THISTLE FAMILY 1011 



35. C. spathulifolium Rydb. Stem 6-8 dm. high, slightly tomentose; 

 lower leaves oblaiiceolate, 1-2 dm. long, remotely serrate; stem-leaves pinnately 

 cleft, with oblong or ovate lobes and slender spines, glabrate above, densely 

 tomentose beneath; heads several, about 3 cm. high; bracts glabrous or shghtly 

 floccose on tlie edges, lanceolate, the outer with short slender spines, the inner 

 acuminate; corollas rose-colored or whitish. Carduus spathulaliis Osterhout, 

 not Gaudin. Mountains: Colo. Mont. Au. 



36. C. nidulum (M. E. Jones) Rydb. Stem 5-7 dm. high, floccose-tomen- 

 tose; leaves tomentose on both sides, lanceolate in outline, pinnatifid, with tri- 

 angular lobes, with stout yellow spines 1-2 cm. long; heads scattered, campanu- 

 late, 2.5-3 cm. high; outer and middle bracts ovate to lanceolate, with stout 

 spines, those of the middle ones fully 1 cm. long; inner bracts linear-subulate, 

 attenuate, red-tipped; corolla purplish (?). CnicusnidulusM. E. Jones. Carduus 

 nidulus Heller. Red sand: Utah — Ariz. So7i. — Submont. My-Je. 



37. C. pulchellum (Greene) Woot. & Standi. Stem 3-10 dm. high, loosely 

 floccose when young; leaves white-tomentose beneath and deciduously floccose 

 above, pinnatifid, with linear-oblong or lanceolate divisions, armed with short 

 weak spines; heads scattered, about 4 cm. high and 3 cm. broad; outer and middle 

 bracts ovate to lanceolate, slightly floccose on the margins, with short and weak 

 spines less than 5 mm. long; inner bracts linear-lanceolate, attenuate, purplish; 

 corollas rose or purphsh. Carduus pulchellus Greene. Mountains and valleys: 

 Colo. — Utah. Submont. Jl. 



C. pulchellum Xundulatum. Resemhling C. pulchellum in habit, but the involucres 

 more hemispheric, the bracts broader and with a narrow glutinous ridge, and the inner 

 ones not so elongate as in that species; differing from C. undulatum in the narrower 

 segments of the leaves, the glabrate upper sm'face, the somewhat purple-tipped inner 

 bracts, and the inconspicuous dorsal ridge. Utah — Colo. 



38. C. arizonicum (A. Gray) Petrak. Stem 5-10 dm. high, floccose; leaves 

 white-tomentose beneath, loosely floccose above, jjinnatifid, with lanceolate or 

 triangular lobes and rather weak yellow spines; heads solitary or scattered, 4-4.5 

 cm. high, 3-4 cm. broad; outer and middle bracts ovate to lanceolate, with short 

 yellow spines, slightly floccose on the margins, the innermost hnear-lanceolate, 

 attenuate, purple-tipped; corollas crimson. Cnicus arizonicus A. Gray. Car- 

 duus arizonicus Greene. Mountains: Ariz. — Utah — (? Wyo.) Son. — Submont. 

 My-Au. 



39. C. griseum (Rydb.) K. Sch\im. Stem stout, sparingly floccose when 

 young; basal leaves oblanceolate in outline, thin, glabrate above, grayish tomen- 

 tose beneath, deej^ly pinnately divided; segments 3-4 cm. long, deeply 2-3-lobed 

 and toothed, with rather slender spines 3-5 mm. long, the upper less deeply 

 divided, sessile and half-clasping by the dilated rounded shortly decurrent base; 

 heads about 3 cm. high and broad; outer bracts narrowly lanceolate, with a long- 

 attenuate tip gradually changing into a flat spine, and somewhat laciniate or 

 spinulose-dentate on the margin, the inner ones less rigid, their tips not spinose, 

 long-attenuate, scarious and somewhat crisp; flowers ochroleucous. Carduus 

 griseus Rydb. Mountains: Colo. Submont. — Subalp. Jl-Au. 



40. C. modestum (Osterhout) Rydb. Stem 6-8 dm. high, slightly arachnoid- 

 pubescent; lower leaves oblanceolate in outline, 1-2 dm. long, pinnately parted 

 into triangular divisions, white-tomentose beneath; spines small; upper leaves 

 lanceolate and less divided; heads scattered, small, 1.5 cm. high; bracts somewhat 

 floccose, the middle ones with somewhat broadened spines, the inner unarmed; 

 flowers whitish. Carduus modestus Osterh. Canons: n Colo. Au. 



C. Centaureae X modestum. Resembling C. Centaureae in habit, but the bracts 

 scarcelj' dilated and with flat short spines. Colo. 



41. C. canovirens Rydb. Stem 0-10 dm. high, more or less floccose, striate; 

 leaves about 2 dm. long, grayish green, slightlj' floccose on both sides or glabrate 

 in age above, the lower petioled, the upper more or less decurrent, deeply pin- 

 nately divided, with lanceolate or triangular lobes, tipped with moderatelv strong 

 spines; heads scattered, usually many, 2-3 cm. high; bracts more or less floccose 

 on the margins, with broad glutinous ridges, the innermost attenuate into a 



