52(5 A. HESSELBO 



The form found is robust, light green, highh' shining and difiers 

 in habit by the leaves bcing verj' decidedly Iwo-rowed, spreading. 

 Gemmæ, which were, bj' the by, qiiite typical, occurred only extremel}' 

 few in number. 



274. Amblystegium Sprucei (Bruch) Br. eur. 



Commonly distributed over the whole of Iceland. 



Grows in rocli-clefts, dark ravines and caves, and among fallen 

 blocks of rock, usually scantily woven into the tufts of other mosscs 

 such as Plagiotheciiun piilchellum, Amphidiiim Mougeollii. Lophozia MiillerL 

 L. hcterocolpos and Mninm orthorrhynchnm, but occasionally also in tiny 

 cushions or as delicate, cobweb-like coverings on roofs in caves. In 

 Esja it was found up to about 400 metres above sea-level. Only sterile 

 specimens have been found. 



275. Amblystegium fluviatile (Sw.) Br. eur. 



SW. Iceland; Tungufoss (F.)!, delerniined by C. Jensen. 

 Only a few stems were found, intermixed with other mosses, for 

 instance Braclujthecium riviilare, Hijpnum ochraceiim, etc. 



276. Amblystegium serpens (L.) Br. eur. 



N. Iceland: Akureyri, fr. (Grl.)!; Myvatn, fr. (Grl.)!. W. Iceland: 

 Reykjavik 1. Vestmannaey!, fr. 



In Iceland this species is as variable as it is in other piaces. The 

 specimens from Mwatn were very robust, with leaves 1.33 mm. long 

 and 0.65 mm. broad, erectly spreading, and distinctly toothed in their 

 lower half, with rather long and strong nerve, and cells 0.010—0.012 mm. 

 broad and 4—6 times as long. Xear Reykjavik it grew in large cushions. 

 1—2 cm. deep, on a stone wall near the sea-side. In the plant from 

 the latter locality the leaves were broadlj^ ovate, longly pointed and 

 almost entire at the margin, with cells 0.009—0.011 mm. broad and 

 2 — 3 times as long. The form from Vestmannaey is very slender. with 

 leaves 0.7 mm. long and 0.3 mm. broad, with very short nerve which 

 in the branch leaves was just indicated immediately above the leaf-base. 

 On Vestmannaey the fruit was quite unripe on July 6th: in N. Iceland 

 it was ripe at the end of July. 



277. *Subsp. Amblystegium Juratzkanum Schimp. 



N. Iceland: Fagriskogur (St.)!. S. Iceland: Drangshlid!, fr.; Vest- 

 mannaey!. 



The plant from Drangshlid was quite typical and bore ripe capsules 

 at the end of July. The specimens which were collected on the base 

 of a birch-trunk in Fagriskogur agreed fairly well with the form described 

 by Limpricht (Kryptogamenflora, vol. III, p. 323) under the name of 

 Amblystegium radiadc. The leaves taper from an ovate-lanceolate base 



