WEEDS OP THE BUCKWHEAT FAMILY. 



67 



22. POLYGON UM AVICULARE L. 

 X. 1.) 



Knot-grass. Door-weed. Goose-grass. 



Stem prostrate or sub- 

 erect, slender, dull bluish- 

 green, 4-18 inches long; 

 leaves oblong or linear, 

 i-| inch long, nearly ses- 

 sile. Flowers axillary, in 

 clusters of 1-5, s in a 1 1 

 short-stemmed, greenish 

 with white or pink bor- 

 ders ; stamens 5-8. Seeds 

 dull black, 1/10 inch long, 

 .'{-angled and minutely 

 granular. (Fig. 34.) 



Very common, form- 

 ing mats of spreading, 

 wiry, jointed stems in 

 yards and along path- 

 ways and roadsides 

 where the ground is 

 much trodden; also in 

 cultivated lands. June- 

 No v. This is one of the 



social weeds, such as plantain, burdock, catnip, etc., which accom- 

 panied the white man in his march across and conquest of the 

 North American Continent. Holmes refers to it in the lines: 



"Knot-grass, plantain all the social weeds, 

 Man's mute companions, following where he leads/' 



An infusion of it was formerly supposed to retard bodily growth 

 and is referred to by Shakespeare in the lines: 



"(iet you gone, you dwarf; 

 You minimus, of hindering knot-grass made." 



The erect knot-grass (P. crcclnm L.) is also often found with 

 the common form. It is erect or ascending, 1-2 feet high and has 

 the leaves and often the flowers yellowish, the former 1-2 inches 

 long. Both species are attacked by a mildew and sometimes by a 

 smut. 



Remedies: pulling or mowing before the seeds ripen; thorough 

 cultivation with hoed crops; cement and concrete; walks for vards. 



Fig. 34. Showing the flower and fruit. (After Small.) 



