WEEDS AND WEED SEEDLINGS. 



45 



almost or quite prostrate. It is an annual, and the ordinary tillage of 

 cultivation is usually sufficient to keep it down. 



The seedlings (fig. 17) somewhat resemble those of chickweed. 

 The cotyledons are oval or oval-lanceolate (J- J in. long), smooth, entire, 

 and stalked, the stalks being at first erect and the blades curved out- 

 ward. They are slightly fleshy, rather dark green in colour, and 

 dotted beneath. The first true leaves resemble those of the mature 

 plant, in which they are nearly oval, small, and sessile, and spotted 

 beneath. The flowers grow from the leaf axils on long slender stalks. 

 The stem is square, and branched from the base. The seed capsule 

 somewhat resembles a small smooth pea. 



Persicaria 'is a weed oi the family Polygonaceae, which includes 

 Knotweed, Black Bindweed and Docks. This weed is often very 

 plentiful indeed, especially on good soils which are fairly moist. It is 

 a freely-seeding annual, and vigorous, repeated tillage and hoeing are 



Fig. 17. — Seedlings of Scarlet Pimpernel (Anagallis arvensis L.). 

 a, cotyledon stage ; h, second stage ; c, third stage, branching. Natural size. 



ecessary to suppress it. It "is rich in nitrogen, phosphoric acid, 

 potash, and lime, and is considered a nutritious fodder for horses and 

 cattle. 



The cotyledons (fig. 18) are longish-oval in shape, shortly petioled, 

 smooth, and medium green in colour, the portion of the stem imme- 

 diately above the ground being tinged reddish. The first true leaves 

 are elongate-oval to nearly lanceolate, and as the seedling grows the 

 later leaves gradually assume a lanceolate character. The growing 

 seedling soon branches, and thereafter growth is rapid. The leaves of 

 the mature plant are lanceolate, almost sessile, and often bear a black 

 blotch in the centre. The stems are branched, smooth and shiny, with 

 much-swollen nodes, and a deep tinge of red above — hence the weed is 

 commonly named Eedshank. The flowers are very small, white or 

 reddish, and borne in dense clusters or spikes ^ to 1^ inch long. 



Knotweed is also an annual, but is much branched from the base, 

 very slender and prostrate (fig. 19). It is often a serious pest, occurn'iig 



