122 GENUS ARTEMISIA. 



216. Artemisia campestris pacifica (Nuttall). — Root perennial; stems several or 

 numerous, 4 to 6 dm. high, erect from a spreading base, densely leafy below, moderately 

 leafy up to the inflorescence; leaves twice pinnately divided into narrowly linear divisions 

 about 1 mm. wide, canescent or silky pubescent, seldom if ever glabrate; inflorescence 

 an elongated panicle of numerous closely ascending branches, 3 to 12 cm. broad or 

 occasionally narrowed to 1 cm.; heads subsessile, horizontal or erect, hemispheric; 

 involucre 2 to 3 mm. high, about 2.5 mm. broad, glabrous or sparingly short-hairy, 

 greenish; disk-flowers 10 to 25, the corolla 1.8 to 2.5 mm. long. {A. pacifica Nuttall, 

 Trans. Am. Phil. Soc. II, 7:401, 1841.) The common form in western United States: 

 South Dakota and western Nebraska to New Mexico, Arizona, Oregon, Yukon, and 

 Saskatchewan. Type locality, shores of the Pacific at the outlet of the Oregon (Columbia 

 River), in sandy places. Collections: Brookings, South Dakota, September, 1894, 

 Thornber (UC) ; Laramie, Wyoming, Nelson 7983 (Or, NY, UC, as A. camporum Rydberg, 

 minor variation 7);Kiowa Valley, western Nebraska, Rydberg 203 (NY, same variation); 

 Ruxton Dell, Pikes Peak, Colorado, Clements 156 (DS, Gr, NY, US, same variation); 

 La Sal Mountains, Utah, Purpus 7019 (UC) ; near Silver City, New Mexico, October 8, 

 1880, Greene (UC) ; San Francisco Mountains, Arizona, Leiberg 6840 (US) ; Bingen, Klicki- 

 tat County, Washington, Suksdorf 4602 (DS, US) ; Vancouver Island, British Columbia, 

 August 16, 1887, Macoun (NY, US); Clarks Fork Valley, northern Idaho, Leiberg 1580 

 (Gr, UC, NY, US) ; Bozeman, Montana, Blankinship 304 (hb. Blankinship) ; Whiteshore 

 Lake, Saskatchewan, Macoun and Herriot 72832 (NY, minor variation 7, A. camporum 

 Rydberg). 



21c. Artemisia campestris caudata (Michaux). — Root biennial, often very large 

 when growing in sand-dunes, but perhaps never perennial; stem usually single unless 

 injured, erect, 3 to 5 dm. high, leafy at base and up to the inflorescence or sparsely leafy 

 above; leaves twice or thrice pinnately divided into elongated diverging filiform or very 

 narrowly linear divisions 0.5 mm. or less wide, the upper ones more simply cut, glabrous 

 or sometimes canescent when young (in A.forwoodi Watson, minor variation 18) ; inflores- 

 cence a narrowly pyramidal panicle of ascending rather close branches, 3 to 10 cm. broad; 

 heads peduncled, nodding or erect, narrowly hemispheric; involucre 2 to 3 or rarely 3.5 

 mm. high, about as broad, glabrous, yellowish green; disk-flowers 5 to 15, the corolla 

 1.5 to 2.2 mm. long. {A. caudata Michaux, Fl. Bor. Amer. 2:129 1803.) Widely, 

 distributed but most common in the eastern and central States: New Brunswick and 

 Maine to Florida, Texas, Wyoming, Washington, Saskatchewan, and Ontario. (Speci- 

 mens seen from south of Connecticut and Illinois are without roots and their identifica- 

 tion therefore not absolutely positive.) Type locality, sandy banks of the Missouri 

 River. Collections: Pine Point, Maine, Purlin 1097 (N. E. Bot. Club); Lynn Beach, 

 Massachusetts, August, 1887, Summers (US); North Haven, Connecticut, Bissell 878 

 (Gr); Hennepin County, Minnesota, August, 1890, Sandberg (UC); Washington Island, 

 Wisconsin, September 12, 1889, Shuette (Gr, UC) ; sandy barrens near Oquawka, Illinois, 

 August, 1877, Patterson (UC); sand dunes at Millers, Indiana, September 4, 1911, 

 Sherff (US); Blue River, Nebraska, September, 1888, Wibbe (UC); vicinity of Pine 

 Grove, Colorado, Crandall 2640 (US) ; Deadwood, South Dakota, Carr 29 (NY, minor 

 variation IS, A. forwoodi Watson); Willow City, North Dakota, September 11, 1899, 

 Lunell (NY, same variation); near Bingen, Washington, August, 1907, Suksdorf (NY); 

 Brandon, Manitoba, Macoun 12247 (NY). 



21d. Artemisia campestris borealis (Pallas). — Root perennial; stems several, 

 crowded on a multicipital caudex, 1 to 3 dm. high, erect from a sometimes spreading base; 

 densely leafy only below, sometimes moderately leafy to midway of the inflorescence; 

 leaves once or twice ternately divided into linear divisions, mostly 1 to 2 mm. wide, or 



