Suillus tomentosus

Description

Suillus tomentosus is an ectomycorrhizal mushroom in the family Boletaceae. It is one of only a few blue-staining species of Suillus. This very distinctive Suillus is distinguished by the strongly developed, fibrillose-scaly surface of the pileus, the bluing of the context upon exposure, and the absence of a veil or annulus. Although the fibrillose scales are grayish to olivaceous when young, they frequently become red to bright red with age.

The species associates with Pinus hosts in the subgenus Pinus where it exchanges mineral nutrients for photosynthates from its host. It is native to North America and has one of the most widespread distributions in the genus, occurring in both Eastern and Western North America. The species is most commonly found in higher latitudes and/or altitudes in mature forests.

Some people eat this mushroom but it is reported to not be very good, and some have been known to get sick.

Common names: Blue-staining Slippery Jack, Poor Man's Slippery Jack, Woolly-Capped Suillus.

Mushroom Identification

1. Ecology

   Mycorrhizal with two-needle pines, especially lodgepole pine and jack pine; growing scattered or gregariously; summer and fall (also in winter in coastal California); widely distributed in North America but rare or absent in the southeast.

2. Cap

   5-15 cm; convex becoming broadly convex; sticky or fairly dry; at first covered with a fine, grayish, felty covering, but often becoming smoother with age; yellow to orangish-yellow; sometimes developing reddish spots and stains; the margin at first inrolled.

3. Pore Surface

   Brownish to cinnamon when young, becoming brownish yellow to olive-yellow; bruising blue; 1-2 angular pores per mm; tubes to 2 cm deep.

4. Stem

   4-12 cm long; 1-3 cm thick; equal or somewhat club-shaped; yellowish-orange; covered with brownish glandular dots; staining brownish on handling; without a ring.

5. Flesh

   Whitish to yellowish in the cap; yellow in the stem; bluing on exposure.

6. Odor and Taste

   Not distinctive.

7. Chemical Reactions

   Ammonia reddish to grayish or negative on the cap surface; brownish on flesh. KOH pinkish, then purple on cap surface; dark brown on flesh. Iron salts greenish to grayish on cap surface; gray to brown on flesh.

8. Spore Print

   Olive brown when fresh, drying cinnamon brown.

9. Microscopic Features

   Spores 7-12 x 3-5 µ; smooth; subfusoid.

10. Similar Species

    Include S. fuscotomentosus, S. reticulatus, S. variegatus, and Boletus subtomentosus.

Synonyms

1. Boletus tomentosus Kauffman, Papers Mich. Acad. Sci. Arts and Letters 1 :117. 1921

2. Suillus hirtellus var. mutans (Peck) Snell, Lloydia 7:23. 1942

3. Xerocomus lenticolor Snell and Dick, Mycologia 52:448. 1960

Photo sources:

Photo 1 - Author: Johannes Harnisch (Johann) (CC BY-SA 3.0)

Photo 2 - Author: USFWS - Pacific Region (CC BY-SA 2.0)

Photo 3 - Author: Ron Pastorino (Ronpast) (CC BY-SA 3.0)