108 HOW DO SEED PLANTS SUCCEED IN LIFE? 



How may we eradicate weeds? We have seen the harm that 

 weeds do. How can we get rid of them? The best way would 

 be by not letting them get started. In the fall, burn over all lots 

 that contain weeds. Prevent as many weeds as possible from 

 producing seeds, especially those near gardens or fields of grain. 

 This can be done by cutting the weeds before the seeds mature. 

 Keep weeds out of roadside areas by early cutting. Since sheep 

 like some kinds of weeds better than grass, they can be used in 

 some localities to keep down the weeds. But in the main, de- 

 stroying the weeds before they get a start seems to be the most 

 effective means of ridding a place of them. 



Self-Testing Exercise 



Weeds are injurious to man because they (1) his crops. 



Some weeds may (2) cattle. Weeds harbor dangerous 



(3). Hay fever is caused by the pollen of (4). 



Wheat rust is a (5). Farmers often (6) weed 



seeds with (7). Weeds may be eradicated by (8), 



and (9) them before their seeds (10). Some weeds 



are (11) to (12), and some for (13). Poi- 

 son ivy differs from Virginia creeper by having a leaf divided into 



(14) (15). Some poisonous weeds are (16) 



(17) and (18) (19). 



PROBLEM III. HOW ARE FRUITS AND SEEDS SCATTERED? 



Individual Project. Examine the fresh or preserved fruits of huckle- 

 berry, blackberry, wild strawberry, wild cherry, black haw, wild grape, 

 tomato, and currant. Report how many of the above have seeds with 

 hard coatings. Notice that in most, if not in all, edible fruits the fruit 

 remains green, sour, and inedible until the seeds are ripe. In the 

 state of nature, how might this be of use to a plant? 



Adaptations for seed dispersal : fleshy fruits with hard seeds. 



Plants are fitted to scatter their seeds by special appendages or 

 adaptations either in the fruit or in the seed. Various agents, 

 as the wind, water, birds, and other animals, make it possible for 

 the seeds to be taken away from the parent plant. 



