Armillaria mellea

Common Name: honey mushroom
Pileus
Cap 3-13 cm broad, convex at first, becoming nearly plane, sometimes broadly umbonate at maturity, margin finely striate; color varying from yellowish-brown to reddish-brown, the disc darker with fine hair or scales; surface viscid when moist; odor mild, taste acrid.

Lamellae
Gills white to pallid, adnate to subdecurrent, sometimes notched, developing reddish-brown stains in age.

Stipe
Stipe 5-17 cm long, 0.5-3.0 cm thick, tapering towards the base when growing in clusters, enlarged to bulbous at the base when growing apart; tough, fibrous; partial veil cottony forming a superior ring; pallid above the ring, yellowish-brown to reddish-brown below.

Spores
Spores 7-9.5 x 5-7 µm, smooth, elliptical, nonamyloid. Spore print white.

Habitat
Fruiting typically in large clusters, but sometimes singly on wood or buried wood of both hardwoods and conifers. Appearing soon after the first fall rains with continued fruitings through mid-winter.

Edibility
Edible and considered good by many. The button stage is usually collected for the table, the fibrous stipes discarded, although the peeled stipe may be the best part of this fungus for the table. The acrid or bitter taste of fresh specimens disappears with cooking. Note that some people suffer digestive upsets from this mushroom.

Comments
The Honey Mushroom is actually a complex of species, some of which are saprophytic, others parasitic on trees and shrubs causing serious economic losses. Rhizomorphs, thickened strands of mycelium, which aid in the spread of the fungus, can sometimes be seen under the bark of affected trees. At least two recognizable forms of Armillaria mellea occur in the S.F. Bay Area, one with a yellowish-brown cap, the other with a reddish-brown cap. The Honey Mushroom possesses several easy to recognize morphological features: a clustered fruiting habit on wood or buried wood, cap with a dark central disc covered with fine hairs or scales, gills with rusty spots in age, and a tough fibrous stipe with a ring.