POLYGONACE^— BUCKWHEAT 



FAMILY 



PINK KNOTWEED. SMARTWEED 



Polygonum Pennsylvdnicum 



One of our native common weeds which bears pink 

 spikes above leafy stems; in moist ground, by the road- 

 side or over the fence, on rubbish heaps and in waste 

 places, from midsummer to frost. Nova Scotia to the 

 Gulf of Mexico, west to Minnesota and Texas. July- 

 October. 



Stems. — Erect, one to three feet high, smooth, simple 

 ^. branched, often reddish, the joints swollen and sheathed. 

 The sheaths are united stipules called ocreae. The upper 

 branches and peduncles often glandular. 



Leaves. — Lanceolate or long-oval, two to ten inches 

 long, ciliate,* acute or acuminateat apex; petiole short. 



OcrecB cylindric, naked; glabrous. 



Flowers. — Small, pink, borne in dense, terminal, obtuse 

 spikes, one to three inches long. 



Calyx. — Small, pink or greenish, five-parted. 



Corolla. — Wanting. 



Stamens. — Eight or ten. 



Pistil. — Ovary one; style two-parted. 



Fruit. — A shining, circular, flattened seed within the 

 protecting calyx. 



This Polygonum grows in colonies whenever it can 

 and is the plant chiefly responsible for the masses of 

 pale-pink flowers in low meadows and neglected fields 



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