VENE S UP HE ЬЕ оа. Ы 
1909]  Fernald,— Representatives of Potentilla Anserina 3 
* Achenes corky with a deep groove; stems, petioles, and rachis of the 
leaves densely pubescent, with at first ascending and later spreading 
hairs. 
Leaves silvery on both sides. l. A. argentea. 
Leaves green and glabrate above. 2. A. Anserina. 
Achenes not corky, without a groove; stem, petioles, and the rachis of 
the leaves glabrous or slightly appressed-hairy and glabrate. 
Petals usually over 1 em. long, rounded-obovate. 
Bractlets lanceolate, longer than the sepals; leaves usually 3—4 dm. 
long. 3. A. pacifica. 
Bractlets elliptic or oblong, shorter than the sepals; leaves 1-2 dm. 
long. 4. A. occidentalis. 
Petals 6-8 mm., rarely 1 em. long, usually elliptic-obovate. 
Leaflets elliptic-obovate to oblanceolate, many-toothed, silky as well 
as tomentose beneath; bractlets nearly equaling the sepals or 
even exceeding them. 
Upper leaflets rounded at the apex, with more than 20 linear- 
lanceolate teeth; petals elliptie, about 6 mm. long; pistils few. 
5. A. Babcockiana. 
Upper leaflets acute or obtuse at the apex, with less than 20 tri- 
angular-lanceolate or ovate-lanceolate teeth. 
Hypanthium acute at the base; bractlets linear-lanceolate; 
rachis of the leaves appressed-pubescent. (Western species.) 
6. A. subarctica. 
Hypanthium obtuse at the base; bractlets broadly lanceolate; 
rachis of the leaves glabrate or nearly so. (Eastern species.) 
7: А. litoralis. 
Leaflets broadly obovate, 0.5-1 em. long, few-toothed, usually to- 
mentulose beneath but silky only on the veins; bractlets linear 
or lanceolate, much shorter than the sepals. 8. A. Egedii."! 
As stated, the writer finds in studying the American material that 
the characters of the two leading groups in these two treatments are 
very constant. The achene-characters described by Rydberg are 
beautifully clear in all the fruiting material examined, and, associated 
as they are with the peculiarity of pubescence brought out more defi- 
nitely in Wolf's descriptions of his primary groups, indicate that the 
plants of the two groups are scarcely to be considered varieties of one 
species. This view is further strengthened by the fact that the varieties 
of Wolf's first group are all Old World or cireumpolar plants, while 
those of the second group are essentially confined to North America 
and adjacent eastern Asia. 
Potentilla  Anserina (including var. vulgaris), the circumpolar 
1 Rydb. 1. с. 352, 353. 
