Regarded as NT in the Red List Of Threatened Fungi In Norway.
Growing on fallen needles, small twigs and cones, or among moss under Picea,
often in fairly wet, fern rich places. Also found among fallen leaves under Alnus. Summer to autumn. See The
Norwegian Mycology Database.
Pileus 2 - 10 mm
across, conical to campanulate or parabolical, becoming
convex with age, often with a small papilla, translucent-striate,
hygrophanous, delicately pruinose, glabrescent, bright orange
with yellow shades, more yellow with age, but with orange
centre. Lamellae 7 - 10 reaching
the stipe, ascending, broadly adnate, decurrent with a tooth,
pale yellow or whitish with bright yellow edge. Stipe
15-60 x 0.3-0.5 mm, straight to somewhat curved or flexuous,
terete, fragile, entirely puberulous, glabrescent except
for the apex, orange, more brightly coloured at the apex,
attached to the substratum by radiating, fine, yellow to
yellowish-white fibrils. Flesh very thin and fragile. Odour
Basidia 22-28 x 5-6 µm, slender-clavate,
2-spored, with sterigmata up to 7 µm long. Spores
6.6-9.8 x 3.3-5.5 µm, q = 1.6 - 2.3, qav ~ 1.97, pip-shaped, smooth, non-amyloid. Cheilocystidia
13-68 x 7-17 µm, fusiform, lageniform, utriform,
subcylindrical, clavate, with broadly rounded apex, smooth,
sometimes with one or two outgrowths, with yellow contents. Pleurocystidia similar, not frequent. Lamellar trama not vinescent in Melzer's reagent. Hyphae
of the pileipellis 2-8 μm wide, covered with simple to furcate, cylindrical, fairly coarse excrescences 2- 15 x 1-4 μm, sometimes the excrescences are cystidia-like, fusiform to lageniform, up to 40 x 8 μm, terminal
cells smooth to diverticulate. Hyphae
of the cortical layer of the stipe 2-3 µm wide, smooth, terminal cells
(caulocystidia) numerous, in tufts, 13-70 x 7-22.5 µm, globose, ellipsoid,
fusiform, subcylindrical, with yellow contents. Clamp
More microscopic figures.
Maas Geesteranus (1990) described Mycena oregonensis as 4-spored and with clamp connections, based on American material. He also stated that European collections have shown to be 2-spored and devoid of clamps. While Ronikier (2003) confirmed the absence of clamp connections in two Polish collections, Robich (2003: 533-534) claimed that clamps were present at the hyphae of the pileipellis and the cortical layer of the stipe in Italian material.
strobilinoides Peck, an American species
reported by Robich from Italy and from Switzerland
by Métrod, looks similar with it's orange cap.
It differs, however, among several features, by the
cheilocystidia which are densely covered by excrescences,
and by the diverticulate hyphae of the cortical layer
of the stipe and the terminal cells that are equally
(Schaeff.) P. Kumm. also has an orange-red pileus.
The colour, however, usually is more red and it fades
to more yellowish. Besides, it differs microscopally.
The hypoderm is built up by globose to subglobose
cells, while they are elongated in M. oregonensis.
The hyphae of the cortical layer of the stipe in M.
acicula are covered with coarse excrescences
embedded in gelatinous matter, but they are smooth
and dry in M. oregonensis. The cheilocystidia
and the caulocystidia have no yellow contents in M.
Mycena oregonensis is the monotype
of section Oregonenses
Further images on the Internet: