List of Vascular Plants. 27 



Rosaceae. 



Potentilla L. 



75. Potentilla pulchella R. Br. in Ross, Voy., ed. 2, 1819, p. 193; 

 Lange, Consp. Fl. Groenl., 1880, p. 4; Th. Woli; Monogr. Potentilla, 

 1908, p. 151. 



Kruuse, East Greenland, p. 149. 



Among the specimens collected there are some with very small 

 and densely hairy leaves; they represent the extreme limit of f. humilis 

 Lange (1. с); others are more typical and some approach the f. elatior 

 Lange. 



Loc. Hyde Fjord (Peary Land); Cape St. Jacques; Ymers Nunalak; 

 Germania Land: Dove Bugt, Snenæs, Stormkap, Harefjeld; Maroussia Isl.; 

 St. Koldewey. 



Flow. June 28th 08. 



Note. It was rather common on Maroussia Island which is a large, 

 manured nesting-place of sea-fowl. With this exception it does not occur 

 near the coast, and was not found more outward than Stormkap (a single 

 individual from Harefjeld excepted), whence it increases in frequency until, 

 on the gravelly banks at Dove Bugt, it becomes a character plant, just as 

 Lesquerella (see p. 23). — It is a hardy species which endures well botli 

 sand-drifts and snow-storms, but it varies greatly in habit; the wind-affected 

 individuals from the gravelly banks do not bear much resemblance to large 

 sheltered tufts whicli have been snow-covered during winter; they form 

 compact "pillars" with a few living leaves in tlie dense top-rosette (see PI. V). 



76. Potentilla nivea L. Sp. pi. 1753, p. 499; Lange, Consp. Fl. 

 Groenl., 1880, p. 8; P.Rydberg, Monogr. N. Am. Potent., 1898, p. 84; 

 Th. Wolf, Monogr. Potentilla, 1908, p. 233. 



Kruuse, East Greenland, p. 150. 



The specimens collected vary somewhat, as is usual with spe- 

 cimens of arctic P. nivea. But I think that they may all be named 

 var. piimatifida Lehm. (Piigill. plant. IX, Hamburg, 1851, p. 67 ; Th. Wolf 

 (1. c, p. 239) emendavit) under which variety I place f. subquinata 

 Lange (1. с, p. 9). I fully agree with Th. Wolf in not following 

 P. Rydberg (Bull. Torr. Bot. Club., 28, 1901, p. 181), who makes 

 a separate species of Lange's form. 



As to the var. prostrata (Rottböll) Lehm., Monogr. Potent., 1820, 

 p. 184 (P. pros/ra/a Rottböll, Kiöbenhavn, Selsk. Skrifter, Deel 10, 1770, 

 p. 453) much has been written about il, and it has puzzled the au- 

 thors highly. We have in the Copenhagen Herbarium a specimen 

 collected by Holboll at Umanak in West Greenland, and this be- 

 longs without doubt to the s])ecimcns upon which Rottböll's has 

 based his description. This specimen is a very coarse and large- 

 leaved plant with ternate, deeply incised leaves. I think it is a 

 luxurious form of var. piimatifida Lehm., which had been growing 



