| TAXON: | Hyperphyscia adglutinata (Flörke) H. Mayerhofer & Poelt (1979) |
| RECENT SYNONYMS: | – |
| FAMILY: | Physciaceae |
| GROWTH FORM: | Foliose, heteromerous |
| SUBSTRATES: | Basic or nutrient-enriched bark, particularly tree-trunks in shaded situations; rarely on calcareous or eutrophicated siliceous stone |
| PHOTOBIONT: | Trebouxioid alga |
| REPRODUCTION: | Soredia; apothecia, pycnidia rare |
| ASCUS: | If present, cylindric-clavate; apex Lecanora-type; 8 spores |
| SPORES: | Ascospores if present ellipsoidal, brown, 1-septate, thick-walled, 13-19 × 7-9 µm; conidia if present barrel-shaped to subcylindrical |
| NOTABLE FEATURES: | Thallus grey-green, minutely foliose; lobes narrow, branching, sometimes overlapping; underside pale, pressed tightly to substrate, difficult to detach; rhizines pale, few, inconspicuous; soralia punctiform, laminal, usually crater-like, sometimes growing together |
| CHEMICAL TESTS: | – |
| HABITAT: | Parklands and waysides |
| DISTRIBUTION: | Locally frequent in lowland Britain; most common in southern England |
| CONSERVATION STATUS: | Least Concern |
| LICHENICOLOUS FUNGI: | Lichenochora hyperphysciae, Paranectria oropensis |
| IDENTIFICATION DIFFICULTY: | Green 2: Field identification possible with care |
| CONFUSION SPECIES: | Hyperphyscia lucida, Phaeophyscia orbicularis |
FIELD NOTES
Hyperphyscia adglutinata is one of two Hyperphyscia species in Britain. It’s a tiny lichen, so unless you encounter a larger sward, you probably won’t notice it casually. Instead you’ll need to examine a tree-trunk with a hand-lens, especially any grey-green ‘fuzzy’ patches. You’ll encounter it frequently in southern England, especially in parkland, and it’s found elsewhere throughout lowland Britain as well.
H. adglutinata is fairly distinctive. If you find a minutely foliose, grey-green lichen on a tree-trunk, whose lobes are narrow and branching, closely adpressed to the bark, and dotted with crater-like soralia, you can feel fairly confident that you’ve found H. adglutinata. That said, there is one potential confusion species that you should spare a moment to rule out: Phaeophyscia orbicularis.
Mature P. orbicularis grows larger than H. adglutinata, with somewhat wider lobes, a greyer colour and more confluent soralia. It can also be found on stone and hard artificial substrates as much as on bark. But young, small P. orbicularis can look markedly like H. adglutinata, and it takes a bit of care to distinguish them.
Fortunately, there are a few fairly straightforward distinguishing characters:
- P. orbicularis tends to have abundant rhizines, which often protrude beyond the ends of the lobes like the curled bristles of an old brush. By contrast, H. adglutinata has sparse, inconspicuous rhizines.
- As its name suggests, H. adglutinata tends to be quite firmly adpressed to its substrate, and surprisingly difficult to detach. But though its lobes are also flat and adpressed, P. orbicularis is more easily detached.
- The underside of P. orbicularis is black, while that of H. adglutinata is pale.
If for whatever reason you’re unsure about this or that individual thallus, just scan a bit further with your hand-lens. H. adglutinata tends to occur in abundance on a given tree. You should likely be able to find a specimen that you can conclusively identify.
As a final note, H. adglutinata might also be confused with its cousin H. lucida. Discovered by Arno van der Pluijm in the Netherlands in 2020, H. lucida was then found in southern England in 2024. Though records are as yet extremely few, it’s probably existed here for many years, and it may be more widespread than we know.
Compared with H. adglutinata, H. lucida is a bit larger and paler, with broader lobes, less ‘tidy’ soralia, and a shiny, filmy prothallus. But less well-developed forms can be hard to separate. In any case, suspected H. lucida in Britain would have to be confirmed by an expert.
LAB NOTES
Hyperphyscia adglutinata can normally be identified without microscopy.
SPECIMENS
Hyperphyscia adglutinata : England : VC20 Hertfordshire : TL3510 : March 2025 : On Quercus trunk
Hyperphyscia adglutinata : England : VC27 East Norfolk : TG0780 : February 2023 : On unknown bark
