Lactarius fallax

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Lactarius fallax
Lactarius fallax 73918.jpg
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Fungi
Division: Basidiomycota
Class: Agaricomycetes
Order: Russulales
Family: Russulaceae
Genus: Lactarius
Species:
L. fallax
Binomial name
Lactarius fallax
A.H.Sm. & Hesler (1962)
Synonyms [1]

Lactarius picinus var. maritimusA.H.Sm. & Hesler (1962)

Contents

Lactarius fallax
Information icon.svg
Gills icon.png Gills on hymenium
Depressed cap icon.svg Cap is depressed
Decurrent gills icon2.svg Hymenium is decurrent
Bare stipe icon.svg Stipe is bare
Transparent spore print icon.svg
Spore print is yellow
Mycorrhizal fungus.svgEcology is mycorrhizal
Mycomorphbox Question.pngEdibility is unknown

Lactarius fallax, commonly known as the velvety milk cap, is a species of fungus in the family Russulaceae. Found in both spruce and mixed conifer forests, it is a fairly common species in the Pacific Northwest region of North America, with a northerly range extending to Alaska. Its fruit bodies are medium-sized, with velvety, brown to blackish caps up to 3–9 cm (1.2–3.5 in) in diameter bearing a distinct pointed umbo. The caps are supported by velvety stems up to 6 cm (2.4 in) long and 1.5 cm (0.6 in) thick. The mushroom oozes a whitish latex when it is cut, and injured tissue eventually turns a dull reddish color. The eastern North American and European species Lactarius lignyotus is closely similar in appearance, but can be distinguished by its differing range.

Taxonomy and classification

The species was originally described by American mycologists Alexander H. Smith and Lexemuel Ray Hesler in a 1962 publication. [2] Smith made the initial collection in late October 1944, in Rhododendron, Oregon. The publication also described the variety Lactarius fallax var. concolor based on specimens collected in Mount Hood. According to Smith and Hesler, this variety had been to that point generally identified as Lactarius lignyotus in the Pacific Northwest. They described the variety L. lignyotus var. americanus to account for differences such as "spore ornamentation, distant gills at maturity, and the typically slightly acrid taste". [2] However, in their 1979 monograph of North American Lactarius species, they considered L. lignyotus var. americanus to be equivalent (and thus synonymous) to L. fallax var. concolor. [1] The specific epithet fallax is derived from the Latin word "deceptive". [3] The mushroom is commonly known as the "velvety milk cap". [4]

Lactarius fallax is classified in the section Plinthogalus of the subgenus Plinthogalus of the genus Lactarius . Species in this section have brown to blackish caps, and a cap cuticle that contains a dissolved brown pigment. The cuticle of most species is of the trichoderm type—where the outermost hyphae emerge roughly parallel, like hairs, perpendicular to the cap surface. [5]

Description

In the main variety L. fallax var. fallax, the gill edges are brown, similar in color to the cap. Lactarius fallax 73919.jpg
In the main variety L. fallax var. fallax, the gill edges are brown, similar in color to the cap.

The cap of L. fallax is 3–9 cm (1.2–3.5 in) wide, ranging in shape from convex to nearly flat with a small umbo, expanding to plane or becoming shallowly depressed, with or without the umbo. The margin (cap edge) is even or scalloped. The cap surface is dry and velvety, finely wrinkled over the center, azonate (without concentric lines), and dark sooty brown to blackish. The gills are attached to subdecurrent (running shortly down the length of the stem), narrow, crowded, not forked, white at first, and become creamy buff with age. The edges of the gills are brown like the cap, and slowly stain vinaceous (redwine-colored) when bruised. There are several tiers of lamellulae (short gills that do not reach the stem) interspersed among the full-length gills. The stem is 2.5–6 cm (1.0–2.4 in) long, 8–15 mm (0.3–0.6 in) thick, nearly equal in width throughout, dry, solid, unpolished or velvety, and a paler brown than the cap. The flesh is thin, brittle, staining pale vinaceous. The odor is not distinctive, and the taste mild or faintly acrid. The latex is copious, white on exposure, unchanging, slowly staining flesh and gills vinaceous. The spore print is yellowish. The edibility of the mushroom has not been officially documented. [6] The species is one of several brown to nearly black milkcaps that are, according to David Arora, "notable for their beauty, and therefore likely to attract the attention of even the casual collector." [4]

The variety Lactarius fallax var. concolor is nearly identical to the main species in appearance and distribution, but has gill edges that are colored like the gill face. [2]

Microscopic characteristics

The spores are spherical, and ornamented with warts and ridges that form a partial reticulum (a net-like pattern of lines) with prominences up to 2 μm high. They are hyaline (translucent), amyloid (meaning they will absorb iodine when stained with Melzer's reagent), and measure 7.5–10.0 by 7–9.5 μm. The cap cuticle is a trichoderm. [6] The basidia (the spore-bearing cells) are 38–56 by 10–13 μm, club-shaped, four-spored, and hyaline when mounted in a dilute solution of potassium hydroxide (KOH). There are abundant cheilocystidia (cystidia found on the edge of gills), with contents ranging in color from dingy yellow to hyaline in KOH. They measure 32–50 by 3-6 μm, and may be shaped somewhat like a spindle (tapered on each end) or a cylinder, or they may be flexuous (winding from side to side). The pleurocystidia (cystidia found on the gill face) are filamentous, 2.5–5 μm in diameter, and rare to scattered. [2]

Similar species

L. lignyotus is a lookalike species found in Europe and eastern North America. Lactarius lignyotus 41556 crop.jpg
L. lignyotus is a lookalike species found in Europe and eastern North America.

Lactarius lignyotellus and L. lignyotus are similar to L. fallax, and they are all associated with Picea and Abies ; examination of microscopic features cannot be used to distinguish between them. [7] L. lignyotus is restricted in distribution to eastern North America and Europe. Lactarius pseudomucidus is another milk cap with a dark brown cap, but it has a smooth (not velvety) and slimy cap and stem. [4] Another brown-capped eastern North American species is L. gerardii ; it has distantly spaced white gills that run down the stem. [8] L. fuliginellus , which prefers to grow near hardwoods, has close gills. [4]

Habitat and distribution

The fruit bodies of L. fallax grow scattered to grouped together on the ground, or on very rotten conifer logs in alpine areas under standing conifers. They are also found in spruce forests. [9] They are fairly common, and typically found between August and October. L. fallax is distributed in the western United States and Canada, with the northern range extending to Alaska; the eastern range is bounded on the east by the Great Plains. [6] [10] Field observations suggest that the fungus can form ectomycorrhizal associations with Tsuga heterophylla . [11] Hesler and Smith noted that the variety concolor was prevalent under species of Fir. [1]

See also

Related Research Articles

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Lactarius torminosus, commonly known as the woolly milkcap or the bearded milkcap, is a large species of agaric fungus. A common and widely distributed species, it is found in North Africa, northern Asia, Europe, and North America. It was first described scientifically by Jacob Christian Schäffer in 1774 as an Agaricus, and later transferred to the genus Lactarius in 1821 by Samuel Frederick Gray. A variety, L. torminosus var. nordmanensis, is known from the United States, Canada, and Switzerland. L. torminosus officially became the type species of Lactarius in 2011 after molecular studies prompted the taxonomic reshuffling of species between several Russulaceae genera.

<i>Lactarius vietus</i> Species of fungus

Lactarius vietus is a species of fungus in the family Russulaceae, first described by Elias Magnus Fries. It produces moderately sized and brittle mushrooms, which grow on the forest floor or on rotting wood. The flattened-convex cap can vary in shape, sometimes forming the shape of a wide funnel. It is typically grey, but the colour varies. The species has crowded, light-coloured gills, which produce white milk. The spore print is typically whitish, but also varies considerably. The mushrooms typically have a strong, acrid taste and have been described as inedible, but other authors have described them as consumable after boiling. L. vietus feeds by forming an ectomycorrhizal relationship with surrounding trees, and it favours birch. It grows in autumn months and is fairly common in Europe, North America and eastern Asia.

<i>Lactarius indigo</i> Edible fungus in the family Russulaceae from eastern North America, East Asia, and Central America

Lactarius indigo, commonly known as the indigo milk cap, indigo milky, the indigo lactarius, or the blue milk mushroom, is a species of agaric fungus in the family Russulaceae. It is a widely distributed species, growing naturally in eastern North America, East Asia, and Central America; it has also been reported in southern France. L. indigo grows on the ground in both deciduous and coniferous forests, where it forms mycorrhizal associations with a broad range of trees. The fruit body color ranges from dark blue in fresh specimens to pale blue-gray in older ones. The milk, or latex, that oozes when the mushroom tissue is cut or broken — a feature common to all members of the genus Lactarius — is also indigo blue, but slowly turns green upon exposure to air. The cap has a diameter of 5–15 cm (2–6 in), and the stem is 2–8 cm (0.8–3 in) tall and 1–2.5 cm (0.4–1.0 in) thick. It is an edible mushroom, and is sold in rural markets in China, Guatemala, and Mexico. In Honduras, the mushroom is called a chora, and is generally eaten with egg; generally as a side dish for a bigger meal.

<i>Psilocybe makarorae</i> Species of fungus

Psilocybe makarorae is a species of psilocybin mushroom in the family Hymenogastraceae. Officially described as new to science in 1995, it is known only from New Zealand, where it grows on rotting wood and twigs of southern beeches. The fruit body (mushroom) has a brownish cap with lighter coloured margins, measuring up to 3.5 cm (1.4 in) wide. The cap shape is either conical, bell-shaped, or flat depending on the age of the mushroom, and it features a prominent umbo. Although the whitish stem does not form a true ring, it retains remnants of the partial veil that covers and protects the gills of young fruit bodies. P. makarorae mushrooms can be distinguished from the similar North American species Psilocybe caerulipes by microscopic characteristics such as the presence of cystidia on the gill faces (pleurocystidia), and cheilocystidia with more elongated necks. Based on the bluing reaction to injury, P. makarorae is presumed to contain the psychedelic compounds psilocybin and psilocin.

<i>Lactarius subflammeus</i> Species of fungus

Lactarius subflammeus, commonly known as the orange milk cap, is a species of fungus in the family Russulaceae. It is found in western North America in the late summer and fall and is especially common in the Pacific Northwest, where it grows on the ground near conifers like pine and spruce. The brightly colored fruit bodies, which are slimy or sticky, have scarlet caps when young that soon fade to brilliant orange. The stem—typically longer than the width of the cap—is also bright orange but the gills are whitish. The mushroom secretes a whitish latex when it is cut or injured.

<i>Lactarius aspideus</i> Species of fungus

Lactarius aspideus, commonly known as the bright yellow milkcap, is a species of fungus in the family Russulaceae. Distinctive characteristics of the fruit body include the sticky, pale yellow cap, and the abundant latex that stains the mushroom tissue lilac. It is found in North America.

<i>Lactarius alnicola</i> Species of fungus

Lactarius alnicola, commonly known as the golden milkcap, is a species of fungus in the family Russulaceae. The fruit bodies produced by the fungus are characterized by a sticky, vanilla-colored cap up to 20 cm (7.9 in) wide with a mixture of yellow tones arranged in faint concentric bands. The stem is up to 5 cm (2.0 in) long and has yellow-brown spots. When it is cut or injured, the mushroom oozes a white latex, which has an intensely peppery taste. The acrid taste of the fruit bodies renders them unpalatable. The fungus is found in the western United States and Mexico, where it grows in mycorrhizal associations with various coniferous trees species, such as spruce, pine and fir, and deciduous species such as oak and alder. It has also been collected in India. Two varieties have been named: var. pitkinensis, known from Colorado, and var. pungens, from Michigan.

<i>Lactarius pubescens</i> Species of fungus

Lactarius pubescens, commonly known as the downy milk cap, is a species of fungus in the family Russulaceae. It is a medium to large agaric with a creamy-buff, hairy cap, whitish gills and short stout stem. The fungus has a cosmopolitan distribution, and grows solitarily or in scattered groups on sandy soil under or near birch.

<i>Lactarius repraesentaneus</i> Species of fungus

Lactarius repraesentaneus, commonly known as the northern bearded milkcap, the northern milkcap, or the purple-staining bearded milkcap, is a species of fungus in the family Russulaceae. It has a northerly distribution, and is found in temperate regions of North America and Europe, associated with spruce trees. Distinguishing features of its fruit body include the large orange-yellow cap up to 18 cm (7.1 in) wide, cream to pale yellow gills, and a yellow coarsely-pitted stem that is up to 12 cm (4.7 in) long and 3 cm (1.2 in) thick. Cut fruit bodies ooze a white latex that will stain mushroom tissue lilac to purple. Several chemicals have been isolated and identified from the fruit bodies that can modify the growth of plants, and the mushroom also has antibiotic activity against Staphylococcus aureus. L. repraesentaneus is poisonous, and consumption causes stomach aches.

<i>Lactarius affinis</i> Species of mushroom

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<span class="mw-page-title-main">Lactifluus deceptivus</span> Species of fungus

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<i>Lactarius argillaceifolius</i> Species of fungus

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<i>Lactarius rufulus</i> Species of fungus

Lactarius rufulus, also known as the rufous candy cap or the southern candy cap, is a species of fungus in the family Russulaceae. 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.

<i>Lactarius vinaceorufescens</i> Species of fungus

Lactarius vinaceorufescens, commonly known as the yellow-staining milkcap or the yellow-latex milky, is a poisonous species of fungus in the family Russulaceae. It produces mushrooms with pinkish-cinnamon caps up to 12 cm (4.7 in) wide held by pinkish-white stems up to 7 cm (2.8 in) long. The closely spaced whitish to pinkish buff gills develop wine-red spots in age. When it is cut or injured, the mushroom oozes a white latex that rapidly turns bright sulfur-yellow. The species, common and widely distributed in North America, grows in the ground in association with conifer trees. There are several other Lactarius species that bear resemblance to L. vinaceorufescens, but most can be distinguished by differences in staining reactions, macroscopic characteristics, or habitat.

<i>Mycena mustea</i> Species of mushroom in the family Mycenaceae

Mycena mustea is a species of mushroom in the family Mycenaceae. First described as a new species in 2007, the fungus is known only from Kanagawa, Japan, where it grows on dead fallen twigs in lowland forests. The mushroom's dull violet to grayish-violet cap, initially covered with a fine whitish powder, becomes smooth as it matures, and eventually reaches a diameter of up to 10 mm (0.39 in). The stem is slender, up to 90 mm (3.5 in) long, and is covered with stiff white hairs at the base. Underneath the cap are distantly spaced pale brownish gills that are narrowly attached to the stem. Microscopic characteristics of the mushroom include the weakly amyloid spores, the club-shaped cheilocystidia featuring one or more short knob-like protuberances, the absence of pleurocystidia, the diverticulate cap cuticle hyphae, and the absence of clamp connections.

<i>Mycena maculata</i> Species of fungus in the family Mycenaceae

Mycena maculata, commonly known as the reddish-spotted Mycena, is a species of fungus in the family Mycenaceae. The fruit bodies, or mushrooms, have conic to bell-shaped to convex caps that are initially dark brown but fade to brownish-gray when young, reaching diameters of up to 4 cm. They are typically wrinkled or somewhat grooved, and have reddish-brown spots in age, or after being cut or bruised. The whitish to pale gray gills also become spotted reddish-brown as they mature. The stem, up to 8 cm (3 in) long and covered with whitish hairs at its base, can also develop reddish stains. The mycelium of M. maculata has bioluminescent properties. The saprobic fungus is found in Europe and North America, where it grows in groups or clusters on the rotting wood of both hardwoods and conifers. The edibility of the fungus is unknown. Although the species is known for, and named after its propensity to stain reddish, occasionally these stains do not appear, making it virtually indistinguishable from M. galericulata.

<i>Lactarius fuliginosus</i> Species of fungus

Lactarius fuliginosus, commonly known as the sooty milkcap, is a species of fungus in the family Russulaceae. The medium-sized fruit bodies have velvety, grayish-brown caps and crowded gills. It is found in deciduous forests of Asia, Europe, and North America.

<i>Lepiota maculans</i> Species of fungus

Lepiota maculans is a rare species of agaric fungus in the family Agaricaceae. It was originally collected in Missouri, and then 105 years later in eastern Tennessee. It is the only member of Lepiota known to have a pink spore print instead of the usual white or cream color. The fruit bodies have caps up to 4 cm (1.6 in) in diameter, with brownish, sparsely scaled centers. The gills are closely spaced, not attached to the stipe, and discolor reddish at the edges.

<i>Lactarius xanthogalactus</i> Species of fungus

Lactarius xanthogalactus, commonly known as the yellow-staining milkcap is a poisonous species of fungus in the family Russulaceae. The species is found on the west coast of the United States and grows in the ground in association with hardwood and conifer trees. There are several other Lactarius species that bear resemblance to L. xanthogalactus, but most can be distinguished by differences in staining reactions, macroscopic characteristics, or habitat.

References

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  5. Hesler and Smith, 1979, p. 103.
  6. 1 2 3 Bessette AR, Bessette A, Harris DM (2009). Milk Mushrooms of North America: A Field Guide to the Genus Lactarius. Syracuse, New Yorl: Syracuse University Press. pp. 174–75. ISBN   978-0-8156-3229-0.
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  8. Kuo M (March 2011). "Lactarius gerardii". MushroomExpert.Com. Retrieved 2011-06-06.
  9. Trudell, Steve; Ammirati, Joe (2009). Mushrooms of the Pacific Northwest. Timber Press Field Guides. Portland, OR: Timber Press. p. 56. ISBN   978-0-88192-935-5.
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