POLYGONACE.E 



POLYGONACE^E BUCKWHEAT FAMILY 



Polygonum sagittatum, L. 



Red-purple, pink Arrow-leaved Knotweed, 



to nearly white Tear-thumb, 



Arrow-leaved Tear-thumb, 

 August-September Scratch-grass. 



Polygonum: for derivation see acre. 

 Sagittatum: Latin for arrow-shaped. 



THE PREFERRED HABITAT: damp ground. 



THE PLANT: low-lying, or climbing over other plants, 

 sometimes two feet long; the stem light green or coloured 

 with red, slender, weak, four-angled with more or less 

 re-curved prickles on the angles. 



THE LEAVES: alternate; lanceolate, sagittate, or oblong- 

 sagittate; one half inch to three inches long; the mid-ribs 

 or the lower surfaces prickly; obtuse or acute at the apex; 

 the lower petioled; the upper almost sessile; the petioles 

 also with prickles, slightly rough on the margins; the 

 sheaths fringed at the base by a few, bristle-like prickles. 



THE FLOWERS: small, in rather dense terminal heads or 

 racemes. 



THE FRUIT: achenes, smooth and shining. 



Another weak-stemmed and trailing representative of 

 the Family, and another easy to identify. Its flowers 

 may vary from deep pink to a cream white, but its leaves 

 are always sagittate and its soft prickles always, as it 

 were, turned the wrong way. This may be a provision of 

 nature to spread the seeds, for the prickles, with their 

 tin hooks, catch on the fur and wool of animals and the 

 clothes of human intruders. 



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