36 



Nr. :i. c;. H. OsTKMKLi) ; 



lU'cidiMitallv inlroduced l)y thesc colonists. Thai thev have 

 spri'ad soimwlial l)ev()iul the hoiinds ol" the original seltle- 

 niciits (on the Wcsl ('oasl to DisUo, and on the 1-^asl to 

 AngniagsaHk) mav he exphiined by their having aehenes 

 adinirahly adaj)ted to he carried hy the wind; they niay thus 

 have heen transporled over Ihese distances in Ihe course of 

 the 500 — 900 years Ihat have ehipsed since Iheir inlroduclion. 



l-'ar more remarkable, however, is the laet that they have 

 become endemic, being unknown at the present day either 

 in Iceland or Xorway, Nvhence il mnst he presumed Ihal 

 their anceslors were bronght. This can hardly be explained 

 otherwise than by supposing thai in the course of the 

 intervening centuries, new species have taken the place of 

 those originally broughl over. — Il is of course laken for 

 granted thai the specialists in the sludy of Hieracia are 

 right in regarding them as distinct micro-species. — In the 

 very first description given by S. Almquist (1884) mention 

 is made of their close relalionship lo olhcr species; il is 

 slated, for instance, wilh regard to //. rigorosum, thai "of 

 Scandinavian species, H. stricium Fr. Lindeb. exs. no. 94 

 is closely related lo this" and wilh regard lo //. (jvoenUiu- 

 dicum, that "among Scandinavian forms, //. iloi'rensc Fr. 

 pUcdInni Lindeb. is extremely closely akin". That new 

 micro-species can arise among apogamous Hieracia, before 

 our very eyes as it were, I have already shown by culture 

 experimenls (Ostenfkld 1921); the remarkable feature in 

 llic present case is, Ihal the original forms seem to have 

 disappeared. Whether this has taken place in Greenland 

 alone, or also in Iceland — or Norway as the case may 

 be — is of course not easy to determine. 



It seems at any rate as if the (ireenland Archieracia 

 (apart from //. (tlpinuin /..) have dinerentialed out since their 



