n6 COMMON WEEDS 



be extremely troublesome among both corn and root 

 crops on practically all soils, while its seeds are 

 commonly found in clover and grass seed samples. 

 It is a smooth, prostrate annual, much branched from 

 the base, the branches sometimes reaching 3 feet or 

 so in length. The leaves are J to ij inch long, more 

 or less lanceolate or oval, sessile or shortly stalked, 

 with silvery, chaffy stipules at the base. Flowering 

 continues from May to October, the flowers being 

 minute, white, greenish, pink or crimson, and clustered 

 in the axils of the leaves almost the whole length of 

 the reddish stems. 



Knotgrass or Knotweed (Fig. 33), known to farmers 

 also as Surface Twitch, Red Robin, or Hogweed, seeds 

 abundantly, and on some of the light sandy soils is 

 often found in almost incredible quantity, while it 

 also occurs in great abundance on soils highly manured 

 by sheep. 1 Unless seeding be prevented it will be im- 

 possible to eradicate the weed. Where this weed is 

 very plentiful a short rotation should be adopted for a 

 few years, more frequent root or hoed crops affording 

 an opportunity to prevent seeding. Two fallow crops 

 in succession will be even better, and late turnips, or 

 maize in the south, will especially allow of surface 

 cultivation in the spring months to encourage the seeds 

 to germinate for destruction with the harrows. Owing 

 to the prostrate habit of the weed, hand pulling in 

 corn is difficult after the month of May. 



Black Bindweed or Climbing Buckwheat (Polygonum 

 Convolvulus L.) is a most mischievous annual, often 

 confused with the more serious pest Field Bindweed 

 (Convolvulus arvensis) (see p. 102). The two weeds are 

 very similar in habit, the species at present under con- 

 sideration twining round the stems of cereals and other 



i Complete Grazier. 



