288 POLYGON ACE M. [Polygonum. 



on long terminal glandular hairy peduncles, slender but continuous, about 1 

 line long. Style 3-cleft. 



Hongkong, Ilance. Also in Nepal, Assam, and Silhet. 



3. P. barbatum, Linn.; Meisn. in DC. Prod. xiv. 104; Wight, Ic. t. 1798. 

 Stems ascending or erect, glabrous, 2 to 3 ft. high. Stipules sheathing, 

 hairy outside, fringed at the top with long fine bristles. Leaves lanceolate, 

 varying much in breadth and size, usually sprinkled with appressed hairs, 

 especially underneath. Spikes in the slender forms near 3 in. long, with the 

 lower flowers distant, as in P. Hydropiper, shorter and more continuous in the 

 stouter specimens. Style 3-cleft. Nut triangular, smooth. 



In swamps and wet places, Hance, Harland. Common in tropical Asia and Africa, ex- 

 tending northwards to Amoy and Shanghae. 



4. P. Hydropiper, Linn. ; Meisn. in DC. Prod. xiv. 109. A slender 

 erect or decumbent glabrous annual, 1 to 2 ft. high. Stipules sheathing, but 

 rather short, ciliate at the top. Spikes slender and interrupted, the lower 

 clusters usually axillary. Perianth, and often the bracts also, dotted with 

 glands, and the whole plant more or less biting or acrid to the taste. Style 

 usually 2-cleft. Nuts flat. 



In rice-fields, Wilford. Widely spread, and generally common in Europe, central Asia, 

 and North America. 



5. P. glabrum, Willd. ; Meisn. in DC. Prod. xiv. 114; Wight, Ic. t. 

 1799. An erect or ascending branching annual or perennial, 1 to 3 ft. high, 

 glabrous in every part, and the sheathing stipules truncate, without hairs or 

 bristles. Leaves lanceolate, narrowed at the base. Spikes terminal, rather 

 slender, but nearly continuous, 1 to 2 in. long. Perianth small, not dotted. 

 Style usually 2-cleft. Nut flattened. 



In ditches, Ilance. Frequent in the tropical regions both of the New and the Old World. 



6. P. lapathifolium, Linn. ; Meisn. in DC. Prod. xiv. 119. An erect 

 or ascending annual, 1 to 2 feet high; the branches glabrous or slightly 

 hoary. Leaves lanceolate, shortly stalked, either glabrous or nearly so on 

 both sides, or more or less hoary or cottony- white underneath. Stipules 

 sheathing, usually slightly hahy, and sometimes fringed with minute fine 

 bristles at the top. Peduncles always with a few glandular hairs. Spikes 

 oblong or cylindrical, thicker than in any of the above species, seldom above 

 an inch long, usually of a pale-green colour. Perianth slightly glandular- 

 dotted. Style 2-cleft. Nuts flat, but rather thick, concave on both sides.— 

 P. orientate, var. discolor, Benth. in Lond. Journ. Bot. i. 494. 



Hongkong, Hinds. Widely diffused over the northern hemisphere, but most abundant in 

 N. America. The Hongkong specimens have the leaves cottony-white underneath, as is de- 

 scribed of the P.glutinosum, Wall. (Meisn. 1. c. 120), which I have not seen, but which is 

 probably the same species, as the same characters occur in some S. European specimens, 

 distinguished as P. incannm. Some specimens from other islands of the Canton river are 

 glabrous, as in the more common varieties of the plant. 



7. P. orient ale, Linn. ; Meisn. in DC. Prod. xiv. 123 ; Dot. Mag. t. 213. 

 An erect, softly pubescent or hairy annual, 2 to 4 ft. high. Stipules very 

 hairy, sheathing and scarious at the base, but all, except the uppermost, ex- 

 panded at the top into a green, spreading limb. Leaves stalked, ovate, or 



