34 G FLORA OF TEXAS. 



ZINNIA, L. 



Annual herbs ; heads many-flowered; ray-Jloivers pistil- 

 late, disk-jloivers tubular, perfect, 5-lobed ; ray-flowers ob- 

 long, rigid, persistent; leaves sessile, 3-ribbed; scales of 

 involucre imbricated, oval or roundish ; chaff of the coni- 

 cal recei^tacle clasping the disk-flowers; achenia of the 

 disk compressed, with a 1-2-awned pappus; those of the 

 rays 3-angled, destitute of pappus. 



Z. MULTiFLORA. Stem erect, l°-2° high, hairy, branch- 

 ing; leaves oblong-lanceolate; rays red or purple ; chaff oi 

 the receptacle obtuse ; pappus of the disk-flowers 1-awned. 



Z. GRAXDIFLORA. Mentioned by Engelmann as found on 

 the Eed River and its tributaries ; description not given. 



HELIOPSIS, Pers. 



Perennial herhs j heads many-flowered ; ray-floioers pis- 

 tillate ; disk tubular, perfect, 5-tootlied ; achenia trun- 

 cate ; scales of the involucre in 2-3 rows ; exterior leafy ; 

 chaff lanceolate, clasping the achenia ; receptacle conical ; 

 imppus none ; rays yello w. 



H. L^Yis, Pers. Stem 2°-5° liig^^? smooth, slender, 

 branching ; leaves ovate-lanceolate, acuminate, serrate, on 

 slender petioles; scales of the involucre obtuse ; rays deci- 

 duous ; peduncles elongated ; leaves 3-ribbed at the base. 



ECHINACEA, Mcench. 



Heads many-flowered; the ray-floivers pistillate, but 

 sterile, drooping ; those of the dish tubular and perfect ; 

 scales of the involucre lanceolate, imbricated in three or 

 more rows, spreading ; receptacle at length conical ; chaffs 

 of the receptacle rigid, spine-pointed, longer than the disk- 



