438 roLYGONACE^. (buckwheat family.) 



1- Valves smaller, one or more of them conspicuously grain-bearing. 

 ** Indigenous ; leaves not wavi/, none heart-shaped, except the lowest ofn. 5. 



2. R. Britannica, L. (Great Water-Dock.) Tall and 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^Jcle, nearly leafless ; whorls crowded ; pedicels 

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

 or round-ovate, xG^vy obtuse, obscurely heart-shaped at hiise,Jinely reticulated, 

 entire or repand-denticulate (2 - 3" broad), all grain-bearing. (R. orbiculatus, 

 Qyay.) — Wet places, N. Eng. to N. J., west to Minn, and Kan. 



3. R. altissimus, Wood. (Pale Dock.) Rather tall (2-6° high); 

 leaves ovate- or oblong-lanceolate, acute, pale, thickish, obscurely veiny (the cau- 

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

 and panicled, 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. (R. Britannica, Gray; 

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



4. R. salicifolius, Weinmann. (White Dock.) Rather low (1-3° 

 high): root white; leaves nari-owly or linear-lanceolate, or the lowest oblong; 

 whorls much crowded ; pedicels much shorter than the fruiting calyx ; valves 

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

 M-ith a conspicuous often very large grain; otherwise nearly as u. 3. — Salt 

 marshes, from Xewf. to N. Eng., about the Great Lakes, and far Avestward. 



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, loose, the 

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

 shaped, abruptly refexed, 3-4 times longer than the fruiting calyx ; valves dllaied- 

 rhomboid, obtusely somewhat pointed, strongly rugose-reticulated , each bearing a 

 very large grain. — Wet swamps, common. 

 ■•-<• ->-^ Naturalized European weeds ; lower leaves mostly heart-shaped at base. 



R. CRfspus, L (Curled Dock.) Smooth (3-4° high); leaves ivith 

 slronrjly wavy-curled margins, lanceolate, acute, the lower truncate or scarcely 

 heart-shaped at base; ivhorls crowded in prolonged ivand-Uke racemes, leafless 

 above ; valves round-heart-shaped , obscurely denticidate 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 ]\[d. 



R. obtusif6lius, 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 some sharp awl-shaped teeth at base, strongly reticu- 

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



R. SANGufxEUS, L. Leaves oblong -lanceolate, often fiddle-shaped, wavy- 

 margined ; vhorls distant, in long slender leafless spikes ; pedicels very sliort, 

 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. co>rGLO:MERXTUs, Murray. (Smaller Greex Dock.) Like the last, 

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

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



