AND GENERA OF PLANTS. 399 



Hab. On the plains of the Missouri, and along the Platte to the mountains. Certainly distinct 

 from the A. cana of Pursh. 



§. *Tanaceum. — Receptacle convex, pilose or lanigerous. Achenium acutely 

 costate, terminated hy a me7nbranaceous, somervhat lohed margin. — Shrubs, 

 with trifid or twice trifidly-pinnatelj dissected leaves. Capituli as in Abro- 

 tanum. 



Artemisia Fischeriana, and variety ^. vegetior (of Besser,) probably a dis- 

 tinct species. 



Hab. The Bay of St. Francisco, Upper California. If the variety ^. agrees in the character of 

 the receptacle with the species to which it is referred, I have not seen the plant. 



Artemisia * dbrotanoides ; \; canescent and pulverulently pubescent; leaves 

 pseudopinnate towards the extremity, with a few (two pair) of filiform seg- 

 ments; upper leaves entire; panicle simple; capituli hemispherical, large, 

 nodding,, on bracteolate pedicels; sepals oval, broadly scariose on the margin. 



Hab. Near St. Barbara, Upper California. Receptacle somewhat pilose. A shrub with much 

 the appearance of A. Ahrotanum, Common. Branches whitely canescent. 



§. III. Abrotanum. (Bess., Decand.) Florvers heterogamous, all fertile. 



Artemisia *pedatifida; very dwarf and suflfruticose, somewhat canescently 

 tomentose; leaves towards the summit trifid, or more or less subdivided into 

 bifid, or trifid, linear, and very narrow segments; stems numerous, subcsespi- 

 tose, simple, terminating in a short, few-flowered spike; capituli ovate, sessile, 

 subtended by simple or trifid leaves ; inner scales scariose ; florets smooth, about 

 ten. 



Hab. Arid plains of Lewis' River, Rocky Mountains. Flowering in August. A very distinct 

 and peculiar species, with a stout, woody, exfoliating root, sending out tufts of low stems, about 

 three or four inches high, terminating in spikes of from about four to ten flowers; capituli towards 

 the summit, conglomerated by threes; leaflets almost filiform-linear, but flat, often only trifid, but 

 also with the lateral lobes bifid or trifid. 



Artemisia *pumila; herbaceous, very dwarf; leaves linear, sublanceolate, 

 nearly smooth or pubescent, tomentose beneath, trifid or incisely subpinnatifid 

 with few apiculated segments; axills pseudostipular, the stipules simply subu- 

 late, or two or three-cleft; flowers in a simple, leafy spike, sessile, axillary, 

 solitary, or in clusters of two or three; capituli roundish-ovate; inner segments 

 of the involucram oval and scariose; flowers polygamous. 



