ROSACE.*:, (rose family.) 159 



cyme strict and rather close; stamens mostly 30, on a thick pjlandnlar disk. — 

 Rocky hills, N. Brnnswick to N. J., Minn., Kan., and wi-stwnrd. 



* * Stijle terminal; Jlotvers small, i/clluw ; Itares jn'niiale or tcrnate. 

 •4- Annual or biennial ; leajlets incisely serrate, not whilc-tomentose ; stamens 5 - 20. 



2. P. Norvegica, L. Stout, erect, hirsute {i-2° hi^r],) ; leaves temate ; 

 leaflets obovate or ohlong-lanceolate ; ci/rne rather close, leafy ; cali/x lanje ; 

 stamens 15 (rarely 20). — Lab. to N. J., west to Minn, and Kan. (Kn.) 



3. P. riv^lis, Nutt. More slender and branched, softly villous; leaves 

 pinnate, with tiro pairs of closely approximate leajlets, or a single )»air and the 

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

 dijfuse, less leafy; calyx small; ])etals minute; stanieus 10-20 (rarely 5). — 

 Neb. to Mo. and N. Mex., and westward. 



Var. millegrana, Watson. Leaves all ternate ; stems erect, or weak and 

 ascending; achenes often small and light-colored. — Minn, to Mo., N. Mex., 

 and westward. 



Var. pentandra, Watson. Leaves ternate, the lateral leaflets of the lower 

 leaves parted nearly to the base ; stamens 5, opposite to the sepals. — Iowa, 

 Mo., and Ark. 



4. P. suplna, L. Stems decumbent at base or erect, often stout, leafy, 

 subrillous ; leaflets pinnately 5-11, obovate or oblong; cyme loose, leafy ; sta- 

 mens 20; achenes strongly gibbous on the ventral side. (P. paradoxa, Nutt.) — 

 Minn, to Mo., and westward; also eastward along the Great Lakes. — Var. 

 NicoLLETii, AVatscni. Slender; leaflets mostly but 3; inflorescence mucli 

 elongated, leafy, and falsely racemose. — Devil's Lake, Minn. 



•*- 4- Herbaceous perennials, more or less white-tomentose ; leaflets incisely pin- 

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



5. P. Pennsylvanica, L. Stems erect or decumbent at base (}-2° 

 high); leaflets 5-9, white-tomentose beneath, short-pubescent and greener 

 above, oblong, obtuse, the linear segments slightly or not at all rev^lute ; 

 cyme fastigiate but rather open. — Coast of Maine, N. IL, and the lower St. 

 Lawrence, L. Superior, and westward. July, Aug. — Var. strig6sa, Lehm. 

 Stems 6-12' higli ; silky-tomentose throughout ; leaflets deeply pinnatifid, the 

 margins of the narrow lobes revolute; cyme short and close. — Minn, and 

 westward. 



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



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



rather large yellow flowers. 



•»- Leaves pinnate. 



6. P. Hippikna, Lehm. Densely white-tomentose and silky throughout, 

 the upper surface of the leaves a little darker; stems ascending (1 - 1.^ Idgh), 

 slender, branching above into a diffuse cyme; leaflets 5 - 11 , cuneate-oblong, 

 incisely toothed at least toward the apex, diminishing uniformly down the petiole ; 

 carpels 10-30. — N. W. Minn., and westward. 



7. P. efiftisa, Dougl. Tomentose throughout, with scattered villous liairs ; 

 stems ascending (4-12' high), diffusely branched above; leaflets 5-11, inter- 

 ruptedly pinnate, the alternate ones smaller, cuneate-oblong, coarsely-incised-ser- 

 rate or deiitate ; carpels 10. — W. Minn, to Mont. audCol. 



