stem. The gills are up to broad, thin, and the same color as the cap or paler. Microscopic characteristics The spores are broadly ellipsoid, smooth, colorless, amyloid (staining bluish to blue-black when treated with Melzer's reagent), thin-walled, and measure 8–9 by 5–6 µm. The basidia are 40–60 by 10–12 µm, club-shaped, and four-spored. The cheilocystidia (cystidia on the gill edge) are abundant, club-shaped, and measure 30–45 by 10–17 µm. Their tips are covered with one or more, knob-like short excrescences that are colorless and thin-walled. Pleurocystidia (cystidia on the gill face) are absent. The hymenophoral tissue (tissue of the hymenium-bearing structure) is made of thin-walled hyphae that are 12–21 µm wide, cylindrical (but often somewhat inflated), smooth, and contain cytoplasmic brownish pigment. These hyphae are dextrinoid, meaning that they stain reddish to reddish-brown in Melzer's reagent. The cap cuticle is made of parallel, bent-over hyphae that are 2–7 µm wide, and cylindrical. These hyphae are smooth, or can be covered with scattered, warty or finger-like thin-walled diverticulae that are colorless or pale brownish, and dextrinoid. The layer of hyphae underlying the cap cuticle is parallel, cylindrical, hyaline or brownish, and dextrinoid; it has short and inflated cells that are up to 48 µm wide. The stem cuticle is made of parallel, bent-over hyphae that are 3–8 µm wide, and similar to the hyphae of the cap cuticle. The caulocystidia (cystidia on the stem) are 45–88 by 5–8 µm, cylindrical, diverticulate, colorless or brownish, and thin-walled. The flesh of the stem is composed of longitudinally running, cylindrical hyphae that are 8–25 µm wide, smooth, colorless, and dextrinoid. Clamp connections are present in the cap cuticle, the stem cuticle, the gill flesh, and at the basal septa of the basidia. Similar species Mycena clariviolacea is similar to the Brazilian species M. cerasina and the European M. diosma. Mycena cerasina, which belongs in the section Cerasinae of the genus Mycena, differs in having a grayish-purple cap and stem, and forming somewhat utriform (wineskin-shaped) to lageniform (flask-shaped), smooth cheilocystidia. Mycena diosma, classified in the section Calodontes, subsection Purae, may be distinguished microscopically from M. clariviolacea by its smooth, spindle-shaped cheilocystidia and pleurocystidia, and nondiverticulate hyphae in the cortical layer of cap and stem. Habitat and distribution Mycena clariviolacea is known only from Kanagawa, Japan. Fruit bodies are found growing solitary or scattered, on dead fallen twigs in forests that are dominated by oak and