10 THE INDIANA WEED BOOK. 



beds in the bared soil along the tracks where they sprout and grow 

 until ready to take another step in advance. The botanist has 

 learned their ways of migration and knows that if he wishes to 

 find new and interesting species his best pathway will be alongside 

 the railways. 



Many seeds are introduced in the packing about crates of china 

 or glassware, shipments of nursery stock and in baled hay. Many 

 more are distributed by being mixed with commercial seeds, such 

 as those of clover, wheat, flax and grasses. 



On his harrows, plows and cultivators the farmer often carries 

 pieces of rootstocks, bulbs, etc, from one field or farm to another. 

 Perennial weeds such as couch-grass, trumpet-creeper, bouncing 

 bet, bindweed and ox-eye daisy are the ones most generally scat- 

 tered in this manner. Wagons, self-binders and especially thresh- 

 ing machines are responsible for the distribution of many weed 

 seeds which are jostled from them as they pass along the roadways 

 or over the fields from farm to farm. Many a well managed farm 

 often becomes infested with noxious weeds in this way. Barnyard 

 manures, and especially manures hauled from cities and towns 

 where much of the feed-stuffs have been purchased from a distance, 

 are also active agents in the spread of weed seeds. 



The above are some of the indirect ways in which man has 

 brought about the wide distribution of noxious weeds. He is also 

 directly responsible for the spread of many weeds by introducing 

 them into his gardens or fields, cultivating them for a time and 

 then allowing them to escape. Such well known weeds as wild 

 garlic, purslane, tansy, bouncing bet, oxe-eye daisy, chicory, wild 

 carrot, butter and eggs, catnip and motherwort have been widely 

 spread in this way. Suffice it to say that many of our most com- 

 mon weeds are those which have been introduced directly or in- 

 directly by man into some locality, have there been allowed to 

 grow for a few years in his cultivated fields or under his care, 

 and have thus become acclimated and better adapted for a wide 

 and successful migration throughout the land. 



Those weeds which are most common and successful in culti- 

 vated fields are in general those which by reason of a quick growth 

 are enabled to produce and ripen an enormous number of seeds. 

 Careful estimates made by the Iowa and Kansas Experimental 

 Stations show that the number of seeds produced by a single aver- 

 age full grown specimen of 15 of our most common weeds is as 

 follows : 



