Amanita australis
Encyclopedia
Amanita australis is a species of fungus
in the Amanitaceae
family. It is found only in New Zealand, where it occurs in Leptospermum
and Nothofagus
forest. The species was first described by New Zealand mycologist Greta Stevenson in 1962; in the same publication Stevenson also described what she thought was a unique species, Limacella macrospora, but over 30 years later this was reduced to synonymy with A. australis.
Amanita australis produces small- to medium-sized fruit bodies
, with brown caps
up to 9 cm (3.5 in) in diameter covered with pyramidal warts. The gills on the underside of the cap are white, closely crowded together, and free from attachment to the stem
. The stem, which is up to 9 cm (3.5 in) long and 26 mm (1 in) thick, has a ring
and a bulbous base. The mushroom may be confused with another endemic New Zealand species, A. nothofagi
, but can be distinguished by differences in microscopic characteristics.
by Greta Stevenson in 1962, based on specimens she collected in April 1954 around Lake Rotoiti
in Nelson Lakes National Park
, in New Zealand. In the same publication, Stevenson described Limacella macrospora, collected in 1952 at Day's Bay near Wellington
. Stevenson thought this was a new species different from any previously described Limacella
because of its larger size and amyloid
spores. Austrian mycologist Egon Horak later transferred it to the genus Oudemansiella
, but did not provide a reason for making the new combination. In 1986, Pegler and Young proposed a classification for Oudemansiella based largely on spore
structure, but they excluded O. macrospora, considering it a species of Amanita
. Geoff Ridley examined Stevenson's holotype
material and reduced L. macrosporus to synonymy with A. australis in 1993, explaining:
Although Stevenson originally placed the species in Amanita section Phalloideae because of a perceived similarity to A. citrina, it is now classified in section Validae; many species in this section have bulbous stem bases. Ridley suggests an appropriate common name
would be the "straw flycap", while Rodham Tulloss calls it the "far south Amanita". The specific epithet australis means "southern".
is initially convex, later flattening out or even developing a central depression, and reaching diameters of 20 – wide. The cap margin sometimes splits and rolls back to give a ragged appearance. The centre of the cap is dark buff, honey or isabelline
, becoming paler to buff at the margin. The surface is sticky when young or wet, but dries out with age. The remnants of the volva
form conical to pyramidal warts that are most densely aggregated in the center, but become sparse and low towards the margin. They are initially white then greyish-sepia
or isabelline with white to buff tips.
The gills are crowded closely together, free from attachment to the stem, 6 – wide, and white. The lamellulae (short gills that do not extend fully from the cap edge to the stem) have truncated ends. The stem
is 37 – tall, 6 – in diameter, and narrowest at center. It is hollow, and has an abruptly bulbous base that is between 14 and 38 mm (0.551181102362205 and 1.5 in) in diameter. The surface of the stem above the level of the ring
is white and covered in woolly tufts of mycelia; below the ring it is white with buff to greyish transverse, grooved bands. The base may or may not have a rim of volval remnants that are powdery, and a greyish-buff to greyish-sepia colour. The ring
is membranous, white to buff, first hanging freely then later adhering to the stem. The flesh
of the cap is white, occasionally pale isabelline under the center of the cap; the flesh of the stem is white.
The spore print
is white. The spore
s are typically 9–12 by 8–10.5 µm
, spherical to ellipsoid, and thin-walled. They are hyaline
(translucent), and amyloid
—meaning they will stain bluish-black to black in Melzer's reagent
. The basidia are 43.5–76.5 by 10.5–17 µm, mostly four-spored, and clamped at their bases. There are abundant spherical, elliptic or club-shaped hyaline cells on the gill edges, measuring 16–39.5 by 10.5–27.5 µm. The cap cuticle
is 220–270 µm wide, consisting of a gelatin
ised suprapellis (upper layer) and non-gelatinised subpellis (lower layer). The volval remnants on the cap consist of abundant spherical, club-shaped, or turnip-shaped cells, measuring 10–86 by 9–85 µm. These cells are umber
in colour, and arranged in chains perpendicular to the cap surface, becoming smaller and paler at tip of the wart, subtended by moderately abundant hyphae that are 4–10 µm wide. Clamp connection
s are abundant in the hyphae.
. The two species may be distinguished reliably using microscopy—A. nothofagi does not have clamp connections at the base of the basidia, unlike A. australis.A. australis also bears some resemblance to the eastern North American and east Asian species A. abrupta
, which also has an abruptly bulbous stem base.
l association with Southern Beech (genus Nothofagus
) (including New Zealand Red Beech
, Silver beech, New Zealand Black Beech
, Hard Beech), Manuka
, and Kānuka. The mushroom usually grows solitarily, but has on rare occasions been found growing in groups.
Fungus
A fungus is a member of a large 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, Fungi, which is separate from plants, animals, and bacteria...
in the Amanitaceae
Amanitaceae
Amanitaceae are a family of fungi or mushrooms. The family, also commonly called the Amanita family, is in order Agaricales, gilled mushrooms...
family. It is found only in New Zealand, where it occurs in Leptospermum
Leptospermum
Leptospermum is a genus of about 80-86 species of plants in the myrtle family Myrtaceae. Most species are endemic to Australia, with the greatest diversity in the south of the continent; but one species extends to New Zealand, another to Malaysia, and L. recurvum is endemic to Malaysia.They...
and Nothofagus
Nothofagus
Nothofagus, also known as the southern beeches, is a genus of 35 species of trees and shrubs native to the temperate oceanic to tropical Southern Hemisphere in southern South America and Australasia...
forest. The species was first described by New Zealand mycologist Greta Stevenson in 1962; in the same publication Stevenson also described what she thought was a unique species, Limacella macrospora, but over 30 years later this was reduced to synonymy with A. australis.
Amanita australis produces small- to medium-sized fruit bodies
Basidiocarp
In fungi, a basidiocarp, basidiome or basidioma , is the sporocarp of a basidiomycete, the multicellular structure on which the spore-producing hymenium is borne. Basidiocarps are characteristic of the hymenomycetes; rusts and smuts do not produce such structures...
, with brown caps
Pileus (mycology)
The pileus is the technical name for the cap, or cap-like part, of a basidiocarp or ascocarp that supports a spore-bearing surface, the hymenium. The hymenium may consist of lamellae, tubes, or teeth, on the underside of the pileus...
up to 9 cm (3.5 in) in diameter covered with pyramidal warts. The gills on the underside of the cap are white, closely crowded together, and free from attachment to the stem
Stipe (mycology)
thumb|150px|right|Diagram of a [[basidiomycete]] stipe with an [[annulus |annulus]] and [[volva |volva]]In mycology a stipe refers to the stem or stalk-like feature supporting the cap of a mushroom. Like all tissues of the mushroom other than the hymenium, the stipe is composed of sterile hyphal...
. The stem, which is up to 9 cm (3.5 in) long and 26 mm (1 in) thick, has a ring
Annulus (mycology)
An annulus is the ring like structure sometimes found on the stipe of some species of mushrooms. The annulus represents the remaining part of the partial veil, after it has ruptured to expose the gills or other spore-producing surface. An annulus may be thick and membranous, or it may be cobweb-like...
and a bulbous base. The mushroom may be confused with another endemic New Zealand species, A. nothofagi
Amanita nothofagi
Amanita nothofagi is a species of fungus in the Amanitaceae family. Endemic to New Zealand, the species was first described by mycologist Greta Stevenson in 1962. The fruit bodies have dark brown caps that are up to in diameter and covered with patches of soft greyish-brown scales or warts...
, but can be distinguished by differences in microscopic characteristics.
Taxonomy and classification
Amanita australis was first describedSpecies description
A species description or type description is a formal description of a newly discovered species, usually in the form of a scientific paper. Its purpose is to give a clear description of a new species of organism and explain how it differs from species which have been described previously, or are...
by Greta Stevenson in 1962, based on specimens she collected in April 1954 around Lake Rotoiti
Lake Rotoiti, Tasman
Lake Rotoiti is lake in the Tasman Region of New Zealand. It is a substantial mountain lake within the borders of the Nelson Lakes National Park. The lake is fed by the Travers River, water from it flows into the Buller River. The greatest depth is 82 metres and it is surrounded by beech forest...
in Nelson Lakes National Park
Nelson Lakes National Park
Nelson Lakes National Park is located in the South Island of New Zealand.It was formed in 1956 and covers some 1,020 km². It is centered at two large lakes, Rotoiti and Rotoroa. The park also includes surrounding valleys and mountain ranges...
, in New Zealand. In the same publication, Stevenson described Limacella macrospora, collected in 1952 at Day's Bay near Wellington
Wellington
Wellington is the capital city and third most populous urban area of New Zealand, although it is likely to have surpassed Christchurch due to the exodus following the Canterbury Earthquake. It is at the southwestern tip of the North Island, between Cook Strait and the Rimutaka Range...
. Stevenson thought this was a new species different from any previously described Limacella
Limacella
Limacella is a genus of about 20 species of fungi in the Amanitaceae family in order Agaricales. Some of the species have been classified as members of genus Lepiota....
because of its larger size and amyloid
Amyloid (mycology)
In mycology the term amyloid refers to a crude chemical test using iodine in either Melzer's reagent or Lugol's solution, to produce a black to blue-black positive reaction. It is called amyloid because starch gives a similar reaction, and that reaction for starch is also called an amyloid reaction...
spores. Austrian mycologist Egon Horak later transferred it to the genus Oudemansiella
Oudemansiella
Oudemansiella is a genus of fungi in the Physalacriaceae family. According to the Dictionary of the Fungi, the genus contains about 15 species that are widely distributed in tropical and temperate regions. Yang and colleagues revised the genus in a 2009 publication, describing several new species...
, but did not provide a reason for making the new combination. In 1986, Pegler and Young proposed a classification for Oudemansiella based largely on spore
Spore
In biology, a spore is a reproductive structure that is adapted for dispersal and surviving for extended periods of time in unfavorable conditions. Spores form part of the life cycles of many bacteria, plants, algae, fungi and some protozoa. According to scientist Dr...
structure, but they excluded O. macrospora, considering it a species of Amanita
Amanita
The genus Amanita contains about 600 species of agarics including some of the most toxic known mushrooms found worldwide. This genus is responsible for approximately 95% of the fatalities resulting from mushroom poisoning, with the death cap accounting for about 50% on its own...
. Geoff Ridley examined Stevenson's holotype
Holotype
A holotype is a single physical example of an organism, known to have been used when the species was formally described. It is either the single such physical example or one of several such, but explicitly designated as the holotype...
material and reduced L. macrosporus to synonymy with A. australis in 1993, explaining:
The size, shape and amyloid reaction of the spores, the dimensions of the basidia, the presence of clamp connections and lamella margin cells indicate that this is Amanita australis Stevenson and easily fits into the concept of this taxon. ... Macroscopically the specimen lacks the typical pronounced basal bulb to the stipe and volva remnants on the pileus; however, it is not an unknown condition in this taxon.
Although Stevenson originally placed the species in Amanita section Phalloideae because of a perceived similarity to A. citrina, it is now classified in section Validae; many species in this section have bulbous stem bases. Ridley suggests an appropriate common name
Common name
A common name of a taxon or organism is a name in general use within a community; it is often contrasted with the scientific name for the same organism...
would be the "straw flycap", while Rodham Tulloss calls it the "far south Amanita". The specific epithet australis means "southern".
Description
The shape of the A. australis capPileus (mycology)
The pileus is the technical name for the cap, or cap-like part, of a basidiocarp or ascocarp that supports a spore-bearing surface, the hymenium. The hymenium may consist of lamellae, tubes, or teeth, on the underside of the pileus...
is initially convex, later flattening out or even developing a central depression, and reaching diameters of 20 – wide. The cap margin sometimes splits and rolls back to give a ragged appearance. The centre of the cap is dark buff, honey or isabelline
Isabelline (colour)
Isabelline , sometimes called Isabella, is a colour, variously described as pale grey-yellow, pale fawn, pale cream-brown or parchment....
, becoming paler to buff at the margin. The surface is sticky when young or wet, but dries out with age. The remnants of the volva
Volva (mycology)
The volva is a mycological term to describe a cup-like structure at the base of a mushroom that is a remnant of the universal veil. This macrofeature is important in wild mushroom identification due to it being an easily observed, taxonomically significant feature which frequently signifies a...
form conical to pyramidal warts that are most densely aggregated in the center, but become sparse and low towards the margin. They are initially white then greyish-sepia
Sepia (color)
Sepia is a dark brown-grey color, named after the rich brown pigment derived from the ink sac of the common cuttlefish Sepia.The word sepia is the Latinized form of the Greek σηπία, sēpía, cuttlefish.-Sepia in human culture:...
or isabelline with white to buff tips.
The gills are crowded closely together, free from attachment to the stem, 6 – wide, and white. The lamellulae (short gills that do not extend fully from the cap edge to the stem) have truncated ends. The stem
Stipe (mycology)
thumb|150px|right|Diagram of a [[basidiomycete]] stipe with an [[annulus |annulus]] and [[volva |volva]]In mycology a stipe refers to the stem or stalk-like feature supporting the cap of a mushroom. Like all tissues of the mushroom other than the hymenium, the stipe is composed of sterile hyphal...
is 37 – tall, 6 – in diameter, and narrowest at center. It is hollow, and has an abruptly bulbous base that is between 14 and 38 mm (0.551181102362205 and 1.5 in) in diameter. The surface of the stem above the level of the ring
Annulus (mycology)
An annulus is the ring like structure sometimes found on the stipe of some species of mushrooms. The annulus represents the remaining part of the partial veil, after it has ruptured to expose the gills or other spore-producing surface. An annulus may be thick and membranous, or it may be cobweb-like...
is white and covered in woolly tufts of mycelia; below the ring it is white with buff to greyish transverse, grooved bands. The base may or may not have a rim of volval remnants that are powdery, and a greyish-buff to greyish-sepia colour. The ring
Annulus (mycology)
An annulus is the ring like structure sometimes found on the stipe of some species of mushrooms. The annulus represents the remaining part of the partial veil, after it has ruptured to expose the gills or other spore-producing surface. An annulus may be thick and membranous, or it may be cobweb-like...
is membranous, white to buff, first hanging freely then later adhering to the stem. The flesh
Trama (mycology)
In mycology trama is a term for the inner, fleshy portion of a mushroom's basidiocarp, or fruit body. It is distinct from the outer layer of tissue, known as the pileipellis or cuticle, and from the spore-bearing tissue layer known as the hymenium....
of the cap is white, occasionally pale isabelline under the center of the cap; the flesh of the stem is white.
The spore print
Spore print
thumb|300px|right|Making a spore print of the mushroom Volvariella volvacea shown in composite: mushroom cap laid on white and dark paper; cap removed after 24 hours showing pinkish-tan spore print...
is white. The spore
Spore
In biology, a spore is a reproductive structure that is adapted for dispersal and surviving for extended periods of time in unfavorable conditions. Spores form part of the life cycles of many bacteria, plants, algae, fungi and some protozoa. According to scientist Dr...
s are typically 9–12 by 8–10.5 µm
Micrometre
A micrometer , is by definition 1×10-6 of a meter .In plain English, it means one-millionth of a meter . Its unit symbol in the International System of Units is μm...
, spherical to ellipsoid, and thin-walled. They are hyaline
Hyaline
The term hyaline denotes a substance with a glass-like appearance.-Histopathology:In histopathological medical usage, a hyaline substance appears glassy and pink after being stained with haematoxylin and eosin — usually it is an acellular, proteinaceous material...
(translucent), and amyloid
Amyloid (mycology)
In mycology the term amyloid refers to a crude chemical test using iodine in either Melzer's reagent or Lugol's solution, to produce a black to blue-black positive reaction. It is called amyloid because starch gives a similar reaction, and that reaction for starch is also called an amyloid reaction...
—meaning they will stain bluish-black to black in Melzer's reagent
Melzer's Reagent
Melzer's reagent is a chemical reagent used by mycologists to assist with the identification of fungi.-Composition:...
. The basidia are 43.5–76.5 by 10.5–17 µm, mostly four-spored, and clamped at their bases. There are abundant spherical, elliptic or club-shaped hyaline cells on the gill edges, measuring 16–39.5 by 10.5–27.5 µm. The cap cuticle
Pileipellis
thumb|300px||right|The cuticle of some mushrooms, such as [[Russula mustelina]] shown here, can be peeled from the cap, and may be useful as an identification feature....
is 220–270 µm wide, consisting of a gelatin
Gelatin
Gelatin is a translucent, colorless, brittle , flavorless solid substance, derived from the collagen inside animals' skin and bones. It is commonly used as a gelling agent in food, pharmaceuticals, photography, and cosmetic manufacturing. Substances containing gelatin or functioning in a similar...
ised suprapellis (upper layer) and non-gelatinised subpellis (lower layer). The volval remnants on the cap consist of abundant spherical, club-shaped, or turnip-shaped cells, measuring 10–86 by 9–85 µm. These cells are umber
Umber
Umber is a natural brown clay pigment which contains iron and manganese oxides. The color becomes more intense when calcined , and the resulting pigment is called burnt umber. Its name derives from the Latin word umbra and was originally extracted in Umbria, a mountainous region of central Italy,...
in colour, and arranged in chains perpendicular to the cap surface, becoming smaller and paler at tip of the wart, subtended by moderately abundant hyphae that are 4–10 µm wide. Clamp connection
Clamp connection
A clamp connection is a structure formed by growing hyphal cells of certain fungi. It is created to ensure each septum, or segment of hypha separated by crossed walls, receives a set of differing nuclei, which are obtained through mating of hyphae of differing sexual types...
s are abundant in the hyphae.
Similar species
Amanita australis mushrooms that have lost their warts and have had the colours faded may resemble another New Zealand species, A. nothofagiAmanita nothofagi
Amanita nothofagi is a species of fungus in the Amanitaceae family. Endemic to New Zealand, the species was first described by mycologist Greta Stevenson in 1962. The fruit bodies have dark brown caps that are up to in diameter and covered with patches of soft greyish-brown scales or warts...
. The two species may be distinguished reliably using microscopy—A. nothofagi does not have clamp connections at the base of the basidia, unlike A. australis.A. australis also bears some resemblance to the eastern North American and east Asian species A. abrupta
Amanita abrupta
Amanita abrupta, commonly known as the abrupt-bulbed Lepidella, is a species of fungus in the Amanitaceae family of mushrooms. Named for the characteristic shape of its fruit bodies, this white Amanita has a slender stem, a cap covered with conical white warts, and an "abruptly enlarged" swollen base...
, which also has an abruptly bulbous stem base.
Habitat and distribution
Amanita australis is found only on the north and south islands of New Zealand, where it grows in a mycorrhizaMycorrhiza
A mycorrhiza is a symbiotic association between a fungus and the roots of a vascular plant....
l association with Southern Beech (genus Nothofagus
Nothofagus
Nothofagus, also known as the southern beeches, is a genus of 35 species of trees and shrubs native to the temperate oceanic to tropical Southern Hemisphere in southern South America and Australasia...
) (including New Zealand Red Beech
Nothofagus fusca
Nothofagus fusca is a species of Nothofagus, endemic to New Zealand, where it occurs on both the North Island and South Island. Generally it is found on lower hills and inland valley floors where soil is fertile and well drained.It is a medium-sized evergreen tree growing to 35 m tall...
, Silver beech, New Zealand Black Beech
Nothofagus solandri
Nothofagus solandri is a species of Nothofagus, endemic to New Zealand, where it occurs on both the North Island and the South Island. There are two varieties, var. solandri, the New Zealand Black Beech, which occurs at low altitudes up to the mountains, and var...
, Hard Beech), Manuka
Leptospermum scoparium
Leptospermum scoparium is a shrub or small tree native to New Zealand and southeast Australia. Evidence suggests that L. scoparium originated in Australia before the onset of the Miocene aridity and dispersed relatively recently from Eastern Australia to New Zealand. It is likely that on arrival...
, and Kānuka. The mushroom usually grows solitarily, but has on rare occasions been found growing in groups.
External links
- New Zealand Land Care Images