Summary:
Features include a minute, cup-shaped fruitbody clothed with brown hairs, with spore bearing upper surface described as various colors; a distinct short dark stem present or not; growth on wood of hardwoods; and microscopic characters including short spores. Another name, Neodasyscypha cerina (Pers.: Fr.) Spooner, is considered to be in an genus that has an invalid name, according to Dictionary of the Fungi 9th Edition, following Eriksson & Hawksworth. Haines(1) in his Master''s thesis considered this "one of our most common colored species of Dasyscyphus which occurs on hardwood remains (commonly Populus)" (referring to western Washington, with Latin names underlined).

Chemical Reactions:
golden yellow hairs turn olive-brown when mounted in 3% KOH (the golden yellow granules almost completely dissolve in KOH) (Haines)

Microscopic:
spores 5-6 x 2.5-3 microns, elliptic, uniseriate or biseriate; asci 8-spored, reaching a length of 40-50 microns and a width of 4-5 microns, cylindric or subcylindric; paraphyses extending far beyond the asci, reaching a width of 2 microns, filiform [thread-like]; hairs reaching a length of 120 microns and a width of 4-5 microns, "brown, septate, roughened on the outside", (Seaver), spores 4.5-7.5 x 2-3 microns, elliptic to fusoid, colorless, non-septate; asci 8-spored, 40-48 x 3.5-5 microns, cylindric to clavate, with amyloid pore; paraphyses exceeding the asci by 5-10 microns, 2-2.5 microns wide, narrowly lanceolate; hairs 70-140 x 3-4 microns, cylindric, brown, paler toward tip, +/- thick-walled, multiseptate, densely covered with attached granules, (Hansen), spores 4-6 x 2-2.5 microns, short-elliptic, uniseriate, usually without conspicuous inclusions; asci 8-spored, cylindric with rather thick stalk; paraphyses 1.5-2 microns wide at the widest point, filiform [thread-like] "or narrowly lanceolate", "with obtuse apices, barely exceeding the asci", "usually filled with numerous yellow droplets, non-septate"; hairs up to 10 microns long and 4-5 microns wide, cylindric with obtuse tip but tapering slightly at both ends, "golden yellow but turning olive-brown when mounted in 3% KOH, densely covered with coarse, golden yellow granules which almost completely dissolve in KOH", "multiseptate, moderately thick-walled, often filled with storage material", the upper third often colorless; outer excipulum "of one or two layers of subglobose, thick-walled, cells" 5-10 microns in diameter "which are similar to the hairs in color and KOH reaction", "inner excipulum of closely packed, short-celled, parallel, hyaline hyphae", (Haines, the length of the hairs may be an error here and the ascal dimensions are clearly wrong, being identical to the spore dimensions)

Notes:
Lachnum cerinum is found in WA, and also NF, TN, WV, and Europe, (Seaver), and Denmark, Finland, Norway, and Sweden, (Hansen). There is an R. Bandoni collection from BC deposited at the University of British Columbia (as Lachnella cerina).

Synonyms and Alternate Names:
Dasyscyphus cerinus (Pers.) Fuckel
Lachnella cerina (Pers.) W. Phillips
Stereum purpureum (Pers.) Fr.
Thelephora purpurea Pers.