Eriogonum. 



POLYGONACE.E. 



17 



Flowers glabrous : umbels usually compound : peduncles from a 



thick short caudex : leaves round to oblong. 

 Leaves oblong-ovate and cordate : peduncle stout, tall : umbel 



compound, of 6 to 10 elongated rays. 7. 



Leaves oval or rounded : peduncle decumbent : rays few, usu- 

 ally very short and undivided. 8. 

 Involucres with short erect teeth. 



Flowers villous : dwarf, with a short thick caudex : umbel sim- 

 ple of 1 to 4 short rays : leaves glabrous. 9. 

 Flowers glabrous : diffusely branched at base. 



Umbel compound, villous-tomentose : bracts conspicuous. 10. 

 Umbel simple, tomentose, 5 - 8-rayed, often subcapitate : 



bracts and leaves small. 



Somewhat cespitose : leaves oblanceolate, shortly petioled. 11. 

 More diffuse : leaves ovate or oblong. 12. 



Involucre solitary on a leafy-bracteate peduncle. 13. 



Slender annuals : involucres unequally 4-cleft, pedicellate, in diffuse 

 di- or trichotomous cymes or panicles : flower not attenuate at 

 base. 

 Leaves and bracts linear-oblanceolate, hirsute : involucres 1-2- 



flowered : flowers nearly glabrous. 14. 



Bracts oblong, 

 hirsute. 



hispid : involucres 3 - 5-flowered ; flowers very 



15. 



E. COMPOSITUM. 

 E. LOBBII. 



E. FYROL-fiFOLIUM. 

 E. URSINUM. 



E. INCANUM. 

 E. MARIFOUUM. 



E. KELLOGGII. 



E. SPERGULINUM. 

 E. HIRTIFLORUM. 



16. E. BRACHYl'ODUM. 



17. E. DEFLEXUM. 



18. E. NUTANS. 



20. E. CERXIT.M. 



* * Involucres nerveless, with 5 rounded erect teeth, pedicellate, in diffuse di- or trichotomous 



cymose umbels or panicles : bracts temate, mostly small, triangular and rigid : flower not 

 with stipe-like base. Annuals, mostly glabrous above, with radical rounded leaves. 



Leaves all radical, or nearly so. 



Flowers glabrous ; outer segments broad and subcordate, the inner 

 much smaller : pedicels very short, deflexed : leaves tomen- 

 tose. 



Procumbent, glandular, rather rigid. 

 More erect, glabrous above the leaves. 

 Flowers glabrous ; outer segments oblong or broader above, the 



inner narrower : pedicels longer : leaves tomentose. 

 Pedicels deflexed : outer segments scarcely broader above. 



Sparingly branched, low : pedicels minutely glandular : in- 

 volucres eampaimlate. 

 More diffuse, taller : pedicels glabrous : involucres narrowly 



turbinate : leaves obtuse. 19. E. WATSOXI. 



Involucres turbinate-campanulate : leaves acute : flowers more 



attenuate at base ; outer segments broader above. 

 Pedicels erect or spreading : outer segments much broader and 



rounded above. 21. E. TnruBERl. 



Flowers mostly minutely glandular-hispid, longer than the invo- 

 lucre ; outer segments mostly ovate : pedicels long and fili- 

 form. 

 Leaves floccose-tomentose : stem not inflated. 



Greenish bracts and hemispherical involucres minutely glan- 

 dular : leaves rounded : akene thick-lenticular. 

 Bracts ciliate : involucres smooth, turbinate-campanulate : 



leaves renifonn or cordate. 23. E. RENIFORME. 



Bracts glabrous, minute : involucres glabrous : leaves rounded- 

 ovate : outer segments of perianth often becoming much 

 dilated at base. 

 Leaves villous-pubescent : stem sometimes inflated. 



Diffusely much-branched, very slender ; stem rarely inflated : 



involucres minute : flowers A line long. 

 Less branched and internodes more elongated ; stem usually 



inflated : flower and akene a line long. 26. E. JXFLATUM. 



Leaves commonly at the nodes, in the axils of the bracts. 



Tomentose: branches 4- 6-angled : upper leaves lanceolate : invo- 

 lucres hemispherical. 27. E. ANGULOSUM. 



* * * Involucres 5-6-nerved, with as many short erect teeth, sessile (rarely pedicellate) and 

 erect : bracts temate, short and rigid, sometimes foliaceous : flowers not with stipe-like base : 

 more or less white-tomentose. 



22. E. PUSILLUM. 



24. E. THOMASII. 



25. E. TRICHOPODUM. 



