Mutinus ravenelii

What You Should Know

Mutinus ravenelii is a fungus that grows on converted or disturbed soil, usually as a saprophyte on wood chips, straw, sawdust, or compost in parks and gardens, but sometimes also on decayed wood in deciduous and coniferous forests. When young, the mushroom looks like an elongated, white "devil's egg." The apex of the fruiting body is initially dark in color. It is covered with a slimy dark gray mass that smells like carrion or cat feces and contains the spores. Flies are attracted to this smell; they lick off the spores and thus contribute to the spread of the fungus. Spores that have passed through a fly's intestinal tract can still germinate. When the flies have completed their task, a bright red, raspberry-like tip on a pink stem remains. The stem is hollow and spongy in structure, causing the mushroom to fall over quickly.

The "eggs" of Mutinus ravenelii are edible, while the adult fungus itself is not yet known to be edible or poisonous. Ultimate Mushroom does not recommend eating this fungus.

The Latin genus name Mutinus means "penis" or male member; this, of course, relates to the shape of the fungus. The species name ravenelii is a tribute to the American botanist Henry William Ravenel (1814-1887).

Other names: Dog Stinkhorn, Red Stinkhorn, Ravenel's Red Stinkhorn.

Mutinus ravenelii Mushroom Identification

1. Immature Fruit Body

   The immature fruiting body is whitish to faintly yellowish "egg" that is 0.59 to 0.79 inches (1.5 to 2 cm) high and 0.39 to 0.59 inches (1 to 1.5 cm) wide. The surface is smooth, and when sliced, it reveals the stinkhorn-to-be encased in a gelatinous substance.

2. Mature Fruit Body

   The mature fruiting body can grow up to 1.57 to 3.15 inches (4 to 8 cm) high and is 0.39 to 0.59 inches (1 to 1.5 cm) thick at its widest point. It is cylindrical in shape, often with a fairly abruptly rounded-off apex, but can also have a conic apex. It is hollow and spongy, with a fine to moderately pocked surface. The color of the fruit body is pink to nearly red when fresh, becoming paler towards the base and fading to pale pink or whitish. The apex usually becomes perforated at maturity, and when fresh, it is covered with brown spore slime in a narrow apical zone that is sometimes well-defined or even constricted at the lower edge. The apical portion, under the spore slime, is usually darker red, while the base is encased in a whitish, sack-like volva. The fruit body is attached to thin white rhizomorphs.

3. Odor

   The odor of this species is foul while the spore slime is present.

4. Spore Print

   Olivaceous brown.

5. Habitat

   This species is saprobic and can be found growing alone or in groups in forests, parks and gardens, cultivated areas, and woods during the summer and fall seasons. It is distributed throughout North America from the southern Appalachians to the Maritime Provinces, Washington, and Alaska, as well as in Mexico. It is also fairly common in Europe and has been reported in New Zealand.

6. Microscopic Features

   The spores of this species are cylindric or subcylindric and measure 3-5 x 1.5-2 µm. They are smooth and often have two tiny polar droplets, and appear hyaline in KOH. The sphaerocysts of the pseudostipe are irregularly subglobose and measure 19-54 µm across. The walls are 0.5-1 µm thick, and they are smooth and appear hyaline in KOH. The hyphae of the volva are 3-8 µm wide, smooth, and septate, appearing hyaline in KOH. No clamp connections were found.

Mutinus ravenelii Synonyms

1. Aedycia ravenelii (Berkeley & M.A. Curtis) Kuntze (1898), Revisio generum plantarum, 3, p. 441

2. Corynites brevis Ellis (1880), Bulletin of the Torrey botanical Club, 7(3), p. 30

3. Corynites ravenelii Berkeley & M.A. Curtis (1855) [1853], The transactions of the linnean Society of London, series 1, 21(2), p. 151

4. Dictyophora ravenelii (Berkeley & M.A. Curtis) Burt (1896), The botanical gazette (Crawfordsville), 22(5), p. 385

5. Ithyphallus ravenelii (Berk. & M.A. Curtis) E. Fisch., 1888

6. Phallus ravenelii (Berkeley & M.A. Curtis) Berkeley & M.A. Curtis (1873), Grevillea, 2(15), p. 33

Mutinus ravenelii Video

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