MEMOIRS FROM THE DEPARTMENT OF BOTANY OF COLUMBIA UNIVERSITY 
we) 
generally sessile. It is generally quite hairy with long and yellowish white hairs. In 
general habit and flowers it comes near P. Vahliana, which has been mistaken for it; but 
the latter has always only 3 leaflets. 
Spitzbergen, Greenland, arctic coast of America, and Wrangel Island, eastern 
Siberia. 
Greenland: H.C. Hart; Parry; Dr. Hayes, No. 20, 1861; A. Hartz, No. 8022, 1890.1 
Arctic America: R. Bell, No. 1454, 1884 (Hudson Strait); No. 1480a (Diggs Island); 
1893 (Cape Prince of Wales); J. W. Tyrrell, 1893 (lat. 64°, long. 100°).; Dr. Bissel 
(Polaris Bay).  - 
Wrangel Island: J. Muir, 1881. 
74. Potentilla litoralis Rydberg. 
Potentilla litoralis Rydberg, Bull. Torr. Bot. Club, 25 : 264. 1896. 
Britton & Brown, lle Bl 22 204. 
Potentilla Pennsyluanica Gray, Man. 122, 1848; Gray Man. Ed. 2: 119; Ed. 5: 154;? 
Wood, Class Book, 348; Bot. & Flor. 108;2 Wats. Proc. Am. Acad. 8: 553;? Wats. & 
Coult. in Gray, Man. Hd. 6: 159. 
In.usrrations: Britt. & Brown, Il. Fl. 2: f. 1930. Pate 37, f. 1; dissection of 
flower, f. 2; stamen, f. 3; pistil, f. 4; fruiting hypanthium and calyx, f. 5. 
4; 
Stem decumbent or ascending, 2-4 dm. long, simple, slightly appressed silky-strigose. 
Lower stipules lanceolate, scarious and brown, the upper ovate, green, more or less 
toothed. Leaves pinnate, of two approximate pairs of leaflets, the lower pair the smaller, 
or subdigitately 5-foliolate, grayish tomentose and yeiny beneath, nearly glabrous above, 
Leaflets obovate, divided to near the midrib into linear oblong obtuse divisions. Hypan- 
thium strigose and slightly tomentose, in fruit about 8 mm. in diameter. Bractlets lan- 
ceolate-oblong, nearly equalling the ovate-triangular sepals. Petals obovate, cuneate, 
truncate or slightly emarginate, about equalling the calyx. Stamens 20-25. Style short, 
terminal, thickened and glandular at the base. Achenes smooth. 
A near relative of P. Pennsylvanica, but differs in the ascending or spreading stem, 
the sparser pubescence, the leaves, which have fewer and approximate leaflets, often almost 
digitate, and the sepals which are more distinetly ribbed. P. /itoralis is principally a beach 
plant, or at least growing near the coast, while P. Pennsylvanica is an inland, plain or 
mountain species. The following specimens belong to P. /itoralis. 
1 Several other specimens are cited by Lange and Rosenvinge. 2 Includes also the true P. Pennsylvanica. 
