Common Stinkhorn

Appearance

Sometimes called the ''witch's egg'', the immature stinkhorn is whitish or pinkish, egg-shaped, and typically 4 to 6 cm by 3 to 5 cm. On the outside is a thick whitish volva, also known as the peridium, covering the olive-colored gelatinous gleba. It is the latter that contains the spores and later stinks and attracts the flies; within this layer is a green layer which will become the 'head' of the expanded fruit body; and inside this is a white structure called the receptaculum , that is hard, but has an airy structure like a sponge.

The eggs become fully grown stinkhorns very rapidly, over a day or two. The mature stinkhorn is 10 to 30 cm tall and 4 to 5 cm in diameter, topped with a conical cap 2 to 4 cm high that is covered with the greenish-brown slimy gleba. In older fungi the slime is eventually removed, exposing a bare yellowish pitted and ridged surface. This has a passing resemblance to the common morel , with which it is sometimes mistaken. The rate of growth of ''Phallus impudicus'' has been measured at 10–15 cm per hour. The growing fruit body is able to exert up to 1.33 kN/m2 of pressure—a force sufficient to push up through asphalt. The spores have an elliptical to oblong shape, with dimensions of 3–5 to 1.5–2.5 µm.

In North America, ''Phallus impudicus'' can be distinguished from the very similar ''P. hadriani'' by the latter's purplish-tinted volva.

Distribution

The common stinkhorn can be found throughout much of Europe and North America, and it has also been collected in Asia, Costa Rica, Iceland, Tanzania, and southeast Australia. In North America, it is most common west of the Mississippi River; Ravenel's stinkhorn is more common to the east.

Habitat

The fungus is associated with rotting wood, and as such it is most commonly encountered in deciduous woods where it fruits from summer to late autumn, though it may also be found in conifer woods or even grassy areas such as parks and gardens. It may also form mycorrhizal associations with certain trees.

Uses

In Northern Montenegro, peasants rub ''Phallus impudicus'' on the necks of bulls before bull fighting contests in an attempt to make them stronger. They are also fed to young bulls as they are thought to be a potent aphrodisiac.