46 ROSACEAE 



from Winneshiek county. (R. americanus ( Pers. ) Britton. ) 



R. Villosus Ait. Common Blackberry. A perennial shrub, branched, gland- 

 ular-pubescent; stems 3-6 feet high, furrowed, erector reclining, armed with 

 stout recurved prickles; stipules linear or lanceolate: leaflets 3 or 5, ovate or 

 ovate-oblong, coarsely serrate, pubescent beneath; flowers numerous, racemose, 

 petals spreading, much exceding the sepals; fruit black. Thickets; May- 

 June, fruit ripe July-August; common. 



R. baileycmus Britton. Intermediate; stem trailing or ascending, spar- 

 ingly prickly; upper leaves unifoliate; leaflets ovate or oval, pubescent, base 

 rounded or cordate. Forms from Decatur county referred to this species. 



R. canadensis L. Dewberry. Shrubby, trailing, somewhat prickly; bracnh- 

 es 4-12 inches long, erect or ascending; leaflets 3 or pedately 5-7, oval or ovate- 

 lanceolate, thin, cut-serrate; fruit black. Dry soil, fields and woods; April- 

 May, fruit ripe June-July; frequent; Clinton, Muscatine, Johnson, Henry, Ap- 

 panoose, and Decatur counties. The variety invlsui Bailey, is stouter, partly 

 ascending, leaflets larger, coarsely dentate, peduncles elongated. Dry soil; 

 woods; Decatur county. 



GEUM L. Perennial herbs, with odd-pinnate or pinnatifid leaves, and sol- 

 itary or cymose-corymbose flowers. Calyx deeply 5-cleft, usually bracteolate 

 Petals 5, exceeding the calyx, Stamens many, inserted on a disk at the base 

 of the calyx. Achenes many. 



G. album Gmel. Stems 1-2% feet high, glabrate to softly pubescent; stip- 

 ules small, dentate; basal leaves long-petioled, 3-foliolate or of 3-5 pinnately 

 divided divisions, dentate, somewhat lobed; cauline-leaves short-petioled or 

 sessile, 3-5-lobed or divided; flowers white;' sepals lanceolate, reflexed; petals 

 obovate, equalling or shorter than the sepals; head of fruit globose-ovoid, 

 receptacle densely bristly-hirsute. Open woods, borders; June-August; fre- 

 quent. ( G cnnadense Jacq.) 



G. virginianum L. Similar to the preceding, stouter, bristly-hairy: pe- 

 duncles pubescent with reflexed hairs; sepals reflexed; petals creamy-white, 

 spreading, shorter than the sepals; receptacle glabrous or nearly so; style pu- 

 bescent below. Low prairies, woods; June-July; infrequent; Fayette, Benton, 

 Muscatine, Johnson, Decatur, Fremont, Story, Dickinson, and Lyon counties. 



G. macrcphyllum Willd. Stem stout, 1-3 feet high, bristly-hairy: stip- 

 ules broad, foliaceous; basal leaves long-petioled, lyrately and interruptedly 

 pinnate, terminal segment large, reniform to cordate, 3-7-lobed, lateral leafl- 

 ets oval or obovate; stem-leaves short-petioled or sessile, lateral leaflets small, 

 terminal roundish, 3-cleft, lobes cuneate-ovate, all leaflets dentate; flowers 

 terminal, yellow; sepals reflexed, acute; petals obovate, exceeding the sepals; 

 receptacle nearly glabrous; style pubescent below. Low grounds; May-July; 

 infrequent: Winneshiek, Clinton, Winnebago, Cerro Gordo, and Pottawatto- 

 mie counties. 



G. strictum Ait. Similar to the preceding, pubescent; basal leaves inter- 

 ruptedly pinnate, terminal leaflet ovate or cuneate; stem-leaves of 3-5 rhom- 

 bic-ovate or oblong acute leaflets; receptacle downy. Low grounds; June-Au- 

 gust; reported from Fayette county. 



G. triflorum Pursh. Hairy, scapose, 4-14 inches high; root-leaves inter- 

 ruptedly pinnate, divisions laciniate, scape-leaves 2 pairs, opposite; peduncles 

 elongated, bractlets linear, exceeding the erect purple calyx-lobes; petals pur- 

 ple; styles long filiform, plumose in fruit. Prairies and open upland woods; 

 May-June; infrequent; Winneshiek, Allamakee, and Fayette counties. ( O. oil- 



