A. SCOPULORUM. Ill 



long, 0.5 to 1.5 cm. broad; heads heterogamous, subsessile or the lower long-peduncled, 

 inclined to nod; involucre hemispheric, about 4 mm. high, 4 to 6 mm. broad; bracts 11< 

 to 18, ovate or broadly lanceolate, somewhat acute, the inner ones narrowed at base, 

 villous, with greenish narrow backs and broad blackish scarious margins; receptacle 

 copiously villous; ray-flowers 6 to 13, fertile, corolla about 1.5 mm. long, funnelform, 

 often nearly regular and 4- or 5-toothed; disk-flowers 15 to 30, fertile, corolla funnelform, 

 2 to 2.5 mm. long, 5-toothed, long-villous on the teeth and usually also on the throat; 

 style-branches of ray-flowers smooth and obtuse at apex, of disk-flowers truncate and 

 penicillate at summit; achenes nearly cylindric but slightly narrowed at base, mostly 

 truncate at summit, smooth or faintly nerved, not pubescent. 



In the Rocky Mountains from Montana to southern Utah and New Mexico; most 

 common in Colorado; from just below to well above timber-line. Type locality, Rocky 

 Mountains, Colorado. Collections: Spanish Peaks, Gallatin County, Montana, July 20, 

 1901, Vogel (Gr, US); La Plata Mines, Wyoming, E. Nelson 5273 (UC); type collection 

 1862, Parry (Gr) ; Pike's Peak, Colorado, at edge of timber-line, August 7, 1919, Hall R72, 

 also well above timber-line A97 (CI); mountains about headwaters of Clear Creek, 

 Colorado, Patterson 72 (Gr, NY, UC, US) ; Sierra Sangre de Cristo, Colorado, Brandegee 

 788 (UC) ; Bullion Creek near Marysvale, Utah, Jones 5872 (NY) ; La Sal Mountains, 

 Utah, at 3,000 to 3,200 m. altitude, Rydberg and Garrett 8964 (NY, normal form with 

 elongated inflorescence) ; La Sal Mountains, Utah, at 3,300 to 3,600 m. altitude, Rydberg ' 

 and Garrett 8676 (NY, UC, a dwarf form with condensed inflorescence but with the usual 

 small heads); Pecos Baldy, New Mexico, Standley 4313 (NY, US). 



RELATIONSHIPS. 



Artemisia scopulorum is regarded as a direct descendant of A . frigida, which has been 

 evolved in response to alpine conditions. The style-branches and achenes are practically 

 identical, and the bracts are the same in number and similar in shape, while the measure- 

 ments of involucre and corolla overlap, as do the numbers of ray-flowers and disk-flowers. 

 The leaves are distinctly different, and there are considerable differences in size, habit, 

 flower-cluster, and pubescence, characters all readily modified by the environment. 

 This is shown by the form of A . frigida that grows on cold montane plains at 9,000 feet 

 altitude, which is dwarfed, herbaceous, less silky, and with a raceme-like inflorescence. 

 It proves the readiness with which the vegetative features of this plains species may be 

 changed by greater moisture and cold, and suggests the actual line of development to 

 scopulorum. The woody base of frigida is clearly an adaptation to its warmer and 

 drier habitat, and it disappears at higher elevations. Moreover, while the two species 

 have not been found in actual contact, it is probable that they were in recent times, as 

 frigida ascends to 3,000 meters and scopulorum descends to 3,400 meters. Hence, it 

 appears probable that the boreal A. frigida migrated to the southward, becoming more 

 woody and xeroid on the plains, but retaining its herbaceous character in the subalpine 

 region, and developing into the dwarf alpine A . scopulorum on the high peaks of Wyoming, 

 Montana, Colorado, Utah, and New Mexico. 



ECOLOGY AND USES. 



Artemisia scopulorum is a dwarf alpine perennial with short rootstocks, and hence 

 with a gregarious habit. It may occur in small clans in new areas, but it is usually asso- 

 ciated with other species, such as Erigeron unijlorus, Antennaria alpina, Pedicularis 

 parryi, Arenaria fendleri, and Haplopappus pygmaeus, in a mixed society of the alpine 

 sedgeland climax. 



No uses are known for this species, and none are to be expected from its small size and 

 alpine habitat. 



