A. TRIDENTATA. 137 



resinous-granuliferous. {A. tridentata Nuttall, Trans. Am. Phil. Soc. II, 7:398, 1841.) 

 Montana to western Dakotas, New Mexico, Lower California, Washington, and British 

 Columbia, by far the most abundant form over all this region. Type locality, plains of 

 the Columbia River. Collections: Near Glendive, Montana, Sandberg 1010 (Gr, NY, 

 US); Laramie Hills, Wyoming, Nelson 53S5 (UC); near Dulce, New Mexico, Standley 

 8107 (US); Navajo to Hawthorn, Arizona, Griffiths 5798 (US); east of Ensenada, Lower 

 California, Goldman 1117 (US); San Pedro Martir, Lower California, May 6, 1893, 

 Brandegee (UC) ; Alamo Mountain, Ventura County, California, Baldwin 104 (UC); 

 Butte Valley, Siskiyou County, California, Butler 1883 (UC, US); Steins Mountains, 

 Nevada, Griffiths and Morris 656 (NY, US); type collection, "plains of the Columbia 

 and Lewis River," Nuttall (Gr), also "Rocky Mountains and Lewis River," Nuttall 

 (Phila.); eastern Oregon, Cusick 2505 (Gr, NY, UC, US); Bingen, Klickitat County, 

 Washington, Suksdorf 2687 (Gr, US); Kamloops, British Columbia, July 28, 1890, 

 Macoun (NY, US); Big Butte Station, Idaho, Palmer 498 (US). 



256. Artemisia tridentata parishi (Gray). — Shrub normally 10 to 20 dm. high, 

 erect, with ascending branches, the main ones trunk-like ; leaves spatulate (usually very 

 narrowly so) or linear, 2 to 3 cm. long, mostly entire but some obtusely 2- or 3-toothed 

 at the summit; inflorescence openly paniculate, 2 to 10 cm. broad (much condensed 

 in unfavorable seasons); heads narrowly campanulate, 2.2 to 3 mm. broad; involucre 

 canescent; flowers 4 to 6; corolla 2 to 2.5 mm. long; achenes glandular and also short- 

 villous with crisp hairs or these sometimes longer and arachnoid. {A. parishi Gray, 

 Proc. Am. Acad. 17:220, 1882.) Southwestern part of the Mojave Desert, California, 

 extending to the coastal slope along the Santa Clara River, also in western Nevada.' 

 Type locality, Newhall, Los Angeles County, California. Collections (all in California 

 except the last): Near Rosamond, Antelope Valley, Davy 2933 (UC); 2 km. west of 

 Rosamond, Hall 10959; type collection, 1881, Parish 1065 (Gr, NY, UC, US); dry valley 

 bottom at junction of Piru Creek and Santa Clara River, Ventura County, October 20, 

 1919, Hall (UC); Carson Sink Region, west central Nevada, Kennedy 1692 (DS, NY, 

 UC at least as to flowering specimens). 



25c. Artemisia tridentata nova (Nelson). — Shrub 1 to 3 dm. high, with numerous 

 erect slender branches from a spreading base; leaves cuneate or broader, 0.5 to 1.5 cm. 

 long, 3-toothed at the apex, or the upper ones (toward summit of inflorescence) linear 

 and entire; inflorescence a narrow but open panicle, 0.5 to 1.5 cm. broad; heads ovoid, 

 about 2 mm. broad; involucre greenish-yellow and nearly glabrous, except for the short 

 outer canescent bracts ; flowers 3 to 6 ; corolla 2 to 2.5 or 3 mm. long ; achenes resinous. {A . 

 nova Nelson, Bull. Torr. Club 27:274, 1900.) Idaho, Montana, and western Colorado 

 to New Mexico, Arizona, and eastern California, especially on hillsides and ridges of 

 plateaus and desert mountains. Tj-pe locality, Medicine Bow, Wyoming. Collections: 

 Midway between Strevell and Albion, southern Idaho, September, 1919, Hall (CI); 

 near Radersburg, Montana, August 27, 1882, Canby (Gr); Laramie Hills, Wyoming, 

 Nelson 5334 (Gr, NY, UC); Gunnison, Colorado, Underwood and Selby 4OO (US); 

 Panguitch Lake, Utah, Jones 5997 (NY, UC, US); near Dulce, New Mexico, Standley 

 8099 (US) ; mesa west of Buckskin Mountains, Arizona, Jones 6063F (NY, UC) ; Mount 

 Irish, Nevada, Purpus 6333 (UC, US); Silver Canon, Inyo Range, California, Hall 

 10639 (UC). 



25d. Artemisia tridentata trifida (Nuttall). — Shrub 2 to 6 dm. high (perhaps 

 sometimes much higher), usually with erect trunk-like main stems; leaves cuneate or 

 flabelliform, 1.5 to 4 cm. long, deeply 3-cleft into linear or linear-oblanceolate divisions 



' Reported in the original description as occurring also in Cajon Pass, California, but this was an error (Pariah, Zoe 

 6: 120, 1901). 



