206 POLYGONACEAE 
marked with dark spots, often a rather large spot, triangular or other 
formed, near the central part. Waste places. Common. 
8. P. Careyi, Olney. Carey’s Prrsicarta. Plant hairy; clusters of 
flowers long and curved, less dense than the preceding species. Leaves 
narrow lance-shaped, tapering at both ends. Shady swamps, mostly in 
eastern part of our area. 
9. P. orientale, L. Prince’s FeaTueR. Plant 3 to 8 ft. tall, often 
grown in gardens but to some extent naturalized in waste places. Leaves 
3 to 12 in. long, broad egg-shaped with tapering apex. Clusters of fowers 
dense, large, bright rose color. 
10. P. hydropiperoides, Michx. Wirp Water Pepper. Plant 1 to 
3 ft. high, much branching; leaves narrowly lance-shaped to linear; 
collarets conspicuously long and hairy with long bristly borders. Flowers 
arranged on long slender stems in loose series, nearly white. Swamps 
and wet places. Common. 
11. P, Hydropiper, L. (Fig. 2, pl. 33.) Warer PEPPER. SMART 
Weep. Plant 1 to 2 ft. high, smooth. Leaves lance-shaped, sometimes 
linear, tapering at apex. Flowers arranged as in No. 10. Collarets not 
hairy and bordered by short bristles. Wet places. Generally distributed. 
12. P. acre, HBK. (Fig. 4, pl. 33.) Dorrep WATER PEPPER. WATER 
Smart WEED. (P. punctatum, Ell.) Plant 2 to 5 ft. high, smooth. 
Leaves narrow lance-shaped, acute at each end. With conspicuous spots 
on the surface. Flowers greenish-white or tinged with pink. Collaret 
fringed. Wet places; common. 
13. P. virginianum, L. (Fig. 1, pl. 33.) Virernta KNotweep. Plant 
3 to 4 ft. high, growing mostly in woods and shady places. Leaves broad 
egg-shaped with tapering apex, the upper often narrow, all on short leaf- 
stalks. Sheaths hairy, fringed. Flowers arranged on a long slender 
stem, sparse. Flower stem usually occupying 4 the height of the plant 
or more. Rich soil; common. 
14. P. aviculare, L. (Fig. 7, pl. 34.) Door Weep. JKNoT-GRASS. 
Plant very common in neglected door yards, generally prostrate, bluish- 
green. Leaves oblong or lance-shaped, mostly acute at each end 1/4 to 
2/3 in. long, with very short or no leaf-stalk; interval between the joints 
rather longer than the leaves. Flowers very small, green, with white 
borders. Yards and waste places; common. 
15. P. littorale, Link. (Fig. 10, pl. 34.) Store Knotweep. Simi- 
lar to No. 13, but leaves mostly blunt and somewhat broader. Common 
on shores and in waste places. 
16. P. maritimum, L. Srastpe Knotweep. Leaves fleshy, narrower 
and shorter than Nos. 13 and 14, the margins generally rolled; nodes at 
very short intervals; sheaths torn by the swelling of the joints. Sands 
along the seashore. 
17. P. Rayi, Babingt. Ray’s Knotweep, Plant 3 to 24 in. long, 
prostrate, bluish-green; leaves longer and broader than either of the three 
preceding. Naturalized, found in waste places. 
18. P, Fowleri, Robinson. Vow rer’s Knotweep. Differs from P. 
Rayi chiefly in the more obtuse leaves, the oblong calyx lobes and the 
