Hydnellum amygdaliolens

The fruit bodies are medium to large, club‑shaped basidiocarps (cap and stem fused), 75–200 mm across, often lobed or irregular in outline. The pileus (cap) surface is finely felted to smooth, cracking into shallow plates but without erect scales, and ranges from yellowish‑brown to cinnamon or beige, typically darker when wet. The edge is initially slightly inrolled and sterile. The stipe is stout (35–60 by 22–40 mm), simple or branched, with spines (aculei) up to 10 mm long that run partly down the stipe. The spines are whitish at first, becoming brownish towards the base. The flesh is thick—brittle in the cap, fibrous in the stem—and displays a vivid greenish‑blue reaction with potassium hydroxide (KOH), turning orange with time. The taste is extremely bitter and often tingling; the hymenium (spore‑bearing surface) emits a characteristic intense bitter‑almond aroma shortly after collection. Microscopically, the hyphal system is monomitic (only generative hyphae, without clamp connections). Basidia are four‑spored, more or less cylindrical to club‑shaped, 27–34 by 5–6 micrometres] (μm). Spores are somewhat spherical (globose) to ellipsoid, ornamented with nodules or warts, 5.25–6.5 by 4–5 μm (including ornamentation), each containing a single oil drop. Gloeocystidia (oil-containing cystidia) occur abundantly in the cap cuticle.

Sarcodon amygdaliolens is known from scattered Mediterranean climate localities throughout the Iberian Peninsula, fruiting in autumn and winter (November–December). It grows terrestrially under conifers—predominantly maritime pine (Pinus pinaster), but also Scots pine (P. sylvestris) and stone pine (P. pinea)—on acidic, siliceous soils derived from quartzite, schist or granite. Recorded provinces include Guadalajara, Valencia, Cádiz, Cuenca, Salamanca, Badajoz and Almería. Its preference for acid soils and pine stands, combined with the bitter taste and almond scent, make it readily recognised in the field.

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