''Russula atropurpurea'' is an

edible An edible item is any item that is safe for humans to eat. "Edible" is differentiated from " eatable" because it does not indicate how an item tastes, only whether it is fit to be eaten. Nonpoisonous items found in nature – such as some mushroo ...

member of the genus ''

Russula ''Russula'' is a very large genus composed of around 750 worldwide species of fungi. The genus was described by Christian Hendrik Persoon in 1796. The mushrooms are fairly large, and brightly colored – making them one of the most recognizable ...

''. It is dark vinaceous (red wine-coloured) or purple, and grows with

deciduous In the fields of horticulture and botany, the term deciduous () means "falling off at maturity" and "tending to fall off", in reference to trees and shrubs that seasonally shed Leaf, leaves, usually in the autumn; to the shedding of petals, aft ...

, or occasionally

coniferous Conifers () are a group of conifer cone, cone-bearing Spermatophyte, seed plants, a subset of gymnosperms. Scientifically, they make up the phylum, division Pinophyta (), also known as Coniferophyta () or Coniferae. The division contains a sin ...

trees. It is commonly called the blackish purple Russula, or the purple brittlegill.

Taxonomy

Initially described as ''Agaricus atropurpureus'' by German naturalist Julius von Krombholz in 1845, and placed in ''

'' by his countryman Max Britzelmayr in 1893, the binomial name of this mushroom ''R. atropurpurea'' (Krombh.) Britzelm is accepted as being incorrect, and mycologists cannot agree on a suitable replacement.

Distribution and habitat

''Russula atropurpurea'' appears in late summer and autumn. It is common in the northern

temperate In geography, the temperate climates of Earth occur in the middle latitudes (approximately 23.5° to 66.5° N/S of the Equator), which span between the tropics and the polar regions of Earth. These zones generally have wider temperature ran ...

zones, Europe, Asia, and Eastern North America, and is

mycorrhizal A mycorrhiza (; , mycorrhiza, or mycorrhizas) is a symbiotic association between a fungus and a plant. The term mycorrhiza refers to the role of the fungus in the plant's rhizosphere, the plant root system and its surroundings. Mycorrhizae play ...

with oak (''

Quercus An oak is a hardwood tree or shrub in the genus ''Quercus'' of the beech family. They have spirally arranged leaves, often with lobed edges, and a nut called an acorn, borne within a cup. The genus is widely distributed in the Northern Hemisp ...

''), with which it prefers to live. Favouring acid soil, it is occasionally found with beech (''

Fagus Beech (genus ''Fagus'') is a genus of deciduous trees in the family Fagaceae, native to subtropical (accessory forest element) and temperate (as dominant element of Mesophyte, mesophytic forests) Eurasia and North America. There are 14 accepted ...

''), or pine (''

Pinus A pine is any conifer tree or shrub in the genus ''Pinus'' () of the family Pinaceae. ''Pinus'' is the sole genus in the subfamily Pinoideae. ''World Flora Online'' accepts 134 species-rank taxa (119 species and 15 nothospecies) of pines as c ...

'').

Description

Two views of a mature Purple Brittlegill on Kaien Island

The

cap A cap is a flat headgear, usually with a visor. Caps have crowns that fit very close to the head. They made their first appearance as early as 3200 BC. The origin of the word "cap" comes from the Old French word "chapeau" which means "head co ...

is in diameter. It is dark reddish purple, with a dark; sometimes almost black centre. At first it is convex, but later flattens, and often has a shallow depression. It can also be lighter in colour, or mottled yellowish. The

stem Stem or STEM most commonly refers to: * Plant stem, a structural axis of a vascular plant * Stem group * Science, technology, engineering, and mathematics Stem or STEM can also refer to: Language and writing * Word stem, part of a word respon ...

is firm, white, and turns grey with age. It measures 3–6 cm in length and 1–2 cm in diameter. The closely set and fairly broad

gills A gill () is a respiratory organ that many aquatic organisms use to extract dissolved oxygen from water and to excrete carbon dioxide. The gills of some species, such as hermit crabs, have adapted to allow respiration on land provided they are ...

are adnexed to almost free, and pale cream, giving a

spore print 300px, Making a spore print of the mushroom ''Volvariella volvacea'' shown in composite: (photo lower half) mushroom cap laid on white and dark paper; (photo upper half) cap removed after 24 hours showing warm orange ("tussock") color spore print. ...

of the same colour. The flesh is white; with a fruity smell, similar to apples. It tastes moderately hot. The species '' R. brunneviolacea'', and '' R. romellii'' are similar, though both have darker spore prints. As the fruitbodies mature, the caps become concave to collect water during wet weather, and much of the color washes off the rim.

Spores

The

is Whitish, and the subglobose to globose spores ornamented with warts and ridges measure 7-9 x 6-7 μm.

Edibility

This mushroom is said to be the mildest of the hot-tasting ''Russula'' species. It is

if cooked, although not recommended.

References