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Species Information
Summary: Roridomyces roridus is characterized by small size, pale color, A dry cap, and a conspicuous sheath of slime on the stem. It was formerly considered a Mycena. Maas Geesteranus did not consider it a Mycena because of the structure of the pileipellis (cap cuticle). The description was derived from Smith(1) (as Mycena rorida) except where otherwise noted.
It has been found at least in WA, OR, NS, ON, CA, MI, MT, NC, and NY. The University of British Columbia has collections from BC and YT. The University of Washington has collections from WA, OR, AK, MI, and ON. Breitenbach(3) give the distribution as North America and Europe.
Cap: (0.2)0.5-1(1.5)cm across, at first rounded or broadly convex, then expanding to flat or nearly so, often with depressed disc when mature; pale fuscous on disc at first, brownish toward whitish margin, "fading through pale brown to tan and finally whitish or yellowish white", usually rather dingy when old; dry and very finely furfuraceous to subpruinose [somewhat pruinose], margin striate at times, becoming sulcate [grooved], margin often scalloped, (Smith), rounded then bell-shaped, expanding to flat or nearly so, (Arora)
Flesh: thin, moderately fragile; pallid
Gills: adnate, arcuate, becoming decurrent when old, subdistant, 14-18 reaching stem, narrow to moderately broad; white; edges even
Stem: 2-3(5)cm long and about 0.1cm wide, equal, elastic; bluish black near top soon fading to whitish, base becoming sordid brownish when old; covered with a thick glutinous sheath when young, the gluten gradually collecting toward the base in large masses, base hairy
Odor: mild (Arora)
Taste: unknown
Microscopic spores: spores 8-12 x 4-6 microns, from 2-spored basidia 9-12 x 4.5-6 microns, from 4-spored basidia 8-10 x 4-5 microns, narrowly elliptic, strongly amyloid; basidia 4-spored especially in Pacific Northwest or 2-spored especially in eastern North America, sometimes both on same specimen, 26-30 x 5-7 microns; pleurocystidia not differentiated, cheilocystidia abundant, 26-34 x 6-10 microns, "smooth, fusoid ventricose to nearly cylindric, often irregular in outline"; "gill trama reddish to purplish brown in iodine, subhymenium and gill edges not gelatinous; pileus trama corticated by a palisade of inflated pedicellate cells with sordid-brown contents", the cells 25-40 x 15-30 microns above the pedicel, pedicel 12-30 x 3-5 microns, "a narrow band of slender hyphae immediately beneath the palisade layer, the remainder of the trama of floccose tissue composed of more or less enlarged hyphae, all parts except the palisade layer reddish to purplish brown in iodine; stem tissue dark vinaceous brown to purplish in iodine", (Smith), cap cuticle hymeniform, of vesicular elements 15-22 x 13-17 microns, with fine, colorless granules that dissolve in lye [KOH], deeper hyphae cylindric, septa with clamp connections, (Breitenbach), spores 8-12 x 4-6 microns, elliptic, smooth, amyloid, (Arora)
Spore deposit: white (Arora)
Habitat / Range
gregarious on needle beds under conifers and scattered on small sticks or branches of conifer wood (Smith), single or scattered to gregarious on ground and debris under conifers and in mixed woods (Arora), single to gregarious or cespitose [in tufts] among Rubus vines, ferns, and herbs, on twigs, leaves, and other plant remains lying on the ground from the previous year, principally in damp but not wet habitats, May to October, (Breitenbach for Europe), spring, summer, fall
Similar Species
Mycena tenax has a gray-brown to pale gray cap and strong disagreeable odor. Mycena vulgaris has an extremely viscid cap. Mycena clavicularis has a dry grayish cap and mild odor but tends to be larger and has a different microscopic structure of the cap cuticle.
