POLYGON ACE.1<:. (BUCKWHEAT KAMII,V.) 43i) 



* * Annuals, low ; valves bearing long awns or bristles. 



6. R. maritimus, L. (Golden Dock.) Minutely pubescent, diffusely 

 branched, 6-12' hin^h ; leaves lauce-linear, wavy-margined, tlie lower auricled 

 or lieart-shaped at base ; whorls excessively crowdetl in leafy and corni)a<t or 

 interrupted spikes; valves rhonibic-obloug, lance-pointed, each bearing 2-3 

 long awn-like bristles on each side, and a large grain on the l)ack. — Sea-siiore, 

 Mass. to N. C. ; also from 111. to Minn., and westward. 



§ 2. ACETOSA. (Sourkl.) Flowers dioecious, small, in a terminal naked 

 panicle; herbage sour; some leaves halberd -shaped ; smooth perennials, 

 spreading by running rootstocks, Jlowering in spring. 



7. R. haSt^tulus, Baldvv. Stem simple, 1 -2° high ; leaves nearly as in 

 the next; pedicels jointed at or below the middle; valves of the fruiting cali/x 

 round-heart-shaped , thin, finely reticulated, naked, mam/ times larger than the 

 arliene. (R. Engelnianni, /.fif/e/j.) — !S. W. HI. to E, Kan., Tex., and P'la. ; 

 Kiverhead, Long Island ( Yotnig). 



R. AcKTosEM.A, li. (FiKLi) or SifKKi' SoHKKr,.) Low (r)-12' high); 

 leaves narrow-lanceolate or linear, halberd-form, at lc;i.st those of the root, the 

 narrow lobes entire; pedicels jointed with thejlowcr; calces scarcely enlarging 

 in t'niit, orate, naked. — Abundant evervwhere. (Nat. from En.) 



R. AcETosA, L. (SoitKEL DocK.)' Like the last, l)ut taller (I -.3° high) ; 

 leaves oblong or broadly lanceolate ; r(dres enlarging In fruit and urinrular, 

 the outer rejiexed. — Charlotte, Vt., and Penn Yan, X. Y. (Nat. from Eu.) 



4. POLYGONUM, Tourn. Kxotweed. 



Calyx mostly .5-parted ; the divisions often petal-like, all erect in fruit, with- 

 ering or persistent. Stamens 4-9. Styles or stigmas 2 or 3 ; achene accord- 

 ingly lenticular or 3-angular. Embryo jdaced in a groove on the outside of 

 the albumen and curved half-way around it ; the radicle and usually the co- 

 tvledons slender. — Pedicels jointed. Ours all herbaceous, with fibrous roots 

 (except n. 19), flowering tlirougli late summer and early autumn. (Name 

 composed of ttoKvs, many, and yovv, knee, from the numerous joints.) 

 § 1. POLYGONUM proper. Flowers in axillary fascicles or spicate with 

 foliaceous bracts; leaves and bracts jointed upon a very short petiole adnate 

 to the short sheath of the 2-lobed or lacerate scarious stipules : stems striate ; 

 calyx 5 - ^-parted, usually more or less herbaceous ; stamens 3-8, the 3 inner 

 Jilaments broad at base; styles 3; cotyledons incumbent; albumen horny; 

 glabrous annuals, except n. 1. (§ Avicularia, ^felsn.) 

 * Leafy throughout. 



1. P. maritimum, L. Perennial, nt length woody at base (or sometimes 

 annual), prostrate, glaucous, the stout stems very shortly jointed ; leaves thick, 

 oval to linear-oblong (3-10" long), exceeding the nodes; stipules very con- 

 spicuous; sepals petaloid; stamens 8; achene smooth and shining, exserted. — 

 Sea-coast from Mass. to Ga. (Eu.) 



2. P. avieul^re, L. Slender, mostly prostrate or ascending, bluish-green ; 

 leaves oblong to lanceolate (3- 10" long), usually acute or acutish ; sepals 

 hardly 1" long, green with pinkish margins; stamens 8 (rarely 5) ; achene dull 

 and minutely granular, mostly imhuled. — Common everywhere in yards, 

 waste places, etc. (Eu., Asia.) 



