I916. No. 8. MONOGRAPH OF THE NORWEGIAN PHYSCIACEAE. 3 



The early authors attached great importance to the position of the 

 gonidia in the apothecia. If the apothecia contained gonidia, they were 

 called lecanorine, and if not, lecideine. On this basis BiicUia was referred 

 to the lecideine, the other genera to the lecanorine Lichens. Modern S3'ste- 

 matists, however, have more strongl}' emphazised the importance of the 

 spores. 



A related series of evolution, the Theloschisteae, was already in 187 1 

 drawn up by the Norwegian lichenologist J. M. Norman, on the same 

 principles: »Teloschistei sunt Heterolichenes sporis hyalinis 

 - . . in locula remotiora 2 v, 4 constrictis« ^. This section com- 

 prises our genera Blastoiia. Caloplaca, Xanthoria, and Tlieloscliistcs, 

 accordingly Lichens with lecideine as well as with lecanorine apothecia. 

 Zahlbruckner also divides this family into two families: Caloplacaceac 

 with two crustaceous genera Blastenia and Caloplaca, and Theloschistaceac 

 with two foliaceous genera Xanthoria and Theloschistes. 



The relationship between the Biiellieae and the Theloschisteae (sensu 

 latiore) is based on morphological and anatomical characters, but there 

 are also important biological points of resemblance, at least in the genera 

 Rinodina, Caloplaca, Physcia, Auaptychia, and Xanthoria. These genera 

 comprise species, growing under ver}- different conditions. But it may 

 safely be maintained that a relatively larger number of species 

 of these genera have a greater demand for Nitrogen (N) than 

 the species of any other series of Lichen genera. Several spe- 

 cies, e. g. Xanthoria lychnea, and Physcia tribacia, in part also Caloplaca 

 elegans, are directly ornithocoprophilous, and together with Ranialina 

 strepsilis characteristic of prominent rocks and large stones on our high 

 mountains, and (with Rinodina halanina and Lecanora straniinea] of the 

 shores of Northern Norway with their innumerable birds and millions of 

 drying fish. Even if the birds are less numerous, and there is no drying 

 fish, (as in Western and Southern Norway) there is an ample supply 

 of Nitrogen by the shore, and a rich flora of Anaptychia, Physcia, and 

 Xanthoria species. 



The fundamental work on the nitrophily of the Lichens was written 

 by Sernander - who frequentl}' deals with Lichens of these genera. 



It is well known that several species of these genera have a rapidity 

 of growth far beyond what is usual among Lichens. E.xact and copious 



^ NoRiMAN, J. M.: Conjectura de affinitate Heterolichenum (1871) p. 16. 

 ^ Sernander: Studier öfver lafvarnes biologi i. Nitrophile lafvar (1912). 



