330 FLORA OF TEXAS. 



ASTER, Tourn. Aster ; Starwort. 



Heads many-flowered, the rays (white, blue, or purple) 

 in a single series, pistillate ; scales of the involucre more 

 or less imbricated, mostly with herbaceous or leafy tips; 

 receptacle flat, pitted ; achenia usually compressed ; yappus 

 a single row of numerous rough capillary bristles. — Per- 

 ennial (rarely annual) lierls ; leaves alternate; disk-flowers 

 yellow, often changing to purple. 



Aster proper. — Scales of the involucre imbricated in 

 various degrees, with herbaceous tips ; rays numerous ; 

 achenia flattened; pappus of soft capillary bristles, not 

 thickened upward. — Autumnal plants. 



* Leaves uniform, small, sessile, entire, silky or silvery on both sides, mucronate ; 

 scales of the involucre imbricated in ^-several rows ; rays violet-purple. 



A. SERICEUS, Vent. Stem with numerous branches, 

 bearing the large heads (single or 3 in a cluster) at their 

 summits; leaves oblong-lanceolate, silvery; scales of the 

 involucre leafy and spreading; achenia smooth. Stem 

 10-20' high; leaves ^'-1' long; heads &\i0^j, 



A. CONCOLOR, L. Stem mostly simple, slender, bearing 

 toward the summit, the middle-sized heads in a long often 

 compound raceme; leaves lanceolate, silky when young, 

 the lowest ones oblong; scales of the obovoid involucre 

 lanceolate, appressed, the subulate tips spreading ; achenia 

 silky ; root sometimes tuberous. Stem l°-3° high ; leaves 

 erect, -J- -1/ long. 



+ Leaves all clasping and avricled at the base ; heads large ; scales of the 

 involucre linear. 



A. patens, Ait. Stem pubescent, loosely panicled above ; 

 leaves ovate-oblong, with very rough and wavy margins, 

 those on the slender and spreading branchlets very small. 

 — Var., PHLOGiFOLius. Leaves larger, thinner, and less 



