326 



fitted for dissemination by tliis agency. Such fruits are tliose of narrow- 

 leaved doclv, sliowing a round, rough, spongy growth on the outside of each 

 of the close fitting, persistent sepals; of the Asa-Gray sedge, with its in- 

 flated saclv attached to the fruit.; of the arrowhead, with its corliy margined 

 fruits which are able to float on the water. 



Black-seeded Plantain 



The seeds or fruits of many weeds are in one way or another carried 

 by animals. Thus when sliglatly moist, the seeds of peppergrass, plaintain, 

 groundsel, dropseed grass, and many others, are sticky and will adhere to 

 animals' feet or covering. Some sedges, cliickweeds and catchflys have 

 sticky glands, by means of which they cling to passing objects. The fruits 

 of the avens, and the burs of the conanon burdoclv, are armed with hooks, 

 and the fruits of the bidens or beggar's ticks with spines, by means of which 



