Agaricus pattersonae
Encyclopedia
Agaricus pattersonae is an edible species of mushroom. It was first described in the literature in 1907 by Charles Horton Peck
, based on specimens found by A. M. Patterson, a botany student at Stanford University
. This species is placed in section Sanguinolenti of genus Agaricus.
, 5–19 cm in diameter, is initially almost hemispherical in shape, transforming to broadly convex and finally to flattened or with edges upturned in age. The cap surface is dry, with fibrils when young, but later the fibrils form large, dark brown appressed squamules (2–9 mm long x 2–5 mm broad). The cap color may be various shades of brown depending on the maturity of the specimen. The cap flesh is typically 1–3 cm thick, firm, white, and stains deep red 20–30 seconds after injury or bruising. The odor immediately after cutting is mild, faintly spicy, but several minutes may be described as 'fruity'. An edible mushroom, the taste of A. pattersonae is described as mild, pleasant, and slightly sweet.
The gills are free in attachment, close, 5–15 mm broad, and marginate. The light-cinnamon color in young specimens turns to a dark blackish brown in age after the spores develop. Bruised gills stain a vinaceous (wine-colored) red.
The stipe
is usually 8–18 cm long x 2.5–4 cm thick with a bulbous shape. The interior is hollow, with the internal cavity being between 5–9 mm thick. The stem context
somewhat fibrous and white in color, except for the basal section which is yellowish. Bruising or cutting results in a red stain after a minute. The surface of the stipe is barely striate above the annulus
, and smooth below except for fragments of the universal veil
. During development the veils rupture and form an upper veil (partial veil
), which initially hangs from the pileus edge, and a lower veil. As the partial veil disintegrates, it often leaves fragments 2–3 mm in size attached to the margin.
The spores are roughly elliptical in shape, 7–8.5 x 5.5–6.5 µm
. The basidia, which may be 1–, 2–, 3–, or 4–spored (although usually 4–spored during active sporulation), are 26–34 x 7–11 µm, cylinder- to club-shaped, with sterigmata that are 2–3 µm long. Cheilocystidia are 12–32 x 6–15 µm in size, almost cylindrical or club-shaped, and may appear clumped or continuous.
) trees, where it grows singly or in groups. Kerrigan notes that is seems to be restricted to mature trees (age 40+ years) located in the coastal counties of California
, although Smith
mentions that it has also been found in the Great Lakes
regions.
Charles Horton Peck
Charles Horton Peck, born March 30, 1833 in Sand Lake, New York, died 1917 in Albany, New York, was an American mycologist of the 19th and early 20th centuries...
, based on specimens found by A. M. Patterson, a botany student at Stanford University
Stanford University
The Leland Stanford Junior University, commonly referred to as Stanford University or Stanford, is a private research university on an campus located near Palo Alto, California. It is situated in the northwestern Santa Clara Valley on the San Francisco Peninsula, approximately northwest of San...
. This species is placed in section Sanguinolenti of genus Agaricus.
Description
The 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...
, 5–19 cm in diameter, is initially almost hemispherical in shape, transforming to broadly convex and finally to flattened or with edges upturned in age. The cap surface is dry, with fibrils when young, but later the fibrils form large, dark brown appressed squamules (2–9 mm long x 2–5 mm broad). The cap color may be various shades of brown depending on the maturity of the specimen. The cap flesh is typically 1–3 cm thick, firm, white, and stains deep red 20–30 seconds after injury or bruising. The odor immediately after cutting is mild, faintly spicy, but several minutes may be described as 'fruity'. An edible mushroom, the taste of A. pattersonae is described as mild, pleasant, and slightly sweet.
The gills are free in attachment, close, 5–15 mm broad, and marginate. The light-cinnamon color in young specimens turns to a dark blackish brown in age after the spores develop. Bruised gills stain a vinaceous (wine-colored) red.
The stipe
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 usually 8–18 cm long x 2.5–4 cm thick with a bulbous shape. The interior is hollow, with the internal cavity being between 5–9 mm thick. The stem context
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....
somewhat fibrous and white in color, except for the basal section which is yellowish. Bruising or cutting results in a red stain after a minute. The surface of the stipe is barely striate above the annulus
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 smooth below except for fragments of the universal veil
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 , for example, which may resemble a small white sphere at this point, is protected by this structure...
. During development the veils rupture and form an upper veil (partial veil
Partial veil
thumb|150px|right|Developmental stages of [[Agaricus campestris]] showing the role and evolution of a partial veilPartial veil is a mycological term used to describe a temporary structure of tissue found on the fruiting bodies of some basidiomycete fungi, typically agarics...
), which initially hangs from the pileus edge, and a lower veil. As the partial veil disintegrates, it often leaves fragments 2–3 mm in size attached to the margin.
The spores are roughly elliptical in shape, 7–8.5 x 5.5–6.5 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...
. The basidia, which may be 1–, 2–, 3–, or 4–spored (although usually 4–spored during active sporulation), are 26–34 x 7–11 µm, cylinder- to club-shaped, with sterigmata that are 2–3 µm long. Cheilocystidia are 12–32 x 6–15 µm in size, almost cylindrical or club-shaped, and may appear clumped or continuous.
Habitat and distribution
The species is associated with cypress (Cupressus macrocarpaCupressus macrocarpa
Cupressus macrocarpa, commonly known as Monterey Cypress or Macrocarpa, is a species of cypress that is endemic to the Central Coast of California. In the wild, the species is confined to two small populations, near Monterey and Carmel, California. These two small populations represent what was...
) trees, where it grows singly or in groups. Kerrigan notes that is seems to be restricted to mature trees (age 40+ years) located in the coastal counties of California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
, although Smith
Alexander H. Smith
Alexander Hanchett Smith was an American mycologist known for his extensive contributions to the taxonomy and phylogeny of the higher fungi, especially the agarics.-Early life:...
mentions that it has also been found in the Great Lakes
Great Lakes
The Great Lakes are a collection of freshwater lakes located in northeastern North America, on the Canada – United States border. Consisting of Lakes Superior, Michigan, Huron, Erie, and Ontario, they form the largest group of freshwater lakes on Earth by total surface, coming in second by volume...
regions.