Strobilurus trullisatus

What You Should Know

Strobilurus trullisatus is a small mushroom, nondescript in appearance but notable for being highly restricted in habitat: most species grow only on conifer cones. It is recognized by a pale-colored cap with pinkish tones and a yellowish-brown stem base. The fruitbodies often arise from buried cones, so a little excavation may be required to make the substrate apparent.

Strobilurus kemptonae is an older name for this mushroom.

Other names: Douglas-Fir Cone Mushroom.

Strobilurus trullisatus Mushroom Identification

1. Cap

   0.4-1.7 cm broad, convex, expanding to nearly plane and slightly depressed; surface smooth to faintly wrinkled, pallid brown at the disc shading to a pale pinkish, striate margin; flesh thin and white.

2. Gills

   Adnate to adnexed, close, white to pinkish-tan.

3. Stem

   1.5-4.5 cm tall, 0.1-0.2 cm broad, white, subtomentose above, yellowish-brown and pubescent below, orange-brown mycelium at the base; veil absent.

4. Flesh

   Thin; whitish; unchanging when sliced..

5. Spores

   3.5-6 x 2-3 µm, elliptical, smooth, nonamyloid.

6. Spore Print

   White.

7. Habitat

   Solitary to grouped on decaying Douglas fir cones; from late summer in areas of fog drip to mid-winter. Originally described from Alaska; distributed in the Pacific Northwest and northern California and sometimes reported from the Rocky Mountains.

8. Edibility

   Unknown. Too small to be of any culinary value.

9. Microscopic Features

   Basidia 18–22 x 3–5 µm; clavate; 4-sterigmate. Cheilocystidia 30–60 x 5–6 µm; utriform to subcylindric, with a capitate apex; smooth; thin-walled; hyaline in KOH. Pleurocystidia 30–50 x 8–12 (–18) µm; utriform to subcylindric, with a subcapitate to capitate apex; smooth; thin-walled; hyaline in KOH. Pileipellis hymeniform; terminal cells 7.5–12.5 µm wide, obpyriform, hyaline in KOH—with interspersed pileocystidia 35–70 x 5–10 µm, subcylindric to narrowly fusiform, developing a capitate apex, smooth, hyaline in KOH. Clamp connections not found.

Strobilurus trullisatus Look-Alikes

1. Strobilurus occidentalis

   Favors Sitka spruce cones, tends to be browner without a pinkish cast, and has thicker-walled pleurocystidia that lack granular material at the tip (and lack an apical collarette).

2. Strobilurus albipilatus

   May grow on debris, tends to be browner (often grayish brown) and its pleurocystidia lack apical collarettes.

3. Baeospora myosura

   Differentiated by its slightly larger size, crowded gills, weakly amyloid spores, pleurocystidia that lack apical collarettes, hyphae with clamp connections, and cap cuticle composed of repent, radially oriented filamentous hyphae.

Sources:

Photo 1 - Author: jeffreyleeisanaturalist (Attribution 4.0 International)

Photo 2 - Author: hylaeus (Attribution 4.0 International)

Photo 3 - Author: bcislander (Attribution 4.0 International)

Photo 4 - Author: benkeen (Attribution 4.0 International)