POLYGON ACE.*: 



719 



7. Amphibious Polygonum. Polygonum amphibium, Linn. 



(1% 867.) 

 (Eng. Bot. t. 436.) 



A glabrous perennial, usually floating 

 in water, and rooting at the lower nodes. 

 Leaves oblong or lanceolate, rather 

 thick, 3 to 6 inches long, spreading on 

 the surface of the water. Spikes ter- 

 minal, solitary or rarely two together, 

 supported on short peduncles above the 

 water, dense and cylindrical, 1 to \\ 

 inches long, of a rose-red. Stamens 

 usually 5. Styles 2. JNuts flattened. 



In ponds and watery ditches, in Eu- 

 rope, central and Russian Asia, and 

 northern America, to the Arctic regions. 

 Extends all over Britain. Fl. summer. 

 When growing in dried-up ponds or 

 muddy ditches the stems are creeping 

 at the base, then shortly erect, and the 

 leaves are often downy. 



Fig. 867. 



8. Persicaria Polygonum. Polygonum Persicaria, Linn. 

 (Eig. 868.) 

 (Eng. Bot. t. 756. Common Persicaria.] 

 An erect or spreading, branched an- 

 nual, glabrous or slightly hoary, and 

 often turning red, 1 to 2 feet high. 

 Leaves lanceolate, stalked, or the upper 

 ones sessile ; the larger ones 3 to 5 

 inches long, and an inch broad or rather 

 more, often marked in the centre with a 

 dark spot. Stipules more or less fringed 

 at the top with short fine bristles. Spikes 

 terminal, rather numerous, oblong or 

 cylindrical, and seldom above an inch 

 long, dense, but not so regular as in the 

 amphibious P., and there is often a clus- 

 ter of flowers a little below. Flowers 

 reddish or sometimes green, not dotted. 

 Stamens usually 6. Styles usually 2. 

 Nuts flattened but rather thick, smooth 

 and shining, and often concave on one ^S *868 



