266 MISSISSIPPI STATE GEOLOGICAL SURVEY [Bull. 
Occurs with the last throughout the State. Hattiesburg. 
Spring 
Geol. Surv. Herb. 
AMBROSIACEAE. Ragweed Family. 
AMBROSIA L. Ragweed. 
Ambrosia bidentata Michx. lLance-leaved Ragweed. 
Dry open pasture and edges of copses. Oxford. Sum- 
mer. 
Ambrosia trifida L. Tall Ragweed. 
Rich moist soil, borders of lowland fields throughout the 
state. Lafayette Co.; Chickasaw Co. July-Sept. 
Ambrosia artemisiaefolia L. Hogweed. Ragweed. 
Edges of dry upland cultivated fields throughout the 
state. Oxford ;May St. Louis (Allison). July-Sept. 
Allison Herb. 
IVA L. 
Iva imbricata Walt. Seaside Marsh Elder. . 
Damp low beaches along the Gulf Coast. Coastal Islands 
(Tracy.) Summer and Fall. 
Iva frutescens L. Shrubby Marsh Elder. 
Low muddy beaches and brackish marshes along the coast. 
Horn Island. Summer and fall. 
Geol. Surv. Herb. 
Iva caudata Small. 
Low wet ground and swamps. (Small.) Fall. 
XANTHIUM L. 
Xanthium strumarium L. Cocklebur 
Cultivated and low open ground. Summer. 
Xanthium canadense Mill (echinatum Murr.) Common Cockle- 
bur. 
Throughout the state in cultivated ground, especially low 
rich fields. 
