7. Aster hesperius Gray. Marsh aster. 



Erect rhizomatous perennial; stem leaves linear to lance-linear with relatively 

 obscure venation pattern, to 16 cm. long and to 15 mm. broad; leaves of the fairly 

 numerous erect (not secund) head-bearing branchlets much smaller, oblong to 

 subulate; heads hemispheric; involucres 6-7 mm. high, with several rows of 

 strongly graduated phyllaries; rays several mm. long, bluish; mature disk corolla 

 with tube 2.2-2.5 mm. long, throat 2.4-2.7 mm. long and lobes 0.7-1 mm. long, 

 A coerulescens of many auth., not DC. 



In marshy meadows and swampy soils, in seepage along streams and irrigation 

 ditches, rare in Tex. in the Trans-Pecos (at Muzquiz Swamp, Jeff Davis Co., and 

 Guadalupe Mts., Culberson Co.), N.M. (widespread in mts.) and Ariz. (Apache, 

 Navajo and Coconino, s. to Cochise and Pima cos.), Sept. -Oct.; Alta., N.D. and 

 Wise. s. to Calif., Ariz., Chih. and Tex. 



This is exceedingly close to the A. praealtus complex (especially to A. coerules- 

 cens) and the merit of recognizing it as specifically distinct is doubtful. 



8. Aster chilensis Nees. 



Herbaceous perennial; stems slender, 3-6 dm. tall, usually erect, pubescent 

 all around below or only in lines above; lower leaves narrowly oblanceolate, 

 tapering to petiolelike base, the middle and upper leaves lanceolate to linear, 

 usually entire, somewhat clasping, rough-margined, glabrous to more or less 

 pubescent; heads few to many, in a nearly naked closed or open cyme or cymose 

 panicle about 2.5 cm. wide; involucre 4-7 mm. high; phyllaries usually strongly 

 graduate, erect, linear or linear-oblong, the outermost phyllaries usually spatulate 

 and obtuse to acute, the inner ones acuminate, ciliolate, glabrous or pubescent 

 on back; rays 22 to 35, violet or purple, about 8 mm. long. A. adscendens Lindl., 

 A. vallicola Greene. 



In wet mt. meadows, along streams and in seepy soils, openings in forests, in 

 Ariz. (Navajo and Coconino cos.), Aug.-Sept.; Sask. to Wash., s. to Colo, and 

 n. Ariz. 



9. Aster foliaceous Lindl. 



Herbaceous perennial from a creeping rootstock, 2-5 dm. tall; stems commonly 

 reddish, glabrous below; lower leaves oblanceolate to obovate, 5-20 cm. long, 

 1.5-4 cm. wide, narrowed to a conspicuously clasping petiolar base, the margins 

 entire, ciliate-appressed, the upper stem leaves sessile; inflorescence mostly 

 1-headed to corymbose or subcymose with 4 to 6 heads; 9-12 mm. high, to 

 3.5 cm. wide, usually pubescent below the involucre; phyllaries green, subequal 

 in size, with additional large foliaceous bracts sometimes present, glabrous on 

 the back, ciliate-margined, oblong, obtuse to broadly acute at apex; rays 15 to 60, 

 purple, 1-1.5 cm. long; achenes glabrous to sparsely pubescent; pappus white or 

 tawny to occasionally reddish. 



In seepage areas, along streams, in wet mt. meadows and on moist wooded 

 slopes, in N.M. (Rio Arriba and San Miguel cos.) and Ariz. (Navajo, Coconino, 

 Apache and Greenlee cos.), Aug.-Sept.; Alas., s. to N.M., Ariz, and Calif. 



Represented in our region by several weak varieties. 



10. Aster pauciflonis Nutt. Marsh alkali aster. 



Perennial herb from creeping rootstocks; stems erect, simple or branched from 

 the base, 2-9 dm. tall, glabrous except for glandular inflorescence; leaves some- 

 what fleshy, with midvein not prominent, linear or lanceolate-linear, entire, sessile, 

 acuminate at apex, 6-12 cm. long, 3-6 mm. wide, reduced and bractlike on the 

 branches of the corymbiform inflorescence; heads 6-12 mm. wide, 6-8 mm. 

 long; involucre densely glandular-puberulent, the phyllaries linear-lanceolate, 



1622 



