Stylodothis festinationis
Anamorph: not known.
Teleomorph: stromata 0.9-1.9 mm diam., somewhat irregular in shape but usually roughly circular in outline or broadly elliptical with the long axis parallel to that of the host, erumpent through the periderm, often clustered and sometimes juxtaposed, then irregular in shape but not coalescing. Surface irregular but ± flat, strongly roughened, the individual locules sometimes visible as low mounds but the ostioles not visible from the surface. Stromatal tissue composed of thick-walled, dark brown to almost black angular to globose cells (8-) 11-16 µm diam., with Munk pores ca 0.75 µm diam. visible in some side walls. Outer layer hardly differentiated, but with an epinecral layer of dead occluded and flattened cells present in some parts of the external wall. Ascomatal locules up to ca 20 per stroma, 80-110 µm diam., in a single layer, without separate walls but lined with two or three layers of internal tissues similar to those of the stroma but less strongly pigmented. Interascal tissue not present. Asci formed in a fascicle from a small rounded cushion of generative cells, 78-87 x 15.5-17.5 µm, cylindric-clavate, almost sessile, tapering gradually to the base, the apex rounded, thick-walled and fissitunicate, with a very broad shallow ocular chamber, not staining in iodine, (2- to 3-) 4-spored. Ascospores arranged uniseriately, (16.5-) 18-21.5 (-26.5) x 9-11.5 (-12.5) µm, somewhat irregular in shape but mostly ellipsoidal to ovoid, sometimes somewhat inaequilateral, the apices rounded to obtuse, almost all (ca 95%) aseptate but with a small proportion (many of these in asci containing fewer than four spores) with a ± median to strongly submedian septum, that may or may not be constricted; dark chocolate brown, thick-walled, smooth, without a gelatinous sheath or appendages.
Not formally assessed, but the species is known from several localities in the UK and may not be particularly uncommon.
Similar to Stylodothis puccinioides, but with larger and more flattened stromata, and ascospores that are mostly aseptate. S. puccinioides was described from material on Buxus sempervirens and has been reported from a broad range of woody substrata (see e.g. Loeffler 1957), but the distinctive features of S. festinationis correlate well with host data and it is likely that the species are more strongly host-specific than assumed in the past.
On dead stems of Ulex europaeus, including those remaining after partial burning of the plants.
Confirmed from England (VC 11 S Hampshire), Scotland (VC80 Roxburghshire), Ireland (VCH20 Wicklow) and Northern Ireland (VCH39 Antrim). Reports from VC5 S Somerset, VC28 W Norfolk, VC36 Herefordshire and VC101 Kintyre are likely to be this species.