334 DR. HOOKER ON THE DISTRIBUTION OF ARCTIC PLANTS. 



Y ACCii^iVM. 2yubescens, Wormsk. (Plor. Dan. 1516), a Greenland plant, is referred to 

 uliginosmn variety by Lange. 



Vaccinium (Oxyococcus) microcarpmn, E,upr., is included under O. palustrls by Ny- 

 man, and is clearly nothing but a small-fruited state of that plant. 



Calluna vulgaris, L., is mentioned in DeCandoUe's ' Prodromus,' on the authority of a 

 specimen gathered by La Pylaie, as a native of Newfoundland ; but I find no confirmation 

 of this habitat, nor is it found in any part of the American continent. In the 01d"\\^orld 

 it wanders no further east than the Ural district. 



Ledum j)alustre, L. Asa Gray and DeCandolle distinguish two species, by the stamens 

 5 and 10, leaves broad and narrow, and capsules ; but these do not affect diff'erent geo- 

 graphical ranges, and Andersson, a most careful observer, says (Conspect. Veg. Lapp. 

 18, in note), " inter banc varietatem {laUfolitmi) et normalem tarn multi animadvertuntur 

 transitus, ut nuUo modo distingui possint. Nostra planta foliis etiam latioribus, quam 

 specimina Groenlandica, nonnunquamlecta." Of the three included species, L. dUatatum 

 is ranked by Fries with palustre, to which also Grcenkmdicum is referable — L. latifolium. 

 Ait., is merged into palustre by Michaux and in ' Plor. Bor.-Am.' 



Pyrola rotimdifolia, L. This I consider includes cJdorantha, Sw., which, though not 

 found in Arctic Europe, is said by Du.rand (Kane's Yoyage) to be found in Greenland. 

 As, however, Durand does not include grandijlora, Rad., and Lange makes no mention of 

 chlorantha, it is possible that the same species is intended by both authors. 



P. Groenlandica is referred to rotimdifolia in Flor. Bor.-Am., and by DeCandolle ; it is 

 kept distinct by Lange, who refers it to grandijiora, Had. 



P. elliptica, Nut., is certainly only a variety of rotimdifolia, and is in most respects in- 

 termediate between rotundifolia and chlorantha. 



P. media, L. Bentham is inclined to doubt if this be permanently distinct from P. 

 minor. 



Ruprecht (Flor. Samojed.) mentions P. uniflora, L., as a doubtful native of Ivolgujew 

 Island, off the White Sea. 



Gentiana lingulata, Ag. Fries treats this as a distinct variety of Amarella, which 

 alone is Lapponian. After a very careful examination of G. acuta, Mich., I am disposed 

 to regard it as the Lapponian form of Amarella ; I cannot fix characters that will distin- 

 guish them. Grisebach says of it, " Amarellce simillima sed bene distincta species." 



G. involucrata, Rottb. This very rare plant is also Icelandic. 



G. cestiva, R. & S., is va^na y of Grisebach ; it is not found in Lapland, any more than 

 Fleurogyne rotata ; both, however, are Arctic Russian. 



PoLEMONiUM ccernleum, L. I have treated all the arctic forms of this variable plant as 

 constituting an aggregate species. All are regarded as varieties in ' Flora Boreali- Ameri- 

 cana.' Ledebour makes pulchellum different, and includes capitatum and humile under it ; 

 these, however, graduate quite insensibly into cceruleum. Ruprecht finds both in the 

 arctic island of Kolgujew. It is very remarkable that this plant inhabits no part of 

 Greenland but the east coast only, and at a very high latitude. 



