378 COMPOSITiE. Xanthittm. 



cuneate at the base, attenuate at the apex, often entire or only repand-toothed, but sometimes 

 distinctl}"^ 3-lobed, pale green above except the midrib and larger veins, which are vv^hitish like 

 the under surface. Spines yellowish, about half an inch long. Heads axillary, solitary or 

 few together. Fruit half an inch long ; prickles slender. 



Road-sides, waste places, etc. ; not uncommon in the suburbs of New-York, and near 

 Brooklyn on Long Island ; but not yet noticed in the interior of the State. Introduced from 

 Europe. September - October. 



Subtribe II. Heuanthe^, Less. Heads heterogamous and radiate, rarely homogamous and 

 discoid ; the disk-flowers perfect. Receptacle chaffy. Corolla in the perfect flowers 

 often loith fleshy lobes. Anthers blackish, not caudate at the base. Pappus either wanting 

 or coroniform, or awned and often somewhat chaffy, never capillary. — Leaves mostly 

 opposite. 



CONSPECTUS OF THE GENERA. 



Div. 1. HELIOPSIDE^. Rays fertile, rarely none. Achenia with a thick outer integument, not obcompressed. 



21. Heliopsis. Rays 10 - 15. Pappus none. Receptacle conical. 



Div. 2. EUHELIANTHEjE. Rays sterile. Achenia never obcompressed. 



22. RuDBECKiA. Achenia quadrangular. Chafl" boat-shaped or concave. Pappus none, or minute and coroniform. 



Receptacle conical or elongated. 



23. Lepachys. Achenia compressed, somewhat 1 - 2-winged, 1 - 2-toothed at the summit. Chaff truncate. 



24. Helianthus. Pappus of 3 chaffy awns and often 2-4 little scales, caducous. Involucre imbricated. Achenia 



wingless. 



25. AcTiNOMERis. Pappus of 2 persistent scales. Achenia winged. 



Div. 3. COREOPSIDE.1E. Rays sterile. Achenia obcompressed, not rostrate. Awns not hispid downward. 



26. Coreopsis. Achenia mostly smooth. 



Div. 4. BIDENTIDEjE. Rays sterile. Achenia either obcompressed or rostrate. Awns hispid downward. 



27. BiDENs. Achenia with or without a beak. Awns persistent. Corolla of the disk 5-toothed. 



Div. 1. HEi.iopsiDE.a:, DC. Rays pistillate and fertile, ligulate. Achenia never obcompressed; 

 the exterior integument {calyx-tube) thick and firm, often separable from the interior. 

 Pappus none or coroniform,, frequently toothed or with one or more rigid awns. 



21. HELIOPSIS. Pers. syn. 2. p. 473 ; Endl. gen. 2506. oX-EYE. 



[ From the Greek, hclios, the sun, and opsis, resemblance ; so named in allusion to the form of the heads of flowers.) 



Heads many-flowered ; the rays pistillate : disk -flowers tubular, perfect. Scales of the 

 involucre in 2 - 3 series ; the exterior foliaccous and somewhat spreading ; the interior 

 short. Receptacle conical. Achenia partly embraced by the chaff", smooth, quadrangular, 

 or 3-sided and convex externally in the ray-flowers. Pappus none, except a small truncate 

 crown. — Perennial herbs, with rather large terminal heads. Leaves opposite, petiolcd, 

 triplinerved, serrate. Flowers yellow. 



