1 86 Flora of the Palouse Region 



310. ASTER. 



Mostly perennial herbs: leaves alternate: heads solitary, 

 eorymbed or panicled, many-flowered, radiate: ray-flowers several 

 or numerous, in one row, fertile or rarely sterile, white, purple or 

 blue, never yellow: disk-flowers yellow, often turning purple: 

 involucre imbricated; bracts commonly with herbaceous tips: re- 

 ceptacle flat or convex, naked: pappus tawny, simple, of copious 

 slender scabrous capillary bristles: anthers tipped with an ap- 

 pendage: styles appendaged: akenes more or less compressed, 

 rarely slender 4-5-nerved. 



Heads small, less than 1 cm. broad. 



Rays white. A. mulTifeorus. 



Rays violet. A. amethystinuS. 

 Heads larger, 1 cm. broad or more. 



Involucral-bracts coriaceous, appressed. 



Leaves scabrous on both sides. A. conspicuus. 



Leaves smooth on both sides. A. laevis. 



Involucral-bracts with recurved glandular tips. A. canescens. 

 Involucral-bracts green or green-tipped, not coriaceous. 



Whole plant soft-pubescent. A. jessicae. 

 Whole plant nearly glabrous. 



Leaves thickish, somewhat serrate. A. occidentals. 



Leaves thin, entire. A. fremontii. 



A. multiflorus Ait. Perennial, erect, 30-90 cm. high, rough-pubescent: 

 leaves linear or oblong-linear, entire, acute, sessile or somewhat clasping, 

 rigid, 1-3 cm. long or those on the flowering branches much smaller: heads 

 in large panicles, densely crowded, often secund on the spreading branches, 

 nearly sessile: involucres turbinate-campanulate, 3-5 mm. broad, the numer- 

 ous bracts well imbricated, rough-pubescent andciliate, their green tips out- 

 wardly recurved: rays white, 3-4 mm. long: akenes puberulent: pappus sor- 

 did. Infrequent in our limits. 



A. amethystillUS Nutt. Perennial, erect, 30-60 cm. high, sparsely rough- 

 pubescent: leaves not rigid, linear, entire, acute, sessile, 2-6 cm. cm. long, 

 those of the flowering branches much reduced: heads small, usually numer- 

 ous, in rather loose elongated panicles: involucre turbinate, well-imbricated, 

 5-7 mm. broad; the bracts linear, cuspidate-acute, green and spreading at 

 tip, ciliate except at the apex: rays violet, 6-7 mm. long: akenes canescent: 

 pappus sordid. Rocky banks of Snake River at Wawawai. 



A. conspicuus Lindl. Perennial; the stout smooth stems 30-60 cm. high: 

 leaves oblong or obovate, thick and firm, acute or obtuse, serrate, 5-12 cm. 

 long, harshly-scabrous on both sides, all sessile: inflorescence glandular: 

 heads usually many, in large corymbs: involucre campanulate, 10-15 mm. 

 broad; the bracts well imbricated, scarious, mostly acute, ciliate and glandu- 

 lar, many of them green-tipped: rays violet, 1-1.5 cm. long: akenes minutely 

 pubescent: pappus sordid. Open pine woods, Thatuna Hills and Kamiack 

 Butte: also Snake River bluffs near Colton. 



A. laevis L. Perennial, erect, about 1 m. high, glabrous and somewhat 

 glaucous throughout: leaves ovate, oblong or oblong-lanceolate, acute or ob- 



