Inocybe helobia

Long considered a variety of Inocybe lacera, now recognized as an independent taxon characterized by its association with Alnus, Salix, or Populus, caulocystidia restricted to the upper stipe, and irregular spores.

Pileipellis filamentous, composed of hyphae arranged more or less parallelly to slightly interwoven, 5-12 µm wide, with brownish intracellular pigment, septate and clamped.

Caulocystidia present only on the upper stipe, fusiform with apical crystallizations.

Cheilocystidia fusiform, with apical crystallizations, wall thickness 2-3.5 µm, literature reporting lengths up to 75 µm (slightly above those in this study), intermixed with shorter non-crystallized clavate cells.

Pleurocystidia scattered, morphologically and dimensionally very similar to cheilocystidia.

Basidia clavate, 20-30 µm long and 9-10 µm wide, with basal clamps, 4-spored.

Spores ellipsoidal, very irregular, slightly angular, smooth, thick-walled, yellowish-brown under the microscope, with an inconspicuous eccentric apiculus at one end and faint granular internal content.

Herbarium material available: JTP2310/24.