Search

The current use of a 30 million year dateline for accepting genera in the Parmeliaceae is evaluated. Its value is doubtful since evolution obviously went quicker in some lichen groups compared with others. Parallel evolution is also very common among lichens. Polyphyletic genera should always be split, while sister groups may remain split or be combined after considering non-molecular characters. Researchers dealing with the same groups should consult each other in an endeavour to achieve consensus. The most recent changes in taxonomy in the Nordic Parmeliaceae relate to the cetrarioid group, the last large clade to be revised. The division into two large genera, Cetraria and Nephromopsis, is supported, with a recommendation to retain Masonhalea due to its unique non-molecular characters. Three cases of parallel evolution in Cetraria and Nephromopsis are illustrated. Synonymization of Gowardia with Alectoria is supported, whereas synonymization of the parasitic genera Raesaenenia and Nesolechia with Protousnea and Punctelia respectively seems hardly necessary. Segregation of Montanelia from Melanelia is strongly supported, in contrast to the morphologically similar sister groups of Usnea, Dolochousnea and Eumitria, being recognised as separate genera.

Revised information on the morphology, chemistry and distribution of species of Parmelia s. str. in Fennoscandia is presented. Although Parmelia ernstiae was earlier believed to be chemically distinct from P. serrana in terms of lobaric acid, its presence in all studied samples detected by TLC means that these two semi-cryptic species can no longer be chemically separated. All three species are increasing in frequency and spreading northwards in Fennoscandia. Parmelia serrana is reported as new to Zealand in Denmark.

The distinguishing morphological and chemical characters of nine species of Parmelia Ach. s. str. occurring in the southern Baltic region, namely P. barrenoae Divakar et al., P. ernstiae Feuerer & A. Thell, P. fraudans (Nyl.) Nyl., P. omphalodes (L.) Ach. (including both subspecies P. omphalodes ssp. discordans (Nyl.) Skult and P. omphalodes ssp. omphalodes, P. pinnatifida Kurok., P. saxatilis (L.) Ach., P serrana A. Crespo et al., P. submontana Nádv. ex Hale and P. sulcata Taylor, are presented. Four of the species are cryptic or semi-cryptic, being recent segregates from P. saxatilis and P. sulcata based primarily on evidence derived from molecular analyses. P. ernstiae was formerly believed to be chemically distinct from P. serrana by the presence of lobaric acid, but recently this has been reported in both species. Furthermore, three chemotypes of P. serrana have been found by TLC in solvents A, C and G: 1) atranorin, consalazinic, salazinic and lichesterinic acids; 2) atranorin, consalazinic, salazinic, protolichesterinic and lichesterinic acids; 3) atranorin, consalazinic, salazinic, protolichesterinic, lichesterinic and lobaric acids. The first chemotype is rarely found while the other two appear to be common. At least three of the species, P. ernstiae, P. serrana and P. submontana are increasing in frequency in the region and spreading northwards.

A list of 120 taxa observed at the Vadstena Monastery churchyard includes some rare species and a few lichenicolous fungi. Lecanora semipallida is reported from the province Östergötland [Ostrogothia] for the first time.

Results from the excursion of the 20th biennial symposium in Vadstena 11–15 August 2013 are presented. Eight localities in and around Vadstena were visited. Forty-three species are reported as new to the province Östergötland [Ostrogothia], three of which are new to the Nordic countries: Lecanora compallens, Polycoccum kerneri and Tremella caloplacae, five are new to Sweden: Cornutispora ciliata, Pyrenula chlorospila, Thelidium cf. rimulosum, Verrucaria ochrostoma and V. polystictoides, and the following are new to Östergötland: Bagliettoa baldensis, B. calciseda, Briancoppinsia cytospora, Calogaya arnoldii ssp. obliterata, Clypeococcum hypocenomycis, Cornutispora lichenicola, Endococcus exerrans, Fuscidea arboricola, Illosporium carneum, Lepraria elobata, L. jackii, L. vouauxii, Leptochidium albociliatum, Lichenoconium lecanorae, Lichenochora weillii, Marchandiobasidium aurantiacum, Micarea byssacea, Monodictys anaptychiae, M. epilepraria, Parmelia serrana, Phaeosporobolus alpinus, Placopyrenium canellum, Porpidia soredizodes, Pyrenidium actinellum, Rinodina turfacea, Stereocaulon rivulorum, Syzygospora physciacearum, Thelenella muscorum, Tremella phaeophysciae, T. ramalinae, Trichonectria rubefaciens, Verrucaria dolosa, V. inaspecta, V. infumata and V. memnonia.

The 1996 Chagos Expedition provided the first opportunity to study the archipelago’s lichen flora. Seventeen of the 55 islands were ecologically investigated, some in more detail than others, and lists and representative collections of lichens have been assembled for many of them. In all, 67 taxa have been recorded, 52 to specific level. Although the islands have a low biodiversity for cryptogamic plants, as would be expected in terms of their relatively young age, remoteness and small terrestrial surface areas, those taxa that are present are often found in abundance and play significant ecological roles. There is a good correlation between total lichen biodiversity and island size, despite the fact that Cocos nucifera is such an important substratum for cryptogamic plants and its presence on all islands studied provides a consistently high associated species count. Comparisons of lichen floras for ten island and coastal tropical areas show good correlations (based on the Sörensen Coefficient) within the Indian Ocean as would be expected, but poorer correlations exist within and between Pacific Ocean and neotropical floras. Ranked correlations between Chagos and other floras are in the sequence Maldives > Laing Island > Aldabra > Tuamotu > Pitcairn > N.Mariana & Belize > Guadeloupe > Cook. When coefficients are calculated using only the Physciaceae, different correlations and sequences are derived, but the affinities of the Indian Ocean islands remain strong. However, although the lichen flora of Chagos is characteristic for an Indian Ocean, it is dominated by pantropical species.