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 

 P . of about 500 species of 



*ig. 100. Pennsylvania smartweed ,,,,,! A^^^v^ - n/r 



Wlde distribution. Many 



(Polygonum pennsylvanicum). 



are troublesome weeds. 



0.1 \, LIUULUC; 



Spinach, beet, greasewood, sea blite, 

 white sage, and sugar beet belong to this 

 order. 



Winged Pigweed or Western Tumble- 

 weed (Cydoloma atriplicifolium, (Spreng.) 

 Coult.). An annual, diffusely branched, 

 smooth or occasionally pubescent, alter- 

 nately petiolecl, occasionally petioled, flowers 

 in panicles and interrupted spikes; calyx 

 five-lobed, stamens five, styles three, seed 

 horizontal, flat, coats crustaceous; the 4 



winged ^calyx incloses the fruit, the lobes Fig. I0 r. sien- 

 not entirely covering the summit of the der smartweed 

 utricle. Common in the sandhills west of * la ~ 



