20a. Flowers on slender pedicels, forming a loose raceme; leaves linear, jointed at the base (1-3 dm. high; flowers pink or white; chiefly near the Great Lakes) =Jointweed, Polygonella articulata.=

20b. Flowers sessile or nearly so, forming a spike or spike-like raceme --21.

21a. Stipular sheaths at the base of the leaves ciliate at their upper margin --22.

21b. Stipular sheaths not ciliate at the upper margin --28.

22a. Sheaths with spreading borders --23.

22b. Sheaths without a spreading border, appressed to the stem (Smartweed) --24.

23a. Leaves ovate, ac.u.minate; stem erect (1-2 m. high; flowers pink) =Prince's Feather, Polygonum orientate.=

23b. Leaves oblong, obtuse or subacute; spreading or ascending plant of wet soil =Water Smartweed, Polygonum amphibium var. hartwrightii.=

24a. Peduncles with glandular hairs (5-15 dm. high) =Smartweed, Polygonum careyi.=

24b. Peduncles not glandular (1-8 dm. high) (Smartweed) --25.

25a. Sepals beset with minute black dots --26.

25b. Sepals white, pink, or red, not black-dotted --27.

26a. Racemes drooping or nodding at the tip; achene dull-colored =Smartweed, Polygonum hydropiper.=

26b. Racemes erect; achene smooth and shining =Smartweed, Polygonum acre.=

27a. Sheaths smooth; leaves usually with a dark spot near the base =Smartweed, Polygonum persicaria.=

27b. Sheaths hairy; leaves not dark-spotted =Smartweed, Polygonum hydropiperoides.=

28a. Leaves obtuse or somewhat acute at the apex --29.

28b. Leaves ac.u.minate at the apex (5-15 dm. high; flowers white to pink) (Smartweed) --30.

29a. Stem unbranched, erect, bearing a single terminal raceme (5-30 cm.

high; flowers pink) =Bistort, Polygonum viviparum.=

29b. Stem branched, submerged in water or creeping on muddy sh.o.r.es (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 pennsylvanic.u.m.=

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 Bindweed) --35.

34a. Wings of the fruit with wavy-curled margins =False Buckwheat, Polygonum 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.

1a. Leaves linear or nearly so, entire --2.

1b. 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 sh.o.r.e of the Great Lakes =Bug-seed, Corispermum hyssopifolium.=

3b. Erect plants with ascending branches --4.

4a. Leaves glabrous (3-6 dm. tall) =Goosefoot, Chenopodium leptophyllum.=

4b. Leaves minutely ciliate on the margin (bushy branched, 5-10 dm.

tall) =Kochia, Kochia scoparia.=

5a. Princ.i.p.al leaves with a broad truncate, rounded, or hastate base --6.

5b. Princ.i.p.al leaves narrowed to the base --12.

6a. Leaves broadly ovate, with 1-4 large sharp projecting teeth on each side =Goosefoot, Chenopodium hybridum.=

6b. Leaves hastate or triangular-ovate, entire or with many teeth --7.

7a. Leaves entire or merely undulate --8.