Phallaceae facts for kids
Quick facts for kids Phallaceae |
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| The common stinkhorn | |
Scientific classification  |
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| Kingdom: | Fungi |
| Division: | Basidiomycota |
| Class: | Agaricomycetes |
| Order: | Phallales |
| Family: | Phallaceae Corda (1842) |
| Synonyms | |
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Clathraceae Chevall. 1826 |
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Phallaceae is a family of fungi, commonly known as stinkhorns, within the order Phallales. Stinkhorns have a worldwide distribution, but are especially prevalent in tropical regions. They are known for their foul-smelling, sticky spore masses, or gleba, borne on the end of a stalk called the receptaculum. The characteristic fruiting-body structure, a single, unbranched receptaculum with an externally attached gleba on the upper part, distinguishes the Phallaceae from other families in the Phallales. The spore mass typically smells of carrion or dung, and attracts flies, beetles and other insects to help disperse the spores. Although there is great diversity in body structure shape among the various genera, all species in the Phallaceae begin their development as oval or round structures known as "eggs". The appearance of Phallaceae is often sudden, as gleba can erupt from the underground egg and burst open within an hour. According to a 2008 estimate, the family contains 21 genera and 77 species.
Contents
Description
Species of stinkhorns have gasteroid, or internally produced spores. Fruit bodies originate as a gelatinous, spherical, or egg-shaped structure that may be completely or partially buried underground. The peridium, the outer layer of the egg, is white, or purple/red, with two or three layers. The outer layer is thin, membranous, and elastic, while the inner layer is thicker, gelatinous, and continuous. At maturity, the peridium opens up and remains as a volva at the base of the receptaculum.
The porous mushroom is among the fastest growing in the world, extending by 5 mm per minute, so fast that a crackling sound can be heard. Technically it is not really growing, as it uses a form of cellular origami to increase its size by absorbing water.
The fertile portion of the fruiting body is often borne on the end of a wide, fleshy or spongy stalk (as in the Phallales), which may be cylindrical, star-shaped, or reticulate (forming a network). They may be brightly colored, sometimes with a lattice- or veil-like membrane enclosing and protecting the spores. The spore-containing substance, the gleba, is typically gelatinous, often foul-smelling, and deliquescent (becoming liquid from the absorption of water). The gleba is formed on the exterior face of the cap or the upper part of the receptacle.
The basidia are small and narrowly club-shaped or fusiform, short-lived (evanescent), with four to eight sterigmata. The spores are usually ellipsoid or cylindrical in shape, hyaline or pale brown, smooth, more or less smooth-walled, and truncated at the base.
The gelatinous layer of the stinkhorn (Clathrus ruber) contains high concentrations of potassium, calcium, manganese, and iron. A moderate amount of calcium is found in the receptacle and gleba as well as a high amount of manganese is also found in the gleba. Retaining a high potassium concentration is important for the growth of the stem of the fruiting body called the carpophore, where potassium plays a key component in regulating osmotic pressure. This osmotic pressure helps maintain the shape of the carpophore. The calcium found in the gelatinous layer contributes to the slimy characteristics of the gel and protects the carpophore during growth. The strong adhesive gelatinous layer consists of polysaccharides that are formed by the sequestration of calcium ions. The high manganese and iron concentrations in the gelatinous layer and gleba are theorized to produce enzymes that produce sugars and odorous compounds that play a role in attracting insects.
Stinkhorns are edible, but only at the egg stage when the smell is less strong. The inner layer can be cut out with a knife and eaten raw – it is crisp and crunchy with a radish-like taste.
The mushrooms also contains several pharmaceutical compounds with potential for cancer treatment.
Genera
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- Blumenavia Möller (1895)
- Colus Cavalier & Séchier (1835)
- A genus of four species with fruit bodies that are a short stalk from which six columns arise, joining at the top to form a red, arching, clathrate receptaculum. The gleba is smeared on the inside surface of the receptaculum.
- Pseudoclathrus B. Liu & Y.S. Bau (1980)
Volatile compounds
The number and type of volatile compounds produced by stinkhorn mushrooms changes throughout its life course. When the stinkhorn is still in its egg stage, the total amount of volatile substances is relatively low. The sulfuric odorous compounds (that attract insects) is absent. During this stage the mushroom’s veil covers up the slime covered cap that contains the spores. When the stinkhorn grows into a more mature-fruit body, there are over twenty-two volatile compounds found in the mature-fruit bodies including dimethyl oligosulfides, aroma-active phenylalanines and various terpenoids that act as insect attractants. In an over-ripe stinkhorn, forty-one volatile components are present, many of which also act as insect attractants. Dimethyl oligosulfides are not as commonly found in over-ripe fruit as they were in the mature fruit bodies since many of the insects already carried the smelly slime away.
The stinkhorn contains compounds of carrion, such as oligosulfides, and of feces, such as phenol, indole and p-cresol. This provides evidence for mimicry of carrion and feces and convergence in the putrid scents of fungus. The stinkhorn’s scent is similar to that of rotten meat and dog feces. This scent profile supports the assumption that the stinkhorn mimics fly brood sites and food sources. The flies are being lured in by the exploitation of their innate attraction to smell of the decaying animal matter that the stinkhorn gives off.
See also
In Spanish: Phallaceae para niños
