108 GENUS ARTEMISIA. 



ECOLOGY AND USES. 



The ecology of this species as a native plant is unknown; in this country it is a ruderal, 

 associated for the most part with other roadside weeds. 



This herb, now commonly known as wormwood, was much used by the ancients for 

 various maladies and for counteracting witchcraft and necromancy. It is still grown in 

 Europe and to some extent in this country as a medicinal plant. An infusion prepared 

 from the leaves and tops is useful as a mild tonic when taken in moderate doses, but it is 

 very powerful when administered in quantity. It was formerly used also as an anthel- 

 mintic and thus acquired its common name of wormwood. A dark-green volatile oil 

 is obtained by distillation of the dry tops. This oil has the strong odor of the plant and 

 is a powerful local anaesthetic, being useful when applied locally for rheumatic pains and 

 in the form of a liquor as a narcotic stimulant in cerebral exhaustion. It has been found 

 by Charabot and Laloule (Bull. Soc. Chim. France 4:280-290, 1907) that this oil forms 

 most abundantly just before the flowering period and that it is more plentiful in the 

 leaves than in the stems. These investigators suggest that it is used in completing the 

 ripening of the seed. No oil was found in the roots until after the period of flowering, 

 when its relative proportion was considerably increased. Salt of wormwood is the ash 

 left after burning and consists chiefly of carbonate of potash. The well-known absinthe, 

 used especially in France, is a beverage made by infusing the plant in alcohol. In some 

 European countries the leaves are used in place of hops in the manufacture of beer. 



17. ARTEMISIA FRIGIDA Willdenow. Sp. PI. 3:1838, 1804. Plate 11. Prairie 

 Sagewort. 



A perennial herb but often decidedly woody at the base or even somewhat shrubby, 

 1 to 4 dm. high, very fragrant; stems freely branched from the base, decumbent or 

 spreading below, the annual branches erect, very leafy, not striate, cinereous or silky, 

 the old bark brown; basal leaves crowded, petiolate, roundish in outline, 0.5 to 1 cm. 

 long beyond the petiole, twice ternately or quinately dissected into linear or narrowly 

 oblanceolate acute divisions and usually a pair of simple or 3-parted stipule-like divisions 

 at base of petiole, silvery-canescent ; upper leaves like the lower, but less dissected and 

 becoming sessile ; inflorescence a narrow short-leafy panicle with nearly erect racemif orm 

 branches, 10 to 30 cm. long, 1 to 10 cm. broad, or much reduced and raceme-like in dwarf 

 forms of poor soil; heads heterogamous, sessile or short-peduncled, nodding; involucre 

 hemispheric, 2 to 3 mm. high, 4 to 5 mm. broad; bracts 11 to 18, those of the outer series 

 linear and herbaceous (scarcely shorter than the inner), the others lanceolate to ovate, 

 all densely long-villous, the inner with broad whitish scarious margins; receptacle densely 

 villous; ray-flowers 10 to 17, fertile, corolla contracted above, about 1 mm. long; disk- 

 flowers 25 to 50, fertile, corolla funnelform, 1.5 to 2 mm. long, 5-toothed, glabrous 

 or granular-granuliferous especially on the tube; style-branches of ray-flowers obtuse, 

 of disk-flowers truncate and fimbriate at the ends; achenes subcylindric, narrowed at 

 base, truncate or slightly rounded at summit, scarcely ribbed, glabrous. 



On high plains and in the mountains, Saskatchewan to Minnesota, Kansas, western 

 Texas, northwestern Arizona, Utah, British Columbia, and Alaska; also native of Siberia; 

 introduced in Nova Scotia, eastern Canada, and New Jersey. Type locality, Davuria, 

 eastern Siberia. Collections: Vicinity of Ottawa, Ontario, Rolland 6120 (Gr); Fairville, 

 New Brunswick, in train yards, Fernald 2266 (Gr); Custer, Montana, September 10, 

 1890, Blankinship (UC); Brookings County, South Dakota, August, 1892, Thornber 

 (Gr, UC); near Minneapolis, Minnesota, August, 1889, Sandberg (UC, US); Laramie 

 Hills, Wyoming, Nelson 5336 (UC); Thomas County, central Nebraska, Rydberg 1733 

 (Gr, US); Denver, Colorado, Eastwood 122 (Gr, UC); east of Eagle Mountain, Texas, 

 November 1881, Havard (US); near Pecos, San Miguel County, New Mexico, Standby 



