• WordNet 3.6
    • n Armillaria genus of edible mushrooms having white spores an annulus and blue juice; some are edible; some cause root rot
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Century Dictionary and Cyclopedia
  • Interesting fact: The largest living organism ever found is a honey mushroom, Armillaria ostoyae. It covers 3.4 square miles of land in the Blue Mountains of eastern Oregon, and it's still growing.
    • n armillaria A genus of white-spored agarics having the gills decurrent and the stipe furnished with an annulus. A. mellea is a common and widely distributed species, growing about old stumps, and regarded as the cause of certain root-diseases of trees.
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In literature:

Gills adnate, pileus generally smooth, Armillaria.
"Among the Mushrooms" by Ellen M. Dallas and Caroline A. Burgin
Manner of growth is frequently in tufts, and, as with most of the Armillarias, generally parasitic on old stumps.
"The Mushroom, Edible and Otherwise" by M. E. Hard
Agaricus (Armillaria) melleus Vahl.
"Student's Hand-book of Mushrooms of America, Edible and Poisonous" by Thomas Taylor

In news:

Circles in nature — armillaria mushrooms clustered about a round stump.
In eastern Oregon, the 2,400-year-old Armillaria ostoyae mushroom spans 2,200 acres, making it the largest organism in the world.
"Shoestring" rhizomorphs or mycelial cords of Armillaria found along with dead woody roots.