336 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM, 



Potenum annuum Nutt.; Hook. Fl. Bor. Am. 1: 198. 1834. 

 Type locality: "Red River in Louisiana." 

 Range: Vancouver Island to California and Arkansas. 



Specimens examined: Klickitat County, Howell; Fourth Plain, Piper, July 14, 1899; 

 Pullman, Piper 1.537; Clarks Springs, Kreager 106. 

 Zonal distribution: Arid Transition. 



2. Sanguisorba latifolia (Hook.) Coville, Contr. Nat. Herb. 3: 339. 1896. 



Sanguisorba canadensis latifolia Hook. Fl. Bor. Am. 1: 198. 1834. 



Sanguisorba sitchensis C. A. Meyer; Trautv. & Mc3'er, Fl. Ochot. 35. 1856. 



Potenum sitchense S. Wats. Bibl. Ind. 303. 1878. 



Type locality: "Observatory Inlet." Collected by Scouler. 



Range: Alaska to Oregon and Idaho. 



Specimens examined: Silverton, BoncTc in 1889; Snoqualmie Pass, Piper; Big Creek 

 Prairie, Lamb 1394; Fort Vancouver, collector not indicated; Skamania Count}', SvJcsdorf 

 966; Blue Mountains, Horner 415. 



Zonal distribution: Canadian. 



The red-flowered form of this species is referred by Howell a to S. officinalis L. The 

 white-flowered ordinary form was referred to S. media L. in Hooker's Flora. It is also 

 the basis for the entr}- " Poterium canadense B. & II.?" of Suksdorf's list. 



POTENTILLA. 



Cymes leafy; annuals or biennials with small flowers. 



Lower leaves pinnate, upper ternate 1 . P. rivalis. 



Leaves all ternate. 



Petals as long as the sepals 2. P. monspeliensis. 



Petals much shorter than the sepals. 



Cymes loose, rather broad; leaflets oi)lanceolate 3. P. millegrana. 



Cymes narrow, elongated ; leaflets ol)ovate 4. P. biennis. 



Cymes not leaf}^; perennials. 

 Leaves pinnate. 



Flowers white ; receptacle long-bristly 16. P. neirberryi. 



Flowers yellow; receptacle not long-bristly. 



Calyx silky; leaflets 1 to 2 cm. long 14. P. cascadensis. 



Calyx hairy; leaflets 2 to 6 cm. long 15. P. drummondii. 



Leaves digitate. 

 Leaflets 3. 



Plant densely silky-villous 12. P. villosa. 



Plant glabrous or nearly so 13. P. JlabeUifolia. 



Leaflets 5 to 9. 



Low alpine plant, 20 to 30 cm. high; cyme few flowered. 5. P. dissecta. 

 Taller lowland plants, 40 to 80 cm. high; cymes many 

 flowered. 



Leaflets pubescent on both sides. 



Pubescence tomentose 6. P. permoUis. 



Pubescence grayish-silky 7. P.fastigiata. 



Leaflets glabrous at least above. 



Under side of leaves white tomentose. 



Teeth of the leaflets triangular 8. P. gracilis. 



Teeth of the leaflets elongate 9. P. blascKkeana. 



Under side of leaves green. 



Leaflets slightly tomentose beneath .... 10. P. viridescens. 

 Leaflets glabrous on both sides 1 1 . P. nuttaUii. 



a Fl. N.W.Am. 170. 1898. 



