Tylopilus rhoadsiae

Description

Tylopilus rhoadsiae is a bolete fungus in the family Boletaceae. It is one of the rare white boletes and is also unusual because it is mycorrhizal - associated with the roots – with pines. It occurs in the Southeastern United States, Mexico, and Central America. White pores age pinkish & DNS. The cap-colored stem is well netted, esp. in the upper half.

Too bitter to eat but useful for unique approaches like cocktail bitters. It isn’t toxic; just absurdly bitter.

Common names: Pale Bitter Bolete.

Mushroom Identification

1. Ecology

   Primarily mycorrhizal with pines, but also reported under oaks; growing alone, scattered, or gregariously; summer, fall, or over winter; distributed in the southeastern United States, especially along the Gulf Coast.

2. Cap

   4–20 cm; convex when young, becoming broadly convex or nearly flat in age; dry; bald or very finely velvety; whitish to very pale grayish or pale tan; the margin overhanging the pore surface by 1 mm or so.

3. Pore Surface

   Depressed around the stem; white at first, becoming pinkish and, eventually, grayish pink; not bruising; pores circular to angular, 1–3 per mm; tubes to 15 mm deep.

4. Stem

   6–10 cm long; 1–2.5 cm thick; more or less equal, or with a slightly enlarged base; whitish, becoming very pale brownish; reticulate over the upper one-third or so with a fine, brown reticulum; basal mycelium white.

5. Flesh

   White; not staining when sliced.

6. Odor and Taste

   Odor is not distinctive; tastes bitter.

7. Microscopic Features

   Spores 10–14 x 3.5–5 µm; fusiform; smooth; hyaline in KOH. Basidia 4-sterigmate. Hymenial cystidia 35–50 x 7.5–12.5 µm; lageniform to narrowly fusiform; thin-walled; smooth; hyaline to golden in KOH. Pileipellis a poorly defined, collapsing trichoderm; hyaline to brownish-yellow in KOH; elements 5–12.5 µm wide.

8. Similar Species

   The widely distributed bolete Tylopilus felleus is similar in appearance to T. rhoadsiae, but has a very bitter taste, and a darker cap. Tylopilus rhodoconius has a cap that is initially brownish-orange before turning dark brown in age, and a white pore surface that stains brown when bruised

History

The species was described in 1940 as Gyroporus badiceps by William Alphonso Murrill, and later transferred to the genus Tylopilus by Murrill in 1944. In 1942, Wally Snell moved the species to Leucogyroporus, a genus he created to contain several species from Florida originally placed by Singer in Gyroporus; Leucogyroporus has since been subsumed into Tylopilus.

Synonyms

1. Gyroporus rhoadsiae Murrill (1940)

2. Boletus rhoadsiae (Murrill) Murrill (1940)

3. Leucogyroporus rhoadsiae (Murrill) Snell (1942)

Photo sources:

Photo 1 - Author: Richard Kneal (RJK) (CC BY-SA 3.0)

Photo 2 - Author: Richard Kneal (bloodworm) (CC BY-SA 3.0)

Photo 3 - Author: Justin (Tmethyl) (CC BY-SA 3.0)