23G coMi'OsiT.K. (coMi'osrn-: i amii.v.) 



invohicrp ol)lon<;-lincar ; vnvs wod^f-slinpcd, pnlinatcly .T-lolicd ; ovary wingless, 



with liispid margins. — IJivcr-haiiiis, Soiitli Carolina ami (Ji'orgia. September. 



— Stoin 2°-. •3=' hi-li. 



•*--»-•»- Ilaiis purple or rose-cohr. 



IG. C. nudata, ><'utt. Smooth; stem slender, forking above; leaves nl- 

 teniate, distant, terete, and rush-like; rays bright purple, .3-footlied ; aeheniawith 

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

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



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

 ear ; heads small ; rays slightly 3-tootlied ; achcnia wingless, uiiawned. — 

 Swamps, Georgia, jN'h//«//, and northward. July and August. — Stem 8' -12' 

 high. Rays rose-color. 



IS. C. CEmleri, Kll. Leaves broad-lanccolatc, sessile, acute at each end, 

 entire ; i)edunck's axillary and terminal, dichotomously corymbose. — Collected 

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

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

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

 and margined. ( * ) 



5L COSMOS, Cav. 



Scales of the involucre more or less united. Achenia terete or 4-angled, nar- 

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

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

 divided. Disk yellow. Rays purplish. 



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

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

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



52. BIDENS, L. Bkggau-ticks. 



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



the achenia 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 wliite, ofien wanting. Disk 



yellow. 



* Achenia flattened, narroifhi wedge-shaped. 



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

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

 serrate ; heads discoid ; exterior scales of the involucre large, leafy ; achenia 

 2-awned. — Low ground, Florida and northward. July - Sept. ® — Stem 

 2° -5° high. ISIargins of the achenia upwardly ciliate. 



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

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

 3-parted ; heads discoid ; exterior involucre leafy ; achenia 2 - 4-awned, with 

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

 damp soil. July - Sept. ® — Stem 1° - 20 high. 



