436 Lxxm. coMPOSTTvE (OLIVER AND hiern). [Ccnfaiiven. 



99. CENTAUREA, Linn. ; Benth. et Hook. F. Gen. PI. ii. p. 477. 



Capitula heterogamons, florets tubular or dilated above, outer 1- 

 seriate usually larger neuter, or all the florets fertile. Involucre ovoid 

 globose or campanulate, bracts oo-seriate imbricate appressed usually 

 with a terminal scarious or spinescent apex. Receptacle plane densely 

 setose. Style-branches slightly thickened or with a minute papillose 

 annulus at the base. Pappus pluri- or oc-seriate, setaceous or more or less 

 paleaceous, outer setse shorter, or pappus 0. — Herbs with radical or 

 alternate entire toothed or pinnatisect leaves and solitary or variously 

 cymose pedunculate or sessile purple rose white or yellow capitula, in 

 a few species sheathed more or less by the upper leaves. 



A large genus of the Northern Hemisphere chiefly of the Mediterranean region 

 and W. Asia. 



Involucral bracts furnished with a terminal appendix. 



Appendix pectinate, notBipmons {Plectocephalus, D.Don). 



Upper leaves not auriculate. Pappus -^ in. long . 1. C 



varians. 



Upper leaves bi-auriculate. Pappus {^ in, long . . 2. C abyssinica. 

 Appendix spinous. 



Terminal spine long. Setse of pappus long and 

 slender or {Calcit'rapa, Juss.). 



Pappus wanting 3. C Calcitrapn. 



Pappus copious, as long as the achene 4. C. smegalensis. 



Spines palmate, short. Setae of pappus short, stout, 

 compressed, acute {Seridia, Juss,). 



Leaves oval-oblong, obtuse 5, C rhizocephala. 



Leaves linear, acute 6. C. -prcecox, 



Involucral bracts mucronate without appendix. Pappus 

 containing rather long ob.use palese (Microlou' 

 ckus, Cass.). 

 Capitula cymose. Involucral bracts thinly arachnoid 



and scabrid 7. C. Hochstetteri. 



Capitida solitary. Involucral bracts thinly cottony on 



the margin, not scabrid 8. C. somalensis. 



1. C. varians, A. Rich. Fl. Ahi/si^. i. p, 453. An ascending nearly 

 glabrous perennial, 4-15 in. high. Stems decumbent at base, striate, 

 terete, shining, puberulous, simple or nearly so. Radical leaves ellip- 

 tical, obtuse, denticulate, somewhat scabrid on the margins, attenuate 

 at the base into short petiole, 2-5 by J-I5 in. ; upper leaves sessile, 

 gradually smaller and more lanceolate, not auriculate. Capitula solitary 

 pedunculate, campanulate, 1 in. long or nearly so ; peduncle ranging 

 up to 4 in. Involucral bracts appressed, oblong-lanceolate, yellow, 

 going off into a black lanceolate appendix which is decurrent on both 

 sides and pectinate with pale cilia rather longer than the width of the 

 appendix. Ligule of the ray-florets purple. Pappus -^ in. lontr, seta- 

 ceous, tawny. — Plectocephahis cyanoides, Boiss. Diagn. ser. ii., iii. 

 p. 62. 



arile Ziand. Abyssinia, Ouodgerate, Petit! Tchelatchekanne, Q. Billon; 

 Schimper! alt. 9,300 ft., Plowden! Salt! 



2. C. abyssinica, SchuJfz Bip. ex Boiss. Diagn. ser. ii., iii. p. <^2. 

 A robust erect scabrid perennial, 2-5 ft. high. Stems simple or nearly 



