POLTGONACE^. 451 



cal flovrer-spike, 1 to 2 inches long. Perianth piak or rarely white. Styles 3. 

 Stamens longer than the perianth. 



In moist pastures, and meadows, chiefly inhUly districts, in Europe, cen- 

 tral and Russian Asia, and northern America, extending into the Arctic re- 

 gions. Occurs in various parts of Britain, chiefly in the north of England, 

 but is often local, and in some instances a straggler from gardens. Fl. 

 summer. 



7. Amphibious Polygonum. Polygonum ampbibium, Linn. 

 (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 inclies long, 

 spreading on the surface of the water. Spikes terminal, solitary or rarely 

 two together, supported on short peduncles above the water, dense and cy- 

 lindrical, 1 to li inches long, of a rose-red. Stamens usually 5. Styles 2. 

 Nuts flattened. 



In ponds and wateiy ditches, in Europe, central and Eussiain Asia, and 

 northern America, to the Arctic regions. Extends aU 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 dovsmy. 



8. Persicaria Polygonum. Polygonum Persicaria, Li nn . 

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



An erect or spreading, branched annual, glabrous or sUghtly hoary, and 

 often turning red, 1 to 2 feet high. Leaves lanceolate, stalked, or the upper 

 ones sessile ; tlie 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 witli short fine bristles. Spikes tenninal, rather nume- 

 rous, oblong or cyUndrical, and seldom above an inch long, dense, but not 

 so regular as in the amphibious P., and there is often a cluster 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 side. Occasionally there are 3 styles, and 

 the nut is then triangular. 



In ditches, on roadsides, in cultivated and waste places, throughout 

 Europe and central and Russian Asia to the Arctic regions. Abundant in 

 Britain. Fl. all summer and autumn. It varies much in stature and in 

 colom', in the number and density of the spikes, and in the achenes more or 

 less concave or convex on one or both sides. 



9. Pale Polygonum. Polygonum lapatbifolium, Linn. -. 

 (Eng. Bot. t. 1382.) 



Closely resembles the Persicaria P., and is probably a mere variety, dis- 

 tinguished by the pedicels and perianths dotted with small prominent 

 glands. The coloui- of the plant is usually pale green, the stipules seldom 

 fringed, and the nuts usually concave on both sides, but these characters 

 are not constant. 



In cornfields and waste places, with nearly the same range as the Per- 

 sicaria P., but usually in richer soOs, and does not extend so far north. 

 In Britain, recorded from England, Ireland, and southern Scotland. Fl. 

 summer and autumn. Specimens agreeing witli ihe Persicaria P. in eveiy- 

 tliing but the glandular dots, have been described as a third species under 

 the name of P. laxum (Eng. Bot. Suppl. t. 2822). 



