A small grey-blue Phlegmacium of Nothofagus forest, with bitter taste and distinctive NaOH reactions

Pileus: 10-30 mm, dry, hygrophanous. Conical to campanulate to plane. Brown‑grey to grey‑blue, often yellow‑stained at centre. Finely innate‑fibrillose, partly grey‑coated, with whitish‑grey fibrils at the margin when young. No obvious veil patches on pileus. Lamellae
Lamellae: Blue‑grey to dark grey when young. Distant (L = 24, l = 2). Adnate, edge concolorous.
Stipe: 30-55 x 3 mm, cylindrical to slightly clavate. Whitish‑grey to grey‑yellowish, with greyish girdles; sometimes ochraceous from the base upward. Apex pale grey‑blue. Veil pale brown‑grey to grey, fairly copious. Cortina pale blue‑grey, fugitive.
Context: Grey, slightly blue‑marbled; sometimes yellowish to orange in the stipe base.
Odour/taste: Odour none. Taste distinctly bitter.