Phallus indusiatus

Description

Phallus indusiatus is a fungus in the family Phallaceae, or stinkhorns. It has a cosmopolitan distribution in tropical areas and is found in southern Asia, Africa, the Americas, and Australia, where it grows in woodlands and gardens in rich soil and well-rotted woody material. The fruit body of the fungus is characterized by a conical to a bell-shaped cap on a stalk and a delicate lacy "skirt", or indusium, that hangs from beneath the cap and reaches nearly to the ground.

This is an edible mushroom featured as an ingredient in Chinese haute cuisine, it is used in stir-fries and chicken soups. The mushroom, grown commercially and commonly sold in Asian markets, is rich in protein, carbohydrates, and dietary fiber. The mushroom also contains various bioactive compounds and has antioxidant and antimicrobial properties. Phallus indusiatus has a recorded history of use in Chinese medicine extending back to the 7th century AD, and features in Nigerian folklore.

A 2001 publication in the International Journal of Medicinal Mushrooms attempted to determine its efficacy as an aphrodisiac. In the trial involving sixteen women, six self-reported the experience of a mild sexual satisfaction while smelling the fruit body, and the other ten, who received smaller doses, self-reported an increased heart rate. All of the twenty men tested considered the smell displeasing. The study used fruit bodies found in Hawaii, not the edible variety cultivated in China. The study has received criticism. A way to achieve instant sexual satisfaction would be expected to gain much attention and many attempts to reproduce the effect, but none has succeeded. No major science journal has published the study, and there are no studies where the results have been reproduced.

Common names: Bridal Veil Stinkhorn, Bamboo Mushrooms, Bamboo Pith, Long Net Stinkhorn, Crinoline Stinkhorn, Veiled Lady.

Mushroom Identification

1. Fruit Bodies

   Can be found at any time of year. It is fairly easy to find the 'eggs' of this species because they are usually only partly buried in woody debris or leaf letter and the whitish skin stands out clearly. Within the egg, the fruitbody develops. Once the peridium of the egg ruptures to form a volva, the 'horn' emerges in a matter of a few minutes, and then gradually the lacy white veil descends almost to the ground. (The bottom of the veil turns yellowish as it begins to decay.) Fruitbody is typically 15 to 25cm tall; stipe diameter 1.5 to 2.5cm; cap 1.5 to 4cm across.

2. Stem

   The stem is topped by a flat-topped conico-convex cap, broader than the stem, covered in olive-brown spore-bearing gleba. The raised honeycomb texture of the cap is visible beneath the gleba. As soon as the cap emerges from the egg, insects attack it and eat the gleba. Some of the sticky gleba adheres to the legs of the insects; that is how the spores get carried from one location to another. The white stem has the texture and appearance of expanded polystyrene; it persists for just a day or two after the gleba has been consumed by insects.

3. Veil

   From the stem apex, a lace-like skirt or indusium billows out and descends often to substrate level. Like the rest of the fruitbody, the lace is short-lived.

4. Spores

   Ellipsoidal to cylindrical, smooth, 2.5-3.5 x 1-1.5µm.

5. Spore Color

   The slimy gleba, which is dark olive, contains yellowish spores. Their suspension in gleba makes it impossible to produce a conventional spore print.

6. Odor and Taste

   A strong, sickly-sweet odor; no distinctive taste.

7. Habitat

   Phallus indusiatus is found in tropical forests as well as in mulched gardens and other humous-rich disturbed ground.

8. Season

   Throughout the year.

Look-Alikes

1. Phallus multicolor

   Has a yellow skirt.

2. Phallus hadriani

   Which occurs in Britain and Ireland has no skirt and a violet-colored volva; it is found almost always in dunes.

3. Mutinus caninus

   Is much smaller and has a weaker odor; its honeycombed cap is the same diameter as the stipe, and its cap surface is orange rather than white beneath the gleba.

4. Phallus merulinus

   The cap of the Indo-Pacific species 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 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 weight.

5. Phallus duplicatus

   Common in eastern North America and Japan, and widely recorded in Europe, the species has a smaller indusium that hangs 3–6 cm (1.2–2.4 in) from the bottom of the cap and sometimes collapses against the stalk.

6. Phallus cinnabarinus

   Found in Asia, Australia, Hawaii, southern Mexico, and Central and South America, grows to 13 cm (5.1 in) tall, and has a more offensive odor than P. indusiatus. It attracts flies from the genus Lucilia (family Calliphoridae), rather than the houseflies of the genus Musca that visit P. indusiatus.

7. Phallus echinovolvatus

   Described from China in 1988, is closely related to P. indusiatus, but can be distinguished by its volva that has a spiky (echinulate) surface, and its higher preferred growth temperature of 30 to 35 °C (86 to 95 °F).

8. Phallus 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.

Phallus indusiatus Edibility

In the time of China's Qing Dynasty, the species was collected in Yunnan Province and sent to the Imperial Palaces to satisfy the appetite of Empress Dowager Cixi, who particularly enjoyed meals containing edible fungi. It was one of the eight featured ingredients of the "Bird's Nest Eight Immortals Soup" served at a banquet to celebrate her 60th birthday.

Another notable use was a state banquet held for American diplomat Henry Kissinger on his visit to China to reestablish diplomatic relations in the early 1970s. One source writes of the mushroom: "It has a fine and tender texture, fragrance and is attractive, beautiful in shape, fresh and crispy in taste." The dried fungus, commonly sold in Asian markets, is prepared by rehydrating and soaking or simmering in water until tender. Sometimes used in stir-frys, it is traditionally used as a component of rich chicken soups. The rehydrated mushroom can also be stuffed and cooked.

Phallus indusiatus has been cultivated on a commercial scale in China since 1979. In the Fujian Province of China—known for a thriving mushroom industry that cultivates 45 species of edible fungi—P. indusiatus is produced in the counties of Fuan, Jianou, and Ningde. Advances in cultivation have made the fungus cheaper and more widely available; in 1998, about 1,100 metric tons (1,100 long tons; 1,200 short tons) were produced in China. The Hong Kong price for a kilogram of dried mushrooms reached around US $770 in 1982, but had dropped to US $100–200 by 1988. Additional advances led to it dropping further to US $10–20 by 2000. The fungus is grown on agricultural wastes—bamboo-trash sawdust covered with a thin layer of non-sterilized soil. The optimal temperature for the growth of mushroom spawn and fruit bodies is about 24 °C (75 °F), with a relative humidity of 90–95%. Other substrates that can be used for the cultivation of the fungus include bamboo leaves and small stems, soybean pods or stems, corn stems, and willow leaves.

Nutritional analyses of P. indusiatus show that the fruit bodies are over 90% water, about 6% fiber, 4.8% protein, 4.7% fat, and several mineral elements, including calcium, although the mineral composition in the fungus may depend on corresponding concentrations in the growth substrate.

Medicinal Properties

Southern China's Miao people continue to use it traditionally for some afflictions, including injuries and pains, cough, dysentery, enteritis, leukemia, and feebleness, and it has been prescribed clinically as a treatment for laryngitis, leucorrhea, fever, and oliguria (low urine output), diarrhea, hypertension, cough, hyperlipidemia, and in anticancer therapy. Modern science has probed the biochemical basis of these putative medicinal benefits.

The fruit bodies of the fungus contain biologically active polysaccharides. A β-D-glucan called T-5-N and prepared from alkaline extracts has been shown to have anti-inflammatory properties.

Another chemical of interest found in P. indusiatus is hydroxymethylfurfural, which has attracted attention as a tyrosinase inhibitor. Tyrosinase catalyzes the initial steps of melanogenesis in mammals, and is responsible for the undesirable browning reactions in damaged fruits during post-harvest handling and processing, and its inhibitors are of interest to the medical, cosmetics, and food industries. Hydroxymethylfurfural, which occurs naturally in several foods, is not associated with serious health risks. P. indusiatus also contains a unique ribonuclease (an enzyme that cuts RNA into smaller components) possessing several biochemical characteristics that differentiate it from other known mushroom ribonucleases.

Two novel sesquiterpenes, dictyophorine A and B, have been identified from the fruit bodies of the fungus. These compounds, based on the eudesmane skeleton (a common structure found in plant-derived flavors and fragrances), are the first eudesmane derivatives isolated from fungi and were found to promote the synthesis of nerve growth factor in astroglial cells. Related compounds isolated and identified from the fungus include three quinazoline derivatives (a class of compounds rare in nature), dictyoquinazol A, B, and C. These chemicals were shown in laboratory tests to have a protective effect on cultured mouse neurons that had been exposed to neurotoxins. A total synthesis for the dictyoquinazols was reported in 2007.

The fungus has long been recognized to have antibacterial properties: the addition of the fungus to soup broth was known to prevent it from spoiling for several days. One of the responsible antibiotics, albaflavenone, was isolated in 2011. It is a sesquiterpenoid that was already known from the soil bacterium Streptomyces albidoflavus. Experiments have shown that extracts of P. indusiatus have antioxidant in addition to antimicrobial properties.

History

Phallus indusiatus was initially described by French naturalist Étienne Pierre Ventenat in 1798, and sanctioned under that name by Christiaan Hendrik Persoon in 1801.

The fungus was later placed in a new genus, Dictyophora, in 1809 by Nicaise Auguste Desvaux; it was then known for many years as Dictyophora indusiata. Christian Gottfried Daniel Nees von Esenbeck placed the species in Hymenophallus in 1817, as H. indusiatus. Both genera were eventually returned to synonyms of Phallus and the species is now known again by its original name.

The specific epithet is the Latin adjective indūsǐātus, "wearing an undergarment". The former generic name Dictyophora is derived from the Ancient Greek words δίκτυον (diktyon, "net"), and φέρω (pherō, "to bear"), hence "bearing a net".

The Japanese name Kinugasatake (衣笠茸 or キヌガサタケ), derived from the word kinugasa, refers to the wide-brimmed hats that featured a hanging silk veil to hide and protect the wearer's face. A Chinese common name that alludes to its typical growth habitat is "bamboo mushroom" (simplified Chinese: 竹荪; traditional Chinese: 竹蓀; pinyin: zhúsūn).

Synonyms

1. Hymenophallus indusiatus (Vent.) Nees (1817)

2. Dictyophora callichroa Möller

3. Dictyophora indusiata (Vent.) Desv. (1809)

4. Phallus duplicatus Bosc.

Photo sources:

Photo 1 - Author: Alex Popovkin, Bahia, Brazil (CC BY-SA 2.0)

Photo 2 - Author: Carlos Funes (CC BY-SA 4.0)

Photo 3 - Author: Vinayaraj (CC BY-SA 3.0)