178 ROSACES. POTENTILLA. 



leaflets 5-10 pairs, scattered on the slender rachis, 3-5-parted with oblong 

 segments, 2-4 lines long: flowers on slender pedicels in a very diffuse 

 panicle; calyx nearly 2 lines long, broadly campanulate; bractlets lanceo- 

 late, nearly equalling the lanceolate acuminate calyx-lobes; petals white, 

 vjry broadly obovate, 2 lines long, nearly as broad, exceeding the calyx; 

 stamens 15-20 ; carpels numerous ; achenes rugose. On sandy plains, 

 Washington, at Wallula, to California. 



-- +- Leaves digitately 5-7-foliolate. 



P. gracilis Dougl. Ho'ok. Bot. Mag. t. 2984. Villous and more or less 

 tomentose: stems erect, 2-3 feet high: stipules ovate or lanceolate, often 

 long acuminate, entire or sub incised: leaflets mostly 5-7, rarely 3, cune- 

 ate-oblong, obtuse, incisely serrate or pinnatifid, white-tomentose beneath, 

 green and subvillous or appressed-silky above, 1-3 inches long: flowers in 

 a loose subfastigiate cyme, the pedicles at length elongated and slender; 

 bractlets narrow, lanceolate, shorter than the broad acute or lanceolate 

 sepals ; petals broadlv obcordate, 3-4 lines long, exceeding the calyx : 

 achenes very numerous, oblong, dark brown. Common on dry praries 

 and plains, Brit. Columbia to California and the Rocky Mountains. 



P. flabelliformisLehm. 1. c. 12. Appre^sed-silky and more or less 

 white tomentose: stems rather stout, 2-4 feet high, erect, branched above; 

 leaves 5-9-foliolate, the lower long-petiolate; the upper sessile or nearly so'; 

 stipules linear-lanceolate, long-acuminate, mostly 3-toothed, 1-2 inches 

 long ; leaflets linear-oblong in outline, 2-4 inches long, deeply pinnatifid 

 with linear-lanceolate segments, white-tomentose beneath, green and more 

 or less silky above : flowers in ample flat- topped cymes ; bractlets lanceo- 

 late, 2-3 lines Ion/, about half as long as the broad triangular-ovate acute 

 sepals; petals bright yellow, orbicular or brojadly obovate, but little ex- 

 ceeding the sepals. Plains of Eastern Oregon and Washington to the 

 Saskatchewan. 



+----- LOW T , arctic or alpine species : densely villous or subglabrous : ; 

 leaves ternate: flowers few, in a loose cyme, or solitary: the obcordate 

 petals exceeding the calyx : carpels 10-40. 



P. villosa Pall. Pursh Fl. 353. Densely white-tomentose : stems 6-1? 

 inches high : stipules large, oblong, acuminate ; leaflets cuneate-obovate, 

 6-15 lines long, sessile, coarsely incised-serrate : flowers few or solitary, 

 very large : bractlets ovate, obtuse, shorter than the ovate, acute sepals; 

 petals obcordate, 3-6 lines long, exceeding the sepals. On Mount Rainier 

 Washington to Alaska. 



P. flabellifolia Hook. T. & G. Fl. i, 442. P. gelida American authors 

 not Meyer. Nearly glabrous or with scanty minute villous pubescence : 

 stems slender, erect or spreading, 6-10 inches long, 1-3-flowered : stipules 

 oval or oblong, mostly entire : leaflets flabelliform, 6-9 lines long, rounded 

 at the apex and incisely 7-9-toothed, entire at base, the middle leaflet 

 shortly patiolulate: bractlets oblong, obtuse, 3 lines long, equalling the 

 triangular, acute, sepals; petals broadly obovate, 4-6 lines long, bright 

 yellow carpels numerous. Wet banks and meadows of the highest 

 mountains, Oregon to Alaska. 



P. brevifolia Nutt. T. & G. Fl. i, 442. Minutely glandular-pubescent, 

 the calyx very sparingly villous : stems decumbent or ascending, 2-3 inches 

 long: stipules ovate, entire; leaflets suborbicular, 2-3 lines long, 2--3-lobed 

 arid crenately toothed, the middle one petioiulate : bractlets acute shorter 

 than the acute sepals : petals obovate, scarcely exceeding the calyx; style 

 attached below the apex of the ovary. Alpine peaks of Oregon. 



* * Style attached below the middle of the ovary : carpels on short . , 

 stipes: receptacle densely villous: disk not thickened : more or less 

 woody perennials. 



