438 POLYGONACE.E. (BUCKWHEAT FAMILY.) 



H- Fa/res smaller, one or more of them conspicuously grain-bearing. 

 ++ Indigenous; leaves not wavy, none heart-shaped, except the lowest ofu. 5. 



2. R. Britannica, L. (GREAT WATER-DOCK.) Tall arid stout (5 - 6 

 high) ; leaves oblong-lanceolate, rather acute at both ends, transversely veined, 

 and with obscurely erose-crenulate margins (the lowest, including the petiole, 

 1-2 long, the' middle rarely truncate or obscurely cordate at base); racemes 

 upright in a large compound pa-icle, nearly leafless ; whorls crowded ; pedicels 

 capillary, nodding, about twice the length of the fruiting calyx ; the valves orbicular 

 or round-ovate, very obtuse, obscurely heart-shaped at base,,jine/y reticulated, 

 entire or repaud-denticulate (2-3" broad), all graiu-beariug. (R. orbiculatus, 

 Grai/.} Wet places, N. Eug. to N. J., west to Minn, and Kan. 



3. R. altissimus, Wood. (PALE DOCK.) Rather tall (2-6 high); 

 leaves ovate- or ob/ong-lanceolate, acute, pale, thickish, obscurely veiny (the cau- 

 line 3-6' long, contracted at base into a short petiole); racemes spike-like" 

 and pauicled, nearly leafless; whorls crowded; pedicels nodding, shorter than 

 the fruiting calyx; valves broadly ovate or obscurely heart shaped, obtuse or 

 acutish, entire, loosely reticulated (about 2" broad), one with a conspicuous 

 grain, the others with a thickened midrib or naked. (11. Britannica, Gray; 

 not L.) Moist grounds, N. Y. and N. J. to Minn, and Kan. 



4. R. salicifolius, Weinmann. (WHITE DOCK.) Rather low (1-3 

 high); root white; /fares narrowly or linear-lanceolate, or the lowest oblong; 

 whorls much crowded; pedicels much shorter than the fruiting cali/x; valves 

 deltoid-ovate, obtusish or acutish (about 1" long), one, two or sometimes all 

 with a conspicuous often very large grain ; otherwise nearly as n. 3. Salt 

 marshes, from Xc\vf. to N. Eng., about the Great Lakes, and far westward. 



5 R. verticillatUS, L. (SWAMP DOCK.) Rather tall (3-5 high); 

 leaves lanceolate or oblong-lanceolate, rather obtuse, thickish, pale-green, the 

 lowest often heart-shaped at base ; racemes nearly leafless, elongated, louse, the 

 whorls crowded or the lower ones distant; fruit-bearing pedicels slender, club- 

 shaped, abrupt/// reflexed, 3-4 limes longer than the fruiting calyx ; valves dilated- 

 rhombo/d, obtusely somewhat pointed, strongly rugose-reticulated, each bearing a 

 very large grain. Wet swamps, common. 

 f t-i- Naturalized European weeds; lower leaves mostly heart-shaped at base. 



R. CRfsrrs, L (CURLED DOCK.) Smooth (3-4 high); leaves with 

 strong/ // wavy-curled margins, lanceolate, acute, the lower truncate or scarce] v 

 heart-shaped at base ; whorls crowded in prolonged icand-iike racemes, le<(flt-ss 

 ahove ; valves round-heart-shaped, obscure/,// denticulate or entire, mostly all grain- 

 bearing. In cultivated and waste ground, very common. A hybrid of this 

 with the next is reported from Mass., N. Y., and Md. 



R. OBTUsiFdLius, L. (BITTER DOCK.) Stem roughish ; lowest leaves 

 ovate-heart-shaped, obtuse, rather downy on the veins beneath, somewhat wavy- 

 margined, the upper oblong-lanceolate, acute ; whorls loose and distant ; valves 

 ovate-halberd-shaped, with same sharp awl-shaped teeth at base, strongly reticu- 

 lated, one of them principally grain-bearing. Fields, etc., common. 



R. sANGL'fxECS, L. Leaves oblong-lanceolate, often fiddle-shaped, wavy- 

 margined ; whorls distant, in long slender leaf ess spikes ; pedicels very short, 

 jointed at base ; valves narrowly oblong, obtuse, entire, one at least grain-bearing ; 

 veins of the leaf red, or green. Waste and cultivated ground. 



R. CONGLOMER\TUS, Murray. (SMALLER GREEN DOCK.) Like the last, 

 but leaves not fiddle-shaped, and panicle leafy ; pedicels short, jointed below 

 the middle ; valves acutish, all grain-bearing. Moist places. 



