Cnicus, COMPOSITE. 417 



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where Bentham has placed these genera, although the bristles of the pappus are somewhat too 



stout and flattish. 



1. R. scaposa, Gray. Somewhat hirsute as well as glandular : scape a span to 

 a foot high, sometimes with a leaf or two towards the base : involucre 20 30-flow- 

 ered (an inch or less long). 



Sierra Nevada, in the Yosemite and Mono districts, at the elevation of 8,000 to 10,000 feet, 

 Brewer, Bolander, Gray. 



2. R. argentea, Gray. Leaves shorter, only one or two inches long, silvery- 

 silky : scape one to four inches high: involucre narrower, 7 15-flowered (half an 

 inch or more long). 



Higher Sierra Nevada, at 8,000 to 11,000 feet ; Mount Dana to Sonora Pass (Brewer, Bolander), 

 above Donner Lake (E. L. Greene), and on Lassen's Peak, Lemmon. 



TRIBE IX. CY^AEOIDILE. 



The only Californian representatives of the tribe are Thistles, of well-known 

 appearance, and a Centaurea or two, of the Mediterranean region, sparingly natural- 

 ized in fields and around harbors. Even Burdocks are unknown. 



CYNARA SCOLYMUS, Linn., the Artichoke of the Old "World, remarkable for the thick fleshi- 

 ness of the receptacle and scales of the involucre, which are edible, is occasionally spontaneous, 

 probably escaped from cultivation. 



104. CNICUS, Linn. THISTLE. 



Head many-flowered ; the flowers all perfect and fertile, with tubular corollas 

 deeply (often more or less unequally) 5-cleft into narrow lobes. Involucre globular, 

 ovoid, or at maturity sometimes campanulate ; the mostly narrow scales imbricated 

 in many series, more commonly tipped with a spine or cuspidate point. Recep- 

 tacle flat, fleshy, densely clothed with bristles. Filaments commonly papillose- 

 hairy, distinct : anthers sagittate at base, the auricles frequently extended into tails. 

 Style filiform, sometimes thickened or with a pubescent ring or node at the base of 

 the minutely puberulent stigmatic portion ; which in our species is almost always 

 slender, consisting of two filiform branches which are more or less firmly united by 

 their inner faces up nearly or quite to the tip. Akenes glabrous and smooth, thick- 

 walled, obovate or oblong, more or less compressed, attached by their very base. 

 Pappus of copious and rather rigid long and plumose bristles in a single series, con- 

 nected at the very base into a ring, so that they remain united after detaching. 

 Not rarely the bristles of some of the outermost flowers are slightly or not at all 

 plumose. Stout herbs, more commonly biennials, with alternate and usually 

 prickly leaves, and large or middle-sized heads; the flowers purple, red, pale yellow, 

 or white. Benth. & Hook. Gen. PI. ii. 468 ; Gray, Proc. Am. Acad. x. 39. 

 Cirsium, Tourn., DC. Prodr., &c. 



A large genus, widely dispersed over the northern hemisphere, most numerous in the Old 

 World. It seems necessary to follow Bentham in restoring the Linnsean name of Cnicus, includ- 

 ing, however, a good deal more than the Cirsium of Cassini, De Candolle, &c. Two European 

 species, which are common and troublesome in the Atlantic States, seem not to have reached 

 California, viz. 



C. LANCEOLATUS, the common Field Thistle, which is well marked by the leaves being decur- 

 rent on the stem, and their upper surface very harsh or almost prickly. 



C. ARVEXSIS, the Canada Thistle (but not indigenous to Canada), with numerous small heads 

 which incline to be dioecious. 



