Stropharia ambigua

🏷️ Description

Deep in the damp, shaded forests of the Pacific Northwest, a striking mushroom stands tall—Stropharia ambigua, sometimes called the "questionable Stropharia." With its bright yellow, slimy cap adorned with delicate white veil remnants, this fungus is a true showstopper, rivaling even the regal Amanita species in beauty.

🌲 Where to Find It: This saprotrophic mushroom thrives in leaf litter, wood chips, and rich humus, usually beneath conifers, alder, and other hardwoods. It’s common in disturbed areas, often appearing where wood has been handled, and even popping up in urban settings like the University of Washington campus! It favors cool, moist environments and can be found in fall and spring.

🍽️ Edibility – To Eat or Not to Eat? While Stropharia ambigua is not known to be poisonous, its edibility remains uncertain. Some sources suggest caution, and well-known mycologists like David Arora and Orson K. Miller, Jr. do not recommend eating it. So, best to admire this beauty with your eyes, not your plate!

🔎 Identification

🟡 Cap: 1.18 to 5.91 inches (3 to 15 cm) wide, slimy when fresh, ranging from pale yellow to golden brown. Young caps have white veil remnants hanging from the edge.

🌿 Gills: Start whitish to pale gray, maturing to deep purplish-gray to purple-black. The edges remain whitish when fully developed.

📏 Stem: 2.36 to 7.09 inches (6 to 18 cm) tall, 0.39 to 0.79 inches (1 to 2 cm) thick, mostly white, with a fine shaggy texture below the vanishing ring. The base often has white mycelial threads.

🥩 Flesh: Thick, white, and unchanging when cut.

👃 Odor: Not distinctive, but sometimes radish-like or mealy.

🖤 Spore Print: Dark purple-brown to nearly black.

🧪 Chemical Reactions: KOH on the cap turns pale orange.

🔬 Microscopic Features:

• Spores: 10–16 x 6–9 µm, elliptical, smooth, thick-walled.

• Basidia: 4-sterigmate.

• Pleurochrysocystidia: Clavate with golden-refractive inclusions.

• Pileipellis: An ixocutis with poorly defined, hyaline to golden elements.

🌲 Ecology and Habitat: A saprobic mushroom thriving in coniferous forests and wood-chip beds along the West Coast (California to Alaska). Found from fall to spring, often appearing alone or in groups on woody debris. Typically found in deep forest humus, often under conifers, along streams, or in damp shaded areas. Fruiting late fall to mid-winter.

Photo sources:

Photo 1 - Author: Alan Rockefeller (CC BY-SA 4.0)

Photo 2 - Author: Alan Rockefeller (CC BY-SA 4.0)

Photo 3 - Author: Sorrel (CC BY 4.0)

Photo 4 - Author: Sandy Patton (CC BY 4.0)