57 



67a. Leaflets laciniate or deeply lobed (flowers pink or purple, early 



summer) 68. 

 67b. Leaflets merely toothed 69. 



68a. Stem-leaves few, small and opposite (2 4 dm. tall) 



Purple AveiiSj Geum triflorum. 

 68b. Stem-leaves large and alternate (5 20 dm. tall) 



Queen of the Prairie, Filipendula rubra. 



69a. Individual flowers small, not exceeding 6 mm. across, in large 



clusters or spikes 70. 

 69b. Individual flowers more than 10 mm. wide, in few-flqwered 



clusters (Cinquefoil) 71. 



70a. Flowers in dense spikes (5 15 dm. high; late summer) 



Burnet, Sang-uisorba canadeusis. 

 70b. Flowers in panicles Sorbaria, Sorbaria sorbifolia. 



71a. Flowers red or purple (3 6 dm. high; summer) 



Marsh Cinquefoil, Potentilla palustris. 

 71b. Flowers white (5 10 dm. high; early summer) 



Cinquefoil, Potentilla argiita. 



72a. Pistils 5 (5 10 dm. high; flowers white or pink, early sum- 

 mer) 73. 



72b. Pistils 10, in a ring (flowers pink or purple) 68b. 

 72c. Pistils numerous, in a head or close group 74. 

 73a. Stipules linear or 'subulate, 5 8 mm. long 



Bowman's Hoot, Gillenia trifoliata, 

 73b. Stipules leaf-like, 10 25 mm. long, serrate 



American Ipecac, Gillenia stipulate. 

 74a. Flowers red or purple 75. 

 74b. Flowers white 76. 



75a. Leaflets sharply and irregularly toothed or lobed; petals erect, 

 narrowed at the base (3 9 dm. high; early summer) 



Purple Arens, Geum rivale. 



75b. Leaflets finely and regularly toothed, oblong; petals spreading 

 71a. 



76a. Leaflets entire below, 3-toothed at the apex (1 3 dm. high; 

 summer) Cinquefoil, Potentilla tridentata. 



76b. Leaflets toothed all around the margin 77. 



77a. Leaves all trifoliate (25 dm. high; late spring) 17b. 

 77b. Some of the upper leaves merely lobed or dentate (5 8 dm. 

 high) (Avens) 78. 



78a. Stem bristly-hairy (early summer) 



Ay ens, Geum virginianum. 

 78b. Stem softly and finely pubescent (summer) 



Avens, Geum cansdense. 



