About this fungus
Zeller's Bolete is a fungus in the Boletaceae family. Its habitat and field characteristics are summarised below.
A dark-capped western North American bolete with yellow pores and a red-streaked stem. The true species has a dark reddish-purple to nearly black cap and is much less common than the broad traditional field concept suggests.
What to check
Check for yellow pores, a stem patterned red over yellow, pale yellow flesh and no ring or volva. Blue staining may be weak or patchy and is not decisive. Record the exact location, forest type and whether the mushroom is growing in moss or close to moss-covered wood, because modern identification relies on more than colour.
Variation
Cap colour ranges from dark reddish brown to purple-black and may become uneven or cracked with age. Pore and flesh staining varies in strength. Several related western species were previously placed under the same name, so older photographs show a broader range than the strict modern concept.
Lookalikes
Xerocomellus atropurpureus was widely misidentified as Zeller's Bolete in California and has strongly overlapping colours. Xerocomellus diffractus and other regional Xerocomellus species can also be similar. Microscopic characters, location and sometimes DNA are needed for an exact identification.
Habitat and range
The strict modern species is known from southern British Columbia through Washington and Oregon to the northern California coast. It fruits in mature conifer forest, often in moss or around moss-covered stumps and logs. Reports from farther south or outside the Pacific Northwest should be checked against newer regional species concepts.
Food safety
Edibility is uncertain or disputed.
Photographs
Jason Hollinger / CC BY 2.0