THISTLE FAMILY 835 



Heads small, paniculate or corymbose; bracts well 

 imbricate, in several series; rays few or none. 



13. ERICAMERIA. 



Herbs or undershrubs; leaves not glandular-punctate. 

 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 foliaceous outer bracts. 



21. MACROXEMA. 



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. STEXOTUS. 

 Plants with wholly herbaceous stem, woody, 

 if at all, only at the caudex; leaves not 

 evergreen. 

 Bracts, at least the outer, foliaceous or 



with foliaceous tips. 

 Disk-flowers tubular ; plants with a tap- 

 root. 18. PVRROCOMA. 

 Disk-flowers more or less widened up- 

 wards; plants with rootstocks or 

 short caudices. 

 Heads solitary; rays numerous. 



23. TOXESTUS. 

 Heads corymbiform-cymose; rays 



small and narrow. 



24. ORIOCHRTSUM. 

 Bracts not at all foliaceous or merely with 



green tips. 



Bracts slightly if at all unequal and 

 slightly imbricated; heads solitary 

 or few, peduncled. 



45. ERIGEROX. 

 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 vertical 

 rows. 25. SOLIDAGO. 



Inflorescence corymbiform; bracts 

 in distinct vertical rows. 



26. PETRODORIA. 



Rays more numerous than the disk- 

 flowers ; receptacle flmbriolate ; 

 heads corymbose. 



27. EUTHAMIA. 



Bracts of the involucres longitudinally striate; heads in con- 

 gested corymbs. 28. OLIGOXEUROX. 

 b. Ray-flowers blue, pink, or white. 



1. Pappus a mere crown or of few scales or awn-like bristles. 



Pappus of a cup-shaped crown and a single awn ; dwarf annuals, branched 

 at the base. 29. MOXOPTILOX. 



Pappus of a series of long awns or that of the rays of short scales ; annuals 

 or perennials. 30. TOWNSENDIA. 



2. Pappus of numerous capillary bristles. 



a. Rays only slightly if at all exceeding the pappus; annuals. 



Bracts in 2-3 series, the outer foliaceous; stigma-tips acute. 



31. BRACHYACTIS. 

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



46. LEPTILOX. 



b. Rays conspicuous, longer than the pappus, usually equalling or exceed- 



ing the width of the disk. 

 Style-tips lanceolate or oblong to filiform. 



Bracts in a single series, with hyaline-scarious erose-flmbriate mar- 

 gins; dwarf winter annuals. 32. EREMIASTRUM. 

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

 Pappus simple, of similar bristles. 



Plants rush-like, spiny. 33. LEUCOSYRIS. 



Plants not spiny. 



Perennials, with a rootstock or caudex. 



Bracts acuminate, as well as the leaves tipped with 

 callous points or spines; plants with solitary 

 heads at the ends of the stems or branches, and 

 cespitose caudices. 



