26 



5a. The projecting wings of the fruiting calyx (known as valves) 

 with sharp slender teeth Bitter Dock, Rumex obtnsifolins. 



5b. Valves entire or finely dentate, but without sharp slender teeth 

 6. 



6a. Pedicels straight, thickened toward the end, all regularly 

 deflexed, 3 4 times longer than the fruiting calyx 



Swamp Dock, Rumex yerticillatus. 

 6b. Pedicels slender, flexuous, spreading 7. 



7a. Leaves flat or nearly so 8. 



7b. Leaves with strongly crisped or wavy-curled margins; plants 

 usually of cultivated grounds or waste places (510 dm., sum- 

 mer) 12. 



8a. With grain-like tubercles on all 3 valves of the fruit 9. 

 8b. With grain-like tubercles on only one valve, or entirely lack- 

 ing 10. 



9a. Valves broadly cordate, finely toothed 



Water Dock, Rumex brittanica. 

 9b. Valves triangular-ovate, entire or nearly so 



Dock, Rumex mexicamis. 



lOa. Valves oblong Bloody Dock, Rumex sanguineus. 



lOb. Valves broadly heart-shape 11. 



lla. Grain-like tubercle less than half as long as the valve 



Patience Dock, Rumex patientia. 

 lib. Grain-like tubercle more than half as long as the valve 



Tall Dock, Rumex altissiiiius. 



12a. The grain-like tubercle on the valves of the fruit broadly 

 ellipsoid, with rounded apex Sour Dock, Rumex crispus. 



12b. Tubercle ovoid with tapering apex 



Sour Dock, Rumex elongatus. 



13a. Flowers inconspicuous, in small axillary clusters; leaves jointed 



at the base (Knotweed) 14. 

 13b. Flowers more or less conspicuous, in obvious spikes or racemes 



which terminate the stems or branches, or arise from the 



axils of the upper leaves 18. 



14a. Leaves sharply folded lengthwise (1 4 dm. tall) 



Knotweed, Polygonum tenue. 



14b. Leaves flat or nearly so 15. 



15a. The small sepals pink or white at the margin (stems prostrate 

 or ascending) 16. 



15b. Sepals greenish or yellowish throughout (stems erect or ascend- 

 ing) 17. 



16a. Leaves thin; common weed of dooryards and gardens 



Knotweed, Polygonum aviculare. 

 16b. Leaves thick and fleshy; a plant of sandy shores 



Knotweed, Polygonum aviculare var. littorale. 



