482 BOSACBAE (rose family^ 



* * Style terminal ; flowers small ; petals yellow. 



s- Annual or biennial; leaflets incisely serrate, not white-tomentoae ; itameni 



5-20. 



2. P. monspeli§nsis L. Stout, erect, hirsute, 2-9 dm. high ; leaves ^-folio- 

 late; leaflets obovate to oblanceolate, those of the uppermost leaves toothed 

 nearly the whole length ; cyme rather close, leafy ; calyx large ; stamens 15-20. 

 — Open soil, Nfd. to Alaska, s. to D. C, Mo., Kan., and N. Mex. May-Aug. 

 (B. Asia.) 



Var. norv^gica (L.) Rydb. Less hirsute ; leaflets more narrowly oblong, 

 those of the uppermost leaves mostly 8-5-toothed near the end ; inflorescence 

 looser. (P. norvegica L.) — Similar situations, e. Que. to n. N. E., L. Superior, 

 and northwestw. ; occasional on ballast southw. (Eurasia.) 



Var. Iabrad6rica (Lehm.) Femald. Low (1-3 dm. high, in exposed situations 

 acaulescent) ; stem glabrous or sparingly silky-villous ; leaves smoofhish. — Lab. 

 to the alpine regions of the White Mts., N. H. 



3. P. rivsllis Nutt. More slender and branched, softly villous; leaves pin- 

 nate, with two pairs of closely approximate leaflets, or a single pair and the 

 terminal leaflet 3-parted; leaflets cuneate-obovate or -oblong ; cyme loose, often 

 diffuse, less leafy; calyx small; petals minute; stamens 10-20 (rarely 5). — • 

 Neb. to Mo., N. Mex., and westw. May-Aug. 



Var. millegrjna (Engelm.) Wats. Leaves all 3-foliolate ; lateral leaflets not 

 divided ; stems erect, or weak and ascending ; achenes often small and light- 

 colored. (P. leucocarpa Rydb.) — Minn, to Mo., westw. and southwestw. 



Var. pentdndra (Engelm.) Wats. Leaves digitately .3-folio!ate, the lateral 

 leaflets of the lower leaves parted nearly to the base ; stamens 6, opposite the 

 sepals. (P. pentandra Engelm.) — Minn, to Mo. and Ark. 



4. P. parad6xa Nutt. Stems decumbent at base or erect, often stout, leafy, 

 subvillous; leafletspinnately i>-\\,ohoYsXe or oh\oug; cyme loose, leafy ; stamens 

 20 ; achenes strongly gibbous on the ventral side. (P. supina of auth., not 

 L.) — Prairies and river banks, w. N. Y. and Ont. to 111., Mo., N. Mex., and 

 B. C. June-Aug. (Asia.) 



5. P. WicoUdtii (Wats.) Sheldon. Slender; leaflets mostly 3; inflorescence 

 much elongated, leafy, falsely racemose. (P. supina, var. Wats.) — Sandy soil, 

 Mo. {Bush) to N. Dak. 



•1- ^- Herbaceous perennials, more or less white-tomentose ; leaflets incisely 

 pinnatifld ; bractlets and sepals nearly equal ; stamens 20-25. 



6. P. pennsylydnica L. Stems erect or decumbent at base, 2-6 dm. high ; 

 leaflets 5-9, white-tomentose beneath, short-pubescent and greener above, ob- 

 long, obtuse, the linear segments slightly or not at all revolute ; cyme fastigi- 

 ate but rather open. (P. litoralis Rydb.) — Coast of N. H., Me., and the lower 

 St. Lawrence, L. Superior, and westw. June-Aug. 



§ 2. Styles filiform, not glandular at base ; inflorescence cymose. 



* Style terminal ; achenes glabrous ; stamens 20 ; herbaceous perennials, with 

 rather large yellow petals. 



^- Leaves palmate. 



++ Flowers in loose leafy cymes. 



7. P. arg^ntea L. (Silveky C.) Stems ascending or depressed, 1-5 dm. 

 long, paniculately branched at the summit, many-flowered, white-woolly; leaf- 

 lets 5, wedge-oblong, almost pinnatifld, entire toward the base, with revolute 

 margins, green above, white with silvery wool beneath ; calyx white-tomen- 

 tose. — Dry barren fields, etc., N. S. to Dak. and southw. to D. C. June- 

 Sept. (Eu.) 



8. P. INTERMEDIA L. Coarser ; the stont viprlght grayish-tomentulose stems 

 3-7 dm. high ; leaflets 3-6, the lateral and often the terminal deeply cleft, 

 oblanceolate to narrowly obovate, coarsely dentate, green above, grayisl^villous 

 and tomentulnse beneath; cyme somewhat leafy and diffuse ; calyx villous- 



