fraiture in litt.). If pre-1980 records are included, then the range includes Italy and the Republic of Ireland (Dahlberg & Croneborg 2003). Data on fruiting abundance is lacking (numbers of occupied Ammophila plants or ramets), however there are ca. 45 fruiting patches recorded (equivalent to a maximum AOO of ca.180km2).
Considered redlisted in most countries of occurence, thought to be extinct in Ireland.

Population Trend: Uncertain

Habitat and Ecology

Coastal sand dunes, rarely inland dunes growing saprotrophically on Ammophila (possibly also on other Poaceae in same habitat such as Leymus arenarius, which was recorded at one English site). Narrow niche requirements, i.e. dynamic sanddune ecosystems with sparse vegetation of herbs and grasses.

Coastal Sand Dunes


Threats are mainly from conversion of coastal dunes to caravan/camping sites, golf courses or other development and, on a smaller scale, to visitor pressure and recreational disturbance (trampling). Changes in large-scale offshore dredging activities are also suspected to alter coastal dynamics unfavourably for this species, for example by shifting the prevailing deposition from sand to pebbles and shingle accretion. Storm surges and long-term sea level rise, coupled with the associated coastal management responses, present a clear threat to dynamic dune systems upon which this species depends.
Inland dune systems are under even higher threats of overgrowth, tree plantations and other changes of land use causing changes of edaphic and vegetation structures.

Residential & commercial developmentRecreational activities

Conservation Actions

Further research needed to inform practical conservation action

Site/area protectionResource & habitat protectionHabitat & natural process restoration

Research needed

Main focus for conservation is habitat protection and managment of localities, in some places restoring naturla dynamis of dune systems.
The main focus of research should be on systematic survey of suitable habitat to increase confidence in estimating population distribution and size and to discover whether there are strongholds. Surveillance is also important to reveal how its fruiting presence (size and location of occupied grass culms/roots) changes from year to year to assess how ruderal this species is. Population genetics required to estimate the number of genets per plant and to locate the whereabouts of the fungus within the plant (root systems or separate stems).

Population size, distribution & trendsPopulation trendsHabitat trends

Use and Trade


Dahlberg A & Croneborg H. 2003. 33 threatened fungi in Europe. Complementary and revised information on candidates for listing in Appendix I of the Bern Convention T-PVS (2001) 34 rev 2.
Fraiture, A. & Walleyn R. (2005). Distributiones fungorum Belgii et Luxemburgi Fasc. 3. Scripta Botanica Belgica 38: 1-79

Known distribution - countries

Regional Population and Trends

Country Trend Redlisted