THE BRYOI'HY'IA OF ICELAND 538 



Var. fierrafns (Warnst.). 



Isafjordurl, in pools. 



In //. exannulatiim the lengtli of the Icaf-cells varie.s according to 

 the shape of Ihc leaf. In the most conimonly occurring forms with 

 longly pointed leaves the cells are narrow, 6—10 times as long as broad, 

 while short-leaved forms have leaf-cells which are only 4—6 times as 

 long as broad \'q.v. hrachijdictijon (Ren. . such forms are especially met 

 with on cold, wet gravelly ground. Fruit is rather frequent, both in 

 the type and in var. pnrpiirascens, and ripens at the end of July. 



298. Hypnum fluitans (Dill.) L. 

 Åmblystcyiiim finitans (L.) De Xot. 



S. Iceland: Breidabolstadr (F.)!; Breidamerkursandur (Harder I. 

 N. Iceland: Hlejkjuholt (St.)!; Myvatn Grl.;!. 



Monoicous forms, which may be referred to H. finiians occur onh' 

 very scantily and rarely in Iceland. The numerous older records of 

 the occLirrence of this species 'Vahl, Morch, Hornemann, Gronlund, 

 etc.) are, without exccption. due to erroneous determinations, and all 

 the older specimens in the collections fcxcept one) belong to H. exannn- 

 latum or H. Kneiffii. 



H. fluilans grows everywhere in pools or on inundated ground. 

 Near Blejkjuholt Stefiinsson has collected a very peculiar form. with 

 erect, obtuse leaves with short nerve. The cell-tissue of the leaves is 

 very loose, and the cells of the leaf-base diller only slightly from the 

 other cells. 



\ar. falcattini Schimp. Hypnnni H. Schnllzii Limpr.'> 

 This very characteristic form was fgund abundantly. and in fruit, 

 on wet boggy ground near Kaldalon in NW. Iceland. 



294. Hypnum filicinum L. 



Amblysteginm filicinnni (L.) De Not. 



Very common. 



In the grealcr part of Iceland this species is one of the most fre- 

 quent mosses on a damp substratum, especiall}' on wet rocks, but also 

 on gravelly ground and in bogs. In most part of N. Iceland it is some- 

 what rarer, and usually occurs more scantilj'. In S. Iceland it often 

 covers the faces of wet tuti'-rocks in enormous mats and not rarely sets 

 a great quantity of fruit. In the rest of Iceland fruit is rarer and occurs 

 most often in the large, tomentose bog-form. In S. Iceland fruit was 

 ripe in the middle of July. 



Hypnnni filicinnm varies exceedingly. Bog forms and forms from 

 wet gravelly ground are usually denseh' tomentose and regularly pinnately 

 branched. Rock forms, when growing on a more dry substratum, are 

 slender and slightly branched; on wet rocks, especially on tutT. very 

 large and vigorous. often almost likc Hypnnni conimntalnm. 



