170 WEEDS OF THE FARM AND GARDEN 



alternately on the stem, one or two inches long, pointed in 

 the older plants, on which the leaves are persistent, flow- 

 ers inconspicuous, solitary and sessile ; stem and branches 

 red ; calyx five-lobed, persistent inclosing the dry fruit, 

 usually red in color. Sometimes called tumbleweed from 



its habit of rolling over 

 the prairies when dry. 

 By this means the seed 

 is scattered. An intro- 

 duced weed from north- 

 ern Europe, now found 

 in the Mississippi Val- 

 ley, New York, and the 

 Western States. 



Amaranth Family 

 ( Amaranthaceae). 

 Herbs with inconspicuous 

 greenish flowers, imbri- 

 cated with persistent 

 bracts; the flowers usu- 

 ally in terminal spikes 

 or axillary heads ; pistils 



none, calyx herbaceous 

 Fig. 104. Russian thistle (Salsola . 



Kali, var.tcnuif alia). or membranous; stems 



one to five, mostly op- 

 posite; ovule one-celled, ovary solitary; fruit a utricle, 

 one-seeded, seed small, minute. 



Green Pig Weed (Amaranthus retroflexus, L.). A 

 coarse, persistent herb more or less pubescent; leaves 

 dull green, long petioled, ovate or rhombic-ovate ; spikes 

 thick and crowded ; bracts awn-pointed and rigid, exceed- 

 ing the scarious tipped sepals, stamens five ; seed black 

 and shiny. This weed is common -throughout North 

 America, except far northward. 



The Amaranthus hybridus is similar to the preceding but 

 smoother and deeper green; spines and linear-cylindrical 



