''Cyanoboletus pulverulentus'', commonly known as the ink stain bolete, 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 ...

bolete {{refimprove, date=July 2020 A bolete is a type of mushroom, or fungal fruiting body. It can be identified thanks to a unique mushroom cap. The cap is clearly different from the stem. On the underside of the cap there is usually a spongy surfa ...

mushroom A mushroom or toadstool is the fleshy, spore-bearing fruiting body of a fungus, typically produced above ground, on soil, or on its food source. ''Toadstool'' generally denotes one poisonous to humans. The standard for the name "mushroom" is t ...

. It is found in

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 leaves, usually in the autumn; to the shedding of petals, aft ...

and

mixed forest Temperate broadleaf and mixed forest is a temperate climate terrestrial habitat type defined by the World Wide Fund for Nature, with broadleaf tree ecoregions, and with conifer and broadleaf tree mixed coniferous forest ecoregions. These for ...

s, particularly on moist soil on slopes and under

beech Beech (''Fagus'') is a genus of deciduous trees in the family Fagaceae, native to temperate Europe, Asia, and North America. Recent classifications recognize 10 to 13 species in two distinct subgenera, ''Engleriana'' and ''Fagus''. The ''Engle ...

and

oak An oak is a tree or shrub in the genus ''Quercus'' (; Latin "oak tree") of the beech family, Fagaceae. There are approximately 500 extant species of oaks. The common name "oak" also appears in the names of species in related genera, notably ''L ...

trees. A common species, it is found in northern Asia, Europe, North Africa, Central and northern South America, and eastern North America. All parts of the mushroom will stain dark bluish-black after handling. A recent study has revealed this mushroom hyperaccumulates arsenic and therefore it's consumption should be limited.

Taxonomy

''Boletus pulverulentus'' was first described by German mycologist

Wilhelm Opatowski Wilhelm may refer to: People and fictional characters * William Charles John Pitcher, costume designer known professionally as "Wilhelm" * Wilhelm (name), a list of people and fictional characters with the given name or surname Other uses * Mount ...

in 1836. The

specific epithet In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bot ...

''pulverulentus'' means "covered with powder" and refers to the somewhat dry powdery surface of the young

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. Caps typically have a visor, or no brim at all. They are popular in casual and informal se ...

and stalk. The fungus was transferred to the newly created genus ''

Cyanoboletus ''Cyanoboletus'' is a fungal genus in the family Boletaceae. Circumscribed in 2014, it contains four species: '' C. flavosanguineus'', '' C. rainisii'', '' C. sinopulverulentus'', and the type, '' C. pulverulentus''. The gene ...

'' in 2014, where it is the

type species In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specimen ...

. Based on the 28S rDNA, North American collection of this fungus reported in the Genbank database (accession numbe
KF030313
does not match that from Europe.

Description

The cap is convex, flat when old, dark reddish-brown becoming lighter with age, and grows up to in diameter. The flesh is yellow, with a mild taste and immediately turns blackish-blue when handled. The

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 pinkish-tan spore print. A 3.5-centimeter ...

colour is olive brown, and the stalk is long and slender, bright yellow to orange yellow at the top, and reddish-brown at the base. The mushrooms are

, but not particularly desirable.

Spores In biology, a spore is a unit of sexual or asexual reproduction that may be adapted for dispersal and for survival, often for extended periods of time, in unfavourable conditions. Spores form part of the life cycles of many plants, algae, f ...

are smooth, fusoid (fuse shaped) to elliptical, and measure 11–15 by 4–6

µm The micrometre ( international spelling as used by the International Bureau of Weights and Measures; SI symbol: μm) or micrometer (American spelling), also commonly known as a micron, is a unit of length in the International System of Unit ...

. The

basidia A basidium () is a microscopic sporangium (a spore-producing structure) found on the hymenophore of fruiting bodies of basidiomycete fungi which are also called tertiary mycelium, developed from secondary mycelium. Tertiary mycelium is highly-c ...

(spore-bearing cells) measure 22–35 by 6–9 µm. The

cap cuticle The pileipellis is the uppermost layer of hyphae in the pileus of a fungal fruit body. It covers the trama, the fleshy tissue of the fruit body. The pileipellis is more or less synonymous with the cuticle, but the cuticle generally describes th ...

comprises a tissue layer of undifferentiated

hypha A hypha (; ) is a long, branching, filamentous structure of a fungus, oomycete, or actinobacterium. In most fungi, hyphae are the main mode of vegetative growth, and are collectively called a mycelium. Structure A hypha consists of one or ...

e measuring 3–7 µm wide.

Similar species

The eastern North American lookalike ''

Boletus oliveisporus ''Boletus'' is a genus of mushroom-producing fungi, comprising over 100 species. The genus ''Boletus'' was originally broadly defined and described by Carl Linnaeus in 1753, essentially containing all fungi with hymenial pores instead of gil ...

'' can be distinguished from ''C. pulverulentus'' by the pink to reddish colour in the center section of its stipe.

Habitat and distribution

ectomycorrhiza An ectomycorrhiza (from Greek ἐκτός ', "outside", μύκης ', "fungus", and ῥίζα ', "root"; pl. ectomycorrhizas or ectomycorrhizae, abbreviated EcM) is a form of symbiotic relationship that occurs between a fungal symbiont, or mycobi ...

l species, ''Cyanoboletus pulverulentus'' forms associations with

conifer 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 single ...

ous and

trees, particularly

. Fruit bodies appear on the ground, usually singly, in woodland. The bolete is widely distributed, having been reported from northern Asia, Europe, North Africa, Central and northern South America, and eastern North America. Reports of appearances in western North American could refer to the similar ''

Cyanoboletus rainsii ''Cyanoboletus'' is a fungal genus in the family Boletaceae. Circumscribed in 2014, it contains four species: '' C. flavosanguineus'', '' C. rainisii'', '' C. sinopulverulentus'', and the type, '' C. pulverulentus''. The gene ...

'', which stains greenish-black instead of bluish-black.

References

External links