I0l8 



Leaves lanceolate, oblanceolate, or linear, serrate, somewhat lobed, or entire, not 

 piniiatifid. 



Leaves lanceolate, sharply serrate, glabrous above. 16. A. serrata. 



Leaves linear, oblong or lanceolate, entire or lobed. 



Leaves elongated, at length glabrous above. 17. A. longifolia. 



Leaves shorter, oblanceolate, oblong, or lanceolate, tomentose both sides. 

 Heads 4 mm. high, 2.5-3 mm. broad; leaves entire or some of the lower 



toothed, white-tomemose on both sides. 18. A. gnaphalodes. 



Heads 3 mm. high, 2-2.5 mm. broad; leaves, except the upper ones, 



deeply 3-7 lobed, greener above. 19. A. Ludoviciana. 



Leaves cuneate, i cm. long, 3-toothed at the apex. 20. A. Bigclovii* 



* * * Flowers all perfect and fertile; far western species. 



Leaves cuneate, 3-toothed or 3-lobed. ax. A. tridentata. 



Leaves linear, entire. 22. A. cana. 



1. Artemisia caudata Michx. TALL OR WILD WORMWOOD. (I. F. f. 3998.) 

 Root biennial (sometimes perennial?); stems slender, glabrous, tufted, strict, very 

 leafy, 0.6-2 m. high, at length paniculately branched; branches glabrous, or rarely 

 slightly pubescent, nearly erect. Lower and basal leaves and those of sterile shoots 

 slender-petioled, sometimes a little pubescent, 7-15 cm. long, 2-3-pinnatelj 

 divided into lobes about I mm. wide; the uppermost entire and short; heads short 

 peduncled, mostly nodding; bracts of the ovoid-campanulate involucre ovate, or 

 the inner elliptic, glabrous; receptacle hemispheric, naked; central flowers sterile. 

 In dry sandy soil, abundant on sea-beaches, Quebec to Fla. 7 Manitoba, Neb. and 

 Tex. July-Sept. 



2. Artemisia borealis Pall. NORTHERN WORMWOOD. (I. F f. 3999.) 

 Perennial, 12-35 cm. high, densely silky-pubescent all over. Leaves less divided, 

 the basal and lower ones petioled, 2-6 cm. long, the upper sessile, linear and entire 

 or 3-parted; heads about 4 mm. wide in a dense, terminal, rarely branched thyrsus; 

 involucre nearly hemispheric, its bracts brown or brownish, pilose-pubescent or 

 nearly glabrous; receptacle convex, naked; disk-flowers sterile. Me. (according 

 to Fernald); Quebec to Greenland, west through arctic Am. to Alaska, south to 

 Colo. Also in northern Asia. July-Aug. 



3. Artemisia Canadensis Michx. CANADA WORMWOOD. (I. F. f. 4000.) 

 Root perennial (or sometimes biennial); stem pubescent or glabrous, strict, 3-6 

 dm. high, the branches appressed and erect. Leaves usually pubescent, but some- 

 times sparingly so, the basal and lower ones petioled, 5-8 cm. long, 2-pinnately 

 divided into lobes which are shorter and broader than those of Artemisia caudata; 

 upper leaves sessile, less divided; heads short-peduncled, mostly spreading or 

 erect, in small forms the panicle reduced to a nearly or quite simple terminal 

 raceme; involucre ovoid, its bracts ovate or oval; receptacle hemispheric; central 

 flowers sterile. In rocky soil, Hudson Bay to northern Me. and Vt., west to Minn., 

 Manitoba, the Canadian Pacific Coast, south to Ariz, and Neb. July-Aug. 



4. Artemisia dracunculoides Pursh. LINEAR-LEAVED WORMWOOD. (I. F. 

 f. 4001.) Perennial, glabrous; stem somewhat woody, usually much branched, 6-12 

 dm. high, the branches nearly erect. Leaves 3-9 cm. long, 2-4 mm. wide, acute, 

 entire, or the lower and basal ones sometimes 3-cleft or even more divided; heads 

 very numerous, 2-3 mm. broad, nodding, very short-peduncled, racemose-panicu- 

 late; involucre nearly hemispheric, its bracts ovate or oblong, green, scarious- 

 margined; receptacle hemispheric, naked. Dry plains and prairies, Manitoba to 

 the N. W. Terr., Br. Col., Neb., Tex. and Cal. July-Nov/ 



5. Artemisia glauca Pall. SILKY WORMWOOD. (I. F. f. 4002.) Perennial, 

 similar to the preceding species; stems strict, leafy, usually simple or little 

 branched, 3-6 dm. high, pubescent, tomentose or canescent, or glabrous below. 

 Leaves linear, 1-6 cm. long, about 2 mm. wide, entire, obtuse or obtusish, or thfl 

 lower or sometimes nearly all of them 3-cleft into linear lobes 2-4 cm. long; pan- 

 icle narrow, branched, its branches nearly erect; heads drooping, sessile, very 

 numerous, scarcely more than 3 mm. long; involucre hemispheric, its bracts scari- 

 ous-margined, obtuse; receptacle naked. Minn, and Manitoba to the N. W. Terr. 



6. Artemisia filifolia Torn SILVERY WORMWOOD. (I. F. f. 4003.) Stem 

 branched. 3-6 dm. high, the rigid branches nearly erect. Leaves 2-5 cm. long, 

 nearly all 3-parted into filiform entire segments less than I mm. wide, or the upper- 

 most undivided; heads exceedingly numerous, about I mm. broad, racemose, 



