172 MR. NUTTALL'S DESCRIPTIONS OF NEW 



the achenium. Achenium oblanceolate, and compressed, sericeous villous, with only 

 two marginal lines. Receptacle conspicuous, with alveolar margins. 



In the present genus the involucrum is imbricated distinctly, in three to five series 

 of subcarinated scales, the lowest very small. The florets few in number, have a 

 short, five-cleft border. The processes of the style are long and subulate, much 

 exceeding the lower, naked portion. Pappus slender, much less copious, and not so 

 scabrous as in the preceding; more than double the length of the achenium. 

 Achenium somewhat cylindric, smooth, about j^ye lined. Receptacle very small and 

 smooth. 



*OXYTENIA.t 



Capitulum heterogamous, many-flowered, the marginal ones in a single series, 

 apetalous and feminine. Florets of the disk tubular, masculine. Involucrum 

 composed of a single series of imbricated, ovate, rather rigid scales, (about five.) 

 Receptaculum small and flat ; its palea narrow, spathulate and membranaceous, tufted 

 with long hairs. Male Flowers. — Corolla obconic, with a narrow tube ; border 

 five-toothed. Anthers distinct. Female. — Corolla none. Stigmata terete, filiform, 

 smooth. Achenia bluntly obovate, obcompressed and ridged on the inner side, covered 

 with dense white hairs, situated beneath the scales of the involucrum and without 

 pappus. 



0. *ACEROSA. A stout shrub 1 with soft wood, (a branch of which, one of the specimens, is not less than 

 three feet long ;) every part of the plant (in a dried state-, at least) covered with a fine close down. 

 Leaves alternate, four to eight inches long, acerosely, linear and rigid, like those of a pine tree, nearly 

 sessile, pinnatifid, with about two pair of segments, or simply trifid ; both above and below simple ; the 

 divisions about the usual width of the leaves of the common Scotch fur, grooved beneath, but so closely 

 revolute as to be terete. Flowers in terminal fascicles or divided branchlets. In some specimens, the 

 capitulum appears to be smaller and the achenia more woolly, with only about ten male florets, while 

 in others the infertile central florets are about twenty ; the latter appear, therefore, to be male plants 

 chiefly, but they have also female flowers, which are less woolly ; involucrum roundish, of five ovate, 

 acute, imbricated scales; male florets obconic, with a slender tube, covered with yellow glands ; 

 anthers free ; stigmas slender, filiform ; radial florets about five, the number of the involucrum scales ; 

 corolla none ; stigmas two, sometimes, short, linear-oblong, smooth ; achenia obovate, truncate, rigid 

 internally, covered (particularly towards the summit,) with long conspicuous white hairs. 



A large, erect, spreading bush, with the inflorescence of an Iva ; the leaves 

 alternate, acerosely linear and rigid, pinnately divided into trifle or more compound 

 divisions ; capituli sessile, arranged in a compound panicle, as in many Artemisias. 

 The whole plant very bitter, but with very little aroma. In habit more allied to 

 Artemisia than Iva. Appears to be nearly related to Euphrost/ne of Decandolle, as 

 well as to Pijcrothamnus and Cydachana, which last, however, is not sufficiently 

 distinct from Iva. 



t From otvtevrji acuminate. In allusion to the rigid narrow foliage. 



