Honey mushroom (Armillaria ostoyae)

loading
Honey mushroom, fruiting bodies

Top facts

  • The honey mushroom is the largest living organism in the world, with its underground growth stretching up to ten square kilometres.
  • Despite its vast size, only a small percentage of the honey mushroom’s growth is visible above ground.
  • The enormous honey mushroom fungus can weigh around as much as a blue whale.
loading
Loading more images and videos...

Honey mushroom fact file

Honey mushroom description

KingdomFungi
PhylumBasidiomycota
ClassAgaricomycetes
OrderAgaricales
FamilyPhysalacriaceae
GenusArmillaria (1)

The honey mushroom (Armillaria ostoyae) is the largest living organism in the world, although only a small percentage of its growth is visible above ground (4). The fungus’s cap can vary between tan, yellow-brown and dark red, and is covered in darker fibrous scales, especially around the centre (2) (3) (5) (6). The stem is yellow and rounded at the base, gradually becoming red-brown towards the cap (3) (5). There is a white, cotton-like veil towards the top of the stem (2). The gills on the underside of the cap are white in young growth, becoming yellow then pink-brown as the fungus ages (3) (5).

The fruiting bodies of the honey mushroom can be found growing in large clusters, as well as alone (2) (3).

Also known as
dark honey fungus, honey-coloured mushroom.
Synonyms
Agaricus obscurus, Armillaria obscura, Armillaria polymyces, Armillaria solidipes, Armillariella ostoyae, Armillariella polymyces.
Size
Cap width: 2.5 - 9 cm (2)
Stalk length: 5 - 20 cm (3)
Stalk thickness: 1 - 2.5 cm (2)
Underground growth area: up to 10 square km (4)
Top

Honey mushroom biology

The honey mushroom is saprophytic and absorbs nutrients from soil and dead plant matter such as leaf litter or rotten wood (8). To do this, the honey mushroom uses an underground system of thick, brown, root-like hyphae, which permeate the food source and take up the nutrients (2) (6). This particular fungus is an effective decomposer of wood (2).

The fruiting body of the honey mushroom is mostly present above ground between July and November (3).

Top

Honey mushroom range

The honey mushroom is found worldwide in northern parts of North America, Europe and Asia (7).

Top

Honey mushroom habitat

The honey mushroom is usually found living on the trunks and stumps of broad-leaved, deciduous and coniferous trees (5) (6), including aspen (Populus spp.) and balsam poplar (Populus balsamifera), and less frequently birch (Betula spp.) (2).

Top

Honey mushroom status

The honey mushroom has yet to be classified by the IUCN.

Top

Honey mushroom threats

There are not known to be any threats currently facing the honey mushroom.

Top

Honey mushroom conservation

There are not known to be any specific conservation measures currently in place for the honey mushroom.

Top

Find out more

Find out more about the honey mushroom:

Find out more about fungi:

Top

Authentication

This information is awaiting authentication by a species expert, and will be updated as soon as possible. If you are able to help please contact:
arkive@wildscreen.org.uk

Top

Glossary

Deciduous
A plant that sheds its leaves at the end of the growing season.
Hyphae
The branching, threadlike filaments that make up the vegetative (non-reproductive) part of a fungus.
Saprophytic
Term applied to a plant or plant-like organism that absorbs nutrients from dead plant or animal matter.
Top

References

  1. Species 2000 and ITIS Catalogue of Life(July, 2012)
    http://www.itis.gov/
  2. Laursen, G.A. and Seppelt, R.D. (2009) Common Interior Alaska Crytogams:Fungi, Lichenicolous Fungi, Lichenized Fungi, Slime Molds, Mosses and Liverworts. University of Alaska Press, Alaska.
  3. Bessette, A.B., Bessette, A.R and Fischer, D.W. (1997)Mushrooms of Northeastern North America. Syracuse University Press, New York.
  4. Wearing, J. (2010) Fungi:Mushrooms, Toadstools, Molds, Yeasts and Other Fungi. Crabtree Publishing Company, Ontario.
  5. Phillips, R. (2006) Mushrooms. Macmillan, London.
  6. Courtecuisse, R. (1999) Mushrooms of Britain and Europe. HarperCollins, London.
  7. Hanna, J.W., Klopfenstein, N.B., Kim M.S., McDonald, G.I. and Moore, J.A. (2007) Phylogeography of Armillaria ostoyae in the western United States. University of Idaho, Moscow, Idaho. Available at:
    http://forest.moscowfsl.wsu.edu/people/smp/jhanna/JWH2004APS.pdf
  8. Lavender, D.P. (1990) Regenerating British Colombia’s Forests. University of British Colombia Press, Vancouver.
X
Close

Image credit

Honey mushroom, fruiting bodies  
Honey mushroom, fruiting bodies

© Philippe Clement / naturepl.com

Nature Picture Library
5a Great George Street
Bristol
BS1 5RR
United Kingdom
Tel: +44 (0) 117 911 4675
Fax: +44 (0) 117 911 4699
info@naturepl.com
http://www.naturepl.com

X
Close

Link to this photo

ARKive species - Honey mushroom (Armillaria ostoyae) Embed this ARKive thumbnail link ("portlet") by copying and pasting the code below.

Terms of Use - The displayed portlet may be used as a link from your website to ARKive's online content for private, scientific, conservation or educational purposes only. It may NOT be used within Apps.

Read more about

X
Close

MyARKive

MyARKive offers the scrapbook feature to signed-up members, allowing you to organize your favourite ARKive images and videos and share them with friends.

Play the Team WILD game:

Team WILD, an elite squadron of science superheroes, needs your help! Your mission: protect and conserve the planet’s species and habitats from destruction.

Conservation in Action

Which species are on the road to recovery? Find out now »

Help us share the wonders of the natural world. Donate today!

Blog