COMPOSITAE. 965 



branches spreading, often secund; leaves as in the preceding, but more pubescent, 

 with spreading hairs, ciliate; heads as in the preceding, but usually on shorter 

 branchlets; bracts broader with a thick, broad, oval or obovate given portion, 

 hispid and ciliate. On prairies, plains and other open places, Vt. and Pa. to 

 Wash., Tex. and Ariz. Kan' in the East. Aug.-Nov. [A. ciliatus Muhl., not 

 Walt. ; A. tnultiflorus var. exiguus Fernald.] 



75. Aster commutatus Torr. & Gray. White Prairie Aster. (I. F. f. 

 3S03.) Similar to the two preceding species, except in the inflorescence, the stem 

 rough-pubescent, or sometimes nearly glabrous, 4-7 dm. high, with ascending or 

 divergent branches. Leaves linear or linear-oblong, obtuse, entire, sessile or slightly 

 clasping at the base, those of the stem 2-7 cm. long; heads larger than those of A. 

 tnultiflorus, 12-16 mm. broad ; involucre 6-8 mm. high, its bracts squarrose-tipped 

 and sometimes foliaceous; rays 20-30. about 6 mm. long. On prairies and along 

 rivers. N. W. Terr, to western Neb., Tex., Ore., Utah and N. Mex. Aug. -Oct. 



76. Aster tenuifolius L. Perennial Salt-marsh Aster. (I. F. f. 3804.) 

 Perennial, glabrous and fleshy; stem flexuous, striate, at least when dry, sparingly 

 and loosely branched, 3-6 dm. high. Stem-leaves linear, entire, acute, sessile or 

 partly clasping at the base, the lowest lanceolate-linear, 5— 15 cm. long, 4-6 mm. 

 wide, those of the branches minute, bract-like, appressed; heads rather few. 12- 

 25 mm. broad, terminating the branches; involucre turbinate, about 8 mm. high, 

 its bracts lanceolate, acuminate or mucronate, glabrous, green on the back or tip, 

 appressed, imbricated in about 5 series, the outer shorter; rays numerous, longer 

 than the pappus, pale purple or nearly white; pappus tawny; achenes hispid-pubes- 

 cent, 5-nerved. In salt marshes, coast of Mass. to Fla. Aug. -Oct. 



77. Aster exilis Ell. Slim Aster. (I. F. f. 3805.) Annual, glabrous, fleshy; 

 stem slender, usually much branched, the branches usually divergent. Leaves 

 linear to linear-lanceolate. 2-10 cm. long, 2-5 mm. wide, entire, sessile, acute or 

 acuminate, or the lowest narrowly oblong, 6-8 mm. wide and petioled, those of the 

 branches subulate; heads numerous, panicled, about I cm. broad; involucre cam- 

 panulate, about 6 mm. high, its bracts linear-subulate, appressed, imbricated in 3 

 or 4 series; rays purplish, about 4 mm. long, mostly fewer than the disk flowers, 

 longer than the pappus; achenes somewhat pubescent. In moist or wet soil, 

 especially in saline situations, Kans. to Tex., S. Car. and Fla. Aug.-Oct. 



78. Aster subulatus Michx. Annual Salt-marsh Aster. (I. F. f. 3806.) 

 Annual, glabrous and fleshy; stem paniculately branched, flexuous above, 3-18 dm. 

 high, slightly angled, sometimes 25 mm. in diameter at the base, but usually 

 smaller. Stem-leaves linear-lanceolate, acute, entire, sessile by a broad or slightly 

 clasping base, 5-25 cm. long, 2-16 mm. wide, those of the branches very small 

 and subulate; heads numerous, 6-10 mm. broad; involucre campanulate, or at 

 length hemispheric, 4-6 mm. high, its bracts linear-subulate, green, imbricated in 

 3 or 4 series, the outer shorter; rays 20-30, purplish, scarcely exceeding the nearly 

 white pappus, more numerous than the disk-flowers; achenes compressed, minutely 

 pubescent. In salt marshes, coast of N. H. to Fla. Aug.-Nov. 



32. LEUCELENE Greene. 



Low perennial herbs, with much branched leafy stems, sessile, rather rigid, 

 narrow entire leaves and small heads of both tubular and radiate white flowers, 

 solitary at the ends of the numerous slender branchlets. Involucre turbinate, its 

 bracts well imbricated. Disk-flowers perfect, their corollas white, tubular-funnel- 

 form, 5-toothed. Ray-flowers numerous, white, or drying red to rose, pistillate. 

 Style appendages acutish. Achenes elongated, flattened, hispidulous. Pappus a 



\e series of slender rough white bristles. [Greek, referring to the white disk.] 

 One species, or more, native of the southwestern States and Mexico. 



1. Leucelens ericoides (Torr.) Greene. Rusk IIkatii Aster. (I. F. f. 

 3807.) Stems tufted from deep woody roots, corymbosely much branched, 

 7-30 cm. high, hispid or scabrous, the branches erect or diffuse. Leaves hispid- 

 ciliate, erect, or slightly spreading, obtusish or mucronulate, the lower and basal 

 ones spatulate, 6-12 mm. long, tapering into short petioles, the upper sessile, linear 

 or linear-spatulate; heads terminating the branches. 10-16 mm. broad; bracts lan- 

 ceolate, appressed, scarious margined, imbricated in 3 or 4 series, rays 12-15, 



