Hydnellum caeruleum

A species associated with pine forests, with bluish tints on the cap, especially at the margin.

Monomitic hyphal system: pileus surface hyphae cylindrical, moderately thick-walled, 4-6 µm wide, arranged more or less parallelly, with brownish intracellular pigment and emergent clustered terminal elements, septate with some septa bearing coarse clamps.

Subhymenial hyphae hyaline, thin-walled, 2-4 µm wide.

Cystidia and other sterile hymenial elements absent.

Basidia clavate, 26-30 µm long and 5-6 µm wide, without basal clamps, 4-spored.

Spores small, spherical to ovoid, ornamented with coarse warts (nodulose), hyaline, containing a large internal oil droplet, inamyloid in Melzer's reagent.