POLYGONAOE^E. (BUCKWHEAT FAMILY.) 315 



■*- •♦- Branching : leaves radical or at least, the peduncles leafless. 

 ++ Densely white-tomentose. 



12. E. tenellum, Torr. Tall : branches of the woody caudex short and 

 crowded or elongated : leaves ovate or rounded, tomentose on both sides : 

 inflorescence rather sparingly branched, glabrous: flowers white or pinkish: 

 outer sepals broadly obovate or orbicular, the inner linear-oblong. — S. Colo- 

 rado to Texas and Mexico. 



++ ++ Glabrous : involucres turbinate-campanulate. 



13. E. Cernuum, Nutt. Leaves broadly ovate, acute: pedicels deflered : 

 outer sepals oblong or broader above, retuse. — New Mexico and Colorado to 

 Oregon. 



14. E. reniforme, Torr. Low and slender : leaves reniform or cordate- 

 orbicular, densely white-tomentose on both sides : bracts smooth, the margins 

 ciliate : pedicels long and filiform, rarely deflexed, all in the forks or termi- 

 nating the branches : flowers rose-colored, glabrous. — S. W. Colorado to S. 

 California. 



15. E. Thomasii, Torr. Low and very slender: leaves rounded and ovate, 

 small : bracts minute, glabrous : pedicels as in the last : flowers yellowish, often 

 reddish, slightly hispid or glabrous : outer sepals often much dilated below. 

 — S. W. Colorado to S. California. 



* * Leaves not tomentose. 

 +- Leaves all radical or nearly so. 



16. E. inflatum, Torr. Glabrous, diffusely branching, the stem and 

 internodes often inflated : leaves rounded, usually cordate and mostly undulate, 

 pubescent : flowers yellowish, pubescent. — • S. W. Colorado to Arizona, Nevada, 

 and S. California. 



17. E. Gordoni, Benth. A similar species, but glabrous throughout, or 

 the petioles slightly pubescent : flowers glabrous, light rose-color. — Colorado. 



18. E. glandulosum, Nutt. Beset with short-stipitate glands: leaves 

 small, obovate, somewhat villous : involucres glabrous : flowers slightly hispid. — 

 Collected by Dr. Gambel in Colorado or New Mexico. 



•<- -t- Leaves developed at the nodes in the axils of ordinary triangular bracts. 



19. E. divarieatuill, Nutt. Low, grayish-pubescent, branching from 

 the base, branches terete : leaves thickish, all rounded or the upper oblong, 

 petiolulate : involucres very small and few-flowered : flowers whitish, mi- 

 nutely glandular : sepals nearly equal. — W. Wyoming to S. W. Colorado. 



§ 3. Lnvolucres cylindric-turbinate, more or less strongly 5 to 6-nerved, and often 

 becoming costate or angled, with as many short erect teeth, sessile in heads or 

 clusters, or scattered in cymes or along virgate panicled branches : bracts ternate, 

 connate at base, more or less rigid : flowers not attenuate at base. 



* Outer sepals broad and somewhat cordate, the inner much narrower: ovary 



scabrous above. 



20. E. ovalifolium, Nutt. Low, densely tomentose and cespitose, with 

 a short closely branched caudex : leaves round or rarely oblong : bracts very 

 small : involucres in a single close head : flowers rose-colored, white, or yel- 

 low : outer sepals oblong, becoming orbicular, the inner spatulate, often 

 retuse. — From Colorado to N. California and British America. 



