Zeller's Bolete

Description:

Boletus 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.

Habitat:

This species grows solitarily or in small groups on the ground or in forest duff in mature coniferous forests, occasionally abundant on grassy edges of the forest, rarely on badly decayed conifer logs. It is an ectomycorrhizal mushroom, meaning that the fungal hyphae form sheaths around the rootlets of certain trees, exchanging nutrients with them in a mutualistic relationship. The fungus associates with alder, poplar and other hardwoods,[7] and has been shown in laboratory culture to form ectomycorrhizae with Western Hemlock (Tsuga heterophylla).[19] However, it has also been noted to grow around California Redwood, a tree not known to form mycorrizhae.[20] It is known to form long rhizomorphs (aggregations of hyphae that resemble roots), and has been noted to be more abundant in sites with buried wood than without.[21] In British Columbia, it occurs from summer to early winter, although it also appears infrequently in early spring.[15] In California, the mushroom often fruits after the rainy period in autumn through to March or April.[6] The dark coloring of the cap make this species difficult to notice, "unless a glimpse of the yellow hymenium is obtained".[2] Boletus zelleri is distributed in North America in the Pacific Northwest south to California and Mexico.[22] It has also been reported from Tibet,[23] but this may be based on a misidentification.

Notes:

Boletus zelleri is an edible species,[12] although care should be taken to ensure that specimens collected for consumption are free of fly larvae.[13] There is no distinguishable odor, and the taste is alternately described as pleasant,[14] mild,[7] or "slightly acidic".[9] The original species description noted that the texture was "slightly mucilaginous".[2] The mushroom is suitable for preserving or drying.[15] It is harvested and sold commercially in local markets in British Columbia, Canada.