508 FLORA. 



style 8-10 mm. long. Low grounds, N. B. to Penn. and southward in the Alle- 

 ghanies, west to Minn, and to Kans. Blooms earlier than G. Canadense. May-July. 



4. Geum flavum (Porter) Bicknell. Cream-colored Avens. (I. F. f. 1946.) 

 Stem bristly-hairy below, erect, 4-10 dm. tall. Stipules large, often 2.5 cm. long, 

 foliaceous, dentate or lobed. Basal leaves mostly pinnately divided, sometimes 

 only lobed; lower stem-leaves usually also pinnately divided, the terminal segment 

 often elongated; upper stem-leaves sometimes entire; peduncles slender; head of 

 fruit about I cm. in diameter; receptacle bristly -villous; style 6-8 mm. long. In 

 woods, Conn, and N. Y. to Va. and E. Tenn. June-Aug. 



5. Geum urbanum L. European Yellow Avens. Stem 3-6 dm. high, 

 finely pubescent, divaricately branched. Basal leaves simple, reniform and 3 -lobed 

 or pinnately 3-7-foliolate, with rhomboid-cuneate leaflets, very rarely with smaller 

 ones interposed; stem-leaves mostly 3 -foliolate, with rhombic leaflets or the upper- 

 most simple; head of fruit 12-15 mm - m diameter; receptacle pubescent; style 

 5-7 mm. long, purplish. Introduced from Europe and established at Cam- 

 bridge, Mass. 



6. Geum macrophyllum VVilld. Large leaved Avens. (I. F. f. 1947. ) 

 Stout, erect, bristly-pubescent, 3-10 dm. high. Stipules broad, foliaceous; basal 

 leaves petioled, lyrate- pinnate, the terminal segment much the largest, reniform, 

 orbicular or cordate, dentate, 3-7- lobed; lateral leaflets 3-6, oval or obovate, with 

 smaller ones interspersed or borne on the petiole; stem-leaves short-petioled or ses- 

 sile; flowers several, short-peduncled; receptacle nearly glabrous; style 6-8 mm. 

 long; upper internode pubescent below. In low grounds, N. S. to Alaska, Br. 

 Col., N. Y. and Ore. May-July. 



7. Geum strictum Ait. Yellow Avens. (I. F. f. 1948.) Pubescent, 

 branched above, 6-15 dm. high. Stipules broad, foliaceous; basal leaves lyrate- 

 pinnate; leaflets 5-7, obovate, cuneate, dentate or lobed, with a few smaller ones 

 interspersed, the terminal one largest, broadly ovate or cuneate, or rarely orbic- 

 ular or reniform ; stem -leaves sessile or short-petioled, with 3-5 ovate or oblong 

 acute segments ; receptacle dow ny-pubescent; style 6-10 mm. long, the upper inter- 

 node hispid. In swamps or low grounds, Newf. to Br. Col., N. J., Penn., Mo. and 

 Ariz. Also in Asia. June-Aug. A hybrid with G. Canadense has been found in 

 eastern Penn. 



8. Geum rivale L. Purple or Water Avens. (I. F. f. 1940.) Erect, 

 simple or nearly so, pubescent, 3- 10 dm. high. Basal leaves lyrately and inter- 

 ruptedly pinnate, petioled, the later al segments generally few and small, the ter- 

 minal 1-3, much larger, all sharply and irregularly lobed and dentate; stem-leaves 

 distant, short-petioled or sessile, simple, or 3-foliolate ; flowers few, 20-25 mm. 

 broad; petals obovate, emarginate, abruptly narrowed into a claw; head of fruit 

 stalked in the calyx; style 6-8 mm. long. In swamps and low grounds, Newf. to 

 Br. Col., N. J., Penn., Mo. and Colo. Also in Europe and Asia. May-July. 



19. SIEVERSIA R. Br. 



Generally low perennial herbs with odd-pinnate leaves, mostly clustered at 

 the base. Flowers in cymes, or solitary, yellow or purplish. Calyx obconic or 

 hemispheric, 5-lobed and generally 5-bracteolate. Petals 5. Stamens numerous ; 

 filaments filiform. Carpels many, on a short hemispheric receptacle. Style 

 terminal, persistent, filiform, not jointed, pubescent or plumose, 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. 



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

 flowers yellow. 1. S. Peckii. 



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



2. S. cilia t a. 



I. Sieversia Peckii (Pursh) Rydb. Yellow Mountain Avens. (I. F f. 

 1941.) Pubescent with spreading hairs, or glabrate ; stem 1-6 dm. high, erect, 

 simple, 1-8-flowered at the summit Basal leaves petioled. lyrately pinnate, the 

 terminal segment very Large, reniform-orbicular, sharply and irregularly dentate and 

 slightly 3-5-lobed, 7-15 cm. broad; lateral leaflets small, few or none; flowers 



