Hygrophoropsis aurantiaca

Template:Short description
Template:Featured article
Template:Stack begin
Template:Italic title
Template:Taxobox
Template:Mycomorphbox
Template:Stack end

***Hygrophoropsis aurantiaca***, commonly known as the **false chanterelle**, is a species of fungus in the family Hygrophoropsidaceae.
It is found across several continents, growing in woodland and heathland, and sometimes on woodchips used in gardening and landscaping. Fruit bodies (mushrooms) are yellow–orange with a funnel-shaped cap up to Template:Convert across that has a felt-like surface. The thin, often forked gills on the underside of the cap run partway down the length of the otherwise smooth stipe. Reports on the mushroom's edibility vary – it can serve as food, though not a particularly flavorful one, or it can be mildly poisonous.

Austrian naturalist Franz Xaver von Wulfen described the false chanterelle in 1781, noting both its resemblance with the true chanterelles and people's propensity to confuse them. The false chanterelle was then placed in the genus *Clitocybe*, but it was later observed that its forked gills and dextrinoid spores indicated a relationship to *Paxillus*. Genetic analysis has confirmed that it belongs to the order Boletales and is more closely related to boletes.

## Taxonomy

Austrian naturalist Franz Xaver von Wulfen described the false chanterelle as *Agaricus aurantiacus* in 1781, reporting that it appeared in the fir tree forests around Klagenfurt in October. He added that it could be confused with the chanterelle by the inexperienced, but that its true nature was very different; in contrast to its edible lookalike, he described it as "kind of pernicious". The specific epithet is the Latin word *aurantiacus*, meaning "orange". James Sowerby illustrated it and gave it the name *Agaricus subcantharellus*, describing it as a "perhaps unfavourable" variety of *A. cantharellus* (chanterelle). The fungus was placed in the genus *Merulius* by Johann Friedrich Gmelin in 1792, and then *Cantharellus* by Elias Fries in 1821. Bernhard Studer-Steinhäuslin concluded it could only be classified in the genus *Clitocybe* in 1900, based on its white spores, decurrent gills and lack of a ring. It was elevated to the status of genus in Emile Martin-Sans' 1929 publication *L'Empoisonnement par les champignons et particulièrement les intoxications dues aux Agaricacées du groupe des Clitocybe et du groupe des Cortinarius*, with authorship attributed to René Maire. Martin-Sans concurred with Maire's assessment of *Hygrophoropsis*, suggesting that it represented a form intermediate between *Cantharellus* and *Clitocybe*, and was thus worthy of generic ranking. The genus name refers to a resemblance to the genus *Hygrophorus*. It is commonly known as the false chanterelle.

 File:Coloured Figures of English Fungi or Mushrooms - t. 413.jpg
Two varieties described by Derek Reid in 1972, *H. aurantiaca* var. *macrospora* and *H. aurantiaca* var. *rufa*, have since been promoted to distinct species status as *H. macrospora* (1996) and *H. rufa* (2008). Two other varieties of the fungus have been described, but they are not considered to have independent taxonomic significance by Index Fungorum: var. *nana* (Singer 1946), characterized by a small fruit body; and var. *robusta* (Antonín 2000), characterized by a robust fruit body and an odour similar to Maggi seasoning sauce. Pale forms of the fungus are sometimes referred to as var. *pallida*. This taxon was first published by Robert Kühner and Henri Romagnesi in 1953, but later considered invalid as it did not conform to nomenclatural rules. Variety *nigripes*, a taxon with a black-brown stipe, is invalid for similar reasons. *H. aurantiaca* var. *pallida* was published validly in 1995.

In 1979, Egon Horak suggested that *H. aurantiaca* and the New Zealand taxon *H. coacta* were the same species, but neither Index Fungorum nor MycoBank accept this synonymy. According to MycoBank, *H. aurantiaca* has several heterotypic synonyms, that is, they have different types, but are considered the same species:

* *Agaricus alectorolophoides* Schaeff. (1774)
* *Agaricus subcantharellus* Sowerby (1809)
* *Cantharellus brachypodus* Chevall. (1826)
* *Cantharellus ravenelii* Berk. & M.A.Curtis (1853)
* *Merulius brachypodes* (Chevall.) Kuntze (1891)

*Hygrophoropsis aurantiaca* has been confused with the true chanterelles (genus *Cantharellus*) because of overall similarities in appearance. However, the forked gills, frequently off-centre stipe placement, and dextrinoid spores of *H. aurantiaca* suggested a relationship with *Paxillus*, prompting Rolf Singer to classify the genus *Hygrophoropsis* in the family Paxillaceae in 1946. Several pigments have been identified from the fungus, including the orange variegatic acid, methyl variegate, the red variegatorubin, and several derivatives of pulvinic acid. The presence of these pigments suggests a chemotaxic relationship with the Boletaceae, Coniophoraceae, and Paxillaceae—families of Boletales with members that have similar compounds. Molecular phylogenetic analysis confirmed its affinity lay in the order Boletales in 1997, though later research showed it is not closely related to *Paxillus* or other gilled members of the order.

## Description

 File:Hygrophoropsis aurantiaca 52882.jpg
The false chanterelle has a golden-orange cap up to Template:Convert across, initially convex but becoming funnel-shaped as the mushroom matures. The cap margin, which remains rolled in a little, becomes wavy or lobed in age. The cap surface is covered with a fine down. The decurrent gill-like structures are narrow and forked, which is a distinctive and distinguishing feature. They are generally a more intense shade of orange than the cap. Along the stipe, the gills may be slightly crimped. The orange stipe is Template:Convert high and Template:Convert thick, and lacks a ring. It often has a darker, brownish, base. The ability to form sclerotia (compact masses of hardened fungal mycelium) has been documented for *H. aurantiaca* in laboratory studies. These structures contain glycogen and protein that may be used as food reserves during spore germination.

The soft, thin flesh ranges from white to yellowish to golden-orange. It has an odour and taste described variously as indistinct, or unpleasant and earthy. The spore print is white to cream. The oval spores are 5.5–7 by 4–4.5 micrometres (µm), with walls that tend to thicken in age. The spores are cyanophilous, meaning that they will readily stain dark blue in methyl blue solution. Staining with Melzer's reagent often produces a dextrinoid (reddish-brown) colour reaction. Basidia (spore-bearing cells) measure 25–40 by 5–8 µm, and can be two-, three-, or four-spored. Cystidia (large sterile cells on the hymenium) are absent. The cap cuticle is in the form of a trichoderm, where the outermost hyphae are roughly parallel, like hairs, perpendicular to the cap surface. These hyphae are 4–15 µm in diameter, and contain intracellular pigments that impart an orange-brown to yellow-brown colouring to the cells. Clamp connections are present in the hyphae.

Teratological (developmentally abnormal) forms of *H. aurantiaca* were reported to occur in the United Kingdom. The fruit bodies of these specimens were club-shaped with a wrinkled upper surface of convoluted gill tissue. The overall morphology of these forms somewhat resembles species of *Clavariadelphus*. Although the cause of this abnormal development is not known with certainty, environmental pollutants or virus infection have been suggested as contributing factors.

### Similar species

Template:Multiple image
Characteristics typically used in the field to distinguish *Hygrophoropsis aurantiaca* from lookalike species include: the soft, dry consistency of its cap; the crowded, decurrent, and forked gills that are saffron to orange coloured; and the lack of any distinctive taste or odour. The false chanterelle can be distinguished from the true chanterelle (*Cantharellus cibarius*) by its deeper orange colour, brown base to the stipe, velvety cap surface, forked gills rather than gill-like ridges, softer (and thinner) flesh, and lack of the characteristic apricot-smell. The cap surface of *Hygrophoropsis fuscosquamula*, found in Britain, has fine brown scales overlaying a dull orange background. *H. rufa* has velvety brown fur covering its cap, while *H. macrospora* has cream gills and stipe. Microscopically, these three species have larger spores than *H. aurantiaca*. *H. tapinia*, found in a range extending from southern Florida to Central America, is set apart from *H. aurantiaca* by its growth on or under deciduous trees (never conifers), and smaller spores, which measure 3.3–4.8 by 2.5–3.3 µm.

Formerly a member of *Hygrophoropsis*, *Aphroditeola olida* is also similar in appearance to *H. aurantiaca* but can be distinguished from the false chanterelle by its smaller, pinkish fruit bodies and candy-like odour. It also has smaller spores. *Chrysomphalina chrysophylla* has a yellowish brown cap and unforked yellow gills. *Cortinarius hesleri*, an eastern North American species that associates with oaks, has a rusty brown spore print and a cortina in young specimens. The poisonous jack-o'-lantern mushrooms (genus *Omphalotus*) comprise another group of lookalikes; however, they have straight, non-forked true gills. The European wood-rotting species *Haasiella splendidissima*, sometimes confused with *H. aurantiaca*, is most readily distinguished from the latter by its pink spore print and gills that do not fork.

## Distribution, habitat, and ecology

 File:Hygrophoropsis aurantiaca 562212.jpg
*Hygrophoropsis aurantiaca* is a widely distributed species. In Europe and North America, it is found in both hardwood and conifer forests, as well as heathland, in summer and autumn. In Mexico, it is common in coniferous forests. It fruits from the ground or from decaying wood, on burned areas in forests, and is often found near fallen trees and tree stumps. The fungus can also grow on woodchips used in gardening and landscaping, and so it also appears on roadsides and other locations where this material is used. Fruit bodies occur singly to scattered, or in clusters, and can be very abundant. Generally considered a dry weather mushroom, it can be plentiful when other mushrooms are scarce. Other locations where the false chanterelle has been recorded include Africa, Central and South America, northern Asia, Australia and New Zealand. Populations in California represent a complex of undescribed species that are collectively referred to as *Hygrophoropsis aurantiaca* *sensu lato*.

A saprophytic fungus, *H. aurantiaca* obtains nutrients from forest litter and decomposing wood, causing a brown rot on the wood upon which it grows. A Finnish field study on tree stumps in a forest near Helsinki found that the species colonised them after 6–7 years.

*H. aurantiaca* secretes large amounts of oxalic acid, a reducing agent and relatively strong acid. This stimulates weathering of the humus layer of forest soil, and influences the solubility and turnover of nutrients (particularly phosphorus and nitrogen), which in turn affects their availability for use by forest trees.

## Edibility

The false chanterelle has been described as edible (though not tasty) by some experts, but other authors report it as potentially poisonous. Indeed, Fries described it as *venenatus*, meaning "poisonous", in 1821. David Arora speculates that the confusion about edibility may be a result of misidentification with the similar-looking but definitely poisonous *Omphalotus* species. However, extracts made from Nigerian collections were mildly toxic to mice. Some people experience gastrointestinal symptoms after eating the mushroom, possibly due to its high levels of the sugar alcohol arabitol. It was eaten, though not especially highly regarded, by the Zapotec people of Ixtlán de Juárez in Oaxaca. The Tepehuán people of northwestern Mexico also occasionally eat the mushroom, which they refer to in their native language as *guin'xacan* ("delightful") or *kia's gio'* ("iguana lard"); there, it is commonly prepared by roasting over charcoal, or boiling and garnishing with cheese.

## Notes

1. ↑ This taxon is given in the original source as *Haasiella venustissima*; molecular analysis published in 2012 indicates that this is the same species as *H. splendidissima*.

## References

1. ↑ 1.0 1.1 Cite error: Invalid `<ref>` tag; no text was provided for refs named `Jacquin 1781`
2. ↑ 2.0 2.1 Cite error: Invalid `<ref>` tag; no text was provided for refs named `Nilper 1977`
3. ↑ 3.0 3.1 Cite error: Invalid `<ref>` tag; no text was provided for refs named `Sowerby 1809`
4. ↑ Cite error: Invalid `<ref>` tag; no text was provided for refs named `Gmelin 1792`
5. ↑ 5.0 5.1 Cite error: Invalid `<ref>` tag; no text was provided for refs named `Fries 1821`
6. ↑ Cite error: Invalid `<ref>` tag; no text was provided for refs named `Studer 1900`
7. ↑ Cite error: Invalid `<ref>` tag; no text was provided for refs named `Martin-Sans 1929`
8. ↑ Cite error: Invalid `<ref>` tag; no text was provided for refs named `BMS`
9. ↑ Cite error: Invalid `<ref>` tag; no text was provided for refs named `Reid 1972`
10. ↑ Cite error: Invalid `<ref>` tag; no text was provided for refs named `Boekhout 1996`
11. ↑ Cite error: Invalid `<ref>` tag; no text was provided for refs named `Knudsen 2008`
12. ↑ Cite error: Invalid `<ref>` tag; no text was provided for refs named `urlFungorum synonymy: Hygrophoropsis aurantiaca`
13. ↑ 13.0 13.1 13.2 Cite error: Invalid `<ref>` tag; no text was provided for refs named `Singer 1946`
14. ↑ Cite error: Invalid `<ref>` tag; no text was provided for refs named `Antonín 2000`
15. ↑ Cite error: Invalid `<ref>` tag; no text was provided for refs named `Kühner 1953`
16. ↑ Cite error: Invalid `<ref>` tag; no text was provided for refs named `urlFungorum: Hygrophoropsis aurantiaca var. pallida`
17. ↑ Cite error: Invalid `<ref>` tag; no text was provided for refs named `Holec 2013`
18. ↑ Cite error: Invalid `<ref>` tag; no text was provided for refs named `Heykoop 1995`
19. ↑ Cite error: Invalid `<ref>` tag; no text was provided for refs named `Horak 1979`
20. ↑ Cite error: Invalid `<ref>` tag; no text was provided for refs named `urlMycoBank: Hygrophoropsis aurantiaca`
21. ↑ Cite error: Invalid `<ref>` tag; no text was provided for refs named `Schaeffer 1774`
22. ↑ Cite error: Invalid `<ref>` tag; no text was provided for refs named `Chevallier 1826`
23. ↑ Cite error: Invalid `<ref>` tag; no text was provided for refs named `Berkeley 1853`
24. ↑ Cite error: Invalid `<ref>` tag; no text was provided for refs named `Kuntze 1891`
25. ↑ 25.0 25.1 25.2 25.3 25.4 Cite error: Invalid `<ref>` tag; no text was provided for refs named `Arora 1986`
26. ↑ Cite error: Invalid `<ref>` tag; no text was provided for refs named `Besl 1978`
27. ↑ Cite error: Invalid `<ref>` tag; no text was provided for refs named `Bas 1995`
28. ↑ Cite error: Invalid `<ref>` tag; no text was provided for refs named `Nelson 2010`
29. ↑ Cite error: Invalid `<ref>` tag; no text was provided for refs named `Binder 1997`
30. ↑ Cite error: Invalid `<ref>` tag; no text was provided for refs named `Binder 2006`
31. ↑ 31.0 31.1 31.2 31.3 Cite error: Invalid `<ref>` tag; no text was provided for refs named `Kibby 2012`
32. ↑ 32.0 32.1 32.2 32.3 32.4 32.5 32.6 Cite error: Invalid `<ref>` tag; no text was provided for refs named `Courtecuisse 1999`
33. ↑ 33.0 33.1 33.2 33.3 Cite error: Invalid `<ref>` tag; no text was provided for refs named `Phillips 2006`
34. ↑ Cite error: Invalid `<ref>` tag; no text was provided for refs named `Antibus 1989`
35. ↑ 35.0 35.1 35.2 Cite error: Invalid `<ref>` tag; no text was provided for refs named `Buczacki 2012`
36. ↑ 36.0 36.1 36.2 36.3 Cite error: Invalid `<ref>` tag; no text was provided for refs named `Desjarden 2014`
37. ↑ 37.0 37.1 37.2 37.3 37.4 37.5 37.6 Cite error: Invalid `<ref>` tag; no text was provided for refs named `Smith 1975`
38. ↑ Cite error: Invalid `<ref>` tag; no text was provided for refs named `Singer 1972`
39. ↑ Cite error: Invalid `<ref>` tag; no text was provided for refs named `Spooner 2014`
40. ↑ Cite error: Invalid `<ref>` tag; no text was provided for refs named `Lamaison 2005`
41. ↑ Cite error: Invalid `<ref>` tag; no text was provided for refs named `Gómez-Pignataro 1992`
42. ↑ 42.0 42.1 42.2 Cite error: Invalid `<ref>` tag; no text was provided for refs named `Roberts 2011`
43. ↑ 43.0 43.1 Cite error: Invalid `<ref>` tag; no text was provided for refs named `Kuo 2014`
44. ↑ Cite error: Invalid `<ref>` tag; no text was provided for refs named `Bresinsky 1990`
45. ↑ Cite error: Invalid `<ref>` tag; no text was provided for refs named `Vizzini 2012`
46. ↑ 46.0 46.1 46.2 Cite error: Invalid `<ref>` tag; no text was provided for refs named `Miller 2006`
47. ↑ Cite error: Invalid `<ref>` tag; no text was provided for refs named `Guzman 1973`
48. ↑ Cite error: Invalid `<ref>` tag; no text was provided for refs named `Haas 1969`
49. ↑ 49.0 49.1 Cite error: Invalid `<ref>` tag; no text was provided for refs named `Ambali 2008`
50. ↑ 50.0 50.1 Cite error: Invalid `<ref>` tag; no text was provided for refs named `Fransson 2004`
51. ↑ Cite error: Invalid `<ref>` tag; no text was provided for refs named `Hintikka 1993`
52. ↑ Cite error: Invalid `<ref>` tag; no text was provided for refs named `Ammirati 1987`
53. ↑ Cite error: Invalid `<ref>` tag; no text was provided for refs named `Jordan 2004`
54. ↑ Cite error: Invalid `<ref>` tag; no text was provided for refs named `Lindgren 2003`
55. ↑ Cite error: Invalid `<ref>` tag; no text was provided for refs named `Garibay 2007`
56. ↑ Cite error: Invalid `<ref>` tag; no text was provided for refs named `Elizondo 1991`

## External links

* Template:IndexFungorum

Template:Commons

Template:Taxonbar