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07-03-2024 12:40

B Shelbourne B Shelbourne

Macro looks like genus Orbilia, supported by dead

24-02-2024 15:15

Louis DENY

Bonjout ForumTrouvé à Belfort (400m altitude), s

05-03-2024 14:03

Vasileios Kaounas Vasileios Kaounas

Can occur on a pine cone (Pinus nigra) substrate ?

04-03-2024 13:02

B Shelbourne B Shelbourne

Apothecia macro like genus Hyalorbilia, which seem

05-03-2024 08:15

Vasileios Kaounas Vasileios Kaounas

Found in fallen rotten wood (Abies or Juniperus or

04-03-2024 16:15

Thomas Læssøe

Shirai, M.; Hara, K. 1911. Some new parasitic fung

03-03-2024 15:14

Marc Detollenaere Marc Detollenaere

Dear forum,In the moss dunes of Bray-Dunes(F),one

02-03-2024 12:37

Bernard Declercq Bernard Declercq

Hello,I am looking for a pdf of following paper:Ud

01-03-2024 18:06

Marc Detollenaere Marc Detollenaere

Dear Forum,On unidentified moss I found some small

01-03-2024 23:06

éric ROMERO éric ROMERO

Bonjour, Sur laissée de mustélidé indeterminé

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Possible Orbilia eucalypti
B Shelbourne, 07-03-2024 12:40
B ShelbourneMacro 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.
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Hans-Otto Baral, 07-03-2024 16:00
Hans-Otto Baral
Re : Possible Orbilia eucalypti
Yes, clearly this species, the long-spored variant.
B Shelbourne, 07-03-2024 17:42
B Shelbourne
Re : Possible Orbilia eucalypti
Thank you for confirming.

The spores are certainly longer and more variable in shape compared to those in my first collection, which was found on hygric wood on the floor in November. There are other noticeable differences like the apothecia seem less translucent, longer asci to match the spores, and more apically inflated paraphyses.
Hans-Otto Baral, 07-03-2024 17:47
Hans-Otto Baral
Re : Possible Orbilia eucalypti
When on the floor you must also consider O. tremulae.
B Shelbourne, 07-03-2024 20:07
B Shelbourne
Re : Possible Orbilia eucalypti
Yes, I remember that I couldn't decide which of these two species was a better match and you suggested O. eucalypti.