ROSE FAMILY 121 



XI. GEUM L. 



Erect perennial herbs. Basal leaves crowded, pinnate, with. 

 a very large terminal leaflet. Flowers and fruit nmch as in 

 Potentilla, but the akenes tailed with the remains of the styles. 



B. Fl. species 6 (Sieversia). 



1. G. canadense Jacq. White Avens. Stem erect, branching 

 above, smooth or finely downy, 18-24 in. high. Basal leaves pin- 

 nate, or the earliest simple and rounded, long-petioled, serrate or 

 dentate ; terminal lobe larger than the lateral lobes ; stem leaves 

 short-petioled, 2-5-lobed or -parted. Flowers on slender peduncles. 

 Petals white, not longer than the sepals. Styles jointed near the 

 middle, the lower portion persistent and hooked. Ovaries and recep- 

 tacle hairy ; head of fruit globose. Rich woods.* 



2. G. virginianum L. Stem 2-3 ft. high, stout and bristly-hairy. 

 Lower leaves and basal leaves pinnate, varying greatly; upper leaves 

 mostly of 3 leaflets or 3-parted. Petals white or pale yellow, small, 

 shorter than the calyx lobes. Heads of fruit large, on stout, hairy 

 peduncles; the receptacle nearly or quite smooth. Borders of woods 

 and damp thickets. 



3. G. macrophyllum Willd. Lakge-Leaved Avens. Stem stout, 

 erect, bristly-hairy, 1-3 ft. high. Basal leaves lyrate -pinnate, the 

 terminal portion much the largest, kidney-shaped or heart-shaped; 

 lateral leaflets 3-6, with smaller ones between. Flowers terminal, 

 yellow. Style ^| in. long, downy below. In low grounds. 



4. G. rivale L. Water Avens, Purple Avens, Chocolate 

 Root. Stem lJ-2 ft. high, somewhat downy or hairy, simple or 

 nearly so. Basal leaves lyrate and somewhat pinnate, with the divi- 

 sions irregular ; stem leaves few, of 3 leaflets or 3-lobed. Flowers 

 rather large. Petals purplish-yellow, as long as the brownish-purple 

 calyx lobes. Styles long, purplish; stigmas thread-like, feathered 

 with soft hairs, especially in fruit. Wet meadows. 



5. G. triflorum Pursh. Long-Plumed Purple Avens. Softly 

 downy, scapes 6-18 in. high. Basal leaves petioled, tufted, pinnate; 

 the larger leaflets obovate or Oval, cut-toothed, with many smaller 

 ones between. Flowers 3-8, light purple. Styles 1^-2 in. long. In 

 dry or rocky soil. 



XII. RUBUS L. 



Mostly prickly shrubs, producing runners. Leaves alternate, 

 simple or compound ; stipules united to the petiole. Flowers in 

 terminal and axillary clusters, rarely solitary, white (in one 

 American species (No. 3) purple rose color). Calyx hypogynons, 



