3S8 rOLYGON\CKi^E. (IJLCKWIIEAT FAMILY.) 



7. P, articulata, Mcisiu-r. Annual ; stem niudi l)r:uKlicil, slender ; lcavp§ 

 narrowly linear, ulitnse, ilcciduous ; sheaths truncate, pointless; raeenies numer- 

 ous, creet, slender ; braets truneatc, open, the lowest ones pointed ; flowers bright 

 rosc-eolor ; sepals oval or roundish, nearly equal, unehan^cd in fruit; interior 

 filaments rhombie-ovate at the base. (Polygonum articulatum, L.) — Dry sandy 

 soil, Georgia, and northward. Aug. — Stem 6'- 12' high. Leaves 4' -8' long. 

 Racemes l'-3' long. 



3. POLYGONUM, L. KNoxwEF.n. 



Flowei-s perfect. Calyx 5- (rarely 4-) parted, corolla-like, the lolies nearly 

 equal, erect and unchanged in fruit. Stamens 3 - 9 : anthers roundish. Styles 

 2 -;j, distinct or partly united : stigmas entire. Achcnium 3-anglcd or lenticu- 

 lar, enclosed in the persistent calyx. Embryo curved on the outside of the 

 albumen. Radicle slender. — Herbs, with alternate, simple leaves, and sheath- 

 ing stipules. Flowers commonly white or rose-color, variously disposed. 



^ 1. Amblyogonon. Flowers in close! i/-bracted spiles: staniens 7 : style 2-cle/t: 

 achenium lenticular : cotijledons incumbent : allnimen mealy. 



1. P. orientale, L. Hairy; stem tall, branching; leaves ovate, acumi- 

 nate, petiolcd ; sheaths loose, salver-form ; spikes paniclcd, cylindrical, dense, 

 nodding; bracts ovate; flowers large, bright rose-color. — Around dwellings, 

 escaped from cultivation. June - Sept. — Stem 3° - 5° high. Spikes 2' - 3' 

 long. 



§ 2. Persicaria. Flowers in closely-hracted xpiles: stamens 4-8: styles 2-3, 

 or 2-3<lffl: achenium 3-untjled or lenticular: cotyledons accumbent : albumen 

 horny : sheaths cylindrical, truncate. 



* Sheaths naked: style 2-cleft or 2-parted: achenium lenticular. 



2. P. incarnatum, Ell. Stem smooth below, the summit of the branches, 

 peduncles, and calyx sprinkled with glandular dots ; leaves lanceolate, long- 

 acuminate, petiolcd, rough on the margins and veins ; sheaths slender, ajjpressed ; 

 spikes racemed, linear, nodding ; bracts spreading, acute, longer than the pedi- 

 cels ; flowers small, flesh-color. Stamens 6 , style 2-partcd ; achenium ovate, 

 with the sides concave. — Ponds, ditches, &c., South Carolina, and wx-st- 

 ward July-Oct. (l) — Stem 2° - 3° high. Leaves 6' -8' long. Spikes 1'- 2' 

 long. 



3. P. densiflorum, Mcisner. Stem stout, smooth, tumid at the joints, 

 branching above ; leaves lanceolate or oblong-lanceolate, tai^ring at the sum- 

 mit, but rather obtuse, rough on the margins and veins ; spikes racemed or 

 somewhat panided, linear, erect, dense-flowered, the peduncles minutely glan- 

 dular; bracts obliquely truncate, obtuse, shorter than the pedicels; stameiis 

 mostly 6 ; style 2-clcft ; achenium round-ovate, black and shining, with the 

 sides convex — Muddy banks, Florida, and westward. Sept. and Oct. ® — 

 Stem 3° - 4° high Leaves 6' - 10' long. Spikes 2' - 4' long. Flowers white. 



4. P. Pennsylvanieum, L Stem smooth below, the branches and pe- 

 duncles roughened with short glandular hairs ; leuvcj^ short-jietioled, lanceolate, 



