Zeller's Bolete (Xerocomellus zelleri)

Description
Mushroom Identification
Look-Alikes
Video
Synonyms

Description

Meet Xerocomellus zelleri, also known as Zeller's Bolete, a striking mushroom found in both Western North America and parts of Europe! 🗺️ Whether you're trekking through the forests of British Columbia, exploring the woodlands of California, or strolling through European forests, you might just come across this elusive beauty.

With its dark reddish-brown to nearly black cap and vibrant yellow pores, Zeller’s Bolete stands out among the forest floor. 🌲🖤 The yellow stem, streaked with hints of red, adds even more charm to its appearance.

🍂 Season: Summer & autumn 🍁 🧩 Habitat: Found under Douglas firs, conifers, and in European forests as well.

🌟 Fun Fact: This mushroom's cap sometimes has a reddish tint around the edges and grows in the open, without any protective covering—a bold forest performer! 🎭

🥄 Edibility: Though it's not a gourmet star, it's edible and often used as a filler or dried for preservation. Keep an eye out for pesky fly larvae! 🪰👀

📜 History: Xerocomellus zelleri was first discovered by mycologist William Alphonso Murrill in 1912 at the University of Washington. Originally named Ceriomyces zelleri 🍂, Murrill quickly moved it to the Boletus genus 🍄. Over the years, the mushroom’s classification kept changing. In 1944, it was placed in Xerocomus 🌳, but in 1959, mycologists Rolf Singer, Walter Henry Snell, and Esther A. Dick moved it to Boletellus after examining its structure 🔬. Finally, in 2011, it settled into the genus Xerocomellus.

The name zelleri honors Sanford Myron Zeller, a mycologist from Oregon State University, who discovered the first specimens during Murrill’s Seattle expedition 🌲. With its long history of name changes and studies by various scientists, Xerocomellus zelleri has found its place in the world of mushrooms, remaining a subject of interest to this day. ✨

Mushroom Identification

🍄 Cap: The cap of this mushroom measures between 4 and 12 cm (1.6–4.7 in) in diameter. When young, it is convex, flattening with age. Its color ranges from dark brown to nearly black, often with a pale cream margin. Some younger caps may also display a grayish bloom. The surface is uneven and velvety, frequently appearing wrinkled or pitted.

🍖 Flesh: The flesh inside the mushroom is yellow to dirty yellow. Notably, its bruising behavior is inconsistent; at times, it may bruise blue, while other times, it remains unchanged.

🌕 Pores (Underside of Cap): The pores are yellow, turning dirty yellow or greenish-yellow with age. They are slightly angular, with a density of 1–2 pores per millimeter. When exposed to air, they may turn brownish.

🦵 Stem: The stem can grow up to 12 cm (4.7 in) in height and is 1–3 cm (0.4–1.2 in) thick. It starts yellow with red lines but becomes evenly red with age. The stem has a swollen base, is solid (not hollow), and has a fibrous texture.

🎨 Spore Print: The spore print is olive-brown, and it sometimes leaves yellow juice on paper.

🏞️ Habitat: This mushroom is found in conifer forests, often near moss-covered logs. It grows in both North America and Europe, though it is rare across most of its range.

🔬 Microscopic Features: The spores are ellipsoid and smooth, measuring 12–16 μm. There are no clamp connections in the hyphae.

Look-Alikes

Xerocomellus chrysenteron

Olive-brown cap that cracks, revealing flesh that turns pinkish red with age.
Boletellus chrysenteroides

Found in eastern North America, with a velvety to smooth, dark reddish-brown cracked cap, exposing pale flesh.
Boletus mirabilis

Another similar species to watch for, though less detailed in comparison.