POLYGONACEAE (BUCKWHEAT FAMILY) 99 



Stem rigidly upright, sometimes attaining four feet but more often 

 six inches to two feet in height, much branched, slender, slightly 

 ridged, and smooth. Leaves yellowish green, smooth, narrow 

 lance-shaped, pointed at both ends, a quarter-inch to an inch long, 

 with very short petioles conspicuously jointed to the collar-like 

 stipules, which are funnel-form, thin, usually cut and torn. Flowers 

 in axillary clusters, greenish with yellow margins ; stamens three 

 to six; sepals six, the three inner ones small, the outer ones 

 larger, keeled and curving inward at the summit, persistent, their 

 withered remains enfolding the smooth, shining, three-angled 

 achenes when they mature and fall. 



Means of control 



Prevent reproduction by cutting or pulling when in first bloom. 



SWAMP SMARTWEED 



PolQgonum Muhlengergii, Wats. 

 (Polfygonum emersum, Britton) 



Native. Perennial. Propagates by seeds and by rootstocks. 



Time of bloom: July to September. 



Seed-time: August to October. 



Range: Ontario to British Columbia, southward to Virginia, 



Louisiana, and Texas. 

 Habitat : Muddy or dry soil ; fields, low meadows, swamps. 



Although this weed seems to prefer moist soil, it will grow any- 

 where, even on mountains, varying its form to fit its surroundings. 

 When established in field or meadow its creeping, horizontal root- 

 stocks make it difficult to suppress, as by ordinary cultivation they 

 are likely to be broken and further distributed. 



Stems one to three feet long, decumbent or sometimes erect, 

 usually simple, rough with short, appressed hairs, or sometimes 

 smooth and slightly grooved, swollen at the joints. Leaves vari- 

 able, those in wet places usually smooth, rather broad, and heart- 

 shaped at base ; in dry situations narrow, lance-shaped, pointed at 

 base, and covered on both sides with appressed hairs ; loose sheath- 

 ing stipules nearly as long as the petioles. Flowers dark rose- 



