324 FLORA OF TEXAS. 



CCELESTINA, Cass. 



Heads many-flowered ; involucre nearly hemispheri- 

 cal, the scales numerous, imbricated ; receptacle naked or 

 chafly; achenia 5-angled; papj^tus cup-shaped, truncate 

 or more or less prominently toothed ; leaves opposite, 

 toothed ; heads in close corymbs ; jioiuers blue or purple. 



C. MARiTiMA, Torr. and Gray. Stem difi'use, somewhat 

 shrubby at the base, smooth ; leaves ovate, abruptly con- 

 tracted into a slender petiole ; corymbs few-flowered; recep- 

 tacle naked ; pappus a whitish truncated margin. Stem 

 l°-2° long ; flowers blue. 



AGERATUM, L. 



Beceptacle always naked ; pajjpus composed of 5-10 dis- 

 tinct scales. Otherwise like Ooelestina. 



A. CONYZOIDES, L. Leaves ovate, rhombic, or cordate, 

 on rather long petioles ; scales of the pappus 5, slightly 

 serrate, awn -pointed fi'om a broad base. Wet places. Pu- 

 bescence and form of the leaves variable ; flowers white or 

 blue. 



CARPHEPHORUS, Cass. (Liatris, Ell.) 



Heads about 20-flowered ; receptacle chaffy ; pales nar- 

 row, 3-veined and rigid, shorter than the flowers ; stem. 

 simple, leafy, corymbous at top, with middle-sized head of 

 purple flowers ; achenia 10-ribbed ; leaves alternate ; scales 

 of the involucre imbricated in three rows, ovate or lanceo- 

 late, appressed. 



C. TOMENTOSus, Torr. and Gray. Stem erect, downy ; 

 leaves cuneate-lanceolate, 3-ribbed, narrowed into a clasp- 

 ing petiole ; cauline leaves lance-ovate ; scales of the in- 

 volucre lance-ovate, nearly smooth. Stem 2° high, bear- 



