Ravenels stinkhorn

Appearance

The mushroom begins its development in the form of pink-, lilac-, or purple-tinged "eggs" that resemble a puffball. The egg expands rapidly to form a phallus-shaped structure with a yellowish-white stalk and thimble-like cap.

The cap ranges from 1.5 to 4 cm in width and 3 to 4.5 cm in height; the entire fruit body can reach heights of 20 cm. The cap texture is finely granular and it is attached to a white open circlet at the top where it meets the stalk.

In some specimens, this opening is relatively large with a broad margin, and gives the mushroom a truncated appearance. Microscopically, the cap surfaces comprises minute cells and cavities, with a spongy structure similar to that of the stem, but with smaller perforations than the stem. The lower margin of the cap is free from attachment to the stalk, and there is sometimes a membranous veil suspended like a collar around the stem under the cap; the veil can be of varying lengths.

This veil can be seen in dissected eggs where it is present as a distinct, thin membranous tissue between the stalk and the cap before expansion. In this form, the veil is continuous from its attachment with the "primordial tissue" at the base of the stalk and volva below to the tip of the stem at the point where it joins the cap. The veil produced in "P. ravenelli" is distinct from the flaring, net-like "indusium" produced by "Phallus" species like "P. indusiatus". Gleba covers the head and is olive-green to dark brown in color, slimy in texture, and foul smelling. The spores measure 3 to 4.5 µm by 1 to 2 µm, are colorless, elliptical in shape, and smooth in texture. They are thin-walled and covered with a thin, hyaline, sticky coating.

The stalk is hollow and measures 10 to 15 cm tall and 1.5 to 3 cm thick. It can range in color from slightly yellowish to white. At the stalk's base there is usually a white to pink volva. When immature, the fruit body is encapsulated within the volva present as a peridium, which ruptures as the mushroom emerges.

The volva attaches to the substrate with whitish or pinkish rhizomorphs. Rhizomorphs and mycelia that are exposed to air eventually turn whitish in color; those freshly exposed from their substrate usually quickly turn bluish purple. The fungus produces watery and fleshy sclerotia that range in thickness from 1 to 10 mm with a length of up to 30 mm. The sclerotia are irregularly convoluted and lobed, and become hard and horny upon drying. Sclerotia have a color reaction similar to that noted for rhizomorphs, and, after long exposure to air, will gradually turn a uniform dark reddish brown. "Phallus ravenelli" is considered edible if in the egg form, and has a "mild" taste. The foul odor of mature mushrooms would dissuade most from collecting for the table.

Naming

"Phallus ravenelli" is often confused with "P. impudicus" and "P. hadriani". "P. impudicus" has a highly reticulate cap under the gleba. "P. hadriani" also has a pitted cap, and occurs less frequently than "P. ravenelii". The widespread species "Itajahya galericulata" has a roughly spherical cap of several overlapping spongy tissue layers with gleba sandwiched in-between. "Phallus rugulosus" is tall, thin, pale orange, and tapers towards the smooth cap. The cap is blackish olive in color, while the volva is oval and white. It is found in the eastern and southern United States and China. "P. granulosodenticulatus" is a rare Brazilian species with a superficial resemblance to "P. ravenelii". Apart from its distribution, it is distinguished from "P. ravenelii" by its smaller fruit bodies up to 9 cm tall, a cogged cap margin, and somewhat larger spores that measure 3.8–5 by 2–3 µm.

Distribution

Ravenel's stinkhorn is widespread in eastern North America, from Quebec in the north, south to Florida and west to Iowa and Ohio. West of the Mississippi, the common stinkhorn becomes more dominant. In the early 1900s, Lloyd called it the most common phalloid in the United States. The fungus is also found in Costa Rica.

As a saprobic mushroom, or decomposer of organic material, Ravenel's stinkhorn can be found in almost any habitat that includes decaying wood. They are most often found growing in groups, though occasionally singly, on wood chips, rotten tree stumps or sawdust. They are common in urban flowerbeds, parks and lawns, as well as in meadows, cultivated areas and woods. The foul odor of the gleba attracts insects that walk and feed on the spore-bearing surface, and later disseminate the sticky spores to other locales.

Habitat

Ravenel's stinkhorn is widespread in eastern North America, from Quebec in the north, south to Florida and west to Iowa and Ohio. West of the Mississippi, the common stinkhorn becomes more dominant. In the early 1900s, Lloyd called it the most common phalloid in the United States. The fungus is also found in Costa Rica.

As a saprobic mushroom, or decomposer of organic material, Ravenel's stinkhorn can be found in almost any habitat that includes decaying wood. They are most often found growing in groups, though occasionally singly, on wood chips, rotten tree stumps or sawdust. They are common in urban flowerbeds, parks and lawns, as well as in meadows, cultivated areas and woods. The foul odor of the gleba attracts insects that walk and feed on the spore-bearing surface, and later disseminate the sticky spores to other locales.