Notes on Some of the Species. 



Plate 119. — Andropogon Halepense, Brot. var efFusus, Stapf. 



In June, 1901, an assistant in the office of the Agrostologist of the United States 

 of America was directed to make investigations, and to repoi-t on the methods used for 

 the extermination of this grass in places " where it had become a pest." The report was 

 published in pamphlet form, and the following is a summary : — 



" ,1 ohnson grass is a tall, vigorous grass, closelj related to the Sorghums, 

 with a very strong system of long, jointed, underground stems, popularly known 

 as roots. Each joint of this underground stem is capable of producing a new 

 plant. 



" It is a native of the tropics of the Old World, and was first introduced 

 into this country as a hay grass in South Carolina about sixty years ago. 



" It has spread rapidly throughout the entire south to the Pacific coast, ajid 

 thence to British Columbia. It thrives best in rich, moist alluvial or irrigated 

 soil, where it is als j most difficult to eradicate. 



" It is commonly spread by means of its seeds. They are widely scattered 

 from hay, cut after the seed has matured, and are often planted with seed oats. 

 The seeds are unharmed by passing through the digestive tract of animals, and 

 ai^e thus widely scattered in manure. 



" The grass should never be allowed to ripen its seed in meadows, fields, or 

 along roads, fences, or railways. 



" It can be destroyed by hand labour, digging out the underground stems. 



" Under field conditions, it is best, killed by ploughing fallow land during 

 hot, dry weather. The stems are thus exposed to the heat of the sun and soon 

 killed. The same result follows the action of severe frosts. 



" It can also be killed during the cultivation of a cutton crop by much extra 

 hand labour. 



"Various chemical substances have been tried, but none have thus far 

 proved successful and economical. 



" Johnson grass makes a veiy good quality of hay when cut M'hen just in 

 flower, and it may be profitably cultivated throughout the south for this purpose. 



" Meadows should be broken up at least every third year to loosen the 

 matted stems. It is not necessary to 're-seed the meadows when thus treated. 



" Cow peas may be sown in the grass when it is broken in the spring. When 

 broken in the fall, oats may be used with it. It affords good pasture during 

 summer when treated in the same way as meadows." 



Our plant, it will be seen, is the variety " effusus," but from experience in the Botanic 

 Gardens it will be found quite as difficult to eradicate as the type. 



Plate 122. — ^ Andropogon Nardus, Linn, var validus, Stapf, 



Of this grass Baron F. v. Mueller says : " One of the lemon-scented grasses. . . . 

 It yields an essential oil for condiment and perfumery, and is occasionally used for tea. 

 Simmonds gives the export value of this oil as from Ceylon alone at £7,000." 



