Death cap

Description:

The death cap has a large and imposing epigeous (aboveground) fruiting body (basidiocarp), usually with a pileus (cap) from 5 to 15 cm (2–6 in) across, initially rounded and hemispherical, but flattening with age.[17] The color of the cap can be pale-, yellowish-, or olive-green, often paler toward the margins and often paler after rain. The cap surface is sticky when wet and easily peeled, a troublesome feature, as that is allegedly a feature of edible fungi.[18] The remains of the partial veil are seen as a skirtlike, floppy annulus usually about 1.0 to 1.5 cm (0.4–0.6 in) below the cap. The crowded white lamellae (gills) are free. The stipe is white with a scattering of grayish-olive scales and is 8 to 15 cm (3–6 in) long and 1 to 2 cm (3/8–3/4 in) thick, with a swollen, ragged, sac-like white volva (base).[17] As the volva, which may be hidden by leaf litter, is a distinctive and diagnostic feature, it is important to remove some debris to check for it.[19] The smell has been described as initially faint and honey-sweet, but strengthening over time to become overpowering, sickly-sweet and objectionable.[20] Young specimens first emerge from the ground resembling a white egg covered by a universal veil, which then breaks, leaving the volva as a remnant. The spore print is white, a common feature of Amanita. The transparent spores are globular to egg-shaped, measure 8–10 μm (0.3–0.4 mil) long, and stain blue with iodine.[20] The gills, in contrast, stain pallid lilac or pink with concentrated sulfuric acid

Habitat:

The death cap is native to Europe, where it is widespread.[23] It is found from the southern coastal regions of Scandinavia in the north, to Ireland in the west, east to Poland and western Russia,[15] and south throughout the Balkans, in Italy, Spain and Portugal, and in Morocco and Algeria in north Africa.[24] In west Asia it has been reported from forests of northern Iran.[25] There are records from further east into Asia but these have yet to be confirmed as A. phalloides.[26] It is ectomycorrhizally associated with a number of tree species and is symbiotic with them. In Europe, these include a large number of hardwood and, less frequently, conifer species. It appears most commonly under oaks, but also under beeches, chestnuts, horse-chestnuts, birches, filberts, hornbeams, pines, and spruces.[13] In other areas, A. phalloides may also be associated with these trees or with only some species and not others. In coastal California, for example, A. phalloides is associated with coast live oak, but not with the various coastal pine species, such as Monterey pine.[27] In countries where it has been introduced, it has been restricted to those exotic trees with which it would associate in its natural range. There is, however, evidence of A. phalloides associating with hemlock and with genera of the Myrtaceae: Eucalyptus in Tanzania[28] and Algeria,[24] and Leptospermum and Kunzea in New Zealand.[13][29] This suggests the species may have invasive potential.[26] By the end of the 19th century, Charles Horton Peck had reported A. phalloides in North America.[30] However, in 1918, samples from the eastern United States were identified as being a distinct though similar species, A. brunnescens, by G. F. Atkinson of Cornell University.[31] By the 1970s, it had become clear that A. phalloides actually does occur in the United States, apparently having been introduced from Europe alongside chestnuts, with populations on the West and East Coasts.[31][32] Although a 2006 historical review concluded the East Coast populations were introduced, the origins of the West Coast populations remained unclear, owing to the scantiness of historical records.[26] However, a 2009 genetic study provided strong evidence for the introduced status of the fungus on the west coast of North America.[33] Amanita phalloides has been conveyed to new countries across the Southern Hemisphere with the importation of hardwoods and conifers. Introduced oaks appear to have been the vector to Australia and South America; populations under oaks have been recorded from Melbourne and Canberra[34][35] (where two people died in January 2012, of four who were poisoned[36]) and Adelaide,[37] as well as Uruguay.[38] It has been recorded under other introduced trees in Argentina[39] and Chile.[40] Pine plantations are associated with the fungus in Tanzania[28] and South Africa, where it is also found under oaks and poplars.

Notes:

Toxicity Warning sign in Canberra, Australia As the common name suggests, the fungus is highly toxic, and is responsible for the majority of fatal mushroom poisonings worldwide.[1] Its biochemistry has been researched intensively for decades,[31] and 30 grams (1 oz), or half a cap, of this mushroom is estimated to be enough to kill a human.[42] In 2006, a family of three in Poland was poisoned, resulting in one death and the two survivors requiring liver transplants.[43] Some authorities strongly advise against putting suspected death caps in the same basket with fungi collected for the table and to avoid touching them.[18][44] Furthermore, the toxicity is not reduced by cooking, freezing, or drying spotted in a mix forest a few km from my house