372 COMPOSITAE. 



Aster hallii Gray. Glabrous or nearly so; stems slender, erect, 30-60 cm. 

 high, leafy to the top; leaves linear-lanceolate, entire, scabrous on the margin, 

 5-10 cm. long; inllorescence narrow, rather close, often raceme-like; heads 

 small, 6-8 mm. high; involucre campanulate; tegules linear or somewhat 

 spatulate, green-tipped, glabrous, obtuse, erect; ray-flowers white or nearly so, 

 8-10 mm. long. 



In dn.^ ground, western Oregon. 



Aster foliaceus frondeus Gray. Glabrous or sparsely pubescent; stems 

 stout, erect or ascending, simple or usually with a few branches, 20-60 cm. 

 high; leaves few, the lower large, 8-10 cm. long, oblanceolate, tapering into 

 winged petioles; cauline sessile, broadly half-clasping at the base; heads few, 

 large, 1.5-2.5 cm. broad, usually on naked peduncles; involucre 10-14 mm. 

 high, the tegules herbaceous, linear-lanceolate, loose, all about equalling the 

 disk, the outer largest; ray-flowers dark-violet, about 1 cm. long; akenes not 

 glabrous. 



In moist meadows in the mountains at low altitudes. First collected by 

 Lyall on the Cascade Mountains, latitude 49°. 



Aster foliaceus apricus Gray. Yer^' like A. foliaceus frondeus, but dwarf, 

 10-15 cm. high; leaves thicker; heads solitary or few. 



On the higher peaks of the Cascade Mountains at about 2500 m. altitude. 



Aster douglasii Lindl. Glabrous or nearly so; stems erect, 30-120 cm. 

 high; leaves mostly sessile, lanceolate and broadest near the middle, sometimes 

 narrowly linear, acute, serrate near the middle or entire, 5-15 cm. long, those 

 of the branches much smaller; heads usually numerous, panicled; involucre 

 hemispheric, 10-12 mm. high, the tegules green at tip, narrow, acute, the outer 

 sometimes foliaceous and passing into the reduced leaves of the branchlets; 

 ray-flowers pale violet, 10-12 mm. long. 



Common and very variable. First collected by Douglas at the mouth of 

 the Columbia River. 



511. MADIA. Tarweed. 



Annuals; leaves linear or lanceolate, entire or slightly toothed, 

 at least the upper alternate; heads peduncled, clustered; flowers 

 yellow; ray-flowers 1-20 and pistillate, or rarely wanting; disk- 

 flowers 1-5, perfect; receptacle chaffy only at the margin; 

 pappus none or of several small scales in the sterile flowers; ray- 

 akenes laterally compressed, enclosed in the infolded tegules; 

 disk-akenes laterally compressed. 



Heads small, long-peduncled; disk-flower one. M. exigua. 



Heads larger, sessile or short-peduncled; disk-flowers several. 



Leaves all or mostly opposite; perennial. M. madioides. 



Leaves all or mostly alternate; annuals. 



Involucre laterally compressed; ray-flowers 1-5. M. glomerata. 



Involucre campanulate; ray-flowers 5-12. 



Ray-flowers 15-20 mm. long; receptacle bristly. M. elegans. 



Ray-flowers 4-8 mm. long; receptacle glabrous or 

 nearly so. 

 Heads scattered, 6-10 mm. high; herbage moder- 

 ately glandular. M. racemosa. 

 Heads clustered, 10-12 mm. high; herbage very 



glandular. M. saliva. 



Madia exigua (Smith) Greene. Annual; stems slender, erect, usually 

 branched above, hirsute-pubescent below, glandular above, 10-30 cm. high; 



