COMPOSURE. (COMPOSITE FAMILY.) 255 



* # Pappus white ; leaves entire, obscurely veined, firmer and smaller. 



2. S. solidagineus, Nees. Smooth, slender ; leaves linear, rigid, obtuse, 

 with rough margins, tapering to the base ; heads narrow (3" long), in close 

 clusters, few-flowered. Thickets, S. New Eng. to Tenn., and southward. July. 



3. S. tortifolius, Nees. Hoary -pubescent ; leaves obovate or oblong- 

 spatulate, short (-!' long), vertical, both sides alike; heads rather loosely 

 corymbed, obovoid (4 - 5" long). Fine woods, Va. and southward. Aug. 



25. ASTER, L. STARWORT. ASTER. 



Heads many-flowered, radiate; the ray-flowers in a single series, fertile. 

 Scales of the involucre more or less imbricated, usually with herbaceous or 

 leaf-like tips. Receptacle flat, alveolate. Achenes more or less flattened; 

 pappus simple, of capillary bristles (double in 4 and 5). Perennial herbs 

 (annual only in 7 and 8), with corymbed, panicled, or racemose heads ; 

 flowering in autumn. Rays white, purple, or blue ; the disk yellow, often 

 changing to purple. (Name aa-TTjp, a star, from the radiate heads of flowers.) 



Conspectus of Groups. 



Annuals, with copious fine soft pappus 53, 54 



Pappus double 46-48 



Scales closely imbricated, not green -tipped, often scarious-edged .... 49-52 

 Scales closely imbricated, scarcely at all herbaceous ; leaves cordate, serrate . 2, 3 



Scales nearly equal, rigid, more or less foliaceous; pappus-bristles rigid, some 



thickened at top 1 



Scales with herbaceous tips or the outer wholly foliaceous. ASTER proper. 

 Pappus rigid ; stem-leaves sessile, none cordate or clasping ; heads few, large . 4-8 



Leaves silvery -silky both sides, sessile, entire 14, 15 



Lower leaves more or less cordate, petiolate 17-24 



Leaves entire, lower not cordate, cauline sessile with cordate-clasping base . 16 



Involucre (and branchlets) viscid or glandular ; leaves not cordate, mostly entire, 



the cauline all sessile or clasping i ' c i 9-13 



Lower leaves all acute at base ; not glandular nor viscid nor silky-canesoent. 

 Smooth and glabrous, usually glaucous ; scales coriaceous at base ; leaves firm, 



usually entire 25-30 



Hoary-pubescent or hirsute ; scales squarrose ; stem-leaves small, linear, entire 31, 32 

 Scales closely imbricated, not coriaceous at base; branches divaricate; heads 



many, small 33-35 



Remaining species ; branches erect or ascending. 



Stem-leaves auriculate-clasping or with winged-petiole-like base; involucre lax 42-45 

 Stem-leaves sessile, but rarely cordate or auriculate at base .... 36-41 



1 . HELIASTRUM. Pappus simple, coarse and rigid, the stronger bristles 

 somewhat clavate ; scales rigid, more or less foliaceous, nearly equal. 



1. A. paluddsus, Ait. Stems 1 high; glabrous or nearly so; heads 

 high, rather few, racemose or spicate ; outer scales lax, foliaceous ; rays 

 purple; leaves linear, entire. Kan. to Tex., thence to Car. and Ga. 



2. BlOTIA. Involucre obovoid-bell-shaped ; the scales regularly imbricated 

 in several rows, appressed, nearly destitute of herbaceous tips; rays 6-18 

 (white or nearly so) ; achenes slender ; pappus slightly rigid, simple ; lower 

 leaves large, heart-shaped, petioled, coarsely serrate ; heads in open corymbs. 



2. A. COrymb6sus, Ait. Stem slender, somewhat zigzag; leaves thin, 

 smoothish, coarsely and unequally serrate with sharp spreading teeth, taper-pointed f 



