Boletus rubroflammeus | |
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Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Fungi |
Division: | Basidiomycota |
Class: | Agaricomycetes |
Order: | Boletales |
Family: | Boletaceae |
Genus: | Boletus |
Species: | B. rubroflammeus |
Binomial name | |
Boletus rubroflammeus | |
Boletus rubroflammeus | |
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Pores on hymenium | |
Cap is convex | |
Hymenium is adnate | |
Stipe is bare | |
Spore print is olive-brown | |
Ecology is mycorrhizal | |
Edibility is poisonous |
Boletus rubroflammeus is a species of bolete fungus in the family Boletaceae. First described from Michigan in 1971, it is found in the eastern United States and Mexico, where it grows in a mycorrhizal association with hardwood trees. The fruit bodies (mushrooms) of the fungus have caps that are deep red to purplish red, and dark red pores. The stem has coarse, dark red reticulations (raised, net-like ridges) and a narrow yellow area at the top. All parts of the mushroom quickly stain blue when injured or cut. Lookalikes include Boletus flammans , a lighter-colored species that grows with conifers. Other similar species can be distinguished by differences in distribution, morphology, staining reaction, and microscopic characteristics. Boletus rubroflammeus mushrooms are poisonous, and can cause gastrointestinal distress if consumed.
The species was first described by American mycologists Alexander H. Smith and Harry D. Thiers in their 1978 monograph on the boletes of Michigan. The type collection was made by Smith near Ann Arbor, [1] and is stored at the University of Michigan Herbarium. [2] The specific epithet rubroflammeus derives from the Latin words ruber ("red") and flammeus ("flaming"). [3]
The shape of the cap of B. rubroflammeus is convex to broadly convex, and reaches a diameter of 6–12 cm (2.4–4.7 in). The margin of the cap extends slightly beyond the tubes. The cap surface is dry and initially appears appressed-fibrillose (with fibrils pressed down flat against the surface) or has a matted grayish tomentum, but later the hairs slough off and the matted tomentum is present only along the cap margin. In maturity, the center of the caps develop slight cracks. The cap is a deep vinaceous-red color that remains constant throughout the life of the fruit bodies. The flesh is thick, soft, and yellow. Its taste is mild, and it has no distinct odor. On the underside of the cap, the spore-bearing surface comprises vertically arranged minute tubes with pore-like openings. The tubes are yellow, 1–2 cm (0.4–0.8 in) deep, initially adnate (fused) to the stem, but later becoming free from attachment (or nearly so). Individual pores are round and small (about 2 per mm), while the overall pore surface is uneven or pitted. Its color is initially deep red, but fades slightly in maturity; the pore surface quickly turns blue with injury. The stem is 6–8 cm (2.4–3.1 in) long, 1–2 cm (0.4–0.8 in) thick, solid (i.e., not hollow), and equal in width throughout to club-shaped. Inside, it is yellowish with reddish streaks. Most of the stem surface is covered with coarse dark red reticulations, although near the top the color is yellow beneath the reticulations. All parts of the mushroom will quickly stain blue when cut, bruised, or otherwise injured. [1] The mushroom is poisonous, and if consumed can cause gastrointestinal distress; typical symptoms include cramping, nausea, bloating, vomiting, and diarrhea. [4]
Boletus rubroflammeus produces an olive-brown spore print. [4] The spores are smooth, roughly oblong to slightly ventricose (swollen) in face view, in profile view inequilateral, and have dimensions of 10–14 by 4–5 μm. Spores have a broad and shallow suprahilar depression (a depressed area on the dorsal side of the spore that was once attached to the sterigma). They are yellowish hyaline (translucent) in Melzer's reagent, and pale yellow-orange when mounted in a solution of potassium hydroxide (KOH). The basidia (spore-bearing cells) are club-shaped with a long pedicel (stalk), four-spored, and measure 30–40 by 8–9 μm. Pleurocystidia (cystidia on the tube faces) are rare to scattered, 28–37 by 9–15 μm, fusoid (somewhat spindle-shaped) to ventricose, and have a somewhat sharp tip. Cheilocystidia (cystidia on gill edges) are abundant, 18–35 by 5–9 μm, and roughly similar in shape to the pleurocystidia. When mounted in KOH, the cheilocystidia have a dingy orange-yellow color, and walls that are smooth and thin. The tissue of the tubes is bilateral, meaning that they have a central strand of roughly parallel hyphae from which other hyphae diverge. The central strand comprises interwoven hyphae that are floccose and orange-yellow in KOH; the diverging hyphae continue into the hymenium to form a subhymenium that contain smooth hyphae measuring 4–6 μm wide. The cap has a cuticle consisting of tightly interwoven pressed-down hyphae that are usually 3–5 μm wide. The hyphae in the epicuticular zone (a waxy layer on the surface of the cuticle) often have fine granular incrustations that can be seen in both KOH and Melzer's reagent. Clamp connections are absent from the hyphae of B. rubroflammeus. [1]
Distinctive field characteristics used to distinguish Boletus rubroflammeus from similar boletes include the deep purple-red cap and the reticulated stem. [1] B. flammans is similar in appearance, but has a more variable cap color, ranging from dark red to brick-red or reddish-brown, a yellow stem base and less prominently reticulate stem, and it grows under conifers. Rubroboletus rhodosanguineus is also very similar but has more variable cap color with brown to olive tones and its cut flesh has an odor of overripe fruit that intensifies when dry. [4] The European species R. rhodoxanthus has a paler overall color. [1] Another European species, B. permagnificus , has larger spores (13–16 by 5–6.5 μm), weakly decurrent pores, and only associates with oak trees. [5]
In addition to its geographic location, the Colombian species B. pyrrhosceles can be distinguished from B. rubroflammeus by its reddish-brown cap (fading to brownish orange in maturity), a brownish-red to deep red stem that is reticulated only at the top, and shallower tubes—up to 5 mm (0.2 in). [6] B. rhodocarpus , known only from Japan where it grows in deciduous forests, differs primarily in having brownish scales on the cap. [7]
Boletus rubroflammeus is a mycorrhizal species, and its fruit bodies grow scattered or in groups on the ground under hardwood trees. The fungus fruits in summer and autumn months, and tends to appear after hot weather and heavy rains. [1] Known only from North America, its range extends from New England south to Tennessee, and west to Michigan. [4] It has also been recorded from Mexico. [8]
Rubroboletus pulcherrimus—known as Boletus pulcherrimus until 2015—is a species of mushroom in the family Boletaceae. It is a large bolete from Western North America with distinguishing features that include a netted surface on the stem, a red to brown cap and stem color, and red pores that stain blue upon injury. Until 2005 this was the only bolete that has been implicated in the death of someone consuming it; a couple developed gastrointestinal symptoms in 1994 after eating this fungus with the husband succumbing. Autopsy revealed infarction of the midgut.
Suillellus luridus, commonly known as the lurid bolete, is a fungus of the family Boletaceae, found in calcareous broadleaved woodlands in Europe. Fruit bodies appear in summer and autumn and may be locally abundant. It is a firm bolete with an olive-brown cap up to 20 cm (8 in) in diameter, with small orange or red pores on the underside. The stout ochre stem reaches 8–14 cm (3–6 in) high and 1–3 cm (0.4–1.2 in) wide, and is patterned with a red network. Like several other red-pored boletes, it stains blue when bruised or cut.
Exsudoporus frostii, commonly known as Frost's bolete or the apple bolete, is a bolete fungus first described scientifically in 1874. A member of the family Boletaceae, the mushrooms produced by the fungus have tubes and pores instead of gills on the underside of their caps. Exsudoporus frostii is distributed in the eastern United States from Maine to Georgia, and in the southwest from Arizona extending south to Mexico and Costa Rica. A mycorrhizal species, its fruit bodies are typically found growing near hardwood trees, especially oak.
Aureoboletus mirabilis, commonly known as the admirable bolete, the bragger's bolete, and the velvet top, is an edible species of fungus in the Boletaceae mushroom family. The fruit body has several characteristics with which it may be identified: a dark reddish-brown cap; yellow to greenish-yellow pores on the undersurface of the cap; and a reddish-brown stem with long narrow reticulations. Aureoboletus mirabilis is found in coniferous forests along the Pacific Coast of North America, and in Asia. Unusual for boletes, A. mirabilis sometimes appears to fruit on the wood or woody debris of Hemlock, suggesting a saprobic lifestyle. Despite occasional appearances to the contrary, Aureoboletus mirabilis is mycorrhizal, and forms close mutualistic associations with hemlock roots.
Xerocomellus zelleri, commonly known as Zeller's bolete, is an edible species of mushroom in the family Boletaceae. First described scientifically by American mycologist William Alphonso Murrill in 1912, the species has been juggled by various authors to several genera, including Boletus, Boletellus, and Xerocomus. Found solely in western North America from British Columbia south to Mexico, the fruit bodies are distinguished by their dark reddish brown to nearly black caps with uneven surfaces, the yellow pores on the underside of the caps, and the red-streaked yellow stems. The fungus grows in summer and autumn on the ground, often in Douglas fir forests or on their margins. The development of the fruit bodies is gymnocarpic, meaning that the hymenium appears and develops to maturity in an exposed state, not enclosed by any protective membrane.
Suillellus amygdalinus is a fungus of the bolete family found in western North America. The fruit bodies, or mushrooms, are characterized by their thick, red to brown caps, red pores, and the strong bluing reaction observed when the mushroom tissue is injured or cut. The cap can reach diameters of up to 12 cm (4.7 in) and the stipe 9 cm (3.5 in) long by 3 cm (1.2 in) thick at maturity. This mushroom has been found in manzanita and madrone woodlands of central California north to southern Oregon. Although the edibility of the mushroom is not known with certainty, it may be poisonous, and is not recommended for consumption. Other similar red-pored, bluing boletes from North America, including Rubroboletus eastwoodiae, Boletus luridiformis, and B. subvelutipes, can be distinguished from S. amygdalinus either by the color of the cap, the degree of reticulation on the stipe, or by location.
Caloboletus rubripes, commonly known as the red-stipe bolete or the red-stemmed bitter bolete, is a mushroom in the family Boletaceae. It was known as Boletus rubripes until 2014. Fruit bodies (mushrooms) are robust, with caps up to 18 cm in diameter, atop thick stipes 5–12 cm long. Mushrooms are non-toxic, but is so bitter as to be inedible. The mushroom flesh has a very strong bluing reaction when cut or damaged. and forms mycorrhizal relationships, primarily with conifers. It can be differentiated from similar boletes by its cap color and non-reticulate stipe.
Boletellus ananas, commonly known as the pineapple bolete, is a mushroom in the family Boletaceae, and the type species of the genus Boletellus. It is distributed in southeastern North America, northeastern South America, Asia, and New Zealand, where it grows scattered or in groups on the ground, often at the base of oak and pine trees. The fruit body is characterized by the reddish-pink scales on the cap that are often found hanging from the edge. The pore surface on the underside of the cap is made of irregular or angular pores up to 2 mm wide that bruise a blue color. It is yellow when young but ages to a deep olive-brown color. Microscopically, B. ananas is distinguished by large spores with cross striae on the ridges and spirally encrusted hyphae in the marginal appendiculae and flesh of the stem. Previously known as Boletus ananas and Boletus coccinea, the species was given its current name by William Alphonso Murrill in 1909. Two varieties of Boletellus ananas have been described. Although the mushroom may be considered edible, it is not recommended for consumption.
Aureoboletus russellii, commonly known as Russell's bolete, is a species of bolete fungus in the family Boletaceae. An edible species, it is found in Asia and eastern North America, where it grows in a mycorrhizal association with oak, hemlock, and pine trees. Fruit bodies of the fungus are characterized by their coarsely shaggy stem. The yellow-brown to reddish-brown caps are initially velvety, but become cracked into patches with age.
Tylopilus tabacinus is a species of bolete fungus in the family Boletaceae. It is characterized by a tawny-brown cap measuring up to 17.5 cm (6.9 in) in diameter, and a reticulated stem up to 16.5 cm (6.5 in) long by 6 cm (2.4 in) thick. A characteristic microscopic feature is the distinctive crystalline substance encrusted on the hyphae in the surface of the cap. The species is known from the eastern United States from Florida north to Rhode Island, and west to Mississippi, and from eastern Mexico. It is a mycorrhizal species, and associates with oak and beech trees.
Tylopilus alboater, called the black velvet bolete, by some, is a bolete fungus in the family Boletaceae. The species is found in North America east of the Rocky Mountains, and in eastern Asia, including China, Japan, Taiwan, and Thailand. A mycorrhizal species, it grows solitarily, scattered, or in groups on the ground usually under deciduous trees, particularly oak, although it has been recorded from deciduous, coniferous, and mixed forests.
Boletus curtisii is a species of fungus in the family Boletaceae. It produces small- to medium-sized fruit bodies (mushrooms) with a convex cap up to 9.5 cm (3.7 in) wide atop a slender stem that can reach a length of 12 cm (4.7 in). In young specimens, the cap and stem are bright golden yellow, although the color dulls to brownish when old. Both the stem and cap are slimy or sticky when young. On the underside of the cap are small circular to angular pores. The mushroom is edible, but not appealing. It is found in eastern and southern North America, where it grows in a mycorrhizal association with hardwood and conifer trees. Once classified as a species of Pulveroboletus, the yellow color of B. curtisii is a result of pigments chemically distinct from those responsible for the yellow coloring of Pulveroboletus.
Boletus auripes, commonly known as the butter-foot bolete, is a species of bolete fungus in the family Boletaceae. First described from New York in 1898, the fungus is found in eastern Asia, Central America, and eastern North America from Canada to Florida. It is a mycorrhizal species and typically grows in association with oak and beech trees.
Aureoboletus auriflammeus, commonly known as the flaming gold bolete, is a species of bolete fungus in the family Boletaceae. Described as new to science in 1872, it is found in eastern North America, where it grows in a mycorrhizal association with oaks. The caps of the fruit bodies are golden orange, with a yellow pore surface on the underside, and a reticulated (network-like) stem. The edibility of the mushroom is not known.
Boletus carminiporus is a species of bolete fungus in the family Boletaceae. Described as new to science in 1998, the species is found in the southern United States where it grows in a mycorrhizal association with various trees in mixed forests.
Boletus subvelutipes, commonly known as the red-mouth bolete, is a bolete fungus in the family Boletaceae. It is found in Asia and North America, where it fruits on the ground in a mycorrhizal association with both deciduous and coniferous trees. Its fruit bodies (mushrooms) have a brown to reddish-brown cap, bright yellow cap flesh, and a stem covered by furfuraceous to punctate ornamentation and dark red hairs at the base. Its flesh instantly stains blue when cut, but slowly fades to white. The fruit bodies are poisonous, and produce symptoms of gastrointestinal distress if consumed.
Pulveroboletus ravenelii, commonly known as Ravenel's bolete or the powdery sulfur bolete, is a species of bolete fungus in the family Boletaceae. Described as new to science in 1853, the widely distributed species is known from Asia, Australia, North America, Central America, and South America. Mycorrhizal with oak, the fungus fruits on the ground singly, scattered, or in groups in woods. Fruit bodies (mushrooms) have convex to flat, yellowish to brownish-red caps up to 10 cm (4 in) in diameter. On the cap underside, the pore surface is bright yellow before turning dingy yellow to grayish brown with age; it stains greenish blue then grayish brown after injury. A cottony and powdery partial veil remains as a ring on the stipe. The mushrooms are edible, and have been used in traditional Chinese medicine and for mushroom dyeing.
Harrya chromapes, commonly known as the yellowfoot bolete or the chrome-footed bolete, is a species of bolete fungus in the family Boletaceae. The bolete is found in eastern North America, Costa Rica, and eastern Asia, where it grows on the ground, in a mycorrhizal association with deciduous and coniferous trees. Fruit bodies have smooth, rose-pink caps that are initially convex before flattening out. The pores on the cap undersurface are white, aging to a pale pink as the spores mature. The thick stipe has fine pink or reddish dots (scabers), and is white to pinkish but with a bright yellow base. The mushrooms are edible but are popular with insects, and so they are often infested with maggots.
Boletus subluridellus is a species of bolete fungus in the family Boletaceae. Described as new to science in 1971 by American mycologists, the bolete is found in the eastern United States and Canada. It grows on the ground in coniferous and mixed forests in a mycorrhizal association with deciduous trees, especially oak. The fruit bodies (mushrooms) have orangish-red, broadly convex caps that are up to 10 cm (3.9 in) in diameter, with small, dark reddish pores on the underside. The pale yellow stipe measures 4–9 cm (1.6–3.5 in) long by 1.5–2.3 cm (0.6–0.9 in) thick. All parts of the fruit body will quickly stain blue when injured or touched.
Boletus pyrrhosceles is a species of bolete native to Colombia. It was described by Roy Halling in 1992 from material collected on 20 November 1988 near the highway between Pasto and Chachagüí in Nariño Department in the country's southwest, at an altitude of 2700 m. It was classified in section Luridii, and thought most similar to Boletus austrinus, Boletus flammans and Boletus rubroflammeus. The species name is derived from the Ancient Greek words pyrrhos "red" and skelos "legs", referring to its stem.