common stinkhorn

Phallus impudicus, known colloquially as the common stinkhorn, is a widespread fungus recognizable for its foul odor and its phallic shape when mature, the latter feature giving rise to several names in 17th-century England. It is a common mushroom in Europe and western North America, where it occurs in habitats rich in wood debris such as forests and mulched gardens. It appears from summer to late autumn. The fruiting structure is tall and white with a slimy, dark olive colored conical head. Known as the gleba, this material contains the spores, and is transported by insects which are attracted by the odor – described as resembling carrion. Despite its foul smell, it is not poisonous and the young mushroom is consumed in parts of France and Germany
--Sometimes called the witch's egg, the immature stinkhorn is whitish or pinkish, egg-shaped, and typically 4 to 6 cm (1.6 to 2.4 in) by 3 to 5 cm (1.2 to 2.0 in).
--An immature fruiting body ("egg") in longitudinal section
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 (the stalk when expanded), 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 25 cm (3.9 to 9.8 in) tall and 4 to 5 cm (1.6 to 2.0 in) in diameter, topped with a conical cap 2 to 4 cm (0.8 to 1.6 in) high that is covered with a greenish-brown slime termed the gleba. In older fungi the slime is eventually removed, exposing a bare yellowish pitted and ridged (reticulate) surface. This has a passing resemblance to the common morel (Morchella esculenta), with which it is sometimes mistaken. The rate of growth of Phallus impudicus has been measured at 10–15 cm (3.9–5.9 in) 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.