''Amanita onusta'',
commonly known as the loaded Lepidella, the gunpowder Lepidella or the gunpowder amanita,
is a species of
fungus
A fungus ( : fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, separately from t ...
in the
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 ...
family
Amanitaceae
The Amanitaceae is a family of mushroom-forming fungi. ''Amanita'' Pers. is one of the most specious and best-known fungal genera. The family, also commonly called the amanita family, is in order Agaricales, the gilled mushrooms. The family c ...
. It is characterized by its small to medium-sized
fruit bodies that have white to pale gray
caps
Caps are flat headgear.
Caps or CAPS may also refer to:
Science and technology Computing
* CESG Assisted Products Service, provided by the U.K. Government Communications Headquarters
* Composite Application Platform Suite, by Java Caps, a Ja ...
crowded with roughly conical, pyramidal, or irregular gray warts. The
stipe is whitish-gray with woolly or wart-like
veil
A veil is an article of clothing or hanging cloth that is intended to cover some part of the head or face, or an object of some significance. Veiling has a long history in European, Asian, and African societies. The practice has been prominent ...
remnants, and at the base is a spindle- or turnip-shaped base that is rooted somewhat deeply in the soil. The species is distributed in eastern North America, from
Nova Scotia
Nova Scotia ( ; ; ) is one of the thirteen provinces and territories of Canada. It is one of the three Maritime provinces and one of the four Atlantic provinces. Nova Scotia is Latin for "New Scotland".
Most of the population are native Eng ...
to Mexico, and may be found growing on the ground in
deciduous forest
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, ...
s, particularly those with
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 ...
,
hickory and
chestnut. Fruit bodies smell somewhat like
bleaching powder
Bleach is the generic name for any chemical product that is used industrially or domestically to remove color (whitening) from a fabric or fiber or to clean or to remove stains in a process called bleaching. It often refers specifically, to ...
, and their edibility is unknown, but possibly toxic.
Taxonomy
''Amanita onusta'' was first described in 1874 by American mycologist
Elliot Calvin Howe as ''Agaricus onustus''.
Later, in 1891,
Pier Andrea Saccardo
Pier Andrea Saccardo (23 April 1845 in Treviso, Treviso – 12 February 1920 in Padua) was an Italian botanist and mycologist.
Life
Saccardo studied at the Lyceum in Venice, and then at the Technical Institute of the University of Padua wher ...
transferred the species to the genus ''
Amanita
The genus ''Amanita'' contains about 600 species of agarics, including some of the most toxic known mushrooms found worldwide, as well as some well-regarded edible species. This genus is responsible for approximately 95% of the fatalities resul ...
''.
''Amanita'' authority
Cornelis Bas, writing in his extensive 1969
monograph on the genus,
placed the species in his
stirps
In ancient Rome, a gens ( or , ; plural: ''gentes'' ) was a family consisting of individuals who shared the same nomen and who claimed descent from a common ancestor. A branch of a gens was called a ''stirps'' (plural: ''stirpes''). The ''gen ...
''Microlepis'', subsection ''Solitariae'',
section
Section, Sectioning or Sectioned may refer to:
Arts, entertainment and media
* Section (music), a complete, but not independent, musical idea
* Section (typography), a subdivision, especially of a chapter, in books and documents
** Section sig ...
''Lepidellus''.
This grouping of ''Amanita'' mushroom species also includes ''
A. abrupta'', ''
A. atkinsoniana'', ''A. costaricensis'' (a provisionally named species authored by Tulloss, Halling, & G.M. Muell.), ''A. nitida'' (as Coker
described the species) and ''
A. sphaerobulbosa''.
The
Latin
Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...
epithet ''onustusa'' means "charged, load-carrying, burdened",
and a regular adjective derived from ''onus'', "burden"
(the same word that gave the English ''
onus
Onus, from Latin, indicates accountability/responsibility
Onus may also refer to:
* Blame
* Burden (disambiguation)
* Legal burden of proof (''onus probandi'')
As a surname
* Bill Onus (1906-68), Australian Aboriginal political activist, boom ...
'').
''A. onusta'' is
commonly known as the "loaded Lepidella",
or the "gunpowder Lepidella".
Description
The
fruit bodies of ''Amanita onusta'' have
caps
Caps are flat headgear.
Caps or CAPS may also refer to:
Science and technology Computing
* CESG Assisted Products Service, provided by the U.K. Government Communications Headquarters
* Composite Application Platform Suite, by Java Caps, a Ja ...
that are initially broadly
convex
Convex or convexity may refer to:
Science and technology
* Convex lens, in optics
Mathematics
* Convex set, containing the whole line segment that joins points
** Convex polygon, a polygon which encloses a convex set of points
** Convex polytop ...
but flatten out as they mature, reaching diameters of . The cap surface, grayish-white in color, is ornamented with conical or pyramidal raised warts, or flattened, symmetrically arranged gray to brownish gray, grayish brown or grayish-orange small scales (
squamules) that are densely arranged over the surface.
The squamules are less crowded near the edge of the cap (the margin). The margin does not have
striations
Striations means a series of ridges, furrows or linear marks, and is used in several ways:
* Glacial striation
* Striation (fatigue), in material
* Striation (geology), a ''striation'' as a result of a geological fault
* Striation Valley, in ...
, and is typically fringed with remnants of the
veil
A veil is an article of clothing or hanging cloth that is intended to cover some part of the head or face, or an object of some significance. Veiling has a long history in European, Asian, and African societies. The practice has been prominent ...
. The
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 ...
on the underside of the cap are spaced closely together, and either free or narrowly attached to the stipe. They are white to
cream
Cream is a dairy product composed of the higher-fat layer skimmed from the top of milk before homogenization. In un-homogenized milk, the fat, which is less dense, eventually rises to the top. In the industrial production of cream, this process ...
color, and are interspersed with short lamellulae (gills that do not extend completely from cap margin to stipe).
The gills may look as if they are waterlogged.
The
stipe is long, thick, and tapers slightly upwards. It is solid gray to brownish-gray near base, paler towards the top, and appears cottony (
floccose) or hairy (fibrillose). The bulb at the base of the stipe is roughly spindle- to turnip-shaped, and may root deeply into the soil, especially if the soil is loose.
The short-lived
partial veil
In mycology, a partial veil (also called an inner veil, to differentiate it from the "outer", or universal veil) is a temporary structure of tissue found on the fruiting bodies of some basidiomycete fungi, typically agarics. Its role is to isola ...
is white, and attached just below the top of the stipe. It is sticky and in maturity often clings to the upper part of the stipe, or may have some meagre remnants hanging from the cap margin. The
universal veil
In mycology, a universal veil is a temporary membranous tissue that fully envelops immature fruiting bodies of certain gilled mushrooms. The developing Caesar's mushroom (''Amanita caesarea''), for example, which may resemble a small white sphe ...
remains are arranged in rows of warts and patches of gray to brownish-gray small scales over the upper portion of the bulb; below this, the color is a dirty white. The
flesh
Flesh is any aggregation of soft tissues of an organism. Various multicellular organisms have soft tissues that may be called "flesh". In mammals, including humans, ''flesh'' encompasses muscles, fats and other loose connective tissues, but ...
is firm and white.
Fruit bodies can range in smell from mild to "slightly unpleasant".
The odor has been described as resembling "
chloride of lime
Calcium hypochlorite is an inorganic compound with formula Ca(OCl)2. It is the main active ingredient of commercial products called bleaching powder, chlorine powder, or chlorinated lime, used for water treatment and as a bleaching agent. This ...
",
a smell similar to some bathroom disinfectants containing bleach.
Microscopic characteristics
Viewed in deposit, such as with 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 pinkish-tan spore print. A 3.5-centimeter ...
, the
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, ...
are white. Viewed with a microscope, the spores are broadly
ellipsoid to elongate,
translucent
In the field of optics, transparency (also called pellucidity or diaphaneity) is the physical property of allowing light to pass through the material without appreciable scattering of light. On a macroscopic scale (one in which the dimensions ...
, thin-walled,
amyloid
Amyloids are aggregates of proteins characterised by a fibrillar morphology of 7–13 nm in diameter, a beta sheet (β-sheet) secondary structure (known as cross-β) and ability to be stained by particular dyes, such as Congo red. In the huma ...
, and have dimensions of 8.3–11.6 by 4.9–6.6 μm. 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- ...
(spore-bearing cells) are 38–46 by 9–11
μm, club-shaped, mostly 4-spored but some are 2- or 3- spored, with clamps. The cheilocystidia (
cystidia
A cystidium (plural cystidia) is a relatively large cell found on the sporocarp of a basidiomycete (for example, on the surface of a mushroom gill), often between clusters of basidia. Since cystidia have highly varied and distinct shapes that ar ...
found on the edge of a gill) are 23.3–31.5 by 11.6–15.7 μm, ellipsoid, club- to pear-shaped cells, partly in short rows. 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 ...
is up to 168 μm thick, and consists of thin-walled interwoven
hyphae that are 2–5.3 μm diameter, and gelatinized.
Clamp connection
A clamp connection is a hook-like structure formed by growing hyphal cells of certain fungi. It is a characteristic feature of Basidiomycetes fungi. It is created to ensure that each cell, or segment of hypha separated by septa (cross walls), rec ...
s are present in the hyphae of this species—these are short branches connecting one cell to the previous cell to allow passage of the products of
nuclear division.
Edibility
The edibility of ''A. onusta'' is unknown,
but it has been described as "possibly poisonous"
and inedible.
In general, species of ''Amanita'' are best avoided for consumption because of the prevalence of
toxic
Toxicity is the degree to which a chemical substance or a particular mixture of substances can damage an organism. Toxicity can refer to the effect on a whole organism, such as an animal, bacterium, or plant, as well as the effect on a subs ...
species in that genus.
Similar species
''Amanita onusta'' may be confused with ''A. cinereoconia'' because of the similar gray powdery veil remnants on the cap surface.
''A. cinereoconia'' is distinguished from ''A. onusta'' by the absence of
clamps
Clamp may refer to:
Tools and devices
*Brick clamp, an early method of baking bricks
*Clamp (tool), a device or tool used to hold objects in a fixed relative position (many types listed)
** C-clamp
** C-clamp (stagecraft)
**Riser clamp, a device ...
, its powdery-wooly to powdery-warty cap, as well as the absence of warts or scales at the base of the stipe. ''A. cinereoconia'' also smells distinctly of chloride of lime.
Another similar species is ''A. costaricensis'', found only in Costa Rica. ''A. atkinsoniana'', another North American species, has shorter warts that are spaced further apart than those of ''A. onusta'', and the warts on the basal bulb are arranged in parallel rows.
Habitat and distribution
''Amanita onusta'' grows solitary or scattered on the ground in mixed
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 ...
,
hickory and
chestnut forests from southern
New England
New England is a region comprising six states in the Northeastern United States: Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island, and Vermont. It is bordered by the state of New York (state), New York to the west and by the Can ...
to
Texas
Texas (, ; Spanish: ''Texas'', ''Tejas'') is a state in the South Central region of the United States. At 268,596 square miles (695,662 km2), and with more than 29.1 million residents in 2020, it is the second-largest U.S. state by ...
.
The species has a preference for sandy or loose soils.
Its range extends north to Nova Scotia, Canada,
and south to Mexico.
See also
*
List of ''Amanita'' species
References
Cited books
*
{{Taxonbar, from=Q4033862
onusta
Fungi described in 1874
Fungi of North America
Inedible fungi