ParT 4, 1908] ROSACEAE 335 
acute sepals; petals broadly obcordate, a little exceeding the sepals, 5-8 mm. long; stamens 
short, about 20; pistils humerous; styles filiform, rather short. 
TYPE Locality: Labrador. 
DISTRIBUTION: Arctic America from Labrador and Greenland to Alaska, andalpine regions of 
the Canadian Rocky Mountains; also in Siberia and Spitzbergen. 
ILLUSTRATIONS: Fl. Dan. f/, 2291; Britt. & Brown, Ill. Fl. f. 7919, 1920; Lehm. Monog. 
Potent. £/. 17; Mem. Dep. Bot. Columbia Univ. 2: Bl, 32, f. 1-5, LY 15. : a 
116. Potentilla Robbinsiana Oakes; T. & G. Fl. N. Am. 1: 441, as 
synonym. 1838.—Rydb. Bull. Torrey Club 23: 304. 1896. 
Potentilla minima BT. & G. FIN. Am. 1: 441. 1840. 
Potentilla frigida A. Gray, Man. ed. 2. 118. 1856. Not £. frigida Vill. 1789. 
Potentilla minima Robbinsiana Lehm. Rev. Potent. 159. 1856. 
Cespitose perennial, with a short caudex, almost pulvinate; stems 2~3 cm. high, softly 
long-pilose, one-flowered, and with 1 or 2 diminutive leaves ; stipules ovate, obtuse, scarious 
and brown; leaves ternate, short-petioled, villous-pilose, especially beneath; leaflets 0.5-1 
cm. long, obovate, cuneate at the base, deeply incised-serrate with generally obtuse teeth ; 
hypanthium villous, in fruit 5~7 mm. in diameter ; bractlets and sepals oblong, obtuse, sub- 
equal, 2-2.5 mm. long; petals obovate, slightly exceeding the sepals, obcordate at the 
apex; stamens about 20. 
TYPE LOCALITY : White Mountains, New Hampshire. 
DISTRIBUTION : White Mountains of New Hampshire. : 
LG eee Britt. & Brown, Il. Fl. f. 1927; Mem. Dep. Bot. Columbia Univ. 2: pi. 32, 
XXIV. Biflorae. Plant cespitose, the stems subscapose, 1-3-flowered. Leaves ternate, 
with the leaflets divided to near the base into 2 or 3 linear, entire, somewhat revolute seg- 
‘ments, not tomentose. Petals broadly elliptic, yellow, slightly emarginate. Styles long 
-and filiform. Receptacle beset with long hairs. 
117. Potentilla biflora Willd.; Schlecht. Ges. Nat. Freunde 
Berlin Mag. 7: 297. 1815. 
Potentilla bifolia Lehm. Stirp. Pug. 9: 32. 1851. 
Cespitose or pulvinate perennial, with short and thick caudex ; flowering branches scape- 
like, 1- or 2- (seldom few-) flowered, erect, less than 1 dm. high, sparingly hirsute-villous ; 
‘stipules lanceolate, acuminate, brown; leaves basal, ternate, with the middle leaflet deeply 
-3-divided, the lateral ones 2-divided into linear segments 5-10 mm. long, with more or less 
revolute margins, sparingly villous-hirsute, in age nearly glabrous above, and with a strong 
midrib beneath; flowers less than 1 cm. in diameter ; hypanthium sparingly hairy, in fruit 
about 7 mm. in diameter; bractlets oblong, obtuse, about equaling the ovate-lanceolate 
acute sepals, 3.5-4 mm. long; petals obovate, slightly emarginate, longer than the sepals, 
yellow with an orange spot, 4-5 mm. long; stamens about 20; pistils numerous; styles 
filiform, long. . 
TYPE LOCALITY: Eastern Siberia. . ed 
DISTRIBUTION : Eastern Siberia, Alaska, and the arctic coast to the Mackenzie River. 
ILLUSTRATIONS: Lehm. Monog. Potent. £7. 20 ; Lehm. Rev. Potent. £/. 62, 7.1, Mem. Dep. 
Bot. Columbia Univ. 2: Al. 23, f. 6-9. 
XXV. Saxosae. Small glandular-pubescent perennials with thick woody roots and 
caudices. Leaflets pinnate, with few, deeply cut leaflets. Flowers small and few, in open 
‘cymes. Sepals broad, acuminate. Petals narrow, yellow or cream-colored, acutish or 
acuminate. Styles filiform, inserted just below the incurved apex of the ovary. 
118. Potentilla saxosa Lemmon; Greene, Pittonial: 171. 1888. 
Horkelia saxosa Rydb. Mem. Dep. Bot. Columbia Univ. 2: 155. 1898. 
Perennial, slender, about 3 dm. high, pubescent and viscid-glandular; leaves pinnate ; 
leaflets 11-15, reniform-flabelliform, 1-1.5 cm. long, cleft to the middle into oblong 
acutish segments; cyme open, few-flowered; hypanthium saucer-shaped; sepals ovate, 
