POLYGONACEAE (BUCKWHEAT FAMILY) 



103 



Introduced. Annual. Propagates by seeds. 



Time of bloom : June to October. 



Seed-time: July to November. ^ 



Range: Throughout the American Continent except the extreme 



North, and in most parts of the world. 

 Habitat: Soil either dry or moist. Invades nearly all crops. 



The seeds of this weed form one of the most common impurities 

 of commercial seeds, particularly of red clover. In a bulletin 

 issued by the Agricultural Experiment 

 Station of Nevada, concerning "Clover 

 Seeds and their Impurities," it is 

 stated that of red clover samples sub- 

 mitted for inspection (obtained in all 

 parts of the country), 62.9 per cent con- 

 tained seeds of Persicaria. (Fig. 61.) 



Stems six inches to two feet tall, 

 often red or purplish at base, nearly 

 smooth, erect or sometimes spreading. 

 Leaves lance-shaped, smooth or with 

 fine hair roughening the edges, pointed 

 at both ends and generally blotched 

 near the center with a large brownish 

 spot. It is related that Joseph once 

 hurt his hand while working in his car- 

 penter's shop. Mary wished to make 

 a healing poultice with this plant, but 



" She could not find it at her need 

 And so she pinched it for a weed," 



since when its leaves have always 



borne the mark of the Lady's thumb; _ 



, ,. . , L , . , FIG. 61. Ladys Thumb 



the sheathing stipules at their base are (Poiygonum Persicaria). x J. 

 fringed with short bristles. Flower- 

 spikes numerous, dense, erect, a half-inch to two inches long; 

 calyx pink or purplish with four or five obtuse lobes, usually 

 six stamens, and a two- or three-parted style. Achenes lens- 

 shaped or sometimes three-angled, smooth, shining, jet-black. 



In some localities the plant is said to harbor the corn-root 

 aphis, the louse appearing with the first leaves. 



