Amanita islandica
From Wikipedia, the free encyclopedia
| Amanita islandica | |
|---|---|
 | |
Scientific classification  | |
| Kingdom: | Fungi |
| Division: | Basidiomycota |
| Class: | Agaricomycetes |
| Order: | Agaricales |
| Family: | Amanitaceae |
| Genus: | Amanita |
| Species: | A. islandica |
| Binomial name | |
| Amanita islandica Melot (1992) | |
Amanita islandica is a species of basidiomycete fungus in the family Amanitaceae,[1] first described in 1992 from specimens collected in Iceland. The delicate, predominantly white mushroom made by the fungus is characterised by its conical to convex cap measuring 6–8 centimetres across, exceptionally tall and slender stipe up to 20 centimetres in height, and distinctive sack-like cup at the base, while lacking the ring around the stem that many other Amanita species have. Native to subarctic and northern European regions, it forms ecological partnerships with birch trees in Iceland and has also been found in Swedish forests growing among birch and spruce, typically in wet, mossy areas.
Amanita islandica is a ringless Amanita (grisette) described in 1992 by the French mycologist Jean-Louis Melot. Its specific epithet islandica refers to Iceland, where the type specimens were collected. Melot's original publication in Documents Mycologiques established this fungus as a distinct species from other grisettes. A. islandica is classified in Amanita subgenus Amanitopsis (also known as section Vaginatae), the group of Amanitas lacking a partial veil (ring).[2] Within the grisettes it is closely related to species like Amanita nivalis and Amanita vaginata, but differs in morphology and genetics.
Description
This fungus produces delicate white basidiocarps (fruiting bodies). The cap is 6–8 cm in diameter, at first narrowly conical then expanding to convex-conical. It is whitish in colour – pure white to faintly yellowish or greyish in the centre with age. The cap surface is smooth and moist (slightly sticky when wet), with a striate margin (grooved edges) but without any warty patches or universal veil remnants. Gills are free, crowded, and white. The stipe is exceptionally long and slender – up to 15–20 cm tall but only 1.4–2 cm thicksvampar.se. The stem is fragile, hollow in part, and tapers upward. It is entirely white and densely covered with white fibrillose scales or floccose (wooly) fragments, especially in its lower portion. At the base of the stipe sits a large, thick, white volva that forms a free, sack-like cup with lobed edges. There is no ring on the stipe, a key feature of this ringless Amanita. The spore print is white; spores are roughly spherical, roughly 9–11 μm in sizes, and lack an amyloid staining reaction. Clamp connections are absent in the hyphae.[2]
