COMPOSITE FAMILY. 221 



or neutral, always without stamens ; or wnth strap-shaped 

 corollas entirely wanting. Plants destitute of milky or colored 

 juice. (Series II., p. 228.) 



A. Xo strap-shaped corollas or true rays ; i.e. the head discoid. (B, p. 224.) 



♦ Branches of the style filiform-suhulate and rough all over with minute bristles ; 



receptacle not chaffy ; flowers not yellow {* * and « * * this page). 



1. VERNONIA. Heads corymbed, with an Involucre of many imbricated scales, and 15 to 



30 or more rose-purple flowers. Lobes of the corolla slender. Akenes cylindrical, 

 several-ribbed ; pappus of copious hair-like bristles, surrounded at base by an outer 

 set of very short and fine scales or scale-like bristles. Leaves alternate. 



♦ » Branches of the style long and slender or mostly rather club-shaped, obtuse, 



usually fcry minutely puberulent under a lens, the stigmatic surface belotv the 

 middle ; receptacle not chaffy ; flowers not yellow. 



->- Pappus ; leaves opposite. 



2. PIQUERI A. Heads very small, of 3-5 whitish flowers, and involucre of 4 or 6 imbri- 



cated scales. Akene 4-5-ang-led. 



+- -t- Pappus stiff, mostly scale like; leaves whorled or opposite. 



8. SCLEROLEPIS. Heads many-flowered, flesh-colored, the scales of the involucre 

 equal. Corolla 5-toothed. Akenes 5-angled. Pappus a single row of 5 hard, oval, 

 obtuse scales. Leaves whorled. 

 4. AGERATUM. Heads small and few-flowered, blue (in ours; in others rose-colored), 

 with a cup-shaped involucre of imbricated narrow bracts; receptacle flattish ; the 

 pappus of a few chafl'y scales, mostly tapering into a slender stiff rough bristle. 

 Leaves opposite. 



■4- -K -(- Pappus of slender bristles ; leaves various. 

 *+ Stem tu'ining ; involucral scales 4. 



6. MIKANIA. Heads of 4 flesh-colored flowers. Corolla 5-toothed. Akenes 5-angled ; 

 pappus a row of hair-like, naked (barely roughish) bristles. Leaves opposite. 



** ++ Stem erect ; involucral scales more than 4. 



6. EUPATORIUM. Hcadsof 3 or more flowers, and an involucre of several or many scales. 



Corolla 5-toothed. Receptacle flat or merely convex. Akenes 5-angled ; pajjpusarow 

 of hair-like naked (rarely rough) bristles. Leaves alternate, opposite, or whorled. 



7. KUHNl.X. Heads small, of 10-25 dull cream-colored flowers, surrounded by a few lanceo- 



late .scales of the involucre. Corolla slender, barely 5-toothed. Akenes cylindrical, 

 many-striate ; pappus a row of white plumose bristles. Leaves mostly alternate. 



8. LIATRIS. Heads of several or many rose-purple flowers, surrounded by a more or 



less imbricated involucre. Lobes of the corolla rather long. Akenes slender, about 

 10-ribbed ; pappus of many long and slender bristles, which are plumose or else 

 beset with a short beard or roughness for their whole length. Heads spicate or 

 racemose. Leaves alternate, entire, often resinous-dotted. 



♦ » » Branches of the style mostly short, often united, with obtuse or truncate tips. 



naked or sometimes hairy appendaged (or eremoith a minute hairy tip) , the 

 stigmatic surface either e.rtending to the tip or to an appendage; receptacle 

 either naked or chaffy ; flowers of many colors. 



*- Thistles or Thistle-like, the heads with very many flowers, all alike and mostly perfect. 

 Branches of the style short or united, even to the tip. Scales of the involucre 

 many ranked, these or the leaves commonly tipped with prickly or bristly points. 



^^■ Pappus of many long plumed bristles ; receptacle with bristles between the flowers. 



(G5) CNICUS. Scales of the involucre not fleshy-thickened, jirickly-tipped or else merely 

 pointed. Akenes flattish, not ribbed. Filaments of the stamens separate. 



