THISTLE FAMILY 835 



Heads small, paniculate or corymbose; bracts well 

 imbricate, in several series; rays few or none. 



13. Eric.\meria. 

 Herbs or imdershi'iibs ; leaves not glandialar-pimctate. 

 Bracts abruptly acuminate; stems leafy up to the 



sessile heads. 20. Oonopsis. 



Bracts not abruptly acuminate. 



Style-appendages filiform, much longer than the 

 stigmatic portion; low shrubs with whitish 

 bark and fohaceous outer bracts. 



21. Macronema. 



style-appendages of the stigmas ovate or triangu- 

 lar, not longer than the stigmatic portion. 

 Plants low, cespitose, with a woody caudex, 

 more or less evergreen leaves, and solitary 

 peduncled heads. 22. Stenotus. 

 Plants with wholly herbaceous stem, woody, 



if at all, only at the caudex; leaves not 



evergreen. 

 Bracts, at least the outer, fohaceous or 



with fohaceous tips. 

 Disk-flowers tubular; plants with a tap- 

 root. 18. Pyrrocoma. 



Disk-flowers more or less widened up- 

 wards; plants with rootstocks or 

 short caudices. 

 Heads sohtary; rays numerous. 



23. TONESTUS. 



Heads corymbiform-cymose; rays 

 small and narrow. 



24. OrIOCHRTSXIM. 



Bracts not at all fohaceous or merely with 



green tips. 

 Bracts shghtly if at all imequal and 

 sUghtly imbricated; heads solitary 

 or few, peduncled. 



45. ERIGERON. 



Bracts well imbricated and unequal in 



length. 

 Rays not more numerous than the 



disk-flowers; receptacle alveo- 

 late. 

 Inflorescence racemose or panicu- 

 late ; bracts not in vertica 1 



rows. 25. SOLTDAGO. 



Inflorescence corymbiform; bracts 

 in distinct vertical rows. 



26. Petrodoria. 

 Ravs more numerous than the disk- 

 flo wers ; receptacle fimbriolate ; 

 heads corjonbose. 



27. EUTHAMTA. 



Bracts of the involucres longitudinally striate; heads in con- 

 gested corymbs. 28. OUGOXEURON. 



b Ray-flowers blue, pink, or wliite. t, t t +i«^ 



] Pappus a mere crown or of few scales or awn-hke bristles. 



• PappuVof a cup-shaped crown and a single awn; <i:«l^^f^;^J,^^i^^^^^ 



s^t thft hasp ^"' iViUiNUx'iiixjiN. 



PappuTof a series of long awns or that of the rays <>4^^^«^^,^V^4?r' ' 

 or perennials. ^ . , ^0. To\vnse>.dl\. 



' 2 Pannus of numerous capillary bristles. 



fl Kays only shghtly if at all exceeding the pappus; annuals 

 ""- Bricte in^2-3 series, the outer fohaceous; «*i^^^i*/PJ^^^^ 



Bracts in 1-2 series, narrow, not fohaceous; stigma-tips obtuse. 



& Rays conspicuous, longer than the pappus. usuaUy equalhng or exceed- 

 ing the width of the disk. ' 



fttvle-tins lanceolate or oblong to flhform. « i, • ^ ^ 



^^'^Bracts in a single series, ^^ith hyaline-s carious erose-fim^^^^^ mar- 



Kuis- dwarf winter annuals. S2. ^uemiasirum. 



Bracts in at least 2 or usuaUy in more than 2 series. 



Pappus simple, of similar bristles. fucosybis 



Plants rush-hke, spmy. ^^^ UEVLOi^^m^- 



Plants not spiny. , , 



Perennials, vdth a rootstock or caiidex. . . „^ , ^^.l, 



Bmcts acununate. as weU as the leaves tipped mth 



caUous pomts or spmes; plants with sohtary 

 heads at the ends of the stems or branches, and 

 cespitose caudices. 



