Lactarius rufulus
Encyclopedia
Lactarius rufulus, commonly known as the rufous candy cap, is a species of fungus
in the Russulaceae
family. The fruit bodies
have fleshy brownish-red caps
up to 10 cm (3.9 in) wide, and closely spaced pinkish-yellow gills. The stem
is up to 12 cm (4.7 in) long and 3 cm (1.2 in) thick and colored similarly to the cap. The species, known only from California
, Arizona
, and Mexico, grows on the ground in leaf litter near oak
trees. The fruit bodies resembles those of L. rufus
, but L. rufulus tends to grow in clusters at a common base, rather than solitarily or in groups. A distinguishing microscopic characteristic is the near absence of large, spherical cells called sphaerocysts that are otherwise common in Lactarius
species. Lactarius rufulus mushrooms are edible
, and have an odor resembling maple syrup
. They have been used to flavor confections and desserts.
in 1907, based on specimens collected at Stanford University
in California. The type collections were made by A.M. Patterson and S. Nohara, botany students at the Leland Stanford Junior University who made a number of collections during the winter of 1906–07.
Lactarius rufulus is classified in the section Thejogali of the subgenus
Russularia of the genus Lactarius
. The surface characteristics of many species in section Thejogali (as defined by Hesler
and Smith
in 1979) are called rimulose-areolate (irregularly cracked, with the cracks crossing one another) based on a surface with "numerous mounds of inflated cells" paired together with crevices.
The mushroom is commonly
known as the "rufous candy cap".
of L. rufulus is 3 – wide, broadly convex, becoming flattened and eventually shallowly funnel-shaped, sometimes with a slight umbo
. The cap margin (edge) is initially curved inwards but becomes curved upward in maturity. The surface is usually uneven or wrinkled. It is brownish-red at first, but fades to orange-brown with age. The attachment of the gills to the stem is adnate (squarely attached) to subdecurrent (running slightly down the length of the stem). They are packed close together, at first pinkish-yellow, but with age become a darker red or reddish-brown. The gills are not forked, nor do they stain a different color when bruised. The stem
is 4 – long, about 0.5 – thick, nearly equal or slightly enlarged downward, dry, smooth, and reddish-brown. It may be solid or stuffed (filled with cotton-like mycelia), but may become partially hollow with age. The flesh
is firm, white to pinkish-orange, and does not stain when cut. The latex
is scant, yellowish-white on exposure, unchanging, and does not stain tissues. Its taste is acrid. The spore print
is white to creamy yellow.
The mushroom is edible
, with a mild taste and a slight odor of maple syrup
. American author David Arora
suggests that the fruit bodies may be used in a manner similar to the candy cap
mushrooms, despite being not as fragrant. Chefs in the San Francisco Bay Area
have been known to use it for desserts such as ice creams, cakes and caramels.
s are 7–9 by 7–9 µm
, spherical or nearly so, ornamented with a partial to complete reticulum (a system of raised, net-like ridges), with prominences up to 0.5 µm high. The basidia (spore-bearing cells) are both two- and four-spored, and measure 45–52 by 9–11 µm. The cap cuticle
is a poorly formed layer of inflated cells with scattered filamentous pileocystidia (cystidia
on the cap). Somewhat unusual for a Lactarius, L. rufulus lacks or has few swollen cells (sphaerocysts) in the cap and stem.
when dried. Another lookalike is Lactarius thiersii, but it has a smaller cap and stem and has mild-tasting flesh and latex. The flesh and latex of Lactarius rufus
have a strongly acrid taste, and its fruit bodies are stouter and lack an umbo. Additionally, L. rufus typically grows in a caespitose manner—with the fruit bodies clustered at a common base, and has more pallid colors and a more intense odor than L. rufulus. L. vinaceorufescens
has a yellowing latex.
l species, and lives in a mutualistic association with oak
species. The fungus forms an ectomycorrhizae—characterized by an external sheath that surround the rootlets of the oak. The fungus receives soluble carbohydrate
s that are byproducts of the plant's photosynthesis
, while affording the plant greater access to soil nutrients needed for growth. The fruit bodies of L. rufulus grow scattered or in groups on the ground under oak, usually from January to March; their appearance is uncommon. Once thought to be only in California
(where they are most prevalent in the southern part of the state), they were reported from Mexico in 1998, and from Arizona
in 2006.
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 Russulaceae
Russulaceae
The Russulaceae are a family of fungi in the order Russulales. According to a 2008 estimate, the family contains 1243 species. Its species typically have fruit bodies with friable, chalk-like stalks, that break with a distinct crack, somewhat like a carrot but with porous flesh...
family. The 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...
have fleshy brownish-red 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 10 cm (3.9 in) wide, and closely spaced pinkish-yellow gills. 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 up to 12 cm (4.7 in) long and 3 cm (1.2 in) thick and colored similarly to the cap. The species, known only from 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...
, Arizona
Arizona
Arizona ; is a state located in the southwestern region of the United States. It is also part of the western United States and the mountain west. The capital and largest city is Phoenix...
, and Mexico, grows on the ground in leaf litter near oak
Oak
An oak is a tree or shrub in the genus Quercus , of which about 600 species exist. "Oak" may also appear in the names of species in related genera, notably Lithocarpus...
trees. The fruit bodies resembles those of L. rufus
Lactarius rufus
Lactarius rufus is a common, medium sized member of the Lactarius genus, whose many members are commonly known as milkcaps. Known by the common name of the Rufous Milkcap, or the Red Hot Milk Cap in North America...
, but L. rufulus tends to grow in clusters at a common base, rather than solitarily or in groups. A distinguishing microscopic characteristic is the near absence of large, spherical cells called sphaerocysts that are otherwise common in Lactarius
Lactarius
Lactarius is a genus of mushroom-producing fungi. The genus, collectively known commonly as milk-caps, are characterized by the fact that they exude a milky fluid if cut or damaged...
species. Lactarius rufulus mushrooms are edible
Edible mushroom
Edible mushrooms are the fleshy and edible fruiting bodies of several species of fungi. Mushrooms belong to the macrofungi, because their fruiting structures are large enough to be seen with the naked eye. They can appear either below ground or above ground where they may be picked by hand...
, and have an odor resembling maple syrup
Maple syrup
Maple syrup is a syrup usually made from the xylem sap of sugar maple, red maple, or black maple trees, although it can also be made from other maple species such as the bigleaf maple. In cold climates, these trees store starch in their trunks and roots before the winter; the starch is then...
. They have been used to flavor confections and desserts.
Taxonomy
The species was first described by American mycologist Charles Horton PeckCharles 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...
in 1907, based on specimens collected 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...
in California. The type collections were made by A.M. Patterson and S. Nohara, botany students at the Leland Stanford Junior University who made a number of collections during the winter of 1906–07.
Lactarius rufulus is classified in the section Thejogali of the subgenus
Subgenus
In biology, a subgenus is a taxonomic rank directly below genus.In zoology, a subgeneric name can be used independently or included in a species name, in parentheses, placed between the generic name and the specific epithet: e.g. the Tiger Cowry of the Indo-Pacific, Cypraea tigris Linnaeus, which...
Russularia of the genus Lactarius
Lactarius
Lactarius is a genus of mushroom-producing fungi. The genus, collectively known commonly as milk-caps, are characterized by the fact that they exude a milky fluid if cut or damaged...
. The surface characteristics of many species in section Thejogali (as defined by Hesler
Lexemuel Ray Hesler
-External links:* Finding Aid for the Lexemuel Ray Hesler Collection, 1899-1982...
and 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:...
in 1979) are called rimulose-areolate (irregularly cracked, with the cracks crossing one another) based on a surface with "numerous mounds of inflated cells" paired together with crevices.
The mushroom is commonly
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...
known as the "rufous candy cap".
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...
of L. rufulus is 3 – wide, broadly convex, becoming flattened and eventually shallowly funnel-shaped, sometimes with a slight umbo
Umbo (mycology)
thumb|right|[[Cantharellula umbonata]] has an umbo.thumb|right|The cap of [[Psilocybe makarorae]] is acutely papillate.An umbo is a raised area in the center of a mushroom cap. Caps that possess this feature are called umbonate. Umbos that are sharply pointed are called acute, while those that are...
. The cap margin (edge) is initially curved inwards but becomes curved upward in maturity. The surface is usually uneven or wrinkled. It is brownish-red at first, but fades to orange-brown with age. The attachment of the gills to the stem is adnate (squarely attached) to subdecurrent (running slightly down the length of the stem). They are packed close together, at first pinkish-yellow, but with age become a darker red or reddish-brown. The gills are not forked, nor do they stain a different color when bruised. 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 4 – long, about 0.5 – thick, nearly equal or slightly enlarged downward, dry, smooth, and reddish-brown. It may be solid or stuffed (filled with cotton-like mycelia), but may become partially hollow with age. 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....
is firm, white to pinkish-orange, and does not stain when cut. The latex
Latex
Latex is the stable dispersion of polymer microparticles in an aqueous medium. Latexes may be natural or synthetic.Latex as found in nature is a milky fluid found in 10% of all flowering plants . It is a complex emulsion consisting of proteins, alkaloids, starches, sugars, oils, tannins, resins,...
is scant, yellowish-white on exposure, unchanging, and does not stain tissues. Its taste is acrid. 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 to creamy yellow.
The mushroom is edible
Edible mushroom
Edible mushrooms are the fleshy and edible fruiting bodies of several species of fungi. Mushrooms belong to the macrofungi, because their fruiting structures are large enough to be seen with the naked eye. They can appear either below ground or above ground where they may be picked by hand...
, with a mild taste and a slight odor of maple syrup
Maple syrup
Maple syrup is a syrup usually made from the xylem sap of sugar maple, red maple, or black maple trees, although it can also be made from other maple species such as the bigleaf maple. In cold climates, these trees store starch in their trunks and roots before the winter; the starch is then...
. American author David Arora
David Arora
David Arora is an American mycologist, naturalist, and writer. He is the author of two popular books on mushroom identification, Mushrooms Demystified and All That the Rain Promises and More.......
suggests that the fruit bodies may be used in a manner similar to the candy cap
Candy cap
Candy cap or curry milkcap is the English-language common name for several closely related edible species of Lactarius; L. camphoratus, L. fragilis, and L. rubidus...
mushrooms, despite being not as fragrant. Chefs in the San Francisco Bay Area
San Francisco Bay Area
The San Francisco Bay Area, commonly known as the Bay Area, is a populated region that surrounds the San Francisco and San Pablo estuaries in Northern California. The region encompasses metropolitan areas of San Francisco, Oakland, and San Jose, along with smaller urban and rural areas...
have been known to use it for desserts such as ice creams, cakes and caramels.
Microscopic characteristics
The sporeSpore
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 7–9 by 7–9 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 or nearly so, ornamented with a partial to complete reticulum (a system of raised, net-like ridges), with prominences up to 0.5 µm high. The basidia (spore-bearing cells) are both two- and four-spored, and measure 45–52 by 9–11 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 a poorly formed layer of inflated cells with scattered filamentous pileocystidia (cystidia
Cystidium
A cystidium is a relatively large cell found on the hymenium of a basidiomycete , often between clusters of basidia. Since cystidia have highly varied and distinct shapes that are often unique to a particular species or genus, they are a useful micromorphological characteristic in the...
on the cap). Somewhat unusual for a Lactarius, L. rufulus lacks or has few swollen cells (sphaerocysts) in the cap and stem.
Similar species
Lactarius rubidus is similar in appearance to L. rufulus, but it has watery to whey-like latex and develops a strong odor of maple syrup or butterscotchButterscotch
Butterscotch is a type of confectionery whose primary ingredients are brown sugar and butter, although other ingredients such as corn syrup, cream, vanilla, and salt are part of some recipes...
when dried. Another lookalike is Lactarius thiersii, but it has a smaller cap and stem and has mild-tasting flesh and latex. The flesh and latex of Lactarius rufus
Lactarius rufus
Lactarius rufus is a common, medium sized member of the Lactarius genus, whose many members are commonly known as milkcaps. Known by the common name of the Rufous Milkcap, or the Red Hot Milk Cap in North America...
have a strongly acrid taste, and its fruit bodies are stouter and lack an umbo. Additionally, L. rufus typically grows in a caespitose manner—with the fruit bodies clustered at a common base, and has more pallid colors and a more intense odor than L. rufulus. L. vinaceorufescens
Lactarius vinaceorufescens
Lactarius vinaceorufescens, commonly known as the yellow-staining milkcap or the yellow-latex milky, is a poisonous species of fungus in the Russulaceae family. It produces mushrooms with pinkish-cinnamon caps up to wide held by pinkish-white stems up to long. The closely spaced whitish to...
has a yellowing latex.
Ecology, habitat and distribution
Lactarius rufulus is a mycorrhizaMycorrhiza
A mycorrhiza is a symbiotic association between a fungus and the roots of a vascular plant....
l species, and lives in a mutualistic association with oak
Oak
An oak is a tree or shrub in the genus Quercus , of which about 600 species exist. "Oak" may also appear in the names of species in related genera, notably Lithocarpus...
species. The fungus forms an ectomycorrhizae—characterized by an external sheath that surround the rootlets of the oak. The fungus receives soluble carbohydrate
Carbohydrate
A carbohydrate is an organic compound with the empirical formula ; that is, consists only of carbon, hydrogen, and oxygen, with a hydrogen:oxygen atom ratio of 2:1 . However, there are exceptions to this. One common example would be deoxyribose, a component of DNA, which has the empirical...
s that are byproducts of the plant's photosynthesis
Photosynthesis
Photosynthesis is a chemical process that converts carbon dioxide into organic compounds, especially sugars, using the energy from sunlight. Photosynthesis occurs in plants, algae, and many species of bacteria, but not in archaea. Photosynthetic organisms are called photoautotrophs, since they can...
, while affording the plant greater access to soil nutrients needed for growth. The fruit bodies of L. rufulus grow scattered or in groups on the ground under oak, usually from January to March; their appearance is uncommon. Once thought to be only in 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...
(where they are most prevalent in the southern part of the state), they were reported from Mexico in 1998, and from Arizona
Arizona
Arizona ; is a state located in the southwestern region of the United States. It is also part of the western United States and the mountain west. The capital and largest city is Phoenix...
in 2006.
External links
- Mushroom Observer Images