178 SYNGENESIA. FRUSTRANEA. 



sile and scabrous, equally green on both sides; flo\vers 

 fastigi.ate, numerous; calix squarrose, segments linear; 

 rays linear, very numerous. Hab. In Upper Louisiana, 

 on tile banks of rivurs; probably to the sources of tlie 

 Missouri. Disk yellow; flowers often nearly double. 11* 

 altissimus 12. stnt7iiOsus. 13. prostratus. 14. decapcta- 

 lus. 15. mnhijiorus. 16. mollis. 17. macrophyllus. Scarce- 

 ly distinct from //. decapetalvs. 18 angiistifolius. 



A genus of about SO species exclusively indigenous to 

 North and South America, with the exception of //. coch- 

 inchinemis and //. irulicus of India and I^gypt, scarcely dis- 

 tinct from H. animus. 



590. RUDBECKIA. L. 



Calix subcqual, mostly consisting of a double 

 series of leaflets. Receptacle paleaceous, conic. 

 Pappus a 4-toothetI margin. 



Herbaceous; leaves alternate, entire, lobed orpinnatifid» 

 flowers terminal; disk often dark, rays 3rellow, rarely 

 brown, in Ji. purpurea purple. — Stigma often obtuse. 



Species. 1. R. purpurea. Obs. Stem nearly smooth. 

 Root perpendicular. Rays imperfectly styliferous. Scales 

 of the receptacle acuminated; calix imbricated, squarrose. 

 fi. * serotina. Stem hispid; root horizontal; flowers later; 

 rays bidentate. Flowers purple. Hab. On the plains of 

 Lower Louisiana. 2. amplexifoUa. 



3. Idsrvigata? Ph. Obs- Leaves subcorjaceous, very 

 smooth and lucid; radical spathulate-ovate, obtuse, those 

 of the stem not acuminated; peduncles few, long, and na- 

 ked; flowers fastigiate; disk oblong. Hab. In the Pine 

 forests of Georgia. ^. discolor. Vn. 5. spathulata. Leaves 

 very smooth and entire, spathulate-ovate, and amplexi- 

 caule; stem smooth, 1 or few-flowered; rays of the corolla 

 3-toothed. Hab. In the mountains of Carolina, v. s. In 

 Herb. Muhl. 



6. gracilis. Herb. Banks, mss. Slender and pubescent; 

 stem 1 to 3-flowered, peduncles very long; leaves spathu- 

 late-ovate, remotely denticulate. Hab. In Pine forests 

 from Virginia to Florida. Calix spreading; disk conic, 

 brown. 7. aristata. 8. fulgida. 9. hirta. 10. aspera, 

 Persoon, M. radula? Vn. 11. triloba. Oes- Scales of the 

 receptacle awned. /3. suhtomentosa, Mich. 



12. columnaris. Hispid; stem nearly simple, 1 or few- 

 flowered, peduncles very long; radical leaves nearly en- 

 tire, cauline pinnalifid, segments linear-lanceo.aie; calix 

 simple, 5 to 8-leaved, rays 5 to 8; disk cylindric, eion- 



