page_title: Armillaria luteobubalina
section_title: Description
hierarchical_section_title: Armillaria luteobubalina / Description
caption_attribution_description: English: The honey mushroom Armillaria luteobubalina Watling &amp; Kile. Photographed in Dandenong Ranges National Park, Victoria, Australia.
context_page_description: Armillaria luteobubalina, commonly known as the Australian honey fungus, is a species of mushroom in the family Physalacriaceae. Widely distributed in southern Australia, the fungus is responsible for a disease known as Armillaria root rot, a primary cause of Eucalyptus tree death and forest dieback. It is the most pathogenic and widespread of the six Armillaria species found in Australia. The fungus has also been collected in Argentina and Chile. Fruit bodies have cream- to tan-coloured caps that grow up to 10 cm in diameter and stems that measure up to 20 cm long by 1.5 cm thick. The fruit bodies, which appear at the base of infected trees and other woody plants in autumn, are edible, but require cooking to remove the bitter taste. The fungus is dispersed through spores produced on gills on the underside of the caps, and also by growing vegetatively through the root systems of host trees. The ability of the fungus to spread vegetatively is facilitated by an aerating system that allows it to efficiently diffuse oxygen through rhizomorphs—rootlike structures made of dense masses of hyphae.
context_section_description: Up to 10 cm (4 in) in diameter, the cap is convex to flattened in shape with a central umbo (a rounded elevation) and is various shades of cream, yellow and tan. The cap surface is covered with darker scales and feels rough to the touch. The cap edge, or margin, is rolled inward in young specimens. The crowded gills are sinuate and white to cream in colour initially, brownish-cream or pinkish brown in maturity, and sometimes with yellow or rust-coloured marks close to the margins. The stem is central (that is, it joins the cap in the centre) and is up to 20 cm (8 in) long by 1.5 cm (1 in) thick. It is slightly thicker at its base than its apex, sometimes almost bulb-like. The stem surface is streaked with fibrils that run up and down its length. It has a floppy yellow wool-like ring which may develop irregular, jagged edges with time. The flesh is white, and in the stem has a woolly or stringy consistency. Although it has a hot-bitter taste, Armillaria luteobubalina is edible, and cooking removes the bitterness.
caption: Mushroom caps are covered with tiny scales and have an umbo.
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