BUCKWHEAT FAMILY. 567 
36. Polygonum Zuccarinii Small. Japanese Knotweed. (Fig. 1353.) 
Polygonum cuspidatum Sieb. & Zuce. F1. Jap. Fam. 
Nat. 2:84. 1846. Not Willd. 1825. 
Polygonum Zuccarinti Small, Mem. Dept. Bot. Col. 
Coll. 1: 158. fl. 66. 1895. 
Perennial, glabrous, more or less scurfy, stem 
stout, erect, woody below, terete or slightly 
angled, much branched, 4°-S° tall. Leaves ob- 
long-ovate or ovate-lanceolate, petioled, 2/6’ 
long, acuminate-cuspidate at the apex, truncate 
or subcordate at the base, reticulate-veined on 
both surfaces, their margins undulate; ocreae 
oblique, smooth, fugacious; racemes mostly ter- 
minal, panicled, 2’-4’ long, or axillary, many- 
flowered, more or less pubescent; flowers green- 
ish-white, long-pedicelled; outer segments of the 
5-parted calyx very broadly winged in fruit; 
stamens 8; style 3 parted; achene 3-angled, nar- 
‘rowly oblong or oblong-pyramidal, 11(//-1%4/’ 
long, black, smooth, shining. 
Escaped from cultivation near Philadelphia, Pa., 
Schenectady, N. Y., and Atlantic Highlands, N. J. 
Native of Japan. July-Oct. 
37- Polygonum sagittatum I, Arrow-leaved Tear-thumb. (Fig. 1354.) 
Ws / / Polygonum sagittatum 1, Sp. Pl. 363. 1753. 
Annual, light green, stem slender, weak, de- 
cumbent, or climbing over other plants by the 
abundant sharp recurved prickles which arm its 
4 prominent angles. Leaves lanceolate-sagittate or 
oblong-sagittate, 14’—3/ long, obtuse or acute at the 
apex, slightly rough on the margins, the lower pe- 
tioled, the upper subsessile; petioles and lower sur- 
face of the midribs prickly; ocreae oblique, not 
ciliate, fringed at the base by a few bristle-like 
prickles; flowers in rather dense terminal heads or 
racemes; calyx greenish or rose-colored ; stamens 
usually 8; style 3-parted to below the middle; 
achene 3-angled, oblong-pyramidal, thick-pointed, 
14” long, dark red, smooth, shining. 
In wet soil, Newfoundland and Nova Scotia to the 
Northwest Territory, south to Florida and Kansas. 
Ascends to 3000 ft, in Virginia. July—Sept. 
38. Polygonum arifolium L,. Halberd- 
leaved Tear-thumb. (Fig. 1355.) 
Polygonum arifolium I,. Sp. Pl. 364. 1753. 
Perennial, stem ridged, reclining, 2°-6° long, the 
ridges armed with recurved prickles. Peduncles 
and pedicels glandular or pubescent; leaves broadly 
hastate, long-petioled, 1/-10’ long, pubescent or 
glabrous beneath, the apex and basal lobes acumi- 
nate; petioles and stronger nerves prickly; ocreae 
oblique, fringed at the summit with short bristles 
and at the base with slender prickles; flowers in 
terminal and axillary heads or racemes; calyx rose- 
color or greenish, 4-parted; stamens 6; style 2-parted. 
achene lenticular, broadly obovate, 2’ long, strongly 
biconvex, dark brown, smooth, shining. 
In moist or wet soil, New Brunswick and Ontario to 
Minnesota, south to South Carolina. July-Sept. 
