230 pot.yoonack.t:. 



Const il II r))f.% — ItH only important coiiHtituout in a voliitilc oil. 



Pi't'itarnlionx. — Olnim clicnopoilii — oil of j'hcnopodiimi. — I'nllitd Slali'A 

 Phnnnnvopdia, Tho bniiHod weeds nro HoiiH'tiincs luliiiiiiiHtered in ,siil»- 

 slni'.ce or dccioctioii. 



Mi-ilnal /'nij'-'iiii's mid I'srx. — Chciiopoilium is used solely lis iiii uii- 

 thelmintic for liuiibrieoul worniH. 



POLYCONACEIiC. 



(linrni'U'r afllir Orh'r. — Herbs with iUtenmIe, eoiniiioiily entire leaves, 

 and stipules in the i'onii of meiid>raiiiice()us slieatlis iibovo the swollen 

 joints of the stem. Flowers coniinoiily perfect, ('alyx IJ- to (J-clefi, more 

 or less persistent. Stamens l to 12, inserted on the ba.sc of the calyx. 

 Ovary free, 1-ceiled ; styles or sti«^niaH 2 or H. Fruit a seeddikc nutlet, 

 eonunonly trial m'uliir. 



All order comprising fewNortli American {^'enera, and these are lar^icly 

 represented by coiiimou weeds, many of them possessing more or less 

 acrid proi)erties. The most imjiortant plants of the order ai"0 buckwheat 

 (Fatjopi/rum) and rhubarb {liheiiiii). 



POL YG ON U M. — Knot WRKD. 



Chnracfor <>f Ihr (tcmix. — Calyx commonly r»-pavted, tho lobes often 

 petaloid, withering or persistent. Stamens 4 to !). Styles or stiymas 2 or 

 M. Fruit a lenticular or triangular achenium, surrounded by the erect lobes 

 of the calyx. 



Polygonum Hydropiper Linm'. — Smarhrced, Water- Pepper. 



J)es(ripti.oii.—F\n\veYH niostl}' greenish, in nodding spikes, usually short 

 or interruiited. Stamens (5. Style 2- to 3-parted. Achenium dull, minutely 

 striate, Hat or obtusely triangular. A smooth aimnal, 1 to 2 feet high. 

 Leaves lanceolate, tapering to both ends, minutely pellucid-punctate. 



llahilal. \\\ damp i)laces ; very common. 



Polygonum acre H. B. K. {I', pu net/dam Elliott). — Wafer Smarlioeed. 



Description. — Flowers whitish or flesh-colored, in erect spikes. Sta- 

 mens 8. Style mostly 8-parted. Achenium smooth, shining, sharply tri- 

 angular. A nearly smooth perennial. Stem ascending, rooting at the de- 

 cumbent base, 2 to 5 feet high. Leaves larger and longer than in the 

 preceding species. 



ITalntat. — In wet places ; common, especially southward. 



Polygonum Bistorta Linm'.— 7?/.stor^ 



Description. — Flowers pink or white in a dense oblong or cylindrical 

 spike, 1 to 2 inches long. Styles 3. A perennial with a thick, cylindrical, 

 somewhat flattened i-ootstock. Stem erect, simple, 1 to 2 feet high, ter- 

 minating in a llower spike. Leaves mostly radical on long petioles, ovate- 



