132 .MollTKN I'. l'tillSII II. 



and soiitliwards to Ni'w Foiiiidland. \i\ Robinson «."v: Fehnai n a vaiiety 

 dHatatiini is stated down to llu' Mounlains ol' Maine and to Ihc (ii-eat 

 Lakes. II \no are rii,dit, (hat wmild hr a Inxiiriaiil \uv\\] ()\ L.d('Clunbens 

 L. groe/iland i cii ni is a lowland plant rant^in<f tlii'ou*j;h tlic Bort'al 

 parts nf tlu' whole North American continont, the American analo^on 

 to tlie Eurasiatic L. pahistrc. Besides Soutliern Greenland it perhaps 

 also cnttM-s the Boreal Northwestern parts ol" Asia (accordiii^; to I.kde- 



BOUR). 



To Greenland the species of Leduin immigrated in postglacial time. 

 L. decumbens probably came from the Nortli, over Smilh" Sound. Its 

 area in West Greenland is now widely separated from its main distril»n- 

 tion in Arctic America, and therefore the immigration probably took 

 place during the milder climate of an interglacial period. A much larger 

 gap separates the Greenland stock of L. groenlandicum from its con- 

 tinual American area. It is one of the numerous representatives of the 

 Boreal American Fore st -Flora occurring in Southern Greenland, 

 the immigration of which to Greenland is still totally enigmatic. 



i 228. Rhododendron lapponicum (L.) WMil. 



In rather dry heath and on rock shelves. 



Very common throughout the whole area. 



Widely distributed in Greenland, without soiithern limit, in 

 the Southern parts however scarcer (Ros.); the nortliprn limit not known. 

 but is to be searched for north of 76°. 



Ranging from the shore line to considerablc allitudcs. 



Early flowering and abundantly fructificating. 



Not much varying; ordinarily prostrate, in Ihe stuitliern parts 

 in sheltered positions forms like erect shrubs or dwarf trees occur. 



Covered by snow during winter, iml not by lliii k layers. 



i 229. Loiseleuria procumbens i L. i l)isv. 



( )n snnny spots in liralli. on clilTs, somclinics on fcll-lields. 



Common throughout the gneissic parts, scarce on basalt, ofteii ab- 

 sent over wide areas here. (Comp. I.cdii/n.) 



Widely distributed in West Greenland without southern limit; 

 the northern linut still iinknown. in l'^ast Greenland not north of GT'IG'. 



Ascends to great altitudes. 



Abundantly flowering and fruiting. 



Normally covered by snow during winter. 



