Bridal Veil Stinkhorn

Appearance

Immature fruit bodies of "P. indusiatus" are initially enclosed in an egg-shaped to roughly spherical subterranean structure encased in a peridium. The "egg" ranges in color from whitish to buff to reddish-brown, measures up to 6 cm in diameter, and usually has a thick mycelial cord attached at the bottom.

As the mushroom matures, the pressure caused by the enlargement of the internal structures cause the peridium to tear and the fruit body rapidly emerges from the "egg". The mature mushroom is up to 25 cm tall and girded with a net-like structure called the indusium that hangs down from the conical to bell-shaped cap.

The netlike openings of the indusium may be polygonal or round in shape. Well-developed specimens have an indusium that reaches to the volva and flares out somewhat before collapsing on the stalk. The cap is 1.5–4 cm wide and its reticulated surface is covered with a layer of greenish-brown and foul-smelling slime, the gleba, which initially partially obscures the reticulations.

The top of the cap has a small hole. The stalk is 7–25 cm long, and 1.5–3 cm thick. The hollow stalk is white, roughly equal in width throughout its length, sometimes curved, and spongy. The ruptured peridium remains as a loose volva at the base of the stalk. Fruit bodies develop during the night, and require 10–15 hours to fully develop after emerging from the peridium.

They are short-lived, typically lasting no more than a few days. At that point the slime has usually been removed by insects, leaving the pale off-white, bare cap surface exposed. Spores of "P. indusiatus" are thin-walled, smooth, elliptical or slightly curved, hyaline, and measure 2–3 by 1–1.5 μm.

Naming

"Phallus multicolor" is similar in overall appearance, but it has a more brightly coloured cap, stem and indusium, and it is usually smaller. It is found in Australia, Guam, Sumatra, Java, Borneo, Papua New Guinea, Zaire, and Tobago as well as Hawaii. The cap of the Indo-Pacific species "P. merulinus" appears smooth when covered with gleba, and is pale and wrinkled once the gleba has worn off. In contrast, the cap surface of "P. indusiatus" tends to have conspicuous reticulations that remain clearly visible under the gleba. Also, the indusium of "P. merulinus" is more delicate and shorter than that of "P. indusiatus", and is thus less likely to collapse under its own weight. Common in eastern North America and Japan, and widely recorded in Europe, the species "P. duplicatus" has a smaller indusium that hangs 3–6 cm from the bottom of the cap, and sometimes collapses against the stalk.

Found in Asia, Australia, Hawaii, southern Mexico, and Central and South America, "P. cinnabarinus" grows to 13 cm tall, and has a more offensive odor than "P. indusiatus". It attracts flies from the genus "Lucilia", rather than the house flies of the genus "Musca" that visit "P. indusiatus". "P. echinovolvatus", described from China in 1988, is closely related to "P. indusiatus", but can be distinguished by its volva that has a spiky surface, and its higher preferred growth temperature of 30 to 35 °C. "P. luteus", originally considered a form of "P. indusiatus", has a yellowish reticulate cap, a yellow indusium, and a pale pink to reddish-purple peridium and rhizomorphs. It is found in Asia and Mexico.

Distribution

The range of "Phallus indusiatus" is tropical, including Africa South America, Central America, and Tobago. In North America, its range is restricted to Mexico. Asian localities include Indonesia, Malaysia, India, Southern China, Japan, and Taiwan. It has also been collected in Australia.

Food

Like all "Phallus" species, "P. indusiatus" is saprobic—deriving nutrients from breaking down wood and plant organic matter. The fruit bodies grow singly or in groups in disturbed ground and among wood chips. In Asia, it grows among bamboo forests, and typically fruits after heavy rains. The method of reproduction for stinkhorns, including "P. indusiatus", is different from most agaric mushrooms, which forcibly eject their spores. Stinkhorns instead produce a sticky spore mass that has a sharp, sickly-sweet odor of carrion. The cloying stink of mature fruit bodies—detectable from a considerable distance—is attractive to certain insects. Species recorded visiting the fungus include stingless bees of the genus "Trigona", and flies of the families Drosophilidae and Muscidae. Insects assist in spore dispersal by consuming the gleba and depositing excrement containing intact spores to germinate elsewhere. Although the function of the indusium is not known definitively, it may visually entice insects not otherwise attracted by the odour, and serve as a ladder for crawling insects to reach the gleba.