1909]  Fernald,— Representatives of Potentilla Anserina 7 
rhachises; and the laterally compressed round-backed, not furrowed, 
achenes. That it merits specific recognition there can be no question, 
but prolonged study has failed to show that it differs in constant or 
even apparent characters from Potentilla pacifica Howell ' (P. Anserina, 
var. grandis T. & G., Argentina pacifica Rydberg). In all essential 
characters — pubescence, bractlets, petals, achenes, etc., — the plant 
of the Atlantic salt marshes is like that of the Pacific coast, though 
Rydberg's descriptions make it differ in its smaller flowers (see above) 
and its more obovate or oval leaflets. In the outline of the leaflets 
P. pacifica shows considerable variation, and many of the northwestern 
specimens cannot be distinguished by this character from the plant of 
the Atlantic coast. ‘There seems to be no reason, then, why the two 
plants should be kept apart by the artificial character set up for them. 
It is interesting to find, as our knowledge of temperate floras should 
lead us to expect, that P. pacifica extends by way of the Aleutian 
Islands to the coast of eastern Asia and south to Japan, a fact 
already brought out by Wolf, who, although overlooking the impor- 
tant achene-character of the plant and therefore treating it as P. 
Anserina, var. grandis, states its range as the Pacific and Atlantic 
coasts of America and the east coast of Asia.? 
As Potentilla pacifica approaches the northern limit of its range it 
becomes dwarfed and its leaflets are rapidly reduced in number until, 
in northern Labrador, Greenland, arctic Alaska, and northeastern 
Siberia, it often has only 7-15 small leaflets. This dwarfed arctic and 
subarctic extreme is P. Anserina, var. groenlandica Tratt., but, so far 
as the material at hand shows, it is to be considered a dwarfed phase 
of P. pacifica rather than a true variety. On the coast of New 
England and eastern Canada, Dr. Rydberg's P. litoralis, which is said 
to have the “leaves 1-3 dm. long," with the “upper leaflet 2-3 cm. 
long," becomes dwarfed under adverse conditions and has leaves 
barely 3 сш. long, with as few as 13 leaflets, the terminal 7 mm. long, 
1 Howell, Fl. N. W. Am. i. 179 (1898). 
2 These plants which occur in Eastern North America and in northeastern Asia but 
not in Europe make a considerable portion of our flora — one hundred or more spe- 
cies; Onoclea sensibilis, Cypripedium arietinum, Habenaria bracteata, Polygonum arifo- 
lium, P. sagittatum and P. scandens, Geum strictum, Phryma  Leptostachya, &c. 
Several such plants are associated in salt marshes or brackish soil on both the Atlantic 
and Pacific coasts with Potentilla pacifica; for example, Poa eminens, Glaux maritima, 
var. obtusifolia, and Gentiana Amarella, var. acuta. 
3 See Wolf, 1. c. 676. 
