Contribution. 1. 83 



stenophylla is distinguished from that one by its dark colour, 

 smoothness and gloss, proportionally feeble and pliable stipe, 

 long and narrow lamina, which is cut up in more or less 

 numerous and narrow segments, and with a cuneate base. In 

 several places along the coast of Norway I have met with 

 a form having the quoted habit and outward appearance, 

 and consequently I have referred it to f. stenophylla. The 

 form from Finmarken represented in Lam. Norw. t. 3, fig. 

 5 has the base of the lamina a little broader, but otherwise 

 fully agreeing with typical stenophylla. The consistence of 

 the lamina is more solid than by the other forms except f. 

 valida, but the stipe is less solid than by f. genuina when 

 it grows in exposed localities. Stromfelt also points out 

 a difference with regard to the structure. In this respect 

 there is, according to my experience, a pretty large variation 

 by the forms of L. digitata. For inst. f. valida has not sel- 

 dom proportionally small cells in the intermediate layer of 

 the lamina, and the consistence as solid as by f. stenophylla, 

 the same colour, smoothness and gloss when it grows in cer- 

 tain localities, for inst. Borgeveer in Lofoten, and here it is 

 very characteristic. In other localities, however, it is so 

 nearly related to f. genuina that no limit hardly may be 

 drawn between them. Other striking examples as to the 

 variation of the outward appearance and sometimes also the 

 structure by the Luminaries afford L. saccharina as well as 

 L. hyperborea, no doubt greatly dependent on the place af 

 growth. What a difference between L. saccharina f. linearis 

 with a short stipe, 20 — 30 cm. in length, a thick, coriaceous 

 and rugose lamina 3.5 m. in length but only 10 — 12 cm. in 

 breadth, and the form borealis growing in enclosed sounds 

 or quiet bays, sometimes with a stipe of nearly 1 m in length, 

 and a thin lamina about 1.5 m. long and nearly the same 

 breadth, with a smooth surface. But every transition is to 

 be found. And so also L. hyperborea growing in exposed 



