Dog Stinkhorn

Description

The Dog Stinkhorn is a small, slender mushroom shaped like a pointed finger, 10–16 cm tall and about 1 cm thick. It is yellowish-white or pale orange, and the tip is covered with a dark olive, slimy spore mass that disappears over time and exposes an apricot or orange tip. It grows from a whitish egg, partly buried in the litter, and a volva remains at the base.

It grows in summer and autumn, usually in small groups, in damp, shady broadleaf woods on fertile soils, on fallen leaves and woody debris. In Poland it is rare. Young fruiting bodies smell mild, while older ones have an unpleasant odour that attracts insects.

It can be told apart from the common stinkhorn by its smaller size, slender shape and weaker smell. The mushroom is inedible.

Identification features

Cap

No distinct cap in the usual sense: the top of the fruiting body is pointed and conical, covered with a thin layer of gleba, i.e. a dark olive-brown, slimy spore-bearing mass with a strong smell. Once the gleba has been dispersed, the tip is apricot or yellow-orange; beneath the gleba it is dark orange.

Hymenophore (underside of the cap)

No gills or tubes. The hymenophore is the gleba covering the upper part of the fruiting body, in which the spores develop.

Stem

The young fruiting body is egg-shaped (2–4 cm tall, 1–2.5 cm wide), whitish, partly buried in the litter, with white mycelial cords at the base. The egg has a tough outer covering (peridium) and a gelatinous inner layer. After the egg ruptures, the fruiting body grows within a few hours to a height of 10–16 cm and a thickness of about 1 cm. The stem (receptaculum) is cylindrical, very fragile, pitted, usually slightly curved, and yellowish-white, yellow or pale orange. A volva made of the remains of the egg stays at the base.

Flesh

Spongy, hollow inside, fragile. The smell of young fruiting bodies is sometimes pleasant, resembling tobacco or fruit; older fruiting bodies smell similar to the common stinkhorn, but much weaker (it has also been described as smelling of cat faeces). The flesh should not be tasted.

Spore print and spores

Spores ellipsoid, smooth, coloured (olive in mass), 4–5 × 1.5–2 µm. The spores are dispersed by insects attracted by the smell of the gleba.

Habitat and distribution

Ecology. Grows on broadleaf litter and on small woody debris, usually in small groups. It is a saprotroph. The fruiting bodies are sometimes eaten by ants and developing fly larvae.

Distribution. Widespread: Eurasia and eastern North America, recorded on all continents except Africa and Antarctica. In Poland it is rare; in the Red List of Plants and Fungi of Poland it has category V (vulnerable). It was formerly under strict protection in Poland, but was removed from the list of protected species on 9 October 2014; it is currently not legally protected in Poland. It is not on the list of mushrooms approved for sale in Poland.

Fruiting. Summer and autumn, until late autumn.

What can it be confused with?

• Mutinus ravenelii (mądziak malinowy, Ravenel's stinkhorn) — Pinker, with a red tip; a North American species, spreading in Europe.
• Mutinus elegans — A North American species, very similar to M. ravenelii; short and stocky, with a more pointed tip.
• Phallus impudicus (common stinkhorn) — Larger, with a distinct, net-like cap covered with gleba and a very strong, unpleasant smell.

Never rely on a single feature. If you are not sure — do not pick it; show the mushroom to a qualified mushroom expert.

Interesting facts

• The generic name derives from the Roman deity Mutinus Titinus; the epithet caninus means "canine". Similar associations can be seen in French names, e.g. "phallus de chien".
• The fruiting body grows from the egg to its full height within a few hours.
• The smell of the gleba attracts insects, which carry the spores on their bodies and in their digestive tracts.
• Until 9 October 2014 it was a strictly protected species in Poland; it now has Red List category V.