Boletus subvelutipes
Description
Boletus subvelutipes is a bolete fungus in the family Boletaceae. Its fruit bodies have a brown to a 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. It is found in Asia and North America, where it fruits on the ground in a mycorrhizal association with both deciduous and coniferous trees. The fruit bodies are poisonous and produce symptoms of gastrointestinal distress if consumed.
Found under hemlock and occasionally another conifer; the lookalike oak-lover is genetically distinct. The flesh has sometimes been reported as tasting a bit acidic, but that is not a reliable characteristic and may indicate one of the as-yet-unnamed subspecies. The hairs at the stem base (which look more like velvet than hairs) are also unreliable. Specimens showing the velvety hairs typically have a yellow fuzz when young, which quickly turns dark red.
The mushrooms can be used in mushroom dyeing to produce beige or light brown colors, depending on the mordant used.
Common names: Red-mouth Bolete, Velvety-stemmed Bolete.
Mushroom Identification
Ecology
In the grass at woods' edge, with white oak, northern red oak, slippery elm, shagbark hickory, and sassafras nearby; growing gregariously.
Cap
6-11 cm; convex, becoming broadly convex to flat; dry or sticky; bald; reddish-brown; dark brown after drying.
Pore Surface
When young pinkish-orange (OAC 693) with yellow areas; when mature dingy orange-brown; bruising promptly blue; depressed at the stem, even in buttons; pores angular, 2 per mm at maturity; tubes to 15 mm deep.
Stem
45-60 x 9-12 mm; slender; equal; tough; bright yellow under dense red floccules; becoming brownish basally; bruising blue; base velvety, crimson.
Flesh
Yellow in the cap; bright yellow in the stem; staining quickly blue on exposure.
Odor and Taste
Not distinctive.
Chemical Reactions
Ammonia negative to orangish on cap; erasing blue to orange on flesh. KOH red on cap; orange on flesh. Iron salts grayish on cap and flesh.
Spore Print
Olive.
Microscopic Features
Spores 12-15 x 4.5-5.5 µ; fusiform; yellowish in KOH; smooth. Hymenial cystidia infrequent; fusiform; not projecting. Pileipellis a trichoderm of densely packed cylindric elements 2.5-5 µ wide; terminal elements cylindric with rounded apices; hyaline to orangish brown or brownish-orange in KOH. Caulocystidia fusiform; hyaline to brownish in KOH; 35-50 µ long.
Look-Alikes
Boletus luridus
Has tubes sunken about the stalk, netted pattern on the stalk, and no reddish hairs at the base.
Boletus gansuensis
Found in the Gansu Province of China, is similar in appearance to B. subvelutipes. The Chinese species can be distinguished by its longer and narrower spores measuring 12.0–15.5 by 6.0–7.0 μm, smaller fruit bodies with a cap diameter of 6–8 cm (2.4–3.1 in), and shorter tubes up to 1.2 cm (0.5 in) deep.
History
The species was originally described by American mycologist Charles Horton Peck in 1889 from specimens collected in Saratoga, New York. In 1947 Rolf Singer described form glabripes from specimens he collected in Alachua County, Gainesville, Florida. Synonyms include names resulting from generic transfers to the genera Suillus by Otto Kuntze in 1888, and to Suillelus by William Alphonso Murrill in 1948.
Synonyms: Suillus subveluptipes Kuntze (1898), Suillellus subvelutipes (Peck) Murrill (1948).
Photo sources:
Photo 1 - Author: the3foragers (CC BY-SA 3.0)
Photo 2 - Author: Bill (boletebill) (CC BY-SA 3.0)
Photo 3 - Author: Dave W (CC BY-SA 3.0)
Photo 4 - Author: Joshua Hutchins (MycoMaven) (CC BY-SA 3.0)
