WEEDS. 159 



III. Forage Plants. 



None of the native or naturalized forage plants take rank with 

 red clover, timothy and blue grass, which are cultivated for this 

 special purpose. Nevertheless there are among them many- 

 species which contribute liberally to the forage supply of the 

 county. Indeed during dry seasons all species which are not 

 protected by harsh structures, such as spines, etc., or by poison- 

 ous, or at least disagreeable, products with repelling taste and 

 odor, are eaten more or less by cattle. Formerly the native 

 herbs, especially grasses, which covered the prairies, formed 

 valuable pasture and hay, but so little of the original prairie 

 remains that most of these species have disappeared, or are 

 found only sparingly. With the exception of the clovers the 

 best forage plants are grasses. The most valuable species of 

 prairie and meadow were Cinna, Calamagrostis and the two 

 species of Andropogon. Of less value are Bromus ciliatus and 

 kalmii, and Agropyron tenerum and occidentale, while coarser, 

 harsher grasses like Muhlenbergia mexicana and glomerata, 

 Spartina and Leersia have little beyond bulk to recommend 

 them. Among introduced plants, in addition to the ubiquitous 

 blue grass and timothy, Agrostis alba, Dactylis and Setaria 

 glauca have some fodder value, the last chiefly in stubble fields. 

 IV. Weeds. 



All plants which have sufficient persistence and adaptability 

 to become weeds are of public interest. Among the plants of 

 Winneshiek county there are not only many introduced weeds, 

 but some of the native plants have so far changed their habits 

 that they, too, have become pernicious weeds. Among the most 

 vicious of the former, both because of abundance and persist- 

 ence, are the following: black bind-weed (Polygonum convol- 

 vulus), curly dock (Rumex crispus), the species of Amaranthus, 

 plantain (PI ant a go major), both species of Brassica, shepherd's 

 purse (Bursa), both sweet clovers (Melilotus), round-leaved 

 mallow (Malva rotundifolia), wild parsnip (Pastinaca), ground 

 ivy (Glecoma), chickweed (Alsine media) , purslane (Portu- 

 laca), the thornapples (Datura), dandelion (Taraxacum), 

 prickly lettuce (Lactuca scariola), dog-fennel (Anthemis), 

 burdock (Arctium), field-thistle (Carduus lanceolatus) , Canada 

 thistle (C. arvensis) and the panic grasses (Panirum crus-galli 



