ROSACEAE. 



VOL. II. 



i. Sibbaldiopsis tridentata (Soland.) Rvdb. Three- 

 toothed Cinquefoil. Fig. 2258. 



Potentilla tridentata Soland. in Ait. Hort. Kew. 2: 216. 1789. 



Sibbaldiopsis tridentata Rydb. Mem. Dep. Bot. Col. Univ. 2: 

 187. 1898. 



Tufted, woody at the base, much branched, branches 

 erect, i'-i2' high, pubescent with appressed hairs. Stip- 

 ules lanceolate, entire ; leaves mostly petioled, 3-foliolate ; 

 leaflets of the lower one oblanceolate, 3-toothed or some- 

 times 2-5-toothed at the obtuse apex, cuneate at the base, 

 coriaceous, dark green and shining above, pale and mi- 

 nutely pubescent beneath, i'-i' long; upper leaflets lin- 

 ear or oblong, often acute and entire ; flowers 1-6, in a ter- 

 minal cyme, white, 3"-s" broad ; bractlets shorter and 

 narrower than the ovate acute calyx-lobes, which are 

 shorter than the obovate-oval petals. 



In rocky places, especially on mountains, Greenland to New 

 Jersey, on the higher southern Alleghanies. shores of Lake 

 Superior, and west to Manitoba. Mountain five-finger. June- 

 Aug. Recorded from Scotland, apparently erroneously. 



14. DASIPHORA Raf. Aut. Bot. 167. 1838. 



Shrubs with firm unequally pinnate leaves, scarious sheathing stipules, and large mostly 

 yellow flowers. Calyx-tube saucer-shaped. Bractlets, calyx-lobes and petals 5. Petals 

 rounded,' not clawed. Stamens about 25, in 5 clusters around the hemispheric receptacle; 

 filaments filiform; anthers flat. Pistils numerous on the receptacle; style club-shaped, glan- 

 dular above, lateral; stigmas lobed. Achenes densely covered with long straight hairs. Seeds 

 amphitropous, ascending. [Greek, bearing hairs, referring to the hairy achenes and receptacle.] 



About five species, natives of the north temperate and arctic zones. Only the following typical 

 one occurs in North America. 



i. Dasiphora fruticosa (L.) Rydb. Shrubby 

 Cinquefoil. Fig. 2259. 



Potentilla fruticosa L. Sp. PI. 495. 1753. 

 Dasiphora riparia Raf. Aut. Bot. 167. 1838. 

 Dasiphora fruticosa Rydb. Mem. Dep. Bot. Col. Univ. 2 : 

 188. 1898. 



Shrubby, much branched, stems erect or ascending, 

 very leafy, 6'~4 high, the bark shreddy. Stipules 

 ovate-lanceolate, membranous, acute or acuminate, en- 

 tire; leaflets 5-7, oblong, linear-oblong, or somewhat 

 oblanceolate, entire, acute or acutish at each end, 6"-i2" 

 long, silky-pubescent, the margins revolute ; flowers 

 terminal, densely cymose, or solitary, bright yellow, 8"- 

 15" broad; petals nearly orbicular, exceeding the ovate 

 calyx-lobes and bractlets; stamens 15-20; -style lateral, 

 filiform; achenes, disk and receptacle long-hairy. 



In swamps or moist rocky places, Labrador and Green- 

 land to Alaska, south to New Jersey, Illinois, Minnesota, in 

 the Rocky Mountains to Arizona, and in the Sierra Nevada 

 to California. Also in northern Europe and Asia. Called 

 also hardback and prairie weed. A troublesome bushy weed 

 in northern New England. June-Sept. 



15. DRYMOCALLIS Fourr. Ann. Soc. Linn. Lyon II. 16: 371. 1868. 

 [BOOTTIA Bigel. Fl. Bost. Ed. 2, 206. 1826. Not Adans. 1763.] 



Perennial glandular herbs, with unequally pinnate leaves and cymose flowers. Calyx- 

 tube short and broad. Bractlets, calyx-lobes and petals 5. Petals neither clawed nor emar- 

 ginate. Stamens 20-30, in 5 clusters on the thickened margin of the 5-angled disc ; filaments 

 filiform; anthers flat. Receptacle hemispheric or somewhat elongated, bearing numerous 

 pistils. Style nearly basal; stigma minute. Seed orthotropous, ascending. [Greek, woodland 

 beauty.] 



About 30 species, natives of the north temperate and subarctic zone. Besides the following, 

 some 25 others occur in western North America. Type species : DrymocalHs rubricaulis Fourr. 



