E-Flora BC: Electronic Atlas of the Flora of British Columbia

Summary:
Features include 1) resupinate growth on wood, usually coniferous, 2) a whitish to pale yellow or ochraceous fruitbody, interrupted to reticulate/tufted and continuous, and bristly under a strong lens from cystidia, 3) spores that are allantoid, smooth, and inamyloid, 4) basidia that are basally thick-walled, and are amyloid, dissolving in KOH, 5) cystidia that are cylindric, narrowing to the obtuse and encrusted apex, thick-walled with the capillary lumen gradually or more often abruptly expanded, the apex thin-walled (usually on one side), obtuse, and encrusted, the cystidia usually strongly amyloid, and walls dissolving in KOH, 6) a monomitic hyphal system, the hyphae with clamp connections.

Tubulicrinis calothrix has been found in BC, OR, AB, ON, PQ, AZ, CO, IA, IL, LA, MA, NM, NY, PA, TN, and WI, (Ginns), as well as HI, Latvia, (Weresub(3)), and Denmark, Finland, Norway, and Sweden, (Hjortstam).

Fruiting body:
"resupinate, at first thin and discontinuous, mostly porulose but as a rule well distinguishable", then thicker and up to 0.01-0.025cm thick; "whitish to pale yellow or ochraceous"; "continuous but with more or less pronounced tufts", not or very rarely rimulose [finely cracked], under a strong lens pilose from projecting cystidia; margin thinning out, (Hjortstam), "thin and delicate to almost cushiony" (rarely up to 0.02cm in depth), usually easily separable; "white, sometimes somewhat grayish, rarely creamy"; "interrupted to densely reticulate and continuous, broadly effused, with indeterminate margin, pruinose, and hispid", (Weresub(3)), a densely knit reticulum, cushiony, continuous to glebulous [lumpy, clod-like]; creamy; smooth or somewhat punctate, distinctly and regularly hispid, (Weresub(4))

Microscopic:
SPORES 6-7(8) x 1.5-1.8(2) microns, "allantoid, smooth, thin-walled"; BASIDIA 4-spored, 12-15 x 4-5 microns, "subclavate, in relatively dense clusters", after sporulation often stemmed and basally thick-walled, mostly with a strong amyloid reaction, basidia with basal clamp connection; CYSTIDIA cylindric, often numerous, 80-120 microns long and 6-8 microns wide in the middle part, "narrowing to the obtuse and encrusted apex, with the capillary lumen gradually or more often abruptly expanded, with an asymmetric wall thickening", amyloidity variable, but usually strong; HYPHAE monomitic, 2-2.5 microns wide, "thin-walled or with slightly wall thickening", "in the subhymenial tissue fairly dense, inamyloid but remnants of old basidia often intermingled in the tissue giving it a more or less strong amyloid reaction", all hyphae with clamp connections, (Hjortstam), SPORES (4.5)5-7 x (1.5)2-3 microns, cylindric, smooth, inamyloid, thin-walled; BASIDIA 4-spored, (8.5)11-17.5 x (3.75)4-5.5 microns, with basal walls thickened, typically amyloid, also dissolving or swelling in KOH, sterigmata 3.5-4 microns long, more or less erect; CYSTIDIA 45-75(125) microns long, (4.5)5-7.5(8.5) microns broad just above the branching base, usually narrowing slightly to a neck width of 4-5.5(7) microns, then most frequently broadening somewhat to an apical width of (4)4.5-6(7) microns, capillary lumen "sometimes obliterated toward the base, expanding more or less abruptly about one-sixth to one-third of the distance from the apex", "walls amyloid, thick, thinning toward the tip, typically extending somewhat like a hood along one side and over the summit of the otherwise comparatively thin-walled, obtuse head, the walls swelling and dissolving in KOH, the ''hood'' often showing a more delayed reaction"; HYMENIUM "apparently proliferating anew above the husks of old basidia, generally amyloid"; SUBICULAR HYPHAE 2-2.5(4.5) microns wide, comparatively rare or obscure, with clamp connections, "walls more or less thickened, swelling in KOH and usually dissolving, typically more or less pronouncedly amyloid", (Weresub(3)), cystidial base bi-rooted (Weresub(4))