WEEDS OF SPECIAL CROPS 59 



asters, goldenrod and European bindweed, are perennial. 

 Marsh elder (Iva ciliata), poverty grasses (Aristida dicho- 

 toma), dead nettle or henbit (Lamium anplexicaule), are 

 abundant annuals. The Virginia plantain (Plantago vir- 

 ginica), pokeweed (Phytolacca decandra), Carolina 

 crane's-bill (Geranium carolinianum), turkey-foot grass 

 (Eleusine indica), and sida (Sida spinosa) are the common 

 weeds; the large and small ragweeds should also be in- 

 cluded in this list. 



FrorrX western Iowa to Denver the weeds are much the 

 same as in Iowa and New England, except the false rag- 

 weed or marsh elder, Mexican fireweed, yellow and 

 white sweet clover, Russian thistle, buffalo bur, vegeta- 

 ble oyster plant, wild licorice, tarweed or rosin weed 

 (Grindelia squarrosa), perennial ragweed (Ambrosia psil- 

 ostachya), prickly poppy (Argemone intermedia), woolly 

 thistle (Cirsium canesccns), Fremont's goosefoot (Chen- 

 opodinm Fremontii) and annual sunflowers (Helianthus 

 annuus and H. petiolaris) are common. The latter are 

 abundant from western Iowa to Texas. The cleome is 

 abundant on the plains. 



In the interior basin, awned brome grass, conium, wild 

 barley, peppermint, caraway, horehound (Marrubium 

 vulgare), pineapple weed and black medic are among the 

 common weeds. 



In California the more important weeds are wild lic- 

 orice, spiny cocklebur, wild heliotrope, crowfoot grass, 

 crab grass, milk thistle, storksbill, bur clover, tarweed, 

 wild carrot, etc. 



In Maryland and Virginia, wild onion, dandelion, wild 

 carrot, prickly lettuce, sweet clovers, horseweed, cockle- 

 bur, Mexican tea and pigweed are common. 



In the Gulf states the narrow-leaved sneezeweed, pig- 

 weed (Boerhaavia), sida, morning glory (Ipomoea hedera- 

 cea), croton (C. capitatus and C. monanthogynus), crab 

 grass, etc., are the common weeds, and westward in 



