Amanita pachycolea Stuntz in Thiers & Ammirati
Mycotaxon 15: 158-161. 1982.

Common Name: Western Grisette

• Pileus

  Cap 8-18 cm broad, rounded at first, then convex, finally plane and slightly umbonate at maturity; surface viscid when moist; color dark brown, fading to light brown in age, occasionally with a remnant of universal veil tissue; margin conspicuously and deeply striate.

• Lamellae

  Gills adnexed to free, close white with brown edges.

• Stipe

  Stipe 10-25 cm long, 1-3 cm thick, equal to narrower at the apex; pallid, covered with fine brown scales. Annulus absent. Universal veil forming a thick, membranous sac-like volva, sometimes developing rusty stains.

• Spores

  Spores 11.5-14.0 x 10-12 µm, smooth, nonamyloid, globose to subglobose. Spore print white.

• Habitat

  Found commonly from mid-fall to mid-winter in mixed hardwood coniferous forest.

• Edibility

  Edible but not choice.

• Comments

  Amanita pachycolea can be recognized by its large size, dark brown, deeply striate cap, absence of a ring, and well developed thick white, membranous volva. Its cousin, Amanita vaginata, is similar but smaller, has a cap which is not nearly so deeply striate, and is grayish rather than brown. Both species, however, can develop rusty stains on the volva.

• Other Descriptions and Photos
  • Michael Boom: Amanita pachycolea (CP) -- young sporocarp with veil patch on cap
  • Taylor F. Lockwood: Amanita pachycolea (CP) -- young sporocarp just emerged from the volva
  • Fred Stevens: Amanita pachycolea (CP) -- very dark sporocarps
  • Michael Wood: Amanita pachycolea (CP)
  • Michael Wood: Amanita pachycolea (CP)
  • Michael Wood: Amanita pachycolea (CP) -- a large one!
  • Boleslaw Kuznik -- Hunting for Mushrooms: Amanita pachycolea (CP)
  • Nathan Wilson: Amanita pachycolea (D & CP)
  • Robert Rich: Amanita pachycolea (D & CP)
  • Spotlight on Fungi: Amanita pachycolea (D & CP)
  • Arora (1985): p. 290 (D), plates 65,66 (CP)
  • Arora (1991): p. 72 (D & CP)
  • Jenkins: p. 73 (D)
  • Thiers (1982): p. 33 (D)

  (D=Description; I=Illustration; P=Photo; CP=Color Photo)