POLYGONACE^E. (BUCKWHEAT FAMILY.) 430 



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



6. R. maritimus, L. (GOLDEN DOCK.) Minutely pubescent, diffusely 

 branched, 6-12' high; leaves lance-linear, wavy-margined, the lower auricled 

 or heart-shaped at base ; whorls excessive!}' crowded iii leafy and compact or 

 interrupted spikes ; valves rhombic-oblong, lance-pointed, each bearing 2-3 

 long awn-like bristles on each side, and a large grain on the back. Sea-shore, 

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



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

 panicle; herbage sour; some leaves halber d -shaped ; smooth perennials, 

 spreading by running rootstocks, flowering in spring. 



7. R. hastatulus, Baldw. Stem simple, 1-2 high ; leaves nearly as in 

 the next; pedicels jointed at or below the middle; valves of the fruiting calyx 

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

 uc/iene. (K. P^ngelmauni, Ledeb.) S. \\ '. 111. to E. Kan., Tex., and Ela. ; 

 Kiverhead, Long Island (Young). 



R. ACETOSELLA, L. (FIELD or SHEEP SORREL.) Low (6-12' high); 

 leaves narrow-lanceolate or linear, halberd-form, at least those of the root, the 

 narrow lobes entire; pedicels jointed with the flower ; valets scarcely enlarging 

 in fruit, ovate, naked. Abundant everywhere. (Nat. from Eu.) 



R. ACETOSA, L. (SORREL DOCK.)" Like the last, but taller (1 -3 high) ; 

 leaves oblong or broadly lanceolate ; valves enlarging in fruit and orbicular, 

 the outer reflexed. Charlotte, Vt., and Penn Yan, N. 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 placed in a groove on the outside of 

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

 tyledons slender. Pedicels jointed. Ours all herbaceous, with fibrous roots 

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

 composed of TTO\VS, many, and yow, knee, from the numerous joints.) 

 1. POLYGONUM proper. Flowers in axillary fascicles or spicate u-ith 

 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 - (j-parted, usually more or less herbaceous ; stamens 3 - 8, the 3 inner 

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

 glabrous annuals, except n. 1. ( Avicularia, Jfeisn.) 



* Leafy throughout. 



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

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

 <>val 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. aviculare, L. Slender, mostly prostrate or ascending, bluish-green ; 

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

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

 and minutely granular, mostly included. Common everywhere in yards, 

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



