112 GENUS ARTEMISIA. 



19. ARTEMISIA PATTERSONI Gray, Syn. Fl. 1': 453, 1886. Plate 12. Alpine 

 Sagewort. 



A perennial herb with a branched or cespitose rootstock, 1 to 2 dm. high, mildly odor- 

 ous; stems several, unbranched, erect, moderately leafy, not striate, tomentulose or 

 glabrate, not turning red; basal leaves crowded, petiolate, 2 to 4 cm. long including the 

 petiole, obovate-oblong or spatulate in outline, once pinnately parted into few lobes, 1 to 

 2 mm. wide or only trifid from the summit, silky-canescent; upper leaves much reduced, 

 mostly entire, silky like the lower; inflorescence (of 2 to 5 racemosely arranged heads or 

 reduced to a single terminal head) 1 to 5 cm. long, about 1 to 1.5 cm. broad; heads hetero- 

 gamous, subsessile or the lower long-peduncled, mostly horizontal or nodding; involucre 

 broadly hemispheric, about 5 mm. high, 5 to 8 mm. broad (up to 12 mm. in pressed 

 specimens); bracts 15 to 30, ovate, or broadly lanceolate, acutish, the inner ones nar- 

 rowed at base, villous, with greenish backs and broad blackish scarious margins; recep- 

 tacle copiously villous; ray-flowers 7 to 27, fertile, corolla about 2 mm. long, funnelform, 

 irregularly toothed; disk-flowers 32 to 120, fertile, corolla funnelform, 2.5 to 3 mm. long, 

 5-toothed, glabrous or rarely sparsely villous; style-branches of ray-flowers lanceolate, 

 acutish, of disk-flowers flat, penicillate at the truncate apex; achenes nearly cylindric, 

 slightly narrowed at base, broad at summit, smooth or faintly nerved, not pubescent. 



High mountains of Colorado and New Mexico, apparently always above timber-line. 

 Type locality, Rocky Mountains of Colorado. Collections: Type collection, 1862, 

 Parry (Gr, type of A. scopulorum var. monocephala Gray) ; about the headwaters of Clear 

 Creek, Gray's Peak, and vicinity, July 30, 1885, Patterson 74 (Gr, UC, US) ; Pike's Peak, 

 above timber-Hne, Hall 11079 (UC); summit of Mount Garfield (Baldy), Colorado, 

 Clements 415 (DS, Gr, NY, US); Long's Peak, Colorado, E. L. Johnston 689 (NY); 

 Baldy, New Mexico, August 14, 1910, Wooton (US). 



SYNONYMS. 



1. Artemisia monocephala Heller, Muhl. 1:118, 1905. A. patlersoni. 



2. A. SCOPULORUM var. MONOCEPHALAGray, Proc. Acad. Phila. for 1863:66, 1863. The original name for 

 A. pattersord, as indicated later. 



RELATIONSHIPS. 



Artemisia patter soni appears to be directly derived from A. scopulorum, and so recently 

 that all of the characters overlap,with the exception of the number of disk-flowers, where 

 they meet. This is further indicated by the fact that it appears to be known from but 

 four high peaks— Gray's Peak, Long's Peak, and Pike's Peak in Colorado, and Mount 

 Baldy, New Mexico. While the two species are now often found together on these peaks, 

 the smaller plants, reduced leaves, and larger heads of pattersoni indicate that it was 

 developed at greater altitudes or on colder slopes, and then migrated into the area of 

 scopulorum. 



This species is very similar in general characters to A. scopulorum, so much so that it 

 sometimes has been taken for the extreme alpine form of this more common species. 

 Both were first described by Gray, and at the same time. Having only the one-headed 

 form of the present species, this authority named it A. scopulorum var. monocephala. 

 Later, however, Patterson called Gray's attention to differences previously overlooked 

 and the latter then described it as a distinct species, A. pattersoni (Syn. Fl. P:453, 1886), 

 which was characterized as follows: 



More dwarf and white-tomontose, but sometimes glabrate in age; leaves 3- to 5-parted or cleft, or uppermost 

 entire; heads much larger and broader, solitary or 2 to 5, 40- to 50-flowered; corollas glabrous; receptacle 

 extremely long-woolly. (Syn. Fl. P:453, 1SS6.) 



This is not merely a dwarf of scopulorum, as is evident from the occurrence of a truly 

 dwarf form of the latter, in which the essential characters of pattersoni — cut of leaf, large 

 heads with numerous flowers, long glabrous corollas, etc. — are not attained. Such 



