426 ROSACEAE 



Petals slightly if at all exceeding the sepals, 5-7 mm. long. 



Bractlets linear-lanceolate, about two-thirds as long as the lanceolate 

 sepals; leaflets obovate, irregularly or doubly toothed. 



9. D. cilandulosa. 

 Bractlets oblong or oblong-lanceolate: sepals ovate-lanceolate; leaflets 

 more evenly simple-toothed, the lateral ones inclined to be orbicu- 

 lar. 10. D. arizonica. 

 Leaflets incised, with lanceolate teeth. 11. D. incisa. 

 Sepals oval or broadly ovate, rarely lanceolate, rounded and mucronate at the apex. 

 Petals 7-8 mm. long, a-scending in anthesis; leaves densely hairy; plant stout. 



1. D. agrimonioides. 

 Petals less than 6 mm. long, spreading or reflexed in anthesis. 



Petals 4-6 mm. long; calyx and hypanthiuni in fruit together 10-12 mm. long; 



petioles conspicuously long-hairy; petals yellow. 12. D. oregana. 

 Petals 2-4 mm. long; calyx and hypantliium in fruit together 6-10 mm. long: 

 petioles mostly short-hairy; petals whitish. 

 Petals obovate; sepals twice as long as broad. 13. D. albida. 



Petals orbicular or nearly so; sepals half longer than broad. 



14. D. micropctala. 

 Style filiform or nearly so, more than twice as long as the ovary; plant about 2 dm. liigh; 

 petals much exceeding the sepals; leaflets rhombic-obovate. 15. D. rhomboidea. 



1. D. agrimonioides (Pursh) Rydb. Stem stout and erect, 3-10 dm. 

 high, striate, generally densely glandular- or viscid-hirsute; basal leaves many; 

 leaflets 7-11, strongly veined, densely pubescent on both sides; upper three 

 leaflets larger than the others, usually 4—5 om. long, doubly serrate, the odd one 

 commonly rhomboid, the others usually obliquely ovate; flowers 12-18 mm. in 

 diameter; bractlets lanceolate, much smaller than the oblong-ovate, acute or 

 mucronate sepals. PotentUla arguta Pursh. Meadows and rocky places: N.B. 

 — D.C.— Colo.— Mack. Plain— Submont. Je-Au. 



2. D. corymbosa Rydb. Stem 3-8 dm. high, branched above; basal leaves 

 pinnate, with 7-11 leaflets; upper leaflets broadly obovate, 3-5 cm. long, usually 

 rounded at the apex, sparingly short-hairy, coarsely and deeph' doublj- serrate, 

 with ovate teeth; lower leaflets more orbicular; sepals ovate-lanceolate, acute, 

 5mm. long. Meadows: Alta. — B.C. — n Colo. — Wash. Suhmont. — Mont. Je-Au. 



3. D. convallaria Rydb. Stem tall, erect, 4-10 dm. high, long-villous ; 

 basal leaves several, ])innate; leaflets 9-11, slightly long-pubescent or glabrate, 

 the upper 3-5 cm. long, rhombic-obovate and acute, coarsely serrate and in- 

 cised, the lower leaflets more ovate; flowers 10-18 mm. in diameter; petals broadly 

 obovate, white, a little longer than the sepals; sepals ovate-lanceolate. Valleys: 

 Mont. — N.M. Submo^U.—Mont. J^Au. 



4. D. pseudorupestris Rydb. Stem erect, slender, striate, 2-3 dm. high, 

 or in lower meadows (var. intermedia) 4-5 dm. high; basal leaves several; leaflets 

 7-9, sparingl}- and finely pubescent or glabrate, the terminal one obovate to cimeate- 

 flabelliform, the lateral ones obliquely elhptic or nearly orbicular, all coarsely 

 serrate and incised; stem-leaves few and small, tlie leaflets 3-5 and more rhombic; 

 flowers 15-20 mm. in diameter; petals broadly obovate, exceeding the sepals by 

 a third; sepals ovate-lanceolate, pointed. Mountains: Alta. — n Wyo. — Ida. 

 Sulnnont. — Suhalp. Je-Au. 



5. D. foliosa Rydb. Stem stout, 4-5 dm. high; basal leaves 1-1.5 dm. long, 

 with about 9 leaflets, the upper leaflets rhombic-obovate, 4-5 cm. long, sparingly 

 hairy and glandular-atomiferous, coarsely and more or less doubly serrate; lower 

 leaflets more rounded; upper stem-leaves 3-5-foliolate, all with rather large and 

 rhombic leaflets; cyme rather open and corymbiform; sepals lanceolate, acute or 

 acuminate, 5-6 mm. long; petals yellow, roimded-obovate, about 8 mm. long. 

 Mountains: Mont. — Wyo. — ne Utah. Submont. — Mont. Je-Au. 



6. D. valida (Greene) Piper. Stem stout, tall, 4-10 dm. high, erect; basal 

 leaves pinnate; leaflets 7-11, more or less pubescent or glabrate, 3-6 cm. long, 

 the terminal one broadly obovate, the lateral ones obhquely elliptic or nearly 

 orbicular, all coarsely serrate; stem-leaves with fewer, sometimes more rhombic 

 and acutish leaflets; flowers 18-22 mm. in diameter; sepals ovate-lanceolate, 

 pointed; petals yellow, broadly elliptic or nearly orbicular, 8-10 mm. long. 

 D. glutinosa (Nutt) Rydb. Meadows: B.C. — -Ida. — n Utah — Wash. Submont. 



7. D. fissa (Nutt.) Rydb. Stem low, 2-3 dm., or sometimes 4 dm. high, 

 very leafy; basal leaves with short petioles, pinnate; leaflets, as a rule, 9, nearly 



