• Macro and habitat suggest Hymenoscyphus s.l., confirmed by micro.
• Spores and excipulum suggest H. s.s., but the apothecia have a more grey colour than I have seen before.
• It looks similar to H. fucatus but the spores are slightly shorter on average.
• Otherwise, there are similarities with H. scutuloides but the spores are wider, or H. aff. vitigenus but the LBs in the spores seem different.

Habitat: On dead stems of various herbaceous plants, including Urtica dioica and possibly Bromus slyvaticus and Rubus fruticosus agg., on the ground, wet when found and ground muddy, generally shady and damp area, on the side of a low bank, separated from a small river by a path, flooding in very wet weather, after rain, Salix nearby, mixed deciduous woodland, Low Weald, southern England, late-October.

Apothecia: Many thousands, even hundreds on some stems, < ~1 x 2 mm, gregarious to 3-4+ caespitose, whitish when immature but soon becoming reddish-grey colour, darker with age, cupulate to discoid, disc apparently soon becoming plano-concave, sub-stipitate to stipitate.

Low magnification: Receptacle more brownish, disc whitish and slightly pruinose, margin relatively indistinct but often slightly darker, undulating more in larger apothecia, stipe like receptacle but often slightly more translucent, obconical to narrow-cylindrical, two appear fused at the stipe, .

Asci: Cylindrical-clavate, with croziers, rings bb, Hymenoscyphus type.

Spores: Ellipsoid-fusoid to slightly clavate, mostly heteropolar, then with the apex more rounded and the base more acute, slightly curved or asymmetric in profile view, and often slightly scutuloid and slightly restricted in the centre, 2-4 large LBs and many smaller ones, possibly some very short setulae seen occasionally, apparently uninucleate when mature, but becoming uniseptate outside the ascus and more oblong to distinctly clavate, some with brownish walls, two septate spores seen germinating from the side close to the hook and septa or the basal end.

- Apothecia 1, free spores or stuck to the receptacle, many septate, in water: (20.1) 20.2 - 23.0 (23.7) × (5.0) 5.4 - 6.6 µm, Q = (3.2) 3.3 - 4.1 (4.5), N = 24, mean = 21.7 × 5.9 µm, Q mean = 3.7.
- Apothecia 2, discharged from asci, aseptate, in water: (20.1) 20.6 - 25.0 (25.4) × (4.8) 5.0 - 6.0 (6.5) µm, Q = (3.2) 3.8 - 4.8 (5.2), N = 20, mean = 23.2 × 5.5 µm, Q mean = 4.3.

Paraphyses: Narrow-cylindrical, apex with Hymenoscyphus type VBs, VBs relatively large and sometimes hard to resolve or coalescing quickly.

Structure of the excipulum seems comparable to other species in Hymenoscyphus s.s., but lots of organish-brown exudate in the ectal excipulum, inside the stipe, and around the external network of hyphae.