82 COMPOSITiE. 



ring or node below. Akenes tliickish and hard. Pappus setose or rarely paleaceous. 



Leaves alternate, the teeth or margins often prickly. (Nearl}"- all the indigenous 



American representatives are Thistles.) 



Ckyptostemma calendulacea, of S. Africa, of the tribe Arcfotidere (lying between this 

 tribe and Anthemidece, and to which belongs Gazania of the gardens], is a ballast-weed at some 

 ports in California, which it has reached via Australia. 



Suhtribe I. CarduinejE. Akenes attached by their very base, mostly very glabrous : 



flowers all perfect (one Thistle dioecious), in ours numerous or in the first genus 



rather few in the head. 



* Filaments distinct. 



-)— Leaves never prickly : style-branches partly distinct, sleuder . akenes obloug . filanieuts 

 glabrous. 



195. SAUSSUREA. Involucre obovoid to oblong; bracts appressed, muticous. Receptacle 

 with setiform chaff among the flowers, or rarely naked. Pappus of numerous plumose 

 bristles, more or less connate in an indurated ring at base, so falling from the akene in 

 connection; with commonly some onter and smaller bristles, either less plumose or naked, 

 which are separately deciduous. 



196. ARCTIUM. Involucre globidar; bracts slfnder-subulate or aristifurm and spreading 

 above the broader appressed base, hooked at tip. Receptacle densely setose. Pappus of 

 numerous short and rigid or chaffy bristles, separately deciduous. 



•i— H— Leaves more or less prickly; style-branches concreted to or near the tip into a fili- 

 form or rarely short-cylindrical body ; a pubescent ring below this either manifest or ([uite 

 obsolete • akenes obovate or oblong, compressed or somewhat turgid . pappus simple ; its 

 numerous bristles connate into a ring at base and falling from the akene in connection : 

 filaments bearded or papillose-pubescent, rarely glabrous : involucre of numerous much 

 imbricated and often prickly-tipped bracts, ma^y-flowered. 



197. CARDUUS. Bristles of the pappus naked, or at most barbellulate, not plumose: 

 otherwise like C'niciis. 



198. CNICUS. Bristles of the pappus long- and soft-plumose, or only their tips naked, or 

 those of some marginal flowers occasionally almost naked to the base. Receptacle densely 

 villous-setose. 



199. ONOPORDON. Receptacle fleshy, alveolate, not setose: pappus not plumose: other- 

 wise like C'nicus. 



Cynaea, Artichoke, Cardoon, is sparingly cultivated, but not naturalized. 



* * Filaments raouadelphous below, glabrous ; otherwise as preceding subdivision. 



200. SILYBUM. Involucre depressed-globose, of rather large and rigid bracts in a few 

 series ; their upper portion herbaceous, spinose along the margins, and tapering into a 

 rigid prickle, widely spreading. Receptacle and flowers nearly as in common Thistles. 

 Bristles of the pappus numerous in more than one series, flattish, barbellulate-ciliolate or 

 scabrous. 



Subtribe II. Centaurine.^. Akenes obliquely attached by one side of tlie base or 

 more laterally. 



201. CENTAUREA. Involucre ovoid or globose, many-flowered, mostly firm or rigid; 

 bracts appressed and variously appendaged. Receptacle densely setose. Flowers sometimes 

 all hermaphrodite and with corollas equally or obliquely 5-cleft into narrow lobes ; more 

 commonly the marginal ones neutral or sterile, and their corollas sometimes enlarged and 

 widely spreading, forming a kind of false ray. Style-branches either concreted or partly 

 separate. Akenes obovoid or oblong, turgid or compressed, usually smooth and glabrous, 

 with a large epigynous disk, commonly surrounded by an elevated entire or denticulate 

 margin. Pappus various, setose or partly paleaceous, occasionally obsolete or wanting. 



Tribe X. MUTISIACE^E. (Ser. Labiatiflor^, PC.) Heads in one subtribe ho- 

 mogamous, the hermaphrodite flowers all with regularly 5-cleft corollas ; otherwise 

 either homogamous or heterogamous and corollas bilabiate in the hermaphrodite 



