Scattered in leaf humus and on needle beds,
both in deciduous as well as in coniferous woods, and also in more open heathland. Summer to autumn. Common all over the region covered.
Pileus 10-50 mm across, parabolical to planoconvex, with or without an obtuse umbo, often also centrall depressed, sulcate, translucent-striate, hygrophanous, glabrous, colours very variable, pale pink with a lilaceous tinge, pinkish grey, violaceous grey, to dark violet, but also white, yellow or light blue, often with a pale violet flush. Lamellae 20-40 reaching the stipe, ascending, becoming subhorizontal, adnate to somewhat sinuate-adnate, sometimes also decurrent with a short tooth, dorsally intervenose at age, whitish to pale pink or pale violet, the edge convex, concolorous. Stipe 40-90 x 2-7 mm, hollow, tough, equal or broadened below, straight to curved, terete to somewhat compressed, smooth, pruinose above, glabrous farther below, whitish to pinkish or violet, pinkish purple, the base more or less densely covered with long, coarse, whitish fibrils.
Basidia 27-30 x 6-8 µm, clavate, 4-spored. Spores 6-9.5 x 4-5.2 µm, Q 1.4-2.1, Qav≈1.7, pip-shaped, smooth, amyloid. Cheilocystidia 25-75 x 11-18 µm, forming a sterile band, fusiform, clavate, subcylindrical, short- to long-stalked, smooth, apically broadly rounded, sometimes more attenuated or mucronate. Pleurocystidia similar. Lamellar trama brownish vinescent in Melzer's reagent. Odour and taste raphanoid. Hyphae of the pileipellis 2-5 µm wide, smooth. Hyphae of the cortical layer of the stipe 2-4 µm wide, smooth, caulocystidia 25-72 x 9-15 µm, fusiform, clavate to subcylindrical, smooth. Clamp connections present in all tissues.
Maas Geesteranus (1989) recognized eight forms of M. pura. Possibly some of these forms will turn out to be different species. In a recent study by Harder et al. (2010) there was no support for regarding the different colour varieties of M. pura as separate species, although they found several different clades within the Mycena pura morphospecies. Instead, they indicated a possible environmental basis of the colour differentiation. This said, both Mycena diosma and Mycena rosea were clearly separated in their analyses.
According to Krieglsteiner and Schwöbel (1982) the vivid colours and the odour are the most important differential characters to identify M. diosma. Maas Geesteranus (1989 b) stated that the lamellae of M. pura are white to somewhat coloured, but always pale, while they are dark brownish violet to dark violet in M. diosma. The odour of the latter is said to be sweetish fragrant mixed with a component resembling the scent of a wooden cigar box, but raphanoid when cut or bruised. Harder et al. (2010) pointed at the scarcity of the pleurocystidia as an important character.
M. rosea can be distinguished from M. pura on account of the pink colours, but as pointed out by Maas Geesteranus (1989b): "In spite of the fact that Mycena rosea, once shown, is easily distinguishable from M. pura already in the field, it is rather embarrassing to find that the differences are not readily translated into words and it is rather a surprise to learn that microscopically there is no difference between the two species." In my experience, M. rosea can be distinguished from M. pura by the +/- uniform pink colours and a more robust stature, including a widened stipe base.
Mycena dura, described from Austria (Maas Geesteranus & Hausknecht 1994), is characterized by a densely fasciculate habit; in young specimens a very dark brown pileus with some purplish shade; a tough stipe that is white with a silvery lustre and a white-tomentose base and lack of coarse fibrils; and by the cheilocystidia occuring mixed with the basidia (a heterogeneous lamellar edge).
Perreau-Bertrand et al. (1996) described a new species, M. sororia, from France, based on electrophoretic studies. It can, according to the authors, be separated from M. pura on account of a pink pileus with lilaceous shade. It may seem that the spores are somewhat larger in M. sororia as well. M. sororia has, according to Perreau-Bertrand et al (1996), biochemical affinities to M. rosea but it differs from the latter by the more violaceous pink colour of the pileus which is also more dry in touch, and by the pinkish white to purplish pink stipe, cylindraceous or fusiform, not widened at the base. Moreover M. sororia presents somewhat larger spores than those of M. rosea. A problem with this taxon is that the authors did not define M. pura, so that it is difficult to prove their theory on new material. Until further investigations have been done M. sororia must remain a nomen dubium.