COMPOSITAE (COMPOSITE FAMILY) 



453 



POVERTY WEED 

 Iva axillaris, Pursh. 



Other English name: Small-flowered Marsh Elder. 



Native. Perennial. Propagates by seeds and by rootstocks. 



Time of bloom : June to August. 



Seed-time: July to September. 



Range: Manitoba to British Columbia, southward to Nebraska, 



New Mexico, and California. 

 Habitat : Cultivated crops, grain fields, meadows, and waste places. 



A very pernicious weed, difficult to suppress because of its exten- 

 sive system of tough, woody rootstocks which send up many fruiting 

 stalks, causing it to form dense patches, crowding 

 and starving all other growth. It intrudes in 

 most crops and thrives almost anywhere, but 

 seems to have a preference for soil that is alkaline. 

 The whole plant has a rank, unpleasant odor, 

 causing it to be disliked by grazing animals. 



Stems six inches to nearly two feet high, erect, 

 diffusely branched and very leafy. Leaves nar- 

 rowly oblong or obovate, a half -inch to two inches 

 long, somewhat thick and fleshy, rough-hairy, 

 three-nerved, entire and sessile ; the lower ones 

 opposite, those near the top alternate. Heads 

 inconspicuous, solitary, axillary, and drooping, 

 the central florets sterile; bracts of the involucre 

 united into a five-lobed cup, surrounding the fer- 

 tile pistillate florets which are usually four or five 

 in number. Achenes ovoid, flattened, sometimes 

 keeled on one side, varying in color from green to 

 almost black; they have no pappus. (Fig. 316.) 



FIG. 31 6. 

 Poverty Weed 



(Iva axillaris). 

 X J. 



Means of control 



Prevent all seed production by repeated close cuttings through- 

 out the growing season. The rootstocks must be starved to death 

 after the manner of Horse Nettle or Perennial Sow Thistle, by short 

 rotations with cultivated crops well fertilized and so well tilled 

 that no leaf-growth is permitted to store the weed's underground 



