248 COMPOSITE. Oxytenia. 



78. OXYTENIA, TS T utt. (*Owenfc, pointed, "in allusion to the rigid 

 narrow foliage.")- -PI. Ganib. 172; Benth. & Hook. Gen. ii. 353; Gray, Bot. 

 Calif, i. 343. Single species, Artemisia-like in habit; fl. autumn. 



O. acerosa, NCTT. 1. c. Shrubby, but soft-woody, 3 to 5 feet high, canescent, with erect 

 brain-lies sometimes leafless and rush-like : leaves when present alternate, piiinately 3-5-parted 

 into long filiform divisions, or uppermost entire: heads numerous (2 lines long), iu dense 

 panicles. Dry plains, S. W. Colorado to S. E. California, Gnmbel, Wheeler, Brandegee, &c. 



79. DICOHIA, Torr. & Gray. (At'?, twice, used for two, and Koptc, a bug, 

 from the aspect of the two akenes of the original species.)-- Emory Rep. 143, & 

 Bot. Mex. 8G, t. 30; Gray, Froc. Am. Acad. xi. 76, & Bot. Calif, i. 01.3. 



D. caiiescens, TOUR. & GRAY, 1. c. Herb a foot to a yard high, witli annual root, stem 

 becoming liguescent at base and widely branched, herbage cauescent with appressed pubes- 

 cence and the branches hispid, becoming green and scabrous in age : lower leaves opposite, 

 lanceolate and oblong, coarsely toothed or laciniate ; upper alternate, ovate or roundish, all 

 petioled : heads sparsely and irregularly racemose-paniculate, along sleuder nearly leafless 

 branchlets, nodding in fruit : fertile flowers 2 : inner la-acts of the involucre pelatoid-scarious 

 (yellowish white), orbicular and deeply concave, accrescent in fruit (becoming 3 or 4 lines 

 long), then inflated-saccate and loosely or partly enclosing the laciniately wing-margined 

 akeue, falling with it. Desert washes, S. E. California and adjacent Arizona to S. Utah. 



D. Brandegei, GRAY, 1. c. Strigulose-canescent, diffusely and alternately branched (base 

 of stem unknown): leaves of the branches oblong-lanceolate or partly spatulate, obtuse, 

 mostly entire, an inch or less long and with slender petiole: heads sparse, racemose-panicu- 

 late ; some all male : corollas sparsely hirsute : fertile flower solitary ; its dilated-euueate 

 hyaline subtending bract hardly accrescent or surpassing the outer involucre : akeue naked 

 and exserted, bordered with pectinate callous teeth connected by an indistinct scarious mar- 

 gin. Sandy bottoms of the San Juan, near the boundary between Colorado and Utah, 

 Brandcyec. Little Colorada, N. Arizona, Rusby, iu flower only. 



80. HYMENOCLEA, Torr. & Gray. ('Y/^V, membrane, used for wing, 

 and /<Aeui>, to enclose.) -- Two known species, of low and much branched shrubby 

 plants, minutely canescent, or else glabrous and smooth ; with slender diffuse 

 branches, bearing profuse scattered or glomerate paniculate small heads, the two 

 sexes intermixed, or the female in lower axils : leaves all alternate and linear-fili- 

 form ; the lower sparingly and irregularly pinnately parted : fl. summer and 

 autumn. --PL Fendl. 70 ; Gray, PI. Wright, i. 104, Bot. Calif, i. 343. 



H. Salsola, TOUR. & GRAY, 1. c. Fructiferous involucre fusiform, strobilaceous ; the ample 

 orbicular silvery-scarious wings spirally alternate, imbricated over each other, radiately 

 spreading when mature and dry. Torr. PI. Fremont (Smiths. Contrib.) 14, t. 8. Saline soil 

 iu the desert region, S. California, adjacent Arizona, and Nevada; first found by Fremont. 



H. moilOgyra, TORR. & GRAY, 1. c. Fructiferous involucre smaller (2 lines long), winged 

 only at the middle by a whorl of obovate or rhombic-reniform radiating scales of smaller 

 size. S. California through Arizona to S. W. Texas; first coll. by Coulter. (Adj. Mex.) 



81. AMBROSIA, Tourn. RAGWEED. (Ancient Greek and also Latin 

 name of several plants, as well as of the food of the gods.) --Weedy or coarse 

 herbs ; with mostly lobed or dissected opposite and alternate leaves, and dull in- 

 conspicuous flowers ; in summer. Sterile heads racemose or spicate, and with 

 no subtending bracts ; the fertile below, commonly in small clusters in the axils 

 of leaves or bracts: fl. summer and autumn. Lam. 111. t. 765; Grertn. Fruct. 

 t. 164; Schk. Handb. t. 292; Torr. & Gray, Fl. ii. 354. Fructiferous nut-like 

 involucre called for shortness "fruit." 



