GENUS 25. 



ROSE FAMILY. 



273 



2. Sieversia ciliata (Pursh) Rydb. Longplumed Purple Avens. Prairie-smoke. 



Fig. 2282. 



Geum ciliatum Pursh, Fl. Am. Sept. 352. 1814. 

 Geum triflorum Pursh, loc. cit. 736. 1814. 

 Sieversia ciliata Rydb. in Britton, Man. 509. 1891. 



Softly pubescent with short or spreading hairs, sea- 

 pose; scape 6'-i8' high, simple, 3-8-flowered at the 

 summit. Basal leaves tufted, petioled, interruptedly 

 pinnate with many small leaflets interspersed among 

 the obovate or oval laciniate numerous larger ones ; 

 leaves of the scape 2 opposite small sessile pairs, the 

 elongated peduncles commonly bearing another simi- 

 lar pair; flowers several, showy, 6"-g" broad; bractlets 

 linear, slightly exceeding the purple lanceolate acute 

 erect calyx-lobes; petals purplish, erect, about equal- 

 ling the bractlets; head of fruit sessile; style filiform, 

 i '-2' long and strongly plumose throughout in fruit, 

 not jointed. 



In dry or rocky soil, Newfoundland and Labrador to 

 New York, British Columbia, Illinois, Iowa, North Dakota, 

 and in the Rocky Mountains to Arizona. Races differ in 

 pubescence, and in the shape and toothing of the leaflets. 

 Johnny smokers. May-July. 



26. DRYAS L. Sp. PI. 501. 1753. 



Low tufted herbaceous shrubs, with simple petioled stipulate leaves white-canescent 

 beneath, and white or yellow, rather large perfect solitary flowers on slender scapes. Calyx 

 persistent, not bracted, its tube concave, glandular-hirsute, 8-9-lobed. Petals 8 or 9, obovate, 

 larger than the calyx-lobes. Stamens , inserted on the throat of the calyx; filaments subu- 

 late. Carpels o, sessile, inserted on the dry receptacle; style terminal, persistent, elongated 

 and plumose in fruit. Seed ascending, its testa membranous. [Name Latin, a wood- 

 nymph.] 



Three species, natives of the cold-temperate and arctic parts of the north temperate zone. Type 

 species : Dryas octopetala L. 



Flowers white ; sepals linear. 



Leaves oval or ovate, coarsely crenate. i. D. octopetala. 



Leaves ovate, or ovate-lanceolate, subcordate, entire or nearly so. 2. D. integrifolia. 



Flowers yellow ; sepals ovate ; leaves crenate. 3. D. Drummondii. 



i. Dryas octopetala L. White 

 Mountain Avens. Fig. 2284. 



Dryas octopetala L. Sp. PI. 501. 1753. 



Dryas chamaedrifolia Pers. Syn. 2: 57. 1807. 



Stems prostrate, woody at the base, 

 branched, 3'-6' long. Stipules linear, ad- 

 nate to the petiole ; leaves oval or ovate, 

 coarsely crenate all around, green and gla- 

 brous above, densely white-canescent be- 

 neath, generally obtuse at each end, i'-i' 

 long; scape terminal, erect, i'-s' long, 

 pubescent; flower white, about i' broad; 

 sepals linear, acute or acutish, glandular- 

 pubescent, persistent; style about i' long, 

 plumose and conspicuous in fruit. 



Labrador and Greenland and throughout 

 arctic America, south in the Rocky Mountains 

 to Utah, Colorado, and to British Columbia. 

 Also in arctic and alpine Europe and Asia. 

 Wild betony. June-Aug. 



