COMPOSITAE (composite FAMILY) 585 



and green: leaves lanceolate, pinnatifid and toothed, furnished with abundant 

 weak prickles: heads loosely cymose, 2-3 cm. high, dioecious; in staminate 

 plants ovate-globular, -prith the flowers well exserted; the pistillate oblong- 

 campanulatei the flowers less exserted; bracts of the involucre oppressed, 

 short, with v^ry small, weak, prickly points. — A troublesome weed introduced 

 from Europe; becoming too common in Canada and bur range. - 



2. Carduus Parryi (Gray) Greene, Proc. Am. Acad. Sci. Phil,a. 362. 1892. 

 Green, lightly arachnoid and villous when young, 3-7 dm. high: leaves lanceo- 

 late, sinuate-dentate, not decimreut, moderately prickly: heads several and 

 spicately glomerate or more racemogely paniculate, m.ore or less bractose- 

 leafy at base; accessory and outer proper bracts or some of them pectinately 

 fimbriate-ciliate down the sides; themnermost with more or less dilated or 

 margined, mostly lacerate-fimbriate tips: corollas pale?yellow, the Ibbe^ longer 

 than the throat : pappus of, fine, soft bristles, none of them obviously cla'vellate. 

 Cnicus Parryi. (C. viridiflorus Greene, in herb.): — Colorado and Utah to New 

 Mexico and Arizona. 



. 3. Carduus americanus (Gray) Greene, 1. c. Stems rather slender, 3-8 dm. 

 high, branching above, the branches bearing solitary or scattered naked 

 heads: leaves white-tomentose beneath, lanceolate or broader, sinuately pin- 

 natifid or some merely dentate, others pinnately parted, weakly prickly: heads 

 erect, about 25 mm. high; prmcipal bracts of tne involucre n^ked-edged or 

 merely fimbriate-ciliate below, and the dilated scEirious apex as broad as. long, 

 fimbriate-lacerate, tipped with barely exserted cusp or mucro; innermost 

 with lanceolate, nearly entire, scarious tips: flowers. ochroleucous; str.oiiger 

 pappus-bristles dilated-clavellate at tip. (C, Qerday,reae Rydb. Bull. Torr. 

 Bot. Club 28: 507. 1901; C. erosus Rydb; 1. c; C. griseus Rydb. 1. c;)— 

 Mountains of our range and northwestward. 



3o. Carduus americanus perplexans (Rydb.) A. Nels. _ Leaves oblanceolatp 

 to lanceolate, merely toothed, and with weak, yellowish prickles: flowers 

 sometimes pink or purplish; the bracts slightly glandular on the back. C. 

 perplexans Rydb. 1. c. 32: 132. 1905.) — Wyoming and Colorado. 



4. Carduus Hookerianus (Nutt.) Heller, Cat. N. A.' Plants 7. 1898. 

 Arachnoid white-wOoUy to'glabrate, stout: leaves pinnatifid; the short lobes 

 rather distant, sparsely prickly base little or not at all decurrent: h^ads few 

 and sessile in a terminal cluster or scattered, 3-4 cm. high, somewhat bracteose- 

 leafy at base; proper bracts tapering from a broadish base into a. rather rigid, 

 subulate, prickly point, also somewhat viscidly long-wopUy: corollas' white or 

 whitish; pappus-bristles not clavellate-tipped. (C. Osierhoutii Rydb. I.' c. 32: 

 131. 19.05; C. Kelseyi Rydb. Mem. N. ,Y. Bot. Card. 1-' 449. 1900.)— Moun- _ 

 tains qf our range and farther northward. 



4a. Carduus Hookerianus eriocephalus (Gray) A; N^ls. More arachnpid- 

 pubescent on the involucre and the leaves usually greener and more gjabrate. 

 (Cnicus eriocephalus Gray; Carduus scopidorum Greene, 1. c; C. Tweedyi Rydb. 

 1. c; C. araneosus Osterh. Bull. Torr. Bot. Clul?; 32: 612,; 1905; C, Eatonii 

 Gray, a form usually more glabrate on the involucre thpuigh often E^rachnoid- 

 wooUy on the herbage ; C. canovirens Rydb. 1. c. (?) ; C. pijlcherrimus Rydh. Bull. 

 Torr. Bot. Club 28: 510. 1501.) — Same range as the species, " ". 



46. Carduus Hookerianus hesperius (Eastw.) ,A. , Nets.!, The anthers 

 pubescent, not essentially different otherwise. {CniciCs hesperius Eastw. Proc. 

 Cal, Aca4. Sci. III. 1: 122.1898.)— On Mt. Hesperus, Colorado. ■'"'' 



5. , Carduus foliosus Hook, Fl. Bor, Am. 1 : 303, 1$38; Steins erect,'!striot, 

 striate, 3-5 dm. high, somewhat woolly, leafy tp. the cluster of few sessile 

 heads: leaves commonly elongated,. Unear-lanceolate, laciniately dentate, 

 with rather rigid prickles, arachnoid-tomentpse beneath': heads 'broa.d, 4-5 

 cm. high, leafy-bract30se; involucral bracts thin-coriaceous, some of the inner 

 with more conspicuous, erose, scarioUs tips: corollas pale or white, withlobts 

 equaling or longer than the throat. \C. s!cariosus (Nutt.)' Heller^ is merely the 

 more tomentose form; C. coloradensis Rydb. 1. c. 132.]-|-Colpraao to Montana 

 and Oregon. . ; ' 



6. Carduus Drunmiondii (T. & G.) Coyille, Contr. U. S- Nat. Herb. 4: 142, 



