Artemisia. COMPOSITES:. 419 



11. A. trrfida (Nutt. ! I.e.): shrubby, silky-canescent ; leaves 3-parted 

 towards the apex ; the segments linear, obtuse ; heads spicate, somewhat glo- 

 merate, in a simple panicle, obovoid, 8-flowered ; exterior scales of the invo- 

 lucre ovate, canescent ; the inner oblong, glabrous, with scarious margins. 



/i. rigida (Nutt.! 1. c.) : leaves rigid, more silky and shining; the seg- 

 ments rather acute. 



Plains of the Rocky Mountains and Oregon, Nuttall! — Plant 6-8 inches 

 high. 



§ 3. Receptacle naked {not hairy) : heads heterogamous ; the flowers all fertile. 

 — Abrotanum, (Tourn.) Bess. 



* Perennial or shrubby. 



12. A. Lindleyana (Bess.): shrubby, canescent towards the summit; 

 leaves nearly linear, canescently tomentose beneath ; heads spicate-panicu- 

 late, somewhat hemispherical, erect; scales of the involucre canescent, 

 scarious at the apex, the outermost foliaceous ; corolla glabrous. Bess, in 

 Hook. I. c, cV DC. I.e. 



a. legitima (Bess. 1. c.) : leaves entire, an inch to an inch and a half in 

 length. 



/3. hrevifolia (Bess. 1. c.) : leaves an inch long, in fascicles ; the primary 

 having probably fallen away. 



y. subdentata (Bess. 1. c.) : leaves linear-lanceolate, somewhat toothed at 

 the apex ; involucre white and tomentose. 



(5. Coronopus (Bess. 1. c.) : leaves pinnatifid-toothed towards the apex. — 

 A. pumila, Nutt. 1 



" North West Coast of America, Douglas, in herh. LindV, ex Besser. 

 Probably from the interior of Oregon — This species is unknown to us : per- 

 haps the following, of which we have only seen an imperfect specimen, is 

 one of its forms. 



13. A. pumila (Nutt.) : dwarf, herbaceous, perennial, slightly tomentose- 

 pubescent ; leaves scattered, linear, entire, or sparingly laciniate or incised 

 towards the apex; heads sessile, subglobose, few, in a simple somewhat leafy 

 spike; scales of the involucre scarious, slightly tomentose ; the exterior ovate, 

 the inner broadly oval ; " flowers polygamous." — Nutt. ! in trans. Amer. 

 phil. soc. I. c. p. 399. 



Lewis River, in the Rocky Mountains. — Stems simple, 6-8 inches high, 

 from a somewhat woody base. Leaves an inch or more in length, scarcely 

 a line wide ; the teeth or lobes (one or two on each side) subulate. Nutt. 



14. A. pedatifida (Nutt. ! 1. c.) : dwarf, suffruticose, somewhat canescent 

 or cinereous, csspitose ; leaves 3-parted ; the lateral segments often 2-3-cleft, 

 linear, obtuse ; heads obovoid, sessile, bracteate, seldom clustered, few, in a 

 simple spike ; scales of the involucre ovate, pubescent, with shining scarious 

 margins ; corolla glabrous. 



Arid plains of Lewis River, in the Rocky Mountains, Nuttall! Aug. — 

 " A very distinct and peculiar species, with a stout woody root, sending out 

 tufts of low stems, three or four inches high, terminating in spikes of 4-10 

 flowers." Nutt. 



15. A. longifolia (Nutt.) : herbaceous (frequently woody at the base), 

 tomentose ; flowering stems simple ; leaves narrowly lanceolate-linear, 

 elongated, acute, entire, with revoiute margins, tomentose-canescent beneath, 

 at length almost glabrous above ; the lower occasionally 3-5-cleft or lacini- 

 ate ; the lobes linear ; heads cylindric-ovate, somewhat glomerate, sessile, 

 few-flowered ; involucre tomentose. — Nutt. '. gen. 2. p. 142, Sf in trans. 

 Amer. phil. soc. I. c. ; not of Bess, in Hook. I. c. S^c. 



