80 MEMOIRS FROM THE DEPARTMENT OF BOTANY OF COLUMBIA UNIVERSITY 
Potentilla nivea arctica Cham. Linnaea, 2: 21. 1827. 
Walp. Ann. 2: 508; Walp. Rep. 2: 26; Lehmann, Stirp. Pug. 9: 68; Del. Sem. 
Hort. Hamb. 1850: 11; Lange, Consp. Fl. Groenl. 9. 
?Potentilla frigida Grey. Mem. Soc. Wern. 430.* 
Macoun, Cat. Can. Pl. 140. Wetherill, Bot. Peary Aux. Exp. 5. 
Potentilla fragiformis parviflora Traut; according to Nathorst, Oefy. Kong. Vet. Ak. 
Forh., 1884: 23-40. 1884. 
Potentilla nivea concolor Don, Gard. Dict. 2: 550. 1832. 
Durand, Journ. Acad. Phil. 1856: 190. 
Iutustrations: Lehm. Mon. Pot. pl. 17; Britt. & Brown, Il. Fl. 2: f. 1920. 
Puate 32, f. 1; dissection of flower, f. 2; pistil, f- 3; stamen, f. 4; fruiting hypanthium 
and calyx, f. 9. 
Cespitose ; stems 2-9 em. high, generally one-flowered, pilose. Stipules broadly ovate, 
scarious and brown. Leaves ternate, pilose on both sides, short-petioled; leaflets broadly 
obovate-orbicular, toothed, with short and broad teeth, of which the terminal one is often 
the smallest. Hypanthium pilose-hirsute ; bractlets oblong to elliptic, obtuse, about 
equalling the ovate acute sepals. Petals broadly obcordate, a little exceeding the sepals. 
Dr. Watson states that this is a depauperate form of P. emarginata. As understood 
by Lehmann it is a plant much nearer related to P. fragiformis. The habit is cespi- 
tose as in P. emarginata, but the teeth of the leaves are rounded, the terminal one 
generally smaller, and the bractlets are broadly elliptic and enlarge in fruit as in P. 
fragiformis, from which it differs mainly in size, being in every respect smaller, and in 
the fact that the flowering stems searcely exceed the leaves. A connecting link is f med 
by the Greenland P. Friesiana, which very closely resembles P. nana except that the 
flowering stems are elongated as in P. fragiformis. Probably all three are but forms of 
one species. Specimens collected by W. E. Meehan, No. 22, 1892, at McCormack Bay, 
are intermediate between this and P. Friesiana. P. nivea arctica, at least as to Richard- 
son’s plant must be included in P. nana. It ranges through aretic America from Labra- 
dor to Alaska, and is also found in eastern Siberia. 
Greenland: Ryder, 1887; Th. M. Fries, 1871 (Disco). 
Labrador & Hudson Bay : Kohlmeister; R. Bell, 1864 (Worthingham, Diggs and 
Upper Savage Tslands). 
Rocky Mountains « Drummond; John Macoun, No. 643, 1885 (Silver City); 1890 
(Selkirk Mountains, Roger’s Pass); No. 16744, 1897 (Forget-me-not). 
Mackenzie River : Geological Survey of ¢ ‘anada, No. 1487, 1886. 
Alaska : G. S. Oldmixon, No. 628, 1882 (Pt. Barrow). 
