Inedible lookalike
Bitter Bolete
Tylopilus felleus
The bitter bolete's pores turn pinkish with age, its stem carries a coarse brown net rather than a fine white one, and its flesh is intensely bitter. It leaves a pinkish-brown spore print.
King Bolete
Boletus edulis
Edible
Also called porcini, cep, penny bun.
The king bolete is the porcini of Italian cooking: a heavy brown-capped mushroom with pores instead of gills and a thick, netted stem. It grows with conifers and some hardwoods, and its most common lookalike is the bitter bolete.
The tell
A brown bun-shaped cap over white to olive-yellow pores that do not bruise blue, on a fat stem with fine white netting near the top.
Field marks
What to look at
Cap, underside and stem show in a photo. The spore print does not, and it is often the deciding check.
- Cap
- Convex, broadening with age, 3 to 10 inches across. Light brown to reddish brown, smooth, and slightly sticky when wet. The surface is often paler near the edge.
- Underside
- Pores instead of gills. White and tightly packed in young specimens, turning yellow and then olive-yellow with age. They do not bruise blue.
- Stem
- Thick and club-shaped or bulbous, white to light brown, with a fine white net pattern (reticulation) over the upper part. No ring.
- Flesh
- White, firm and thick, not changing color when cut. Smell and taste mild and nutty.
- Spore print
- Olive-brown.
- Size
- Cap 3 to 10 inches (8 to 25 cm); stem 4 to 10 inches (10 to 25 cm) tall and up to 3 inches (8 cm) thick.
Where and when
Where and when it grows
- Habitat
- On the ground under spruce, pine, fir and hemlock, and with birch, oak and other hardwoods in some regions. Often along trails and forest edges.
- Grows on
- Soil, near the roots of host trees.
- Season
- Summer through fall, and into winter along the Pacific Coast.
- Range
- Across northern North America and the western mountains, with several closely related king bolete species in other regions.
Lookalikes
What the king bolete gets confused with
Each card says how to tell the two apart.
Red-pored boletes
Several large boletes have red or orange pores and flesh or pores that bruise blue. Some cause severe gastrointestinal illness. The king bolete's pores are white to olive-yellow and do not bruise blue.
EdibleBay Bolete
Imleria badia
The bay bolete has a chestnut-brown cap, pale yellow pores that bruise blue-green, and a smooth stem with no netting.
More side-by-side comparisons
Edibility
What the field guides say
Edible
Field guides list the king bolete as a choice edible, and it is sold fresh and dried as porcini. Insect larvae often tunnel through the flesh of older specimens. The bitter bolete, its most frequent confusion, is not poisonous but is bitter enough to spoil a dish; some red-pored boletes cause severe gastrointestinal illness.
This page states what field guides record. It is not advice to eat, taste or handle anything, and a photo cannot settle edibility. If someone has eaten a wild mushroom that may be toxic, call poison control (1-800-222-1222 in the US) right away, before symptoms start: the deadliest species act hours later.
FAQ
Questions about the king bolete
Is king bolete the same as porcini?
Yes. Porcini is the Italian name for Boletus edulis and its close relatives. Cep and penny bun are names used in France and Britain.
How do you tell a king bolete from a bitter bolete?
Look at the pores and the stem. King bolete pores are white to olive-yellow and its stem has a fine white net near the top. Bitter bolete pores turn pinkish, and its stem carries a coarse, dark brown net.
Where do king boletes grow?
On the ground under conifers such as spruce, pine, fir and hemlock, and with some hardwoods including birch and oak. They are most common in northern and western North America.
Sources
Where these facts come from
- Boletus edulis
MushroomExpert.com
- Boletus edulis
Beaty Biodiversity Museum, University of British Columbia
- Boletus edulis
MykoWeb, California Fungi
- Boletus edulis
Index Fungorum
Also on Mushrooms.id
Related species
Leccinum insigne
Photo coming
Edible, upsets some people
Aspen Bolete
Leccinum insigne
An orange to reddish-brown cap on a whitish stem covered in small dark scabers, under aspen.
Edible, peel the cap
Slippery Jack
Suillus luteus
A slimy brown cap over yellow pores, and a large membranous ring that is purplish underneath, under pines.
Baorangia bicolor
Photo coming
Edible
Two-Colored Bolete
Baorangia bicolor
A rose-red cap and stem with bright yellow pores that bruise blue slowly.
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