COMPOSITAE 



COMPOSITE FAMILY 



TALL WORMWOOD 



Artrmisia caiidata Michx. 



Several kinds of Wormwood occur in Illinois, mostly in 

 sandy soil, and some of them are very difficult to distinguish. 

 The Wormwoods and Sagebrush of the west are Artemisias. 

 A flowering plant called 

 Broom Rape, which has 

 no green tissue, often 

 grows as a root para- 

 site on Wormwood. 



The Tall Wormwood 

 grows only in sandy soil 

 from Quebec, Ontario 

 and Manitoba to Indi- 

 ana, Nebraska and 

 Texas, and is especially 

 common along Lake 

 Michigan. It is one of the 

 few plants that can grow 

 on dune sand, where 

 there is extremely little 

 organic food matter. The 

 slender stems are much 

 branched, very leafy and 

 1-6 feet high. 



The lower and basal leaves, as well as those of the sterile 

 shoots, are 3-6 inches long, slender petioled and 2-3 times pin- 

 nately divided into very narrow linear lobes. The upper leaves are 

 sessile or nearly so and pinnately divided or the topmost entire. 



The blooming season is July to September. The numerous 

 heads are very small, very short peduncled, mostly nodding, and 

 only the outer flowers of each head produce akenes, the inner 

 ones being sterile. The involucre is composed of ovate bracts and 

 is smooth. There are neither ray flowers nor pappus. 



The Biennial Wormwood, Artemisia biennis Willd., is widely 

 distributed nearly throughout the state as a weed. It is not, however, 

 strictly biennial, but annual or winter annual, and a better name is 

 False Tansy or Bitterweed. It is smooth and the stem is very leafy, 

 usually branched and 1-4 feet high. The leaves are 1-3 inches long 

 and once or twice pinnately divided into narrow, toothed lobes. 

 The very small heads are exceedingly numerous in crowded axillary 

 clusters. The flowers are greenish yellow and all produce akenes. 



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