Summary:
Section Adonidae (Smith), Section Calodontes (Maas Geesteranus). Features include 1) a hygrophanous, striate cap that is various shades or mixtures of lilac, pink, beige, purple, yellow, gray, blue-gray, pale blue, blue-green with a yellowish center, pale yellow flushed pale bluish or pale violet at the margin, whitish tinged purple or blue at center, or white, 2) gills that are whitish or tinged cap color, 3) a stem that is colored like cap or whitish, 4) a radish-like odor and taste, 5) growth on the ground, 6) white spore deposit, and 7) microscopic characters. Smith describes Mycena subaquosa, similar to Mycena pura (in radish odor, spores, and cystidia). Smith says that white forms of M. pura differ from M. subaquosa in having an odor not exceptionally strong, colors usually faintly pinkish or lilac on disc and top of stem, and stature different from M. subaquosa which also has bald translucent stem, (Smith(1)). Maas Geesteranus synonymizes M. subaquosa with Mycena pura forma alba. The description below that is derived from Maas Geesteranus is for forma pura, but he also describes 1) forma alba that is white, 2) forma ianthina that is light blue with a violaceous or grayish shaded cap, paler concolorous gills and reddish violet stem, 3) forma lutea with pale yellow to almost citrine cap, sometimes flushed with pale bluish or pale violet at margin, lilac or very pale violet gills, and pale violet stem, 4) forma multicolor with fairly pale sky blue to grayish blue cap with fulvous umbo, pale grayish blue gills, lilac to pinkish purple stem that is yellowish at base, 5) forma purpurea with white cap, white to pinkish gills, and violaceous stem, and 6) forma roseoviolacea with dingy pink or violaceous pink cap more reddish at center, whitish gills that become concolorous, and stem concolorous with cap. Hardera(1) found multiple phylogenetic species within the Mycena pura complex, most of them cryptic, but different molecular techniques gave somewhat different results.

Cap:
2-5(6.5)cm across, obtusely umbonate or convex becoming broadly convex or flat, sometimes with uplifted margin; hygrophanous, "various shades or mixtures of lilac, pink, gray, and blue-gray, but varying also to blue-green with a yellowish center, or whitish tinged purple or blue at the center"; smooth, translucent-striate when moist, (Arora), 2-5cm across, shallowly parabolic, becoming bell-shaped to flat-convex, with or without obtuse umbo, sometimes with concentric depression around umbo, sometimes with central depression; hygrophanous, color variable, pale pink, lilac, or beige; smooth, bald, translucent-striate, more or less sulcate [grooved], (Maas Geesteranus for M. pura f. pura), 2-4(6.5)cm across, "obtuse when young with the margin straight or slightly incurved, becoming obtusely umbonate, convex", flat, or with elevated margin, disc rarely slightly depressed; hygrophanous, variable in color, bright rosy red, purplish, purplish tan, lilac, lilac gray, bluish gray, yellowish, or white with a faint bluish or purplish tinge on disc; moist, naked, translucent-striate, (Smith)

Flesh:
thin, soft, (Arora), thin, but thicker at center; whitish, (Maas Geesteranus), moderately thick, usually abruptly tapered halfway to margin; "purplish, livid bluish to sordid lilac, becoming pallid or whitish", (Smith)

Gills:
adnate or adnexed; usually tinged cap-color, but sometimes grayish or white, edges pallid, (Arora), adnate or sinuate-adnate or short decurrent, 20-35 reaching stem, up to 0.8(1.2)cm broad, interveined; whitish to pale pink, edges colored as faces, (Maas Geesteranus), adnate, adnexed, or uncinate, close to subdistant, broad, becoming ventricose [broader in middle] and 0.5-0.8cm broad, interveined; "tinged purplish lilac or bluish, often shaded more or less with gray, sometimes white, edges whitish", (Smith)

Stem:
3-7(10)cm x 0.2-0.7cm, equal or widening in lower part, hollow; pallid or cap-colored or paler; smooth, (Arora), 4-8(9)cm x 0.2-0.7(0.8)cm, equal or thicker below, hollow, tough, straight to curved, round in cross-section to somewhat compressed; whitish to pinkish; smooth, pruinose in upper part, bald further down, "the base more or less densely covered with long, coarse, somewhat woolly, whitish fibrils", (Maas Geesteranus), (3)4-10cm x 0.2-0.6cm, round in cross-section or compressed, equal, sometimes widening in lower part, hollow, toughish; whitish or cap-colored, often paler or with only slightly different tones; bald or scabrous-pruinose, sometimes somewhat scaly, sometimes twisted-striate, base slightly mycelioid, (Smith)

Odor:
radish-like (Arora, Maas Geesteranus, Smith)

Taste:
radish-like (Arora, Maas Geesteranus, Smith)

Microscopic spores:
spores 5-9 x 3-4 microns, elliptic to cylindric, smooth, amyloid (Arora), spores 7.4-8.1(9.2) x 3.4-4.9(5.6) microns, pip-shaped [elliptic], smooth, amyloid; basidia 4-spored, 25-35 x 6-7 microns, clavate, with clamp connection; cheilocystidia forming a homogeneous band on gill edge, 35-70(90) x 7-18 microns, fusiform, utriform, clavate, short-stemmed to long-stemmed, clamped, rounded at top, or more rarely narrowed or mucronate [abruptly pointed from a flatter surface], near the cap margin sometimes covered with a few small cylindric excrescences, pleurocystidia similar, caulocystidia 30-100 x 6.5-21.5 microns, fusiform, elliptic, smooth, (Maas Geesteranus), spores 6-9(10) x 3-3.5 microns, subcylindric to narrowly elliptic, amyloid; basidia 4-spored; pleurocystidia "scattered, rare or abundant", 40-70(100) x 10-20(25) microns, "ventricose with obtuse apices or elongated into a tapered neck, occasionally with one or two obtuse protuberances, sometimes saccate above a narrow pedicel", cheilocystidia abundant, similar to pleurocystidia or saccate, (Smith)

Spore deposit:
white (Arora)

Notes:
Mycena pura has been found at least in BC, WA, OR, ID, AL, CA, CO, MA, MI, MT, NC, NJ, NY, OH, TN, WI, and WY, and is known from NS to BC in Canada, (Smith). It has also been found in QC (Bigelow), and Europe (various forms), India and Japan (in some form), (Maas Geesteranus). Breitenbach(3) give the distribution as North America, Europe, Asia, and North Africa.

EDIBILITY

not recommended: edible according to some sources, but containing muscarine according to one study, (Arora)

Synonyms and Alternate Names:
Mycena subaquosa A.H. Sm.