DESCRIPTIONS OF SOME COMMON WEEDS 



167 



This is an annual, from one to four feet high, with smooth 

 stem and whitish flowers. It is common in low grounds. 

 Goosefoot Family (Chenopodiaceae). Herbs or occa- 

 sionally shrubs, frequently 

 succulent ; leaves mostly 

 alternate without stipules ; 

 flowers small, greenish, 

 regular or slightly irregu- 

 lar; clustered or solitary in 

 the axils of the leaves; 

 calyx two to five lobed or 

 two to five-parted or (rare- 

 ly) a single sepal ; stamens 

 as many as the lobes or oc- 

 casionally fewer; ovary one- 

 celled, ovule solitary; fruit 

 utricle with a thin mem- 

 brane (pericarp) or rarely 

 an achene. A small order 

 of about 500 species of 

 wide distribution. Many 

 are troublesome weeds. 

 Spinach, beet, greasewood, sea blite, 

 white sage, and sugar beet belong to this 

 order. 



Winged Pigweed or Western Tumble- 

 weed (Cycloloma atriplicifolium, (Spreng.) 

 Coult.). An annual, diffusely branched, 

 smooth or occasionally pubescent, alter- 

 nately petioled, occasionally petioled, -flowers 

 in panicles and interrupted spikes; calyx 

 five-lobed, stamens five, styles three, seed 

 horizontal, flat, coats crustaceous; the 

 winged calyx incloses the fruit, the lobes Fig. 101. Slen- 

 not entirely covering the summit of the d . e j . smartweed 



. , _' . Ll ... M1 f (Polygonum la- 



utricle. Common in the sandhills west of p a t/ii folium). 



Fig. ioo. Pennsylvania smartweed 

 (Polygonum Pennsylvanicum). 



