366 COMPOSITAE. 



SOS. EUTHAMIA. 



Erect scabrous perennials with narrow alternate leaves; 

 flowers in numerous small heads in terminal flat-topped corym- 

 bose panicles; heads many-flowered, the ray-flowers yellow, 

 equalling and more numerous than the disk-flowers; receptacle 

 fimbrillate; akenes villous. 



Euthamia occidentalis Nutt. Glabrous; stems 90-120 cm. high, erect, 

 branched above; leaves linear, entire, 3-nerved, the principal ones 5-10 cm. 

 long; heads peduncled, in small corymbs; tegules narrow, acute; ray-flowers 

 16-20. 



Common in moist places especially along lake shores; flowering in Sep- 

 tember. 



S06. ERIGERON. Flea bane. 



Herbs; very similar to Aster, but differing in the usually naked 

 peduncled heads; involucre simpler, of narrow erect equal teg- 

 ules, not coriaceous and without herbaceous tips; rays narrower 

 and usually very numerous, often in more than one row, rarely 

 wanting; pappus more scanty or fragile, sometimes with a con- 

 spicuous short outer row; style appendages very short and round- 

 ish or obtuse; akenes mostly 2-nerved. 



Rays very short or wanting. 



Leaves ternately cleft to parted; perennial. E. compositus discoideus. 



Leaves entire; plants not perennial. 



Heads paniculate; involucre glabrous; annual. E. canadensis. 

 Heads corymbose; involucre hirsute, at least 



at base; biennial. E. acris. 



Rays present, conspicuous. 



Plants annual or biennial; stems erect, branched 



above; ray-flowers white. E. ramosus. 



Plants perennial; roots stout. 



Leaves narrow or with narrow lobes; low al- 

 pine plants. 

 Ray-flowers golden yellow; involucre 



woolly. E. aureus. 



Ray-flowers pink or violet, never yellow. 

 Leaves 3-5-cIeft; involucre sparsely 



hirsute. E. compositus trifidus. 



Leaves entire. 



Involucre woolly; leaves spatulate. E. tiniflorus. 

 Involucre hirsutulous; leaves linear- 

 lanceolate. E. pacificus. 

 Leaves flat, rather large and broad, entire or 

 toothed. 

 Stems low; leaves mostly basal. 



Involucre loosely villous; fleshy sea- 

 shore plant. E. glaucus. 

 Involucre not villous. 



Basal leaves dentate; plant produc- 

 ing rosulate offsets. E. oreganus. 

 Basal leaves entire; plant not pro- 

 ducing offsets. 

 Leaves glabrous. E. spatulijolius. 



