False Chanterelle

The species has a golden-orange cap ranging from 2–10 cm (3⁄4–4 in) in diameter, 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 1.5–8 cm (5⁄8–3+1⁄8 in) tall and 0.5–1 cm (1⁄4–3⁄8 in) 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 they will readily stain dark blue in methyl blue solution. Staining with Melzer's reagent often produces a dextrinoid (reddish-brown) colour reaction. …

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 North America, it can be found from July–October to the east and September–January on the West Coast. It can be found in Central and South America, and Mexico, where it is common in coniferous forests. It has also been recorded in 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. 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.

A saprophytic fungus, H. aurantiaca obtains nutrients from forest litter and decomposing wood, causing a brown rot on the wood upon which it grows. 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.

The false chanterelle is considered poisonous and may cause serious digestive problems. Among other toxins, it contains high levels of the sugar alcohol arabitol. The mushroom was sometimes described as edible (though not tasty) until 1999. Fries described it as venenatus, meaning "poisonous", in 1821. Considering the species potentially edible, David Arora speculated that it may have been confused with similar-looking but definitely poisonous species of Omphalotus. Italian mycologist Nicola Sitta has reported that the one attributed case of poisoning he knew of could be attributed to an idiosyncratic reaction as only one of three people eating it got symptoms and concludes that it is harmless. It is eaten in Spain and France, and can legally be sold in France and Belgium. It is not recommended in Italy due to its similarity to poisonous species. It is eaten, though not 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.