466 ORDER 70. COMPOSURE. 



culcs.) Heads discoid ; involucre imbricate ; ray flowers longer than 

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

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

 alternate Ivs. 



* Scales of the involucre with a fringed or pectinate nppendage Nos. 1, 2 



* Scales of the involucre merely ciliate, or tipped with a spine Nos. 3, 4 



1 C. nfgra L. St. erect, branched, pubescent above ; lower Ivs. angular-lyrate, 

 upper lanceolate, dentate, scales ovate, with an erect, capillary, fringed appendage ; 

 ray and disk-fls. alike. 14- A troublesome weed, in meadows and pastures, Mass. 

 St. about 2f high, simple, or oflener divided into elongated branches. Hcls. few, 

 large, terminal, solitary. Fringed appendage of the scales dark brown. Fls. pur- 

 ple. Jl., Aug. Eur. 



2 C. Americana Nutt. St erect, sulcate, sparingly branched ; lower Ivs. oblong- 

 ovate, repand-dentate, upper ones lanceolate, acute, all sessile and glabrous ; lids, 

 few or solitary, very large ; ped. thickened at summit ; ray fls. twice longer than 

 the disk; scales with a pectinate-pinnate, reflexed appendage. (I) Ark. and La., 

 naturalized in 111. (Mead.) Cultivated in gardens. St. 2 to 4f high, with largo, 

 showy, pale-purple hds. Appendages straw-color, f 



3 C. C^anus L. BACHELOR'S-BUTTON. St. erect, branching, downy ; Ivs. linear, 

 entire, downy, the lowest subdentate ; scales ciliate-serrate ; ray flowers much en- 

 larged. CD Cultivated and sparingly naturalized in old fields. It is a hardy an- 

 nual, justly popular for its handsome flowers which are very variable in color. 

 Hds. ovoid, solitary on the ends of the branches. Jl. Sept. Eur. 



4 C. Calcitrapa L. STAR THISTLE. St. diffusely branched, hairy; Ivs. sessile, 

 pinnately lobed, lobes linear, toothed, upper mostly entire ; hds. sessile ; middle 

 scales tipped with a strong, spreading spine with 1 or 2 minute spines each side ; 

 pappus 0. <D (D Va. Fls. purple. Eur. 



92. AMBErVBOA, DC. SWEET SULTAN. Heads discoid ; involucre 

 imbricated ; ray-flowers wanting or larger than the rest, sterile ; pappus 

 of oblong or obovate pales, attenuated to the base, all similar, rarely 

 small or 0. Eastern herbs with alternate Ivs. 



1 A. moschata "VVilld. Lvs. lyrate-dentate ; invol. subglobous, smooth; 

 scales ovate ; ray-flowers scarcely enlarged, not exceeding the disk ; pappus 0. 

 A handsome border annual from Persia. Flowers purple. A variety has white 

 flowers. July Oct. (Centaurea L.) f 



2 A. odorata, a. amboracea. DC. YELLOW SWEET SULTAN. Lower Ivs. 

 broadly subspatulate, dentate, upper lyrate at base ; hds. globous ; ray-fls. en- 

 larged upwards, longer than the disk ; pappus chaffy, a little shorter than the 

 fruit. From Levant. Leaves scarcely pinnatifid. Flowers yellow, f (Centaurea 

 suaveolens Willd.) 



B. GLAUCA. Lvs. often deeply pinnatifid : flowers purple, f (Centaurea glauca 

 Willd.) 



93. CAR'THAMUS, L. SAFFRON. (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 pales ; achenia 4-angled. Oriental herbs. 



C. tinctorius L. St. smooth ; Ivs. ovate-lanceolate, sessile, spi nous-denticu- 

 late. (1) Native of Egypt, but long cultivated in other lands on account of its 

 orange-colored flowers. Stem branching, striate, 1 2f high. Leaves subam- 

 plexicaul, smooth and shining. Heads large, terminal, with numerous long and 

 slender flowers. The latter are useful in coloring, and as a nursery medicine. 

 July, f 



94. CNKUS, Yaill. BLESSED THISTLE. (Gr. KVL&, to prick ; well 

 applied to these herbs.) Heads discoid ; involucre ventricous, imbri- 

 cate with doubly spinous scales ; ray-flowers sterile ; receptacle very 



