1914] Pease,— A Form of Potentilla tridentata 195 
the plate accompanying the desceription.! Theodor Wolf, in his 
Monographie der Gattung Potentilla (1908), 77, records no variety or 
form of the species based upon any character connected with pubes- 
cence or hirsuteness. In the absence, therefore, of definite description 
by the author of P. tridentata or of later segregation, the hirsute- 
leaved plant, which, though apparently not separable geographically 
or in habitat from typical P. tridentata, yet seems to merit some 
recognition, may be described as 
POTENTILLA TRIDENTATA Ait., forma hirsutifolia n. f., foliis utrim- 
que hirsutioribus.— QUEBEC: Paspebiac lighthouse, 27 July, 1902, Wil- 
hams & Fernald; vicinity of Cap à l'Aigle, 18 July, 1905, J. Macoun, 
no. 67050 (the sheet in the Gray Herbarium containing three plants 
of the form and two of typical P. tridentata). Maine: Orono, 1880, 
Z. Furbish; Summit of Mt. Battie, Camden, 1325 ft., 14 July, 1903, 
c. Furbish; Bar Harbor, F. H. Peabody; Southport, 7 Aug., 1894, 
M. L. Fernald. New Hampsuire: Dry pasture 41 miles south of W. 
Milan village, Milan, 20 Aug., 1912, A. S. Pease, no. 13871 (TYPE, 
deposited in Herbarium of the N. E. Botanical Club). Massacuu- 
sETTS: Eastern Point, Gloucester, 7 June, 1896, E. L. Rand & B. L. 
Robinson; Princeton, July, 1893, C. A. Regester. 
Specimens from Orland, Maine, collected by Helen G. Atkins, and 
eU 
Norfolk, Connecticut, collected 27 June, 1906, by C. H. Bissell, show 
a transitional tendency from typical P. tridentata toward this form. 
URBANA, ILLINOIS. 
! Plate 9. The problematical P. retusa O. F. Müller, Fl. Dan. V. fasc. 14 (1780) 4, 
t. 799, described from Greenland, is referred by Willdenow, Spec. plant. ed. 4 (1797) ii. 
1110, and by other authors, including Wolf, to P. tridentata Ait. If this identification 
were undoubted, the name P. retusa would supplant the later P. tridentata and would 
be applicable to the hirsute form here under discussion, for P. retusa was described 
"foliis ternatis, hirtis, apice retuso, tridentato." The original plate, however, shows 
it to have had broadly obovate bright yellow petals, a character which at once 
throws doubt upon its identity with the narrower- and white-petaled P. tridentata. 
