236 COMPOSITE. (composite family.) 



involucre oblong-linear; rays wedge-shaped, palmatcly 3-lobcd ; ovary wingless, 

 with hispid margins. — River-banks, South Carolina and Georgia. September. 

 — Stem 2° -3° high. 



«- -»- -t- Hays purple or rose-color. 



16. C. nudata, Nutt. Smooth; stem slender, forking above; leaves al- 

 ternate, distant, terete, and rush-like ; rays bright purple, 3-toothcd ; aehenia with 

 lacerated wings, 2-awned. — Pine-barren ponds, Florida and Georgia, near the 

 coast. April. — Stem 2° high. Lowest leaves 1° long. Rays 1' long. 



17. C. rosea, Nutt. Smooth; stem low, branching; leaves opposite, lin- 

 ear; heads small; rays slightly 3-toothed ; aehenia wingless, unawned. — 

 Swamps, Georgia, Nutta'l, and northward. July and August. — Stem 8'- 12' 

 high. Rays rose-color. 



18. C. CEmleri, Ell. Leaves broad-lanceolate, sessile, acute at each end, 

 entire; peduncles axillary and terminal, dichotomously corymbose. — Collected 

 near the junction of the Broad and Saluda Rivers by Mr. CEmlcr. Elliott. — 

 Stem 2° -3° high, angular, smooth. Leaves connate by a small membrane. 

 Heads small. Rays about 8, entire. Aehenia wedge-shaped, slightly 2-toothed 

 and margined. ( * ) 



51. COSMOS, Cav. 



Scales of the involucre more or less united. Aehenia terete or 4-anglcd, nar- 

 rowed or beaked at the apex, and crowned with 2-4 downwardly barbed % or 

 hispid deciduous awns. Otherwise like Coreopsis. — Leaves opposite, pinnately 

 divided. Disk yellow. Rays purplish. 



1. C. caudatUS, Kunth. Smooth ; leaves bipinnately divided, with the 

 divisions lanceolate and entire ; aehenia ( 1 ' long) tapering into a very long rough 

 beak, 2-awned ; rays short, 3-eleft, rose-color. — Key AVest, Florida. 



52. BIDENS, L. Bkggar-ticks. 



Chiefly like Coreopsis ; but the exterior involucre often long and leaf-like ; 

 the aehenia compressed, or 3 -4-angled, (not narrowed at the apex,) and crowned 

 with 2-4 persistent downwardly barbed or hispid awns. — Leaves serrate, or 

 pinnately divided, opposite. Rays yellow or white, often wanting. Disk 

 yellow. 



* Aehenia flattened, nan-only wedge-shaped. 



1. B. frondosa, L. Stem tall, branched ; leaves thin, Iong-petioled, pin- 

 nately 3- 5-divided ; the divisions ovate or ovate-lanceolate, acuminate, sharply 

 seriate; heads discoid j exterior scales of the involucre huge, leafy; aehenia 

 2-awned. — Low ground, Florida and northward. July - Sept. (£) — Stem 

 2° -5° high. Margins of the aehenia upwardly eiliate. 



2. B. COnnata, Muhl. Stem low, branched ; leaves oblong-lanceolate, 

 acuminate, roanely serrate, tapering and connate at the base, the lowest often 

 .'! -parted ; heads discoid ; exterior involucre leafy; aehenia 2-4-awned. with 

 downwardly hispid margins. — Western districts of Georgia and westward, in 

 damp soil. July-Sept. ® — Stem 1° - 2° high. 



