570 COMPOSITAE (COMPOSITE FAMILY) 



laciniate divisions and lobes, white beneath with close cottony tomentum, 

 glabrate above: heads glomerate in an interrupted spiciform or virgate 

 panicle, 3-4 mm. high; involucre hemispherical-campanulate, greenish and 

 scarious, glabrous or soon becoming so, 20-30-flowered. [A. elatior (T. & G.) 

 Rydb. as to our range.] In the mountains; Colorado to Montana and Wash- 

 ington. 



20a. Artemisia discolor incompta (Nutt.) Gray, Syn. Fl. 1: 373. 1886. 

 Stouter, with coarser or less dissected leaves, having mostly broader lobes, or 

 the upper entire. Mountains; Wyoming and Montana to California and 

 Washington. 



21. Artemisia Bigelovii Gray, Pacif. R. R. Rept. 4: 110. 1856. Silvery- 

 canescent throughout, 2-4 dm. high: leaves oblong- to linear^cuneate, mostly 

 3-toothed at the truncate apex, 10-14 mm. long: heads very numerous and 

 crowded in the oblong or virgate thyrsiform panicle, tomentose-canescent, 

 containing only 1 or 2 hermaphrodite and as many pistillate flowers, all fer- 

 tile. Rocky banks; Colorado, on the Upper Canadian and Arkansas. 



22. Artemisia trifida Nutt. Trans. Am. Phil. Soc. 7: 398. 1841. Silky- 

 canescent; stems 2-6 dm. high, much-branched: leaves 3-cleft toward the 

 apex or 3-parted, the lobes and entire upper leaves narrowly linear or slightly 

 spatulate-dilated : heads numerous in the contracted leafy panicle, or spi- 

 cately disposed on its branches; involucre 3-9-flowered, the outer or accessory 

 bracts oblong to short-linear or lanceolate. (A. tripartita Rydb. Mem. N. Y. 

 Bot. Gard. 1 : 432. 1900.) Elevated plains in our range and west to the coast 

 States. 



23. Artemisia arbuscula Nutt. 1. c. Dwarf, 1-3 dm. high, with a stout 

 base and slender flowering branches: leaves short, cuneate or flabelliform, 

 3-lobed or parted, with the lobes obovate to spatulate-linear, sometimes again 

 2-lobed; those subtending the heads usually entire and narrow: panicle strict 

 and comparatively simple and naked, often spiciform and reduced to few 

 rather scattered sessile heads: involucre 5-9-flowered. (A. spiciformis Osterh. 

 Bull. Torr. Bot. Club 27: 507. 1900.) High mountains and elevated plains; 

 Colorado and Wyoming to the northwest. 



24. Artemisia tridentata Nutt. 1. c. A shrub or small tree 0.5-5 m. high, 

 much-branched: leaves cuneate, 15-30 mm. long, 3-7-toothed or lobed at 

 the truncate summit, uppermost cuneate-linear: heads very numerous, in 

 large dense panicles; involucre 5-8-flowered, oblong, the outer or acces- 

 sory bracts short, ovate-obtuse, tomentose-canescent. The common SAGE- 

 BRUSH; also called BLACK SAGE. Dry plains and mountains; west of the 

 Missouri. 



25. Artemisia nova A. Nels. 1. c. 27: 274. The shrubby base low, scrag"gy- 

 branched, the herbaceous stems numerous, fascicled, slender, simple, 1-2 dm. 

 high including the narrow spike-like panicle, grayish with a thin tomentum 

 or merely pubescent, as also are the leaves: leaves very narrowly cuneate, 

 1-2 cm. long, 3-toothed at apex, the middle tooth usually longest: panicle 

 leafy at base, naked above, strict and nearly simple; heads small, very nu- 

 merous, only 3-4 mm. long, usually 3-flowered but often only 1 or 2; invo- 

 lucral bracts closely imbricated, greenish, only slightly puberulent. Hillsides 

 and ridges in the foothills and on the plains; Colorado and Wyoming. 



26. Artemisia cana Pursh, Fl. 2: 521. 1814. Shrubby, densely .white- 

 canescent; stem much-branched, 3-7 dm. high: leaves linear, linear-oblong, or 

 narrowly lanceolate, sessile, acute at both ends, 3-5 cm. long, 3-6 mm. wide, 

 usually quite entire, rarely with 2 or 3 acute teeth or lobes: heads numerous, 

 about 3 mm. broad, glomerate or sometimes solitary in the axils of the leaves, 

 or crowded into a naked thyrsus at the summit, 5-9-flowered; involucre ob- 

 long, canescent, the inner bracts oblong or lanceolate, obtuse, usually with 

 1-3 shorter outer ones. Plains and mountain valleys; throughout our range 

 and to the northwest. 



26a. Artemisia cana viscidula Osterh. 1. c. The herbage tending to become 

 glabrate and obscurely Viscidulous. (A. viscidula Rydb. Bull. Torr. Bot. 

 Club 33: 157. 1906.) Colorado and Wyoming. 



