558 POLYGONACEAE. 
g. Polygonum longistylum Small. Long-styled Persicaria. (Fig. 1326.) 
10. Polygonum Persicaria L. l[ady’s 
Thumb. (Fig. 1327.) 
Polygonum Persicaria \,. Sp. Pl. 361. 1753- 
Annual, glabrous or puberulent; stem erect or 
ascending, simple or much branched, 14°-2° 
high. Ieaves lanceolate or linear-lanceolate, 
1/-6’ long, short-petioled or nearly sessile, acu- 
minate at both ends, conspicuously punctate, usu- 
ally 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, 14’-2’ 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, 1//-14’’ long, smooth and shining. 
In waste places, throughout North America, ex” 
cept the extreme north. Naturalized from Europe: 
Often an abundant weed. June-—Oct. 
) 
Polygonum longistylum Small, Bull. Torr. Club, 
21: 169. 1894. 
Annual or perennial, glabrous except the glan- 
dular upper branches and peduncles; stem erect, 
rather slender, 1°-3° tall, becoming somewhat 
woody below. Leaves lanceolate or ovate-lan- 
ceolate, 1’-6’ long, acuminate at both ends, peti- 
oled, their margins undulate, slightly crisped, 
more or less ciliolate; ocreae cylindric, entire, 
brittle, soon falling away; racemes panicled, 
sometimes geminate, 1/-4’ 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; stig- 
mas black; achene broadly ovoid, lenticular, 
slightly gibbous on both sides, long-pointed, 
black, granular, but somewhat shining, 114// 
long. 
In moist soil, Southern Illinois and Missouri to 
Louisiana and New Mexico. Aug.-Oct. 
SI / Bi Y\\ 
11. Polygonum persicarioides H.B.K. 
Southwestern Persicaria. (Fig. 1328.) 
= 
P. persicarioides H.B.K. Nov. Gen. 2:179. 1817. 
Perennial, glabrous or minutely pubescent; stem 
erect, decumbent or creeping, simple or branched, 
1°-3° long. Leaves lanceolate or linear-lanceolate, 
acuminate at both ends, punctate, short-petioled or 
subsessile, 114’-10’ long; ocreae cylindric, glabrous 
or sparingly strigillose, fringed with short bristles; 
spicate racemes more or less panicled, erect, 1/-3/ 
long, narrowly oblong or linear, loosely-flowered; 
calyx rose-color tinged with green, 5-parted to below 
the middle; stamens 8 or fewer, included; style 2-3- 
parted to near the base; achene lenticular and 
bicontex, or 3-angled, more or less gibbous, 1// 
long, ovoid or broadly oblong, short-pointed, black, 
minutely granular, but shining. 
Nebraska to Mexico; widely distributed in tropical 
America. June—Sept. 
