Part 4, 1908] ROSACEAE 347 
late, entire, 5-10 mm. long, the lower brown, scarious, 15 mm. long; basal leaves sev- 
eral, pinnate, grayish appressed-silky; leaflets 3-5 pairs, 1-2 cm. long, of rather firm 
texture, oblong, entire or 3-toothed at the apex, or with a few additional small teeth above 
the middle; cyme branched, open, with slender pedicels; hypanthium finely strigose, 
cupulate, in fruit 3-4 mm. in diameter; bractlets linear, about half as long as the lanceo- 
late acuminate sepals, which are 3-4 mm. long; petals yellow, obovate, about equaling the 
sepals in length; stamens about 20; pistils 5-12; styles filiform. 
TYPE LOCALITY: Oak Creek, near Flagstaff, Arizona. 
DISTRIBUTION : New Mexico and Arizona. 
ILLUSTRATION: Mem. Dep. Bot. Columbia Univ. 2: p/. 55. 
XXXI. Multifidae. Mostly low perennials. Leaves pinnate, with 5-15 incised or dis- 
sected leaflets, more or less tomentose beneath. Petals yellow, obovate, slightly if at all 
emarginate, usually not exceeding the sepals. Style very short, nearly always thickened 
and glandular at the base. 
161. Potentilla Sommerfeltii Lehm. Delect. Sem. Hort. 
Hamb. 1849: 6. 1849. 
Cespitose perennial; caudex covered with the brown scarious broadly ovate stipules ; 
stem 3-5 cm. high, slightly silky, scapose, 1- or 2-flowered; leaves pinnate, with 5 
leaflets, the terminal one stalked, glabrate above, finely tomentose beneath; leaflets obo- 
vate in outline, divided to near the midrib into linear-oblong obtuse segments; bractlets 
oblong, obtuse, much shorter than the similar sepals, which are about 3 mm. long; petals 
obovate-cuneate, slightly emarginate, about 5 mm. long; stamens about 20; pistils many ; 
styles short, slightly thickened and glandular at the base. 
Type LOCALITY: Greenland. ; 
DISTRIBUTION : Spitzbergen, Greenland, and arctic coast of North America. . 
ILLUSTRATIONS : Lehm. Rev. Potent. pl. 10, 7.2; Mem. Dep. Bot. Columbia Univ. 2: p/. 35, 
I-L,2., 
162. Potentilla subarctica Rydberg, sp. nov. 
Potentilla pulchella elatior Lange, Comp. Fl. Groenl. 4. 1880. Not P. elatior Willd. 1815. 
A low perennial, with thick tap-root and short scaly caudex; stems decumbent at the 
base, sparingly villous, more or less purple-tinged, 1-3 dm. high ; basal leaves pinnate, with 
3-5 leaflets, the terminal one usually decidedly stalked ; stipules scarious, brown; petioles 
3-5 cm. long, more or less densely villous; leaflets obovate, green but appressed-silky 
above, grayish-tomentose beneath, deeply cleft into oblong or lanceolate, mostly obtuse 
divisions; the terminal leaflets 2-3 cm. long, the lower ones much smaller; stem-leaves 
mostly 3-foliolate, the lower petioled, the upper sessile; stipules foliaceous, lanceolate 
to elliptic; cyme open; hypanthium villous; bractlets usually elliptic, obtuse, nearly 
equaling the ovate acute sepals, which are about 5.mm. long; petals yellow, broadly obo- 
vate, usually emarginate; stamens about 20; pistils numerous; styles short and glandular 
at the base. 
TYPE LOCALITY: Ritenbenk, West Greenland. ; 
DISTRIBUTION : Greenland and the arctic islands and coast of North America. 
163. Potentilla pulchelia R. Br. Chlor. Melv. 19. 1823. 
? Potentilla sericea Gtev. Mem. Wern. Soc. 3: 430, 1821. 
? Polentilla Keilhavii Sommerf. Mag. Naturvid. II. 1: 244, 1832. 
Potentilla nivea pulchella Durand, Proc. Acad. Phila. 1863: 94. 1863. 
Cespitose perennial, with short prostrate branches from a caudex covered with the brown 
scarious stipules; stems generally less than 1 cm. long, few-flowered, silky-hirsute with 
yellowish hairs; leaves short-petioled, pinnate, with 2 pairs of leaflets and a sessile terminal 
one, yellowish-silky and also a little tomentose beneath ; leaflets obovate-cuneate in outline, 
deeply dissected into linear-lanceolate segments, the lower pair smaller and often entire ; 
hypanthinm yellowish-silky ; practlets oblong, shorter than the ovate sepals, which are 4-5 
