Boletus curtisii

[ Basidiomycetes > Boletales > Boletaceae > Boletus . . . ]

by Michael Kuo

The first time I found Boletus curtisii I thought it was a Suillus, since the mushroom is so slimy and so--well, Suillus-ish. True, I found it under hardwoods, but there are a very few Suillus species described from hardwood habitat, and they are yellow (or yellowish), at that. True, the pore surface is not conspicuously radially arranged (say that three times fast) and true, there are no glandular dots on the stem. In fact, of the five attributes defining Suillus I give to my readers on the page for the genus, Boletus curtisii matches only one feature: the sliminess.

Maybe you won't have as much trouble as I did getting away from Suillus and into the genus Boletus, but I have included Boletus curtisii in my Suillus key, just in case.

Edibility is not known for Boletus curtisii. I don't recommend experimenting--and I don't recommend eating grotesquely slimy things, whether they are "edible" or not.

Description:

Ecology: Mycorrhizal with hardwoods or conifers; growing alone, scattered, or gregariously; summer and fall; primarily southern in distribution but recorded from New England, Michigan, and Illinois.

Cap: 3-9.50 cm; convex, becoming broadly convex or almost flat; very slimy; smooth; bright yellow or orangish yellow; the margin with a pale, overhanging portion.

Pore Surface: Whitish to pale yellow when young, becoming yellowish brown; not bruising; 2-3 pores per mm; tubes 6-12 mm deep.

Stem: 6-12 cm long; .5-1.5 cm thick; more or less equal; slimy; smooth or with tiny fibers near the apex; yellow; basal mycelium white and prominent.

Flesh: Whitish; not staining on exposure.

Odor and Taste: Not distinctive.

Chemical Reactions: Not recorded in the literature, but in my collections ammonia has been negative on the cap and the flesh; iron salts have been negative on the cap and bluish gray on the flesh; and KOH has been negative to pale olive on the cap and orangish on the flesh.

Spore Print: Olive brown.

Microscopic Features: Spores 9.5-17 x 4-6 µ; smooth; elliptical or almost spindle-shaped.

REFERENCES: Berkeley, 1853. (Coker & Beers, 1943; Singer, 1947; Snell & Dick, 1970; Weber & Smith, 1985; Metzler & Metzler, 1992; Both, 1993; Bessette, Roody & Bessette, 2000; Miller & Miller, 2006.) Herb. Kuo 07290307.

Pulveroboletus curtisii is a synonym.

One recent DNA study (Binder & Hibbett, 2004) places Boletus curtisii in a group with Boletus ornatipes and Boletus griseus.

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Cite this page as:

Kuo, M. (2007, January). Boletus curtisii. Retrieved from the MushroomExpert.Com Web site: http://www.mushroomexpert.com/boletus_curtisii.html