A. BIENNIS. 101 



12. ARTEMISIA BIENNIS Willdenow, Phytogr. 11, 1794. Plate 10. Biennial Sagewort. 



An annual or biennial herb from a taproot, 3 to 30 dm. high, nearly inodorous; stem 

 simple up to the inflorescence, erect, striate, glabrous, often tinged with red; basal leaves 

 crowded, widely petioled, 5 to 15 cm. long, twice pinnately parted or divided into lan- 

 ceolate sharply toothed or cleft divisions, glabrous; upper leaves mostly larger, once 

 pinnately parted into lanceolate toothed or entire divisions, glabrous; inflorescence a 

 compound terminal spike, leafy throughout, 10 to 50 cm. long by 1 to 2 cm. broad or 

 rarely the lower branches elongated and the inflorescence thus much broader, the short 

 branches rigidly ascending; heads heterogamous, sessile, crowded, erect; involucre 

 hemispheric, 2 to 3 mm. high, slightly broader; bracts 8 to 14, the outer ones narrow 

 and green, the inner ones nearly orbicular and scarious except along the green midrib, 

 all glabrous; ray-flowers 6 to 22 or perhaps more numerous, fertile, corolla oblique, 

 slightly under 1 mm. long, granular; disk-flowers 15 to 40, fertile, corolla campanulate, 

 about 1 mm. long, 3- or 4-toothed, granular; style-branches flat, truncate; achenes ellip- 

 soid, longitudinally 4- or 5-nerved, glabrous. 



Widely distributed in North America except in the southeast, presumably native only 

 from the northern Rocky Mountains to British Columbia; Nova Scotia to New Jersey, 

 Missouri, New Mexico, southern California, and British Columbia; also in Kamchatka. 

 Type locality, said to be New Zealand, but this is erroneous. Collections: Gloucester 

 County, New Brunswick, Blake 5639 (Or); Longueil, Quebec, Brother Vidorin 1054 

 (US); Naugatuck, Connecticut, August 30, 1903, Bristol (Or); Canton, New York, Phelps 

 1016 (Gr); Wayne County, Michigan, September 16, 1916, Chandler (US); Iowa City, 

 Iowa, Somes 3923 (US) ; Sheffield, Missouri, Bush 3300 (Gr, NY, US) ; Castle Rock, Col- 

 fax County, New Mexico, August 28, 1913, Wooton (US); Palo Alto, California, Baker 

 172 (DS, Gr, SF, US); Columbia River, in Klickitat County, Washington, September 

 29, 1883, Suksdorf (US); Beavermouth, British Columbia, Shaw 1192 (Gr, NY); vicinity 

 of Glacier Park Station, Montana, Standley 17659 (US); Traverse County, Minnesota, 

 September, 1893, Sheldon (US); Thomas Lake, Saskatchewan, Macoun and Herriot 

 72834 (NY). 



REIATIONSHIPS. 



The close connection between this species and the two next following will be discussed 

 under A. annua. It can not be separated from annua on the duration of the root, since 

 this is variable and dependent upon local conditions. The most striking difference is 

 the character of the inflorescence, but even this is untrustworthy in reduced forms in 

 which the small heads closely simulate those of annua. The heads, however, are never 

 nodding and never distinctly pedunculate, and the achenes are larger and more distinctly 

 angled. Mature achenes are 1 mm. long, while those of related species are only 0.5 

 to 0.8 mm. long. Apparently there is a marked difference in the odor of the crushed 

 herbage, but this requires verification by field examination of specimens from numerous 

 widely separated localities. There is little to indicate which of these two species is the 

 more primitive, but the larger heads with more numerous flowers seem to assign this 

 position to biennis. A. annua then becomes a derivative that has undergone a reduction 

 in the number of flowers at the same time that the inflorescence has become more freely 

 branched and the heads smaller in size. 



ECOLOGY AND USES. 



Artemisia biennis is a biennial or annual with a taproot, blooming from August to 

 December. It occasionally forms clans in the grassland formation, but it is typically 

 a ruderal, growing along roadsides and in waste places. In these, as well as in burns, 

 it sometimes makes a pure consocies, but it is usually associated with other weeds, such 

 as Medicago hispida, Madia saliva, and Centaurea melitensis. 



