Dichcetophora. COMPOSITE. 165 



K. efFusa, Gray. Perennial, often 2 feet high, with simple stem branching above into an 

 effuse ample panicle : leaves (an inch or less long) hispid as well as the stem, rigid and sca- 

 brous, oblong, mostly with a broad sessile base : heads very numerous : involucre more 

 turbinate : rays 4 to 7, white : disk-flowers somewhat more numerous, apparently always 

 sterile, and with elongated linear-lanceolate style-appendages : fertile akenes obovate, flat, 

 callous-nerved at the margins (or with one margin 2-nerved). — PI. Lindh. ii. 221; PI. 

 Wright, i. 93. — Hillsides, central parts of Texas, BerluncUer, Lindheimer. 



39. CH^ETOPAPPA, DC. (XatxT?, bristle, and TraTTTroc, pappus.) — Low 

 and small Texano-Mexican winter annuals, diffusely branched; the branches 

 terminated by small heads : rays white or purple : leaves entire, the lower spatu- 

 late, upper gradually becoming linear or reduced to subulate bi-acts. Fl. spring 

 and early summer. — Chcetanihera, Nutt. Jour. Acad. Philad. vii. 111. Chce- 

 tophora, Nutt. in DC. Glicetoimppa & Distasis, DC. Prodr. v. 301, 279 ; Benth, 

 & Hook. Gen. ii. 2G8. Diplostelma, Gray, PI. Fendl. 72. 



C. asteroides, DC. 1. c. Slender, 2 to 10 inches high, pubescent : involucre (2 lines long) 

 rather narrow, of 12 to 14 bracts; rays 5 to 12 : disk-flowers 8 to 12 : style-appendages very 

 obtiLse : akenes slender, little compressed, obscurely few-nerved, pubescent, all the central 

 ones sterile and often awuless : paleaj of the pappus very thin and hyaline, narrowly oblong, 

 not rarely lacerate or cleft. — Torr. & Gray, Fl. ii. 187. CltcEtanthera asteroides, Nutt. 1. c. — 

 Dry ground, Texas to Arkansas and the borders of Missouri. (Adjacent Max.) 



Var. imberbis, Gr.vy. Awns of tlie pappus wanting in all the flowers: the paleae 

 rather broader and sometimes corouiform-coucreted. — Proc. vVm. Acad. xvi. 82. — E. Texas, 

 Wn'r/ht. 



C. Parryi, Gu.vt. More rigid, 9 inches or more high : leaves subcoriaceous, hispidulous 

 audglabrate; involucre (.3 lines long) turbinate: rays 6 or 7 : style-appendages short and 

 very obtuse ; akenes quite glabrous ; the fertile ones fusiform and somewhat compressed, 

 4-nerved, with a pappus of 4 or 5 firmer and cuneiform-quadrate' palea; which are laciniately 

 Mibriate at the truncate apex, and of few or sometimes solitary more delicate awns, these 

 occasionally little longer than the palete, sometimes wanting ; disk-akeues mostly inane and 

 awuless. — Proc. Am. Acad. xvi. 82. Distasis modesta, var.. Gray, Bot. Mex. Bound. 78. — 

 Mt. Carmel, on the Rio Grande, between Texas and Mexico, Parri/. 



C. modesta, Gray, 1. c. Less slender and pubescence more hirsute than in C. asteroides : 

 involucre broadly campanulate ; its bracts obtuser and more numerous : rays 9 to 20 : disk- 

 flowers 40 to 60, all but the central fertile ; their style-appendages narrower and acutish : 

 akenes oblong or linear, much compressed, pubescent when j-onng, with merely marginal 

 nerves or occasionally a facial one, only the central ones sterile : pappus of 5 oblong erose- 

 truncate at length sulworiaceous pale;e, alternating with as many rather rigid awns. — Dis- 

 tasis modesta, DC. Prodr. v. 279. Diplostehna bellioides, Gray, PI. Fendl. 73. — Dry ground, 

 Texas, Berlandier, Wright, &c. (Adjacent Mex.) 

 Distasis'? heterophylla, Hemsl. Biol. Centr.-Am. Bot. ii. 119, of Mexico, is hardly of 



this genus, probably not of the tribe. 



40. MONOPTILON, Torr. & Gray. (Movos, single, tttlXov, feather, al- 

 luding to the solitary plumose bristle of the pappus.) — Jour. Bost. Nat. Hist. Soc. 

 V. 106, t. 13; Benth. & Hook. Gen. ii. 307; Gray, Bot. Calif, i. 30G. — Single 

 species. 



M. bellidiforme, Torr. & Gray, 1. c. A small but pretty annual, much branched from 

 the very base, depressed, villous-hirsute : heads terminating the numerous leafy branchlets, 

 half-inch in diameter, inclusive of the white or \^olet-])ur]5le rays : leaves small, spatulate or 

 linear-spatulate, the uppermost involucrate around the head. — Arid or desert plains, S. E. 

 California to S. W. Utah, Fremont, Parri/, Palmer, Parish. 



41. DICH^T6PH0RA, Gray. (At?, xatV^?, (f>opd, bearing two bristles, 

 i. e. pappus-awns.) — PI. Fendl. 73. — Single species ; in Benth. & Hook. Gen. 



