402 DESCRIPTIONS OF NEW SPECIES 



fringed at the apex. Keceptaculum papillose, naked. Involucrum round- 

 isli-ovate, imbricate; sepals from five to ten in a single or double series, ob- 

 tuse, and broadly scariose on the margin. Achenium turbinate and smooth, 

 three to five-angled, with a vesicular testa, terminated with a small, paleace- 

 ous, unequal cup of three to five, or more, acute scales. — Low alpine, csespi- 

 tose or suffruticose perennials, canescently tomentose, with simple scapoid 

 stems, terminating in a single spherical, or somewhat round lobed cluster of 

 capituli. Leaves alternate, cuneate, pseudopetiolate, once or twice trifid, 

 with the segments linear and entire; florets yellow. Allied to Artemisia, 

 and with the same aroma, but with a different habit.— (The name in allu- 

 sion to its capitate inflorescence.) 



Sphceromeria *capitata; dwarf and csespitose, canescently sericeous; leaves 

 once or twice trifid towards the summit, sheathing at the base, segments linear- 

 oblong; leaves of the scapoid stem simple; capituli conglomerated into a sphe- 

 rical head ; involucrum about five-leaved. 



Hab. On a high hill, near the Red Butes of the Platte, towards its northern sources on the 

 Sweet Water. Flowering in June. Growing on the summit of a rocky hill, in round tufts of 

 densely matted herbage, soft, silky and hoary with pubescence; scapes or scapoid stems slender, 

 three or four inches high, the spherical cluster about the size of a small cherry. Scales of the in- 

 volucrum oval, concave, hairy on the margin. Radial florets short and truncated, two or three- 

 toothed, becoming enlarged and indurated at base. Discal florets about eight or ten, mostly 

 infertile, with rudimental achenia. Style of the ray bifid, obtuse, cleft half way down, minutely 

 pencillate at tip. Achenium somewhat three-sided, the angles terminating in a minute crown of 

 acute pappus. The seed (at least in a young state,) enveloped in a utricular loose testa. The 

 odour of the plant agreeable, almost like that of chamomile. 



SpJimromeria * argentea; suffruticose and somewhat csespitose, whitely and 

 closely tomentose; leaves cuneate, entire, or three-cleft at the summit, the up- 

 permost also minute and undivided; stem simple, terminating in a single, rather 

 round cluster of capituli; involucrum biserial, ten-leaved. 



Hab. In the Rocky Mountains, near the sources of the Platte, and Colorado of the West. 

 Flowering in July. — A very elegant and diminutive shrub, with the taste and odour of wormwood, 

 but more agreeably aromatic ; the flowers bright yellow. Leaves about half an inch long, one to 

 two lines Avide. Stem about four inches high, very slender, like a leafy peduncle, terminating in 

 a round, or hemispherical cluster of three to five capituli. Outer scales of the involucrum ovate. 

 Radial florets about five. Achenia about five-angled, with an unequal pappus of five or more 

 parts, longest on the angles ; testa loose and utricular. Receptacle papillose. Discal florets nume- 

 rous. Stigma truncate, and minutely pencillate. 



