ASCOMYCOTA | LECANOROMYCETES > CALICIALES > Physciaceae

Genus Physcia, meaning 'inflated, sausage-like' - from the form of the type species

Common name:            Hooded Rosette Lichen

Synonym:                    -

Habitat:                         Woodland, wayside trees (for this entry)

Substrata:                     Bark, but also rocks and stone

Growth form:                Corticolous, saxicolous

Thallus:                  Foliose

Apothecia:                    Lecanorine, but rarely fertile

BLS identity rating:        Graded 1/5 (identification should be straightforward)

Thallus variable dependant on substrate and position, but typically spherical when young, generally 2-4cm across, seldom more than 5mm, then somewhat irregular and rather cushion-like, often confluent with other species; lobes loosely appressed, appearing as they are growing up from the substratum, no more than 1mm broad, tips raised with relatively long pale, dark-tipped marginal cilia; the upturned and often bent lobe ends usually become swollen and 'helmet-shaped', often with cream to pale yellow soralia bursting through the upper surface; generally whitish to pale grey when dry, rarely darker, although more of a greenish-grey when moist, covered with few to many pseudocyphellae; underside whitish with sparse, concolourous, often brown-tipped, slender rhizines.

Apothecia uncommon but, when present, to 2mm dia., on short stalks, discs black, sometimes thinly pruinose.

Often found growing intermixed with Physcia tenella, so care needs to be taken when separating and identifying them although, apart from the physical differences in the shape and form of the lobes, Physcia tenella will almost certainly be the smaller and, typically, the slightly darker of the two.

Physcia adscendens is a common and widespread species that can be found on a variety of substrates in many different habitats; some authors describe two or more forms - primarily corticolous and saxicolous; in respect of this entry, the species typically grows on nutrient-rich trees, on the bark of the trunk, branches and twigs; but also on well-lit calcareous rocks, concrete, tombstones etc., as well as occasionally on manmade timberwork.