474 A. HESSELBO 



in bogs and on damp rocks. Var. ylacidlis grows ahvays in cold water^ 

 especially in moss bogs. where in Company with Philonotis it usually 

 forms tlie bulk of tlie vegetation. In the Alpine region Polilia (ilbicans 

 occurs abundantly, even at a height of about 600 metres. There it 

 grows especially in and along watercourses, often filling up their — 

 during summer — dried up beds bj' growing in large cushions both on 

 the ground and on stones. As in P. commiitata, the Alpine forms be- 

 come more compact, with shorter, concave, appressed leaves and looser 

 cell tissue. Such forms have bcen found, for instance, near Dyrafjordur 

 at an altitude of 300—400 metres, Esja at an altitude of about 500— 

 600 metres and near Seljaland at an altitude of about 500 metres. Fruit 

 occurs rathcr rarely, and in the tj'pe, as a rulc, in a small quantity 

 only. .Fruiting specimens of the type wcrc collectcd near Akureyri (ripe 

 July 22), Holt (ripc July 19) and Breiddal (hardly ripe June 19). Var. 

 glacialis was collectcd in fruit near Eyjafjordur (O. D.) and near Kaldalon 

 in NW. Iceland, where the plant grew abundantly on inundated ground 

 along small streams, and was often covered wilh fruit which was not 

 quite ripe at the end of June. 



133. Bryum purpurascens (R. Br.) Br. eur. 



E. Iceland: Seydisfjordur !, common; Vallanes! (H. J.). N. Iceland: 

 Mvvatn (Grl.)!; Akureyri!, common; Husavik!, common. NW. Iceland: 

 common about Isafjordur and Jokulsfjordur!. W. Iceland ; Reykholtdalur 

 (Grl.)!; Xordredalur!; Grimstunga (Grl.)!; Bardshellir Grl.)!. S. Iceland: 

 Traustholtsholm in the Thjorsa (F.)!. 



Grows on damp peaty or sand}' soil, especially near the coast. It 

 occurs abundantly chiefly in piaces where the peat has been pared olf. 

 Near Seydisljordur it was coUected up to a height of about 400 metres. 

 The fruit ripens in the beginning of August. 



Bryiiin purpurascens varies rather considerably in the form of the 

 capsulc and in the structurc of the peristome. The capsule is usually 

 symmetricai. sometimcs slightly asymmetricai, and then reminds one of 

 B. uliginosuin, from which it is, however, easily distinguishable by the 

 large lid. The base of the peristome teeth ffundus) is often large and 

 reddish yellow, and in the majority of the piants which have been in- 

 vestigatcd the lamcllæ are sinuose in the middle, sometimes as strongly 

 so as in Brijuni Idpponicum. The dorsal transverse segments are more 

 or less distinctly transversely striated. The spores varj' somewhat in 

 size, from 0.024 — 0.035 mm. 



It is a pcculiarity with this species that the capsule, on being cut 

 through and warmed in dilutcd ammoniacal water. imparts to the latter 

 a substance which is intensely, but temporarily coloured red by the 

 oxygen in the air. The same is often the case also with B. uliginosum. 

 In the course of time the old capsules turn almost black in colour. 



134. Bryum lacustre Blandow. 



E. Iceland: Berufjordur !; Vallanes (H. J.;!). N. Iceland: Common near 

 Husavik!; common near Eyjafjordur (O. D. ;!); Saudanes (St.)!; Svinadalur!;. 



