418 COMPOSITE. Artemisia. 



filiform; the lower mostly 3-parted; heads very small, crowded in virgate 

 leafy panicles, tomentose, 3-4-flowered; two of the flowers pistillate and fer- 

 tile; the others stamiuate and sterile; receptacle slightly fimbrillate-pilose. — 

 Torr.I in ann. lye. New York, 2. p. 211. A. Plattensis, Nutt.! in trans. 

 Amer.phil. soc. {n. ser.) 7. p. 397. 



Plains of the Platte, very abundant. Dr. James ! Nutlall ! Lieut. Fre- 

 mont! July-Aug. — Plant 1-3 feet high; the branches slender and virgate. 

 Leaves 1-2 inches long, terete (revolute), very slender, white when young, 

 becoming somewhat glabrous when old. 



§2. Receptacle naked: heads homogamous ; the Jloivers all perfect and fer- 

 iiie.^SERiPHiDiuM, Bess. 



8. A. cana (Pursh) : shrubby, much branched, densely canescent through- 

 out; leaves linear-lanceolate, acute, flat, entire (the lowermost cuneiform 

 and sometimes acutely 3-lobed), equally clothed with the close silky tomen- 

 tum on both sides; heads obovoid-hemispherical, axillary, sessile, mostly 

 glomerate or spicate-paniculate, 4-6-flowered; exterior scales of the involucre 

 canescent ; the inner scarious. — Pursh! fl. 2. p. 621 ; Bess. ! in Hook. I. c. ; 

 DC.prodr. 6. p. 105. A. Columbiensis, Nutt.! gen. 2. p. 142, d^ in trans. 

 Amer. phil. soc. (n. ser.) 7. p. 398, excluding the habitat in part. 



Plains of the Upper Missouri and Platte to the Rocky Mountains, Lewis! 

 Nuttall! Mr. Nicollet! Lieut. Fremont! and plains of the Saskatchawan, 

 Drummond! — The leaves of this well-marked species are very seldom in 

 any degree lobed, although there are some obscure indications in Pursh's 

 specimens, collected by Lewis. We believe it has not been found west of 

 the Rocky Mountains; and Mr. Nuttall was mistaken in supposing it to be 

 the "Wild Sage" of Lewis and Clarke's Travels, which so abounds in the 

 woodless sterile plains of the interior of Oregon ; so that the change of specific 

 name was the more unwarrantable. The name of Wild Sage was doubtless 

 applied indiscriminately to several of the ensuing shrubby species, which in- 

 habit the region in question. But the plant given to Pursh by Lewis wiih 

 this name is the A. integrifolia, Pursh (A. Ludoviciana, Nutt.), and was 

 collected on the bluffs of the Missouri, Oct. 1, 1804, upon the homeward 

 journey. 



9. A. tridentata (Nutt.) : shrubby, much branched, densely silvery-canes- 

 cent; leaves crowded or fascicled, narrowly cuneiform, 3-toothed or 3-cleft at 

 the apex, the teeth or short lobes obtuse and approximate ; those of the flower- 

 branchlets often linear and entire ; heads obovoid, spicate-glomerate, disposed 

 in dense compound panicles, 5-6-flowered ; exterior scales of the involucre 

 canescent, the inner scarious. — Nutt.! in trans. Amer. phil. soc. (n. ser.) 7. 

 p. 398. (from specimens not in flower.) 



Plains of the Oregon and Lewis River (Rocky Mountains in herb.), Nutt- 

 all! Wind River Chain of the Rocky Mountains, Liewi. jPre?ttoni.' Aug. — 

 Shrub about a foot high, much branched. Leaves an inch or less in length, 

 3-4 lines wide at the apex, tapering to the base, both sides equally silvery- 

 tomentose ; the teeth or lobes either very short, or 2-4 lines long, seldom again 

 toothed. Heads very numerous, smaller than in A. cana. 



10. A. arhuscula (Nutt.! 1. c): dwarf, shrubby, tomentose-canescent ; 

 leaves short, cuneiform, 3-cleft ; the lobes oblong, obtuse ; the lateral often 

 2-3-lobed ; heads globose-ovoid, 6-10-flowered, sessile, solitary or somewhat 

 clustered, forming a slender interrupted spike or spicate panicle; scales of 

 the involucre oval ; the exterior tomentose, the inner scarious. 



Arid plains of Lewis River, Nuttall ! — Shrub 4-6 inches higli ; the flower- 

 ing branches virgate and rather naked. 



