POL YG ON A CEA E. 36 1 



stamens 6; style 2 -parted to near the base; achene ovoid-oblong, lenticular, about 



2 mm. long, flat or biconcave, smooth, shining. In wet soil, Vt. to 111. and Neb., 

 south to Fla. and La. June-Sept. 



7. Polygonum lapathifolium L. DOCK-LEAVED OR PALE PERSICARIA. 

 (I. F. f. 1324.) Annual, stem erect or ascending, swollen at the nodes, 3-9 dm. 

 high, the peduncles and pedicels glandular. Leaves lanceolate or oblong- 

 lanceolate, 5-25 cm. long, usually broader than those of the preceding, attenuate 

 to the apex, acuminate at the base, short-petioled, ciliate, inconspicuously punctate; 

 ocreae cylindric, ribbed or striate; racemes panicled, 2.5-10 cm. long, drooping, 

 narrow, rather dense; calyx pink, greenish or white, 5-parted; stamens 6; style 

 2-parted to below the middle; achene broadly oblong or ovoid, lenticular, 2mm. 

 long, brownish or black, slightly reticulated but shining, its faces concave. In 

 waste places, throughout temperate N. Am. Nat. from Europe. Sometimes a. 

 troublesome weed. Native also of Asia. June-Sept. 



Polygonum lapathifolium nodbsum (Pers.) Small. Generally robust and glabrous ; 

 stem stout, reddish, purple spotted and with a purple ring below each ocrea, much 

 thickened at the nodes ; leaves conspicuously punctate ; racemes 2.5-7.5 cm - l n g> l ess 

 drooping, often erect ; achene slightly larger. Occasional in the range of the type. 



Polygonum lapathifolium incunum (Schmidt) Koch. Low; stem slender, erect, 

 5-30 cm. high, slightly scurfy ; leaves lanceolate, ovate or oblong, usually narrowed at 

 the base, white-tomentose beneath, glabrous above ; racemes 1-4 cm. long. In waste 

 places, N. S. to Ont., N. Y., and Br. Col. 



8. Polygonum Pennsylvanicum L. PENNSYLVANIA PERSICARIA. (I. F. f. 

 1325.) Annual, glabrous below; stem erect, 3-9 dm. tall, the upper parts, the 

 peduncles and pedicels glandular. Leaves lanceolate, acuminate at the apex, 

 petioled, ciliate, 5-30 cm. long, the upper sometimes glandular beneath; ocreae 

 cylindric, naked, glabrous; racemes panicled, erect, thick, oblong or cylindric, 

 dense, 2.5-5 cm - ^ On g5 calyx dark pink or rose-color, 5-parted; stamens 8 or fewer; 

 style 2-cleft to about the middle; achene orbicular or mostly broader than high, 



3 mm. long, short-pointed, lenticular, smooth, shining. In moist soil, N. S. to 

 Ont., Minn., Fla. and Tex. July-Sept. 



9. Polygonum longistylum Small. LONG-STYLED PERSICARIA. (I. F. f. 

 1326.) Annual or perennial, glabrous except the glandular upper branches and 

 peduncles; stem erect, rather slender, 3-9 dm. tall. Leaves lanceolate or ovate- 

 lanceolate, 2.5-15 cm. long, acuminate at both ends, petioled, their margins 

 undulate, slightly crisped, more or less ciliolate; ocreae cylindric, entire, brittle; 

 racemes panicled, sometimes geminate, 2.5-8 cm. long, rather dense, erect; calyx 

 lilac, 5-parted to below the middle, the lobes petaloid; stamens 6-8, included; 

 style 2-parted, slender, conspicuously exserted; stigmas black; achene broadly 

 ovoid, lenticular, slightly gibbous on both sides, long-pointed, black, granular, 

 but somewhat shining, 2.5 mm. long. In moist soil, S. 111. and Mo. to La. and 

 N. Mex. Aug.-Oct. 



10. Polygonum Persicaria L. LADY'S THUMB. (I. F. f. 1327.) Annual, 

 glabrous or puberulent ; stem erect or ascending, 1.5-6 dm. high. Leaves 

 lanceolate or linear-lanceolate, 215 cm. long, acuminate at both ends, conspicuously 

 punctate, usually with a dark triangular or lunar blotch near the centre, their 

 margins entire or slightly eroded, often ciliate; ocreae cylindric, nearly glabrous, 

 fringed with short bristles; racemes solitary or panicled, 1-5 cm. long, ovoid or 

 oblong, dense, erect ; calyx pink or dark purple; stamens mostly 6; style 2-3- 

 parted to below the middle ; achene broadly ovate and lenticular, often gibbous or 

 3-angled, 2-2.5 mm - l n g> smooth and shining. In waste places, throughout N. Am. 

 except the extreme north. Nat. from Europe. Often an abundant weed. June- 

 Oct. 



11. Polygonum persicarioides H. B. K. SOUTHWESTERN PERSICARIA. 

 (I. F. % 1328.) Perennial, glabrous or minutely pubescent; stem erect, decumbent 

 or creeping, 3-9 dm. long. Leaves lanceolate or linear-lanceolate, acuminate at 

 both ends, punctate, 4-25 cm. long ; ocreae cylindric, glabrous, or sparingly 

 strigillose, fringed with short bristles ; racemes more or less panicled, erect, 

 2 - 5~7-5 cm - l n g> narrowly oblong or linear, loosely flowered; calyx rose-color 

 tinged with green, 5-parted to below the middle; stamens 8 or fewer; style 2-3- 



