24 



roLYGONACE.i^:. /•; 



++ ++ Pedicels erect or somenvhat spreading : outer segments much broader above. 



21. E. Thurberi, Toney. Very slender, G inches high or less, the stem tomen- 

 tose below the panicle: leaves rounded-ovate, obtuse, 3 or 4 lines long: bracts com- 

 paratively large and thick, spreading : pedicels very slender, a half to an inch long : 

 involucres campanulate, nearly a line long, subviscidly j)uberulent : flowers rose- 

 colored or white, halt a line, becoming a line long ; the outer segments with a largo 

 rounded terminal lobe, the inner small and lanceolate. — ]]ot. ]\Iex. Bound. 17G ; 

 Torr. & Gray, 1. c. 183. 



Southern California, Los Angeles to San Bernardino (Thurbcr, Wallace, Parry) ; near ("amp 

 Grant, Arizona, Palmer. The remaining species of this group, E. rotundifoi.ium, Benth., is 

 i-ather stouter, more diffuse, and with larger leaves ; pedicels shorter and more rigid ; flowers 

 from less than a line becoming U lines long, tlie outer segments very broadly dilated above, the 

 inner narrowly oblong : New ilexico and Western Texas. 



H- H- ^- Perianth mostly rninutehj glandular-hispid or -jmberulent, longer than 

 the small involucre, the outer segments mostly ovate: 2>edicels long and fili- 

 form, rarely defiexed. 



++ Leaves fioccose-tomentose, not villous or silky : pedicels all in the forks or ter- 

 minal : stem not inflated. 



22. E. pusillum, Torr. & Gray. Very variable in size, 2 to 20 inches high, 

 becoming rather stout and dillusely ranch-branched : leaves rounded or obovate, 

 obtuse, G to 12 lines broad, usually less tomento.se above: the greenish bracts and 

 involucres minutely glandular-hisi)id : pedicels smooth, 3 to 18 lines long or rarely 

 more, comparatively rather stout : involucres hemispherical-campannlate, a ball' to a 

 line long : flowers yellow or yellowish, often tinged with red, deeply parted, more 

 or less glandular-puberulent, becoming a line long, the outer Sfgments oblong- 

 obovate, the inner oblong : akene short and compressed-globose. — I'roc. Am. Acad, 

 viii. 184; Watson, liot. King Exp. 308. 



A very peculiar species; of dry valleys, from Northwestern Nevada (IfatSDit, Lniuuoa) to 

 Arizona (Pabncr) and San Bernardino County, California, Newberry, Parry. 



23. E. reniforme, Torrey. Low and slender, glabrous : leaves small, reniform 

 or cordate-orbicular and, with the petioles, densely white-tomentose both sides, not 

 at all hairy : bracts smooth, the margins lindiriate with loose hairs : pedicels half an 

 inch Ion" or less : involucres smooth, turbinate-campanulate, nearly a line lon^ 



flowers apparently rose-colored, half a line long, glabrous, segments ovate-oblong, the 

 inner a little smaller. — Fremont's Eep. 317 ; Benth. in DC. Prodr. xiv. 21 ; Torr. 

 & Gray, 1. c. 184, excluding Palmer's Arizona plant with smaller involucres. 



Collected by Frcmmt "on the Sacramento," and hy Cooper at Fort ifohave : imperfectly 

 known. Spcct'inu'ns of E. mhreniformc have been referreil to it. 



24. E. Thomasii, Torrey. Very .slender, a span liigh or often much less, dif- 

 fuse, glabrous ; leaves rounded and ovate, half an inch long or less, usually less 

 tomentose above: bracts minute, glabrous: pedicels filiform, 2 to 15 lines long: 

 involucres glabrous, turbinate-campanulate, \ to 1 lino long : flowers ytdlowish or 

 tinged with red, becoming two thirds of a line long, slightly hispid at ba.se or gla- 

 brous, the outer segments at length often nnich dilated below, the inner linear- 

 oblong or spatulate. -— Pacif. R. Pep. iv. 364 ; Torr. & Gray, 1. c. 184. 



In the valley of the Colorado, from Fort Yuma to Fort Mohave and eastward to S. W. Colo- 

 rado {Brandeyee) ; eastern base of San Bernardino Mountains, Parry. 



++ ++ Leaves more or less villous-pvbescenf, not tomentose : pedicels often scattered 

 and secund on the branchlets : stem often inflated. 



25. E. trichopodum, Torrey. Glabrous, diff"use, I to 1 tnot high, the stem 

 occasionally somewhat inflated; branches very slender: leaves round-cordate to 



