MEMOIRS FROM THE DEPARTMENT OF BOTANY OF COLUMBIA UNIVERSITY 187 
to. SIBBALDIOPSIS. 
Potentilla Soland. in Ait. Hort. Kew. 2: 216. 1789. : 
Trichothalamus Spreng. Anl. 2: 864. In part. 1818. 
Hypanthium almost flat. Bractlets, sepals and petals 5. Petals white, obovate or 
elliptic, neither unguiculate nor emarginate. Stamens about 20 in three series as nor- 
mally in Potentilla, their insertion not distant from the base of the receptacle; filaments 
long and filiform; anthers round, cordate at the base, opening by a longitudinal slit. Re- 
ceptable hemispheric, bearing numerous pistils ; style slender, filiform, lateral; stigma 
truncate; achene turgid, villous; seed ascending and amphitropous. 
A low undershrub with truly trifoliolate, subcoriaceous leayes, which much resemble 
those of Sibbaldia. Torrey and Gray included this in their subgenus Comocarpa, but it 
differs in so many respects from P. fruticosa that I think it is better to regard it as the 
type of a distinct genus. 
I. Sibbaldiopsis tridentata (Soland.) 
Potentilla tridentata Soland. in Ait. Hort. Kew. 2: 216. 1789. 
Vahl,.Symb. 2: 59; Poir. in Lam. Enc. Meth. 5: 601; Persoon, Syn. Pl. 2: 56; 
Willd. Sp. Pl. 2: 1010; Ait. Hort. Kew. Ed. 2,3: 279; Nestler, Mon. Pot. 28 and 66 ; 
Lehm. Mon. Pot. 30 and 190; Sprengel, Syst. Veg. 2: 541; Seringe in DC. Prod. 2: 
585; Don, Gard. Dict. 2: 552; Dietr. Syn. Pl. 3: 180; Walp. Rep. 2: 35; Ann. 2: 470; 
Lehm. Rev. Pot. 22. 
Michx. Fl. Bor. Am. 1: 302; Pursh, Fl. Am. Sept. 353; Nutt. Gen. N. Am. PI. 
1: 310; Eat. Man. Ed. 2, 378; Ed. 3, 407; Ed. 5, 343; Ed. 6, 279; Ed. 7, 456; Bige- 
low, Fle Bost. Ed: 2, 205; Pl. Bost. 218; Torr. Fl. U. S. 495; Comp. 209; Fl. N. Y. 207; 
Torr. & Gray, Fl. N. Am. 1: 445; Eat. & Wr. N. Am. Bot. 372; Gray, Man. Ed. 1, 123 ; 
id. 2,119; Ed. 5, 155; Beck, Bot. 106; Ed. 2, 98; Chapman, Fl. S. U. 8. 124; Darby, 
Bot. So. States, 303; Wood, Class Book, 342; Am. Bot. & FI. 107; Wats. Proc. Am. 
Acad. 8: 562; Wats. & Coult. in Gray, Man. Ed. 6: 160; Bailey, in Gray, F. F. and G. 
Bot. Rev. Ed. 152; Britt. & Brown, Ill. Fl. 2: 215. 
Richardson, in Frankl. Ist Journ. 740; Ed. 2, App. 21; Lehm. in Hook. Fl. Bor. 
Am. 1: 195; Schlecht. Linnaea, 10: 98; Provancher, Fl. Can. 188; Macoun, Cat. Can. PI. 
141; Durand, Journ. Acad. Phil. 1856: 191; Lange, Consp. Fl. Groen. 10 and 236 ; 
Rosenvinge, ibid. 650; Nathorst, Ofver. Kong. Vet. Ak. Forh. 1884 : 31; Meehan, Proe. 
Acad. Phil. 18938: 210. 
? Potentilla retusa Retz. Fl. Scand. Prodr. 123. 1795. 
Don, Gard. Dictr. 2; 550. 
