272 



ROSACEAE. 



Vol. II. 



7. Geum rivale L. Purple or Water Avens. Fig. 2281. 



Geum rivale L. Sp. PI, 501. 1753. 



Erect, simple or nearly so, pubescent, i°-3° high. 

 Basal leaves lyrately and interruptedly pinnate, 

 petioled, the lateral segments generally few and 

 small, the terminal 1-3, much larger, all sharply and 

 irregularly lobed and dentate ; stem-leaves distant, 

 short-petioled or sessile, simple, or 3-foliolate; flow- 

 ers few, terminal, purple or purplish, nodding, g"-i2" 

 broad; petals obovate, emarginate, abruptly narrowed 

 into a claw; calyx-lobes spreading, purple; head of 

 fruit stalked in the calyx; achenes pubescent; style 

 jointed, plumose below, 3"-4" long. 



In swamps and low grounds, Newfoundland to British 

 Columbia, New Jersey, Pennsylvania, Michigan and 

 Colorado. Also in northern Europe and Asia. Indian- 

 chocolate. Evan's- or chocolate-root. Drooping avens. 

 Maiden-hair. Throatwort. Throat-root. Cure-all. May- 

 July. 



Geum pulchrum Fernald, similar, but with smaller 

 clear yellow flowers, found in Quebec, Vermont and Alberta, is presumably a hybrid of this species 

 with G. macrophyllum Willd. 



25. SIEVERSIA Willd. Mag. Gesell. Naturfr. Berlin 5: 397. 1811. 



Mostly low perennial herbs, with odd-pinnate leaves. Flowers in cymes, or solitary, 

 yellow or purplish. Calyx obconic or hemispheric, S-lobed and generally S-bracteolate. 

 Petals 5. Stamens numerous; filaments filiform. Carpels many, on a short hemispheric 

 receptacle. Style terminal, persistent, filiform, pubescent or plumose, not jointed, generally 

 elongating in fruit. Seeds erect, basal. [Named in honor of Sievers.] 



About 15 species of temperate alpine or arctic regions ; besides the following five or six others 

 occur in western and arctic North America. Type species : Dryas anemonoides Pall. 



Leaflets 1-9, terminal one of the basal leaves orbicular-reniform ; style plumose below ; flowers 



yellow. I. 5'. Peckii. 



Leaflets numerous, cuneate ; style plumose throughout ; flowers light purple. 2. S. ciliata. 



I. Sieversia Peckii (Pursh ) Rydb. Yellow Mountain Avens. Fig. 2283. 



Geum Peckii Pursh. Fl. Am. Sept. 352. 1814. 



Geum radiatum var. Peckii A. Gray, Man. Ed. 2, 117. 1856. 



Sieversia Peckii Rydb. in Britton, Man. 508. 1901. 



Sparingly pubescent or glabrate, stem 6-2° high, erect, 

 simple, i-8-flowered at the summit. Basal leaves tufted, 

 petioled, lyrately pinnate, the terminal segment very large, 

 reniform-orbicular, sharply and irregularly dentate and 

 slightly 3-5-lobed, 3'-6' broad; lateral leaflets few or 

 none; flowers yellow, 6"-i2" broad; bractlets of the 

 calyx much shorter than the erect lanceolate calyx- 

 lobes; petals obovate, often emarginate, spreading; 

 style filiform, plumose below, naked above, 6"-8" long, 

 not jointed. 



White Mountains of New Hampshire ; Mt. Kineo, Maine. 

 July-Aug. 



Sieversia radiata (Michx.) Greene, of the high moun- 

 tains of North Carolina, to which this was referred in our 

 first edition, differs in being hirsute-pubescent with spread- 

 ing hairs, and in its broader ovate calyx-lobes. 



