Macro looks like genus Orbilia, supported by dead asci with truncate apex, a single SB, no gelatinous matrix, simple ascus base.

• Section Orbilia, series Orbilia: Dead ascus apex medium to strongly truncate in front view, ascus thin walled, spores more narrow and smaller SBs, vital spore length mostly < 6.5 µm, SBs globose, spore shape, without glassy processes.
• Series Orbilia, key A: Exudate over paraphyses sparse and finely granular, smaller SBs, capitate-clavate paraphyses, spore shape.
• Orbilia eucalypti (complex): Spore shape, spore width, without glassy processes, apothecia colour, spore size, with or without SBs, paraphyses with many small slightly refractive vacuoles, xeric.
• Variant with bright orange apothecia, larger spores, SBs?, and large basal cells.

Preparation and methods: Stored in a damp box attached to wood for several days, two central sections from a single apothecium examined, mounted in tap water, medium pressure applied to squash.

Habitat: On damp and decaying fence rail, decorticated, unidentified deciduous wood, white-rotted (under surface soft and and grainy), top rail ~1.5 m from the ground, presumably xeric, fence next to confluence of two streams, mixed deciduous woodland, southern England, late February, after wet weather and flooding.

Associates: Mollisia/Mollisiaceae sp., small and immature whitish-translucent apothecia not examined yet, chalara-like? dematiaceous anamorph (seems to be illustrated as an associate in the monograph), algae.

Apothecia: Several small groups, scattered to sub-gregarious, one cluster of 3-4, discoid, deep-bright orange, appearing superficial, sessile, appressed, sometimes partly lobate in maturity, slightly gelatinous appearance, soft texture; margin usually conspicuous, usually raised and +/- thick, smooth, more inconspicuous when fully mature with concave disc; disc slightly translucent, grainy appearance, slightly concave to plane, rarely slightly convex.

Asci: Narrow-cylindrical, rarely slightly clavate, often 2-4 (6) spores inversely oriented, inverse orientation more likely in lower spores, some spores rarely horizontally oriented, no discharged asci identified; base simple-septate, bifurcating, shapes Y, H, and h observed. Difficult to determine the vitality of asci without poisoning, many with more truncate apices were still relatively turgid and the content easy to resolve, general measurements ~50-70 × 3-5 µm.
• Mature and presumed vital (looks turgid): Width ~4-5 µm, apex hemispherical to obtuse, 1-1.5-seriate, spores obliquely arranged, pars sporifera ~50-70%
• Mature and presumed dead (contents more opaque or fully flaccid): Width ~3-4.5 µm, medium to strongly truncate in front view, rarely also centrally idented, still hemispherical in profile view, rarely small apical thickening ~0.5-1.3 µm, uniseriate, pars sporifera ~80-90%.

Spores: Broad range of shapes, cylindrical-clavate to smaller ellipsoid-ovoid, shape varies significantly in an apothecium and rarely within a single ascus, often heteropolar with the base more attenuated and acute, sometimes base tail-like and then sometimes curved in profile view (reniform); SBs globose, filum difficult to see, diam. ~0.5-0.7 µm, sometimes no SB or difficult to see amongst LBs?, several LBs around apex and occasionally some around base.
• Measurements of mature, vital spores ejected in water mount, released in squash mount, and inside (living?) asci:
(5.1) 5.6 - 7 (7.9) × (1.9) 2.2 - 2.7 (2.8) µm, Q = (1.9) 2.3 - 2.9 (3.2), N = 30, Me = 6.3 × 2.5 µm, Qe = 2.5.

Paraphyses: Apex slightly to strongly inflated, with shape narrowly-spatulate to clavate-capitate, apex ~1.5-4.5 µm wide, occasionally irregularly inflated (e.g. asymmetrical, mammiform-lanceolate, additional subapical inflation), apical cell longer ~1.5-2x, branching only observed at basal septa, not extending above mature asci, less apically inflated near margin?

VBs: Medium to large, yellowish, medium to slightly refractive VBs in paraphyses, and numerous, conspicuous, smallish, slightly refractive, yellowish-orange VBs in paraphyses, subhymenium, medullary excipulum, and marginal cells, in paraphyses especially found in lower cells and close to septa but often also in apices.

LBs: Frequent, with similar distribution to orange VBs.

Excudate: ~1 µm thick, pale orange-yellow, granular, forming patchy epithecium, coating margin and upper flanks, small granules from epithecium often remaining on apices of asci and paraphyses.

Subhymenium: Darkish orange.

Medullary exc: Pale orange, reduced, sometimes clearly separated from ectal by a layer of several horizontal hyphae.

Ectal exc: Textura prismatica-globosa, cells considerably larger in the centre, external cells more globose, hyaline, generally oriented perpendicular to the surface, marginal cells more elongated-cylindrical.

Subiculum: Appears to be some hyaline anchoring hyphae around the base.