Kriogonum. 



POLYGONACE/E. 



17 



Flowers glabrous : umbels usually coinjiouiid ; 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. E. compositum. 



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

 ally very short and undivided. 8. E. Lobbii. 

 Involucres with short erect teeth. 



Flowers villous : dwarf, with a short thick caude.x : umbel sim- 

 ple of 1 to 4 short rays : leaves glabrous. 9. E. pyrol^kolium. 

 Flowers glabrous : dilluscly branched at base. 



Umbel compound, villous-tomentose : bracts consi)icuous. 10. E. vrsinum. 



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

 bracts and leaves small. 



Somewliat cespito.sc : leaves oblanceolate, shortly petiolcd. 

 More dilfuse : leaves ovate or oblong. 



11. E. INCANUM. 



12. E. MAUIFOLIUM. 



Involucre solitary on a leafy-bracteate peduncle. 13. E. Kelloogii. 



Slender annuals : involucres une(iually 4-cleft, i)edicellate, in diffuse 

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

 base. 

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



flowercil : Howers nearly glabrous. 14. E. sl'EUfiULINUM. 



Ikaets oblong, hispid: involu<:res 3 - Tt-flowered ; flowers very 



hirsute. l,*). E. iiirtiflorum. 



♦ ♦ Involucres nerveless, with 5 rounded erect teeth, pedicellate, in diffiise di- or trichotomous 



cymose umbels or panicles : hnvis ternate, mostly small, triangular and ri"id : flower not 

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

 Leaves all radical, or nearly so. 



Flowers glabrous ; outer segments broad and .subcordatc, the inner 

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

 tose. 

 Procumbent, glandular, rather rigid. 

 More erect, glabrous aljove the leaves. 

 Flowers glabrous ; outer .segments oblong or broader above, the 

 inner narrower : jjcdicels longer: leaves tomentose. 

 Pedicels deflexed : outer segments scarcely broader above. 

 Sjiaringly branched, low : pedicels minutely glandular : in- 

 volucres campanulate. 

 More diffuse, taller : pedicels glabrous : involucres narrowly 



turbinate : leaves obtuse. 

 Involucres turbinate-cam[ianulate : leaves acute : flowers more 



attenuate at base ; outer segiuents broader above. 20. E. CERNUUM. 



Pedicels erect or spreading : outer segments much broader and 

 roundeil alwve. 

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

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

 form. 

 Leaves fioccose-tomentose : stem not inflated. 



Greenish bracts and hemispherical involucres minutely glan- 

 dular : leaves rounded : akene thick-lenticular. 22. E. pusillum. 

 Bracts ciliate : involucres smooth, turbinate-campanulate : 



leaves reniform or cordate. 

 Bracts glabrous, minute : involucres glabrous : leaves rounded- 

 ovate : outer segments of perianth often becoming much 

 dilated at base. 

 Leaves villous-itubescent : stem sometimes inflated. 



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



involucres minute : flowere ^ line long. 

 Less branched and internodes more elongated ; stem usually 

 inflated : flower and akene a line long. 

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



Tomentose: branches 4- 6-angled : uj)per leaves lanceolate : invo- 

 lucres hemispherical. 



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

 erect : bracts ternate, short and rigid, sometimes foliaceous : flowere not with stipe-like base : 

 more or less white-tomentbse. 



If). E. RRACIIYPODUM. 

 17. E. UEFLEXUM. 



18. E. NUTANS. 



19. E. Watsoni. 



21. E. Thurbeki. 



23. E. RENIFORME. 



24. E. TiioMASii. 



25. E. TRICHOPODUM. 



26. E. INFLATUM. 



E. ANGULOSUM. 



