Part 4, 1908] ROSACEAE 365- 
distinctly petiolulate; scape 5-8 cm. long, as well as the pedicels and hypanthium densely 
silky-strigose ; bractlets lanceolate or oblong-lanceolate, 4-5 mm. long, equaling or exceed- 
ing the ovate-lanceolate sepals; petals broadly obovate or orbicular, 5-7 mm. long; achenes. 
in pits. 
Gua collected at Lake Lebarge, Yukon Territory, in 1899, 7. B. Tarleton 38 (herb. N. Y. Bot. 
DISTRIBUTION : Yukon Territory. 
25. SIBBALDIA L, Sp. Pl. 284. 1753. 
Dactylophyllum Spenn. F1. Frib. 1084, in part. 1829. 
Coelas Dulac, Fl. Hautes Pyr. 303. 1867. 
Low, tufted perennial herbs, with short cespitose caudices or rootstocks and ternate- 
leaves. Hypanthium saucer-shaped or cup-shaped, small. Bractlets, sepals, and petals 5. 
Petals yellow, obovate, cuneate, or oblanceolate, scarcely equaling the sepals. Stamens 5, 
inserted not very close to the small receptacle; filaments filiform but short, inclined. Pistils. 
5-20; styles lateral. Ovule and seed attached near the base of the style, ascending and 
amphitropous, 
Type species, Sibbaldia procumbens L. 
1. Sibbaldia procumbens L. Sp. Pl. 284. 1753. 
Potentilla procumbens Clairv. Man. 166. 1811. Not P. procumbens Sibth. 1794. 
Densely cespitose, or with numerous creeping scaly rootstocks ; flowering stems less. 
than 1 dm. high, more or less hirsute-strigose, few-leaved; stipules triangular-obovate to 
lanceolate ; basal leaves on slender petioles, ternate, sparingly appressed-pilose ; leaflets 
1-2 cm. long, broadly cuneate, 3-5-toothed at the apex; stem-leaves similar but short- 
petioled ; flowers few in rather dense cymes; hypanthium 3-4 mm. in diameter, somewhat 
pilose ; bractlets and sepals subequal, broadly oblong or ovate; petals yellow, spatulate, 
shorter than the sepals. 
TYPE LOCALITY: Lapland. 
DISTRIBUTION : Arctic and alpine regions of America from Greenland to Alaska and south in 
the mountains to New Hampshire, Colorado, and California; also in arctic and alpine Europe and 
Asia. 
ILLUSTRATIONS: Fl. Dan. pl. 32; Lam. Tab. Encyc. pl. 221, f.1,; Engl. Bot. pl. 897; Sv. 
Bot. £/. 761; Schkuhr, Handb. p/. 88; Sturm, Fl. Deuts. 17: p/. 5; Baxter, Brit. Bot. pi. 
470; Britt. & Brown, Ill. Fl. f. 1938 ; Mem. Dep. Bot. Columbia Univ. 2: p/. 100, f. 1-5. 
26. SIBBALDIOPSIS Rydb. Mem. Dep. Bot. Columbia 
Univ. 2: 187. 1898. 
Cespitose undershrub with branched caudex and leathery, ternate leaves. Hypanthium 
almost flat. Bractlets, sepals, and petals 5. Petals white, obovate or elliptic, neither 
unguiculate nor emarginate. Stamens about 20, in three series as normally in Potentitla, 
their insertion not distant from the base of the receptacle; filaments long and filiforin ; 
anthers round, cordate at the base, opening by a longitudinal slit. Receptacle hem- 
ispheric, bearing numerous pistils. Styles slender, filiform, lateral; stigmas truncate. 
Achenes turgid, villous. Seeds ascending and amphitropous. 
Type species, Potentilla tridentata Soland. 
1. Sibbaldiopsis tridentata (Soland.) Rydb. Mem. Dep. Bot. 
Columbia Univ. 2: 187. 1898. 
?Potentilla retusa O. F. Miiller, Fl. Dan. 544: 4. 1780. 
Potentilla tridentata Soland. in Ait. Hort. Kew. 2: 216. 1789. 
Caudex woody and creeping; annual branches herbaceous, 1-2 dm. high, sparingly 
appressed silky-strigose ; stipules lanceolate, foliaceous, entire, about 5 mm. long; leaves 
ternate, subcoriaceous, green and shining above, pale beneath; leaflets obovate-cuneate, 
three-toothed at the truncate apex ; cyme open, on a slender peduncle ; flowers about 1 cm. 
in diameter; hypanthium appressed-strigose, in fruit about 5 mm. in diameter; bractlets. 
