80 



MEMOIRS FROM THE DEPARTMENT OF BOTANY OF COLUMBIA UNIVERSITY 



PntcntiJhi nirca ardica Cham. Linnaea, 2 : 21. 1827. 



Walp. Ann. 2 : 508 ; Walp. Rep. 2 : 2(i ; Lehmann, Stirp. Pug. 9 : 68 ; Del. Sera. 

 Hort. Hamb. 1850: 11 ; Lange, Consp. Fl. Groenl. 9. 



fPotcntiUa frigida Grev. jNlem. Soc. Wern. 430.* 



Macoun, Cat. Can. PL 140. WetheriU, Bot. Peary Aux. Exp. 5. 



PotentiUa fragiformis parvlflora Traut.; according to Nathorst, Oefv. Kong. Vet. Ak. 

 Forh., 1884 : 23-40. 1884. 



PotentiUa nirca concolor Don, Gard. Diet. 2 : 550. 1832. 



Durand, Journ. Acad. Phil. 1856: 190. 



Illustrations : Lehm. i\Ion. Pot. pi. 17; Britt. & Brown, 111. Fl. 2 : /. 1920. 

 Plate 32, /. 1; dissection of flower,/. 2; pistil,/. 3; stamen,/ 4; fruiting hypanthium 

 and calyx, f. 5. 



Cespitose ; stems 2-5 cm. 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 (n-ate acute sepals. Petals broadly obcordate, a little exceeding the sepals. 



Dr. Watson states that this is a depauperate form of P. cmarginata. As understood 

 by Lehmann it is a plant much nearer related to P. fragiformis. The habit is cespi- 

 tose as in P. ciaargiiinta, 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. 

 fmgifonnis, from which it differs mainly in size, being in every respect smaller, and in 

 the fact that the floAvering stems scarcely exceed the leaves. A connecting link is formed 

 by the Greenland P. Fricmina, which very closely resembles P. nana except that the 

 flowering stems are elongated as in P. fragifonrda. Probably all three are but forms of 

 one species. Specimens collected by W. E. Meehan, No. 22, 1892, at ]\lcCormack Bay, 

 are intermediate between this and P. Fricsiana. P. nivea ardica, at least as to Richard- 

 son's plant must be included in P. nanct. It ranges through arctic America from Labra- 

 dor to Alaska, and is also found in eastern Siberia. 



Greenland: Ryder, 1887; Th. M. Fries, 1871 (Disco). 



Labrador A: Hiuhon Bay : Kohlmeister ; R. Bell, 1864 (Worthingham, Diggs and 

 Upper Savage Islands). 



R<>cl;j Mcmntain.s: 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 Canada, No. 1487, 1886. 

 Ala.d-a : G. S. Oldmixon, No. 623, 1882 (Pt. Barrow). 



