354 LXXV. COMPOSITE. CARTHAMUS. 



receptacle naked ; achenia of the disk membranaceous ; pappus 0. 

 An oriental genus of annual kerbs. Lvs. alternate. 



C. OFFICINALIS. Pot Marigold. Viscid-pubescent ; st. erect, branched ; Ivs. 

 oblong, acute, mucronate, sessile, subdentate and scabrous-ciliate on the mar- 

 gin ; hds. terminal, solitary ; ach. carinate, muricate, incurved. A common 

 and handsome garden plant, from S. Europe. It has double, lemon-colored, and 

 other varieties. Flowers large and brilliant, generally orange-colored. Jn. Sept.f 



62. CENTAUREA. 



The centaur Chiron, it is said, cured with these his foot wounded by Hercules. 



Heads discoid ; involucre imbricate ; ray flowers larger than the 

 rest, sterile, often wanting ; receptacle bristly ; pappus of filiform, 

 scabrous bristles in several series. A genus of oriental herbs, with al- 

 ternate leaves. 



1. C. NIGRA. Black Knapweed. 



St. erect, branched, pubescent above ; lower Ivs. angular-lyrate, upper lan- 

 ceolate, dentate ; scales of the involucre ovate, with an erect, capillary fringe. 

 1\. A troublesome weed in meadows and pastures, Mass. Introduced from Eu- 

 rope. Stem about 2f high, simple or oftener divided into elongated branches. 

 Heads few, large, terminal, solitary. Scales dark brown. Flowers purple. 

 Jl. Aug. 



2. C. CYANUS. Blue-bottle. Bachelor's-button. 



St. erect, branching, downy ; Ivs. linear, entire, downy, the lowest subden- 

 tate ; invol. scales serrate. (I) Introduced from Europe, cultivated and sparingly 

 naturalized in old fields. It is a hardy annual, justly popular for its handsome 

 flowers, which are very variable in color. Heads ovoid, solitary on the ends 

 of the branches. JL Sept. 



3. C. AMERICANA. Nutt. (C. Nuttallii. Spreng.) 



St. erect, sulcate, sparingly branched ; lower Ivs. oblong-ovate, repand-den- 

 tate, upper ones lanceolate, acute, all sessile and glabrous ; hds. few or solitary, 

 very large ; ped. thickened at summit ; invol. depressed-globose, scales with a 

 pectinate-pinnate, reflexed appendage. (T) Native in Ark. and La., naturalized 

 in 111. Mead. Cultivated in gardens. Stem 2 4f high, with very showy, pale- 

 purple heads. { 



63. AMBERBOA. DC. 



Heads discoid ; involucre imbricate ; ray-flowers wanting or larger 

 than the rest, sterile ; pappus of oblong or obovate paleae, attenuated 

 to the base, all similar, rarely small or 0. Eastern herbs, with alter- 

 nate leaves. 



-1. A. MOSCHATA. Willd. (Centaurea. Linn.} Sweet Sultan. Lvs. lyrate- 

 dentate ; invol. subglobose, smooth ; scales ovate ; ray-Jlowers scarcely enlarged, 

 not exceeding the disk ; pappus 0. A handsome border annual from Persia. 

 Flowers purple. A variety has white flowers. July Oct. 



2. A. ODORATA. a. amboracea. DC. (Centaurea suaveolens. Willd.) Yellow 

 Sweet Sultan. Lower Ivs. broadly subspatulate, dentate, upper lyrate at base ; 

 hds. globose ; ray-fls. enlarged upwards, longer than the disk-; pappus chaffy, a 

 little shorter than the fruit. From Levant. Leaves scarcely pinnatifid. Flow- 

 ers yellow. 



0. glaiica. (Centaurea glauca. Willd.) Lvs. often deeply pinnatifid ; Jlowers 

 purple. 



64. CARTHAMUS. 



Arabic qorthom, to paint ; from its coloring property. 



Heads discoid ; involucre imbricated, outer bracts foliaceous ; 

 flowers all tubular and $ , filaments smooth ; pappus ; receptacle 

 with setaceous palese; achenia 4-angled. Oriental herbs. 



