334 FLORA OF TEXAS. 



nearly smooth ; heads numerous, corymbed; scales of the 

 involucre obtuse; aclienia hairy. Stem 2°-4° high ; the 

 branches spreading; leaves l|-'-2' long. 



BOLTOXIA, L'Her. 



Heads many-flowered ; rays pistillate ; scales of the 

 hemispherical involucre imbricated in two rows, not longer 

 than the disk ; receptacle hemispherical or conical, obscure- 

 ly alveolate ; aclienia flattened, obovate, wing-margined ; 

 paijpus composed of several short chafiy scales, that of the 

 disk-flowers mostly with 2-4 longer awns. — Perennial herhs^ 

 resembling Asters. 



B. DIFFUSA, Ell. Stern with long and slender branches; 

 leaves linear, entire ; heads small, terminal ; achenia nar- 

 nowly margined, hairy; pappus very short, 2-awned. Stem 

 3°-4° high ; rays purplish. 



B. GLASTIFOLIA, L'Her. Stem paniculate ; leaves rigid, 

 lanceolate, sparingly serrate, the upper ones linear, entire ; 

 heads rather large ; achenia broadly margined ; pappus of 

 few short bristles, and 2-4 long aw^ns. Stem 3°-5° high ; 

 rays w^hite. 



SOLID AGO, L. GoLDEiT Rod. 



Heads few or many flowered ; rays 1-16, rarely wanting, 

 pistillate ; (W^\.'floiuers tubular, perfect ; scales of the 

 involucre imbricated, rarely with spreading tips ; achenia 

 terete, many-ribbed ; receptacle flat ; pappus simple, of nu- 

 merous scabrous mostly capillary bristles. — Plant erect; 

 leaves alternate; perennial ; flowers yellow. 



Chrtsastrum. — Scales of the involucre loith herbaceous 

 spreading ti^^s ; bristles of the ^^cipjnis unequal, some of 

 them thickened upward ; racemes short, forming a lo7ig and 

 narroio leafy panicle. 



