A: Generation length was categorized as long-term so change was assessed over 30 years. A decrease in AOO of 9 % and in EOO of 25 % was observed, with the causes (changes in open forest habitats, loss of ancient oaks) only partially understood and may not be reversible. - A2c
B: There is evidence for restricted geographic range (EOO =  571,771 km^2; AOO = 508 km^2) under criterion B but additional conditions were not met.
C: Number of mature individuals is estimated to be less than 1000, with about 234 trees recorded in the UK, 100 in Sweden and only 10 known trees in Germany. There is a potential for overlooked sites, especially in Germany, while in the UK and to a lesser degree also in Sweden the majority of high quality sites are probably located and surveyed in detail. Still also here smaller sites have probably been overlooked, but a doubling seems unlikely. - C2a(i)
D:  Number of mature individuals < 1000 - D1
E:  Insufficient data to assess

Current name: Zeora straminea (Stenh.) L.M. Weber & Ivanovich-Hichins

Synonyms: Lecanora sublivescens (Nyl.) Arnold, Flora, Regensburg 67: 336 (1884)
Biatora straminea Stenh. K. svenska Vetensk-Akad. Handl., ser. 3 34: 196 (1846)
Lecanora expallens f. straminea Arnold Flora, Regensburg 55: 74 (1872)
Lecanora orosthea var. sublivescens Nyl., Flora, Regensburg 55: 248 (1872)
Lecanora sublivescens (Cromb.) A.L.Sm. Mon. Brit. Lich. I: 292 (1918)
Lecanora sulphurea f. straminea (Stenh.) Hedl. Bih. K. svenska Vetensk Akad. Handl.: 56 (1892)
Lecanora symmicta f. straminea (Stenh.) Th.Fr. Jb. nassau. Ver. Naturk. 25 –26: 307 (1871)
Lecanora symmicta var. straminea (Stenh.) Mig. Flora von Deutschl. 12: 303 (1926)
Lecanora varia var. symmicta f. livescens Nyl. Journ. Bot. VII: 50 (1869)
Lecidea orosthea f. sublivescens (Nyl.) Vain., Acta Soc. Fauna Flora Fenn. 57(2): 411 (1934)
Lecidea sublivescens (Nyl.) P.James, Lichenologist 3: 97 (1965)

A species of ancient trees, mostly oak but also beech and ash. Its scarcely present in the UK and Germany as well as in southern Sweden. The loss of such old trees as well as overshading and eutrophication of the bark pose threats to the species.

A rare sub-oceanic species in Europe with most of the world populaition found in Sweden, England and Wales:
Germany – Mecklenburg-Western Pomerania, (hist. Lower Saxony)
Sweden – Gotland, Öland, Småland, Skåne, Blekinge, Östergötland, Södermanland
UK – England: Kent, Sussex, Hampshire, Dorset, Berkshire, Somerset, Herefordshire, Derbyshire; Wales: Montgomery, Radnor, Brecon, Carmarthen, Pembrokeshire, Merionydd, Denbigh; Scotland (1960): Berwickshire

Zeora straminea is a rare species across its range. Overall, a decline has been observed over the last 30 years, even though new localities continue to found, introducing some uncertainty. However, its habitat is generally threatened and declining.

Occurs mainly semi-open or well-lit oaks (Quercus spp.) and beech (Fagus sylvatica) trees, sometimes on ash (Fraxinus excelsior) and field-maple (Acer campestre), in Sweden also rarely on Pinus and Juniperus (Tibell & Hultengren 2015, Westberg et al. 2021, Weber et al. 2023). The species grows mainly on coarse trunks of ancient trees, often in sites with a long forest continuity (Thor & Arvidson 1999, Weber et al. 2023). In England and Wales it is usually found in parks, pasture woodlands or in open fields and hedgerows (Harding & Rose 1986). In Sweden and Germany, it occurs mainly in oak or beech forests, but in Sweden sometimes in mixed coniferous forests and on Gotland in meadows and on sun-exposed and dry sites (Arup & Ekman 1991, Weber et al. 2023)

The loss of ancient trees due to development and/or logging and natural collapse and the shading of the bark by semi-open forests becoming denser or overgrowth by ivy (Helix hedera) are a threat. The loss of continuity of suitable trees on a site is also a concern. Another major threat is the direct eutrophication of bark by farmyard manure as well as atmospheric pollutants, probably limiting the range of this species. Additionally the widespread die-back of ash in Europe caused by Hymenoscyphus fraxineus reduces the availability of substrate (Ellis et al. 2014).

Because Zeora straminea occurs usually on single ancient trees, felling these as part of development should absolutely be avoided. At known sites the overshadowing of the bark can be avoided by removing epiphytic climbers and keeping important man-made open habitats like park and hedges bordering pasture land from getting overgrown. Controlled grazing is one option to control tree regeneration and maintain open conditions. Reducing the widespread nitrogen deposition e.g. by limiting the fertilisation of grasslands would be beneficial.
As Lecanora sublivescens the species is recognized as a UK BAP Priority Fungi Species (JNCC 2007) with a full plan and listed as a species of international responsibility. In England it is recognized as a species of principal importance for the conservation of biodiversity in England, listed in Section 41 of the Natural Environment and Rural Communities Act. (2006), in Wales as a species of principal importance for the conservation of biodiversity in Wales, listed in Section 42 of the Natural Environment and Rural Communities Act (2006) (Woods & Coppins 2012).
Three of the current seven German locations are situated in protected areas.

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