218 CO-MPOSIT.E. (cOMrOSITE FAMILY.) 



Subtrlbe 1. EupatorU-rc. Flowers all perfect and tubular, never truly yellow. 



* Pappus a row of hard scales. 



8. Sclerolepis. Head many -flonereJ. Scales of the involucre equal. Leaves wborled. 



» * I'appus of slender bristles. 



4. Lilatris. Achenia many-rihbcd. Bristles of the pappus plumose or barbellate. Corollas 



red-purple, .strongly 5-lobed. 



5. Kiiliiiiii. Aohenia many -ribbed. Bristles of the pappus very strongly plumose. Corol- 



liui whitish, 5-toothed. 



6. Eu|>atui-iiim. Achenia 5-angled. Bri.«tles of the pappus roughish. Scales of the 



involucre many or several. Ueieptacle of the 5 -many flowers flat or barely convex. 



7. nilkaiiia. Acbenia and pappus as No. 6> Scales of the involucre and flowers only 4. 



8. Couoclluiuin< Acbenia, pappus, &c. as No. 6. Receptacle conical. 



iSubtribe 3. Tussilasinrte. Flowers (sometimes yellow, more or le.'s monoecious or 

 diwi'ious) of 2 sorts iu the same head. 

 * Outer flowers of each (many-flowered) head l>istillate and ligulate. Scape leafless. 

 9 NardoMiiiiu. Heads corymbed. Flowers somewhat dioecious. Pappus capillary. 



10. Tussilujjo. Ilead single ; the outer pistillate flowers in many rows. Pappus capillary. 



♦ * Flowers all tubular. Stem leafy. 



11. Adenocauloii. Uead few-flowered ; the ouler flowers pistillate. Pappus none. 



Tribe III. ASTEROIDEiE. Heads discoid, with the flowers all alike and tuhular ; 

 or else radiate, the outer ones ligulate and pistillate. Bl-auches of the style in the perfect 

 flowers flat, smooth up to where the conspicuous marginal stigmatic lines abruptly termi- 

 nate, and prolonged above this into a flattened lance-shaped or triangular appendage which 

 is evenly hairy or pubescent outside. — Leaves alternate. Keceptacle naked (destitute of 

 chafl^) in all our species. 



Subtrlbe 1. Asterliiere. Flowers of the head all alike and perfect, or the marginal 

 ones ligulate and pistillate. Anthers without tails at the base. 



» Kay -flowers white, blue, or purple, never yellow. 

 ^- Pappus of numerous long and capillary bristles : receptacle flat. 



12. Sericocnrpus. Heads 12 - 15 flowered : rays 4 or 5. Involucre oblong or club-shaped, 



imbricated, carJ;ilaginous. Ac .euia short, narrowed downwards, silky. 



13. Aster. Heads many-flowered. Involucre loosely or closely imbricated, .\chenia flattish. 



Pappus simple, copious. 



14. Eriseroii. Heads many-flowered. Involucre of narrow scales, little imbricated. 



Achenia flattened. Pappus simple and rather scanty, or with some outer minute scales. 



15. DIplopappus. Heads many-flowered. Involucre imbricated. Pappus double; the 



outer obscure, of minute slitt bristles, 

 t- I- Pappus of very short rigid bristles, or none : receptacle conical or hemispherical. 



16. Boltonia. Achenia flat and wing-margined. Pappus very short. 



17. Bellis. Achenia marginless. Pappus none. Recepta<;le conical. 



* * Ray-flowers yellow (in one species of Polidago whitish), or sometimes none at all. 



18. Brachj-rhreta. Heads 8-10 flowered, clustered: rays 4 or 5. Pappus a row of mi- 



nute bristles shorter than the achenium. 



19. !SoIifIii;;o. Heads few - many-flowered : rays 1 - 16. Pappus simple, of numerous slen- 



der and erjual capillary bristles. 



20. Bigelovia. Heads 3- 4-flowered : rays none. Receptacle awl-shapcd. Pappus simple, 



a single row of capillary bristles. 



21. Chrysopsia. Heads many-flowered: rays numerous. Pappus double; the outer of 



very small chaffy bristles, much shorter than the inner of copious capillary bristles. 



Subtrlbe 2. Inulrse. Anthers with tails at their base : otherwise as Subtribe 1. 



22. luulo. Heads many-flowered. Rays many. Pappus capillary and copious. 



