The Lichen Flora

by Ron Bishop

(first published in the CBO Annual Report for 1997)

In June 1996, Professor Mark Seaward of Bradford University, who is Recorder for the British Lichen Society, visited the island and found 114 species of lichen. This greatly extends the list given in the 1986 Report. Not surprisingly, he found the lichen flora to be essentially maritime, with the expected zonations above and within the tide lines. The mostly-siliceous rocks provided the greatest variety of species, with those on bushes or trees and especially on soils being much more limited. Four taxa were new to County Down - Catapyrenium squamulosum (infrequent on walltop cement at the observatory and the pub), Cladonia diversa (occasional on soil and mossy rock), Phaeophyscia nigricans (uncommon on walltop cement at the observatory) and Verrucaria macrostoma forma furfuracea (occasional on the mortar of buildings). More strangely, Lichina spp., commonly found just below or around the high water mark, were not seen.

The more common species are listed below for those who might be interested in this neglected group of organisms. Abundance is given as common (c), locally common (lc), frequent (f), locally frequent (lf) and infrequent (i). Another fifty or so occasional-to-rare species can be found in the full list, which is given in Seaward, M.R.D. & Bishop, R.H. (1997) 'Lichens of Lighthouse Island, Co Down.' Irish Naturalists' Journal Vol 25 No 10 pp 359-365. A copy is in the Observatory library.

a) On rocks (/s = especially/solely on shoreline):

Acarospora fuscata (lf)
Anaptychia runcinata (f/s)
Aspicilia caesiocinerea (lf)
Aspicilia leprosescens (lf/s)
Buellia aethelea (lf)
Buellia cf. stellulata (lf/s)
Buellia subdisciformis (lf/s)
Caloplaca marina (lf/s)
Caloplaca thallincola (lf/s)
Candelariella coralliza (i)
Candelariella vitellina (f)
Diploicia canescens (lf)
Diplotomma chlorophaeum (i/s)
Lecanora actophila (lf/s)
Lecanora campestris (c)
Lecanora helicopsis (lf/s)
Lecanora muralis (lf)
Lecanora rupicola (lf)
Lecanora sulphurea (i)
Lecidea fuscoatra (i)
Lecidea lithophila (i)
Lecidella asema (lc/s)
Lepraria incana (lf)
Ochrolechia parella (lc/s)
Parmelia glabratula ssp. fuliginosa (f)
Parmelia loxodes (lf/s)
Parmelia saxatilis (c)
Parmelia sulcata (f)
Pertusaria corallina (i)
Pertusaria lactea (i)
Pertusaria pseudocorallina (i)
Placynthiella icmalea (i)
Polysporina simplex (lf/s)
Porpidea tuberculosa (c)
Ramalina cuspidata (lf/s)
Ramalina siliquosa (c/s)
Rhizocarpon obscuratum (f)
Rhizocarpon richardii (f/s)
Tephromella atra (lf/s)
Verrucaria maura (lc/s)
Verrucaria mucrosa (lf/s)
Verrucaria striatula (i/s)
Xanthoria candelaria (lf)
Xanthoria parietina (lf)

b) On mortar/cement:

Caloplaca citrina (i)
Caloplaca flavescens (i)
Caloplaca holocarpa (i)
Catapyrenium squamulosum (i)
Collema auriforme (i)
Collema crispum (i)
Collema tenax (i)
Diploicia canescens (lf)
Lecanora albescens (lf)
Lecanora crenulata (I)
Lecanora dispersa (lf)
Phaeophyscia orbicularis (I)
Physcia adscendens (i)
Xanthoria parietina (lf)

c) On trees:

Diploicia canescens (lf)
Lepraria incana (lf)
Opegrapha atra (i)
Parmelia glabratula (i)
Parmelia subaurifera (i)
Xanthoria candelaria (lf)
Xanthoria parietina (lf)

d) On soils:

Cladonia cervicornis (lf)
Cladonia ramulosa (lf)
Placynthiella icmalea (i)
Trapeliopsis granulosa (f)

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