Genus SS.] 



THISTLE FAMILY 



io. Artemisia annua L,. Annual 

 Wormwood. (Fig. 4007.) 



Artemisia annua I,. Sp. PI. 847. 1753. 



Annual, glabrous throughout, much branched, 

 2-5 high. Leaves 2 / -6 / long, finely 2-3-piunateh' 

 dissected into very narrow short obtuse" lobes, the 

 lower and basal ones slender-petioled, the upper 

 sessile and less divided, but none of them entire; 

 heads very numerous, about \' f broad, drooping, 

 borne on very slender peduncles of about their own 

 length or less; involucre hemispheric, glabrous, 

 its bracts few, ovate to oblong; receptacle glabrous; 

 flowers commonly all fertile. 



c * In waste places, Ontario to West Virginia, Tennessee 

 and Kansas, a bad weed in some places. Adventive or 

 naturalized from Asia. Summer. 



11. Artemisia biennis Willd. Biennial 

 Wormwood. (Fig. 4008.) 



Artemisia biennis Willd. Phytogr. n. 1794. 



Annual or biennial, glabrous throughout; stem very 

 leafy, usually branched, i-4 high, the branches 

 nearly erect. Leaves i / -t > / long, 1-2-pinnately di- 

 vided into linear or linear-oblong, acutish, serrate or 

 incised lobes, the lowest petioled, the uppermost less 

 divided or rarely quite entire; heads about i^ // 

 broad, not drooping, sessile and exceedingly numer- 

 ous in axillary glomerules which are crowded, form- 

 ing a compound spicate inflorescence, the subtend- 

 ing leaves much exceeding the clusters; involucre 

 nearly hemispheric, its bracts green, scarious-mar- 

 gined; receptacle naked; central flowers fertile. 



Native in the Northwest Territory and the northwest- 

 ern United States, now widely distributed as a weed from 

 Manitoba to Nova Scotia, south to Missouri, Kentucky 

 and Pennsylvania. Plant not odorous. Aug.-Oct. 



12. Artemisia Stelleriana Bess. Beach 



Wormwood. (Fig. 4009.) 

 Artemisia Stelleriana Bess. Abrot. 79. pi. 5. 1829. 

 Perennial, densely white-tomeutose; stem 

 branched, i-2 / ^ high, bushy, the branches 

 ascending. Leaves obovate to spatulate, x f -\' 

 long, pinnatifid into oblong obtuse entire or 

 few-toothed lobes, the lower petioled, the upper 

 sessile, all densely tomentose beneath, but be- 

 coming green and glabrous above when old; 

 heads racemose-spicate or racemose-glomerate, 

 3 // -4 // broad, not drooping; involucre oblong- 

 campanulate, its bracts tomentose, lanceolate or 

 oblong-lanceolate; receptacle naked; central 

 flowers fertile. 



f Sandy sea-beaches, Maine and Massachusetts to 

 New Jersey. Cultivated in gardens along the coast. 

 Native of northeastern Asia. Occurs also on the 

 coast of Sweden. Foliage similar to that of the 

 Dusty Miller, Cineraria maritima L- July-Aug. 



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