WEEDS OF THE THISTLE FAMILY. 



163 



129. ARTEMISIA BIENNIS Willd. Wormwood. (A. or B. N. 2.) 



Stem erect, very leafy, branched, 1-^1 feet high ; leaves alternate, once 



or twice divided into linear or oblong, 

 toothed lobes. Heads small, numerous, 

 sessile in dense axillary clusters or short 

 spikes; involucre cup-shaped, its bracts 

 green with dry margins; receptacle flat, 

 naked; flowers tubular, greenish. Achenea 

 small, slender; pappus none. (Fig. 123.) 



Common along dry gravelly banks 

 of streams, roadsides and waste places 

 about cities and towns in southern In- 

 diana; less so northward. July-Sept. 

 It has a disagreeable, penetrating odor 

 and a bitter taste. With us it is the 

 most common of 6 or 7 species of so- 

 called wormwoods, all of which are 

 homely, weed-like plants. Remedies: 

 pulling or grubbing; mowing several 

 times before the heads mature. 



Fij. 123. Head of flowers below; s. 

 era above. (After Britton and lii 



:oflcw- 



130. ERECHTITES HIERACIFOLIA L. Fireweed. Pilewort. (A. N. 3.) 

 Stem erect, branching, grooved, succulent, 1-8 feet high; leaves thin, 



alternate, lanceolate or narrowly ovate, cut-toothed, 2-8 inches long. 

 Heads rather large, in an open panicle at the ends of the branches; in- 

 volucre cylindric, swollen at base, its bracts linear in one row; receptacle 

 concave, naked ; flowers white, all tubular. Achene linear-oblong, grooved ; 

 pappus a large tuft of smooth white hairs. 



Frequent in rich moist soil along borders of woods and thickets. 

 Very common in newly cleared ground, especially where brush-piles 

 have been burned. July-Sept. In a deadening caused by fire this 

 weed is the first plant to spring up, often taking complete posses- 

 sion of the soil for a year or two, then giving way to more hardy 

 species. The foliage is often attacked by mildews and a small 

 Carabid beetle (Anisodactylus terminatus Say) is sometimes found 

 by scores feeding upon its ripening seeds. An ointment made from 

 the essential oil is said to be a most excellent remedy for piles. It. 

 seldom occurs in cultivated fields and being an annual is easily 

 controlled by mowing or pulling before the flowers appear. 



131. ARCTIUM MINUS Schk. Common Burdock. (B. I. 1.) 



Stem erect, grooved, fleshy, much branched, 1-5 feet high ; leaves thin, 

 alternate, broadly ovate, pale and somewhat woolly beneath, the lower 

 often 15 inches long, their stalks hollow, grooved, margins wavy or 

 toothed. Heads numerous in dense clusters; involucre f inch broad, sub- 



