2oS THE STORY OF PLANT LIFE 



for flour, being used as a pheasant food. A blue dye 

 is yielded by Polygonum tinctorium. Oxalic and 

 malic acids are yielded by several Docks. 



Persicaria {Polygonum Persicaria). 



With its brilliantly coloured perianth-segments 

 Persicaria, so-called from the spotted leaves, is a 

 handsome plant. The first Latin name has reference 

 to the many-jointed stem with nodes (Greek gonu^ 

 knee), and this is indicated by the name Knot-Grass, 

 which is another name for allied plants. 



Persicaria is found in all parts of the British Isles, 

 Scotland, Ireland and the Channel Islands. In the 

 North of England it grows at an altitude of nearly 

 1500 ft. 



Though common in waste places, and cultivated 

 ground, usually damp ground, ditches, roadsides, it 

 is also found in more native habitats in marshes. It 

 grows, moreover,'on cla}^ or loam in neutral grassland 

 in wet places in the rush association. 



The habit is erect, spreading. The stems are 

 branched, with swollen nodes, smooth or slightly 

 downy, often of a red tinge. The leaves are hairy 

 both sides or woolly below, ovate, lance-shaped, 

 tubercled, stalked, or the upper stalkless, acute, 

 fringed with hairs, \\'ith a spot, black or brown, dotted 

 below. The stipules are fringed with hairs, or fine 

 bristles, and loose. 



The flowers are in dense, short, terminal and 

 axillar\- racemes or spikes, numerous, ovate, oblong 



