29a. Stem unbranched, erect, bearing a single terminal raceme 

 (5 30 cm. high; flowers pink). Bistort, Polygonum viYiparum. 

 29b. Stem branched, submerged in water or creeping on muddy 

 shores (flowers pink) 



Water Smartweed, Polygonum amphibium. 



30a. Raceme single or two; leaves broadly ovate-lanceolate, 



about 3 times as long as wide 



Smartweed, Polygonum muhlenbergii. 

 30b. Racemes numerous; leaves lanceolate, 4 6 times as long 



as wide 31. 



31a. Racemes drooping or nodding at the tip 



Smartweed, Polygonum lapathifolium. 

 31b. Racemes erect Smartweed, Polygonum peiinsylvanicum. 



32a. Leaves arrow-shape, the basal lobes pointing backward 



Tear-thumb, Polygonum sagittatum. 



32b. Leaves halberd-shape, the basal lobes pointing sidewise 



Tear-thumb, Polygonum arifolium. 



33a. The three outer sepals becoming conspicuously winged in fruit 

 (False Buckwheat) 34. 



33b. The sepals all unchanged in fruit, except in size (Black Bind- 

 weed) 35. 



34a. Wings of the fruit with wavy-curled margins 



False Buckwheat, Polygxmum scandens. 

 34b. Wings of the fruit .flat 



False Buckwheat, Polygonum dumetorum. 



35a. Leaf-sheaths with a ring of bristles at the base 



Black Bindweed, Polygonum cilinode. 

 35b. Leaf-sheaths without a ring of bristles 



Black Bindweed, Polygonum convolvulus. 



CHENOPODIACEAE, the Goosefoot Family 



Herbs, with inconspicuous greenish or reddish flowers without 

 petals, in summer. 



la. Leaves linear or nearly so, entire 2. 



Ib. Leaves of a broader shape, usually toothed or lobed 5. 



2a. Leaves rather stiff, narrowly linear or thread-like, with 

 spine-like tips Russian Thistle, Salsola kali var. tenuifolia. 



2b. Leaves soft, not spine-like 3. 



3a. Widely branched, rather diffuse, 1 5 dm. tall; plant of the shore 

 of the Great Lakes Bug-seed, Corispermum hyssopifolium. 

 3b. Erect plants with ascending branches 4. 



4a. Leaves glabrous (36 dm. tall) 



Goosefoot, Chenopodium leptophyllum. 



4b. Leaves minutely ciliate on the margin (bushy branched, 

 5 10 dm. tall) Kochia, Kochia scoparia. 



