Panthercap

Amanita pantherina is currently classified under the family Amanitaceae, although it was previously thought to belong to the family Agaricaceae.⁸ Molecular phylogenetic studies indicate A. pantherina is a close relative to the well-studied Amanita muscaria; however it is most closely related to Amanita subglobosa, a very morphologically similar species that is also differentiated by the presence of clamps at the basidial bases.¹⁶ Phylogenetic research also indicates significant differences between Eurasian and North American varieties of A. pantherina, suggesting a close but relatively old relationship between the two continental populations.⁹

Amanita pantherina physically appears similar to its more well-known relative Amanita muscaria, albeit smaller in size and less vibrantly colored. The cap of the fruiting body of the fungus can vary from yellow-gray to brown, while the stipe is often white or tan.¹⁷ The cap also has a viscid surface when fresh and possesses striate margins.⁸ The cap ranges from 3-18 cm in diameter, and has a convex shape before maturity, growing more planar with age. ^{7, 13} Whitish-brown warts are uniformly distributed across the top of the cap, though they may be washed off by heavy rains. ⁶ The cap primarily consists of filamentous, undifferentiated branching hyphae roughly 1.5-7.5 µm in width.¹⁵ The gills are typically adnexed or free from the stem, closely crowded, and are white in color, becoming melanized with age.^{6, 15} The stipe can vary in length from 4-20 cm and up to 2.5 cm in diameter.⁷ The stipe tapers off to a large white bulb at the base with a skirt-like ring above it. The bulb typically measures around 2-3.5 cm thick.⁶ Within the gills, the basidia lack basal clamps and are typically colorless, possessing 4 sterigmata.^13,9 Spores produced are typically smooth, ellipsoid and apiculate, about 8-14 by 6-10 µm, inamyloid, and either white or colorless with a hyaline appearance.^{7, 6}

Amanita pantherina is an ectomychorrizal species primarily found in coniferous and deciduous forests in temperate to subalpine regions, particularly under conifers such as firs and pines, as well as deciduous aspen species.^{2, 5, 6} They have been found widespread, nearly globally throughout the forests of North and Central America, Europe, Africa, and Asia, although some specimens are believed to be misidentified variants of A. pantherina, or are other species completely, such as its close relative Amanita subglobosa.^{9, 15} A. pantherina can be found fruiting in both spring and fall seasons.⁶

Amanita pantherina contains many of the same toxic, psychoactive compounds as Amanita muscaria in similar concentrations, including isoxazoles such as ibotenic acid (IBO) and muscamol.^{1, 10, 14} Muscamol binds to γ-aminobutyric recepters, producing a mild sedative effect, while IBO serves as an excitatory amino acid, which binds to glutamine receptors, resulting in feelings of agitation and delirium.⁴ Symptoms of poisoning from this species typically begin within an hour and can include anxiety, hallucinations, impaired speech, nausea, seizures, and a deep coma-like sleep.⁴ However, symptoms typically disappear within 6 hours of consumption in mild cases.¹¹ Effects may vary depending on the amount ingested. However, while still toxic, death very rarely occurs as a result of Amanita pantherina consumption. Hospitalization and symptomatic care as needed will help treat a victim suffering from Amanita pantherina poisoning.⁴

Amanita pantherina, commonly referred to as the panther mushroom¹², panther cap^{3, 4}, or European Panther¹⁵, is a toxic basidiomycete fungus belonging to the genus Amanita. Originally thought to be a member of the genus Agaricus, it was first discovered in France and described by Augustin Pyramus de Candolle in 1815 as Agaricus pantherinus. It is generally credited to both de Candolle and Swedish mycologist Elias Magnus Fries, who also described the species as Agaricus pantherina in 1821. The species was later reclassified under the genus Amanita in 1836 by Julius Vincenz von Krombholz to its current name, Amanita pantherina, or more specifically Amanita pantherina var. pantherina.¹⁵

This source provides several high-quality pictures of Amanita pantherina, in addition to helpful information pertaining to taxonomy, morphology, and habitat distribution.

This site provides some helpful information about A. pantherina's morphology, ecology and distribution, and taxonomy, as well as information about its relative species.

This source provides excellent photographs of A. pantherina, as well as extensive background information about the species' morphology, taxonomy, and ecology.