1010 CARDUACEAE 



tomentose, with triangular lobes and weak spines; heads 4-6 cm. high; bracts 

 thin, brownish, the outer ovate, tipped with bristle-like spines; corollas rose- 

 purple. Carduus Drummondii Coville. Hills and mountains: Sask. (Black 

 Hills) S.D. B.C. SubmontMont. Jl-Au. 



28. C. magnificum (A. Nels.) Rydb. Stem tall, 1-2 m. high, purplish, 

 slightly arachnoid, leafy; leaves glabrate above, tomentose beneath, 1-3 dm. 

 long, deeply pinnatifid, with 2-3-cleft divisions with lanceolate lobes; heads race- 

 mosely disposed, each ending a short axillary branch, 4-6 cm. high and broad, 

 leafy-bracted; bracts glabrous except the margin, the outer ones with slender 

 spines; flowers rose-purple. Carduus magnificus A. Nels. Saline flats: Ida. Je. 



29. C. foliosum (Hook.) DC. Stem 2-6 dm. high, more or less arachnoid- 

 hairy; leaves light green, but more or less arachnoid above, tomentose beneath, 

 from deeply pinnatifid, with oblong lobes, to nearly entire, with rather weak yellow 

 spines; heads clustered at the end of the branches, leafy-bracted, 3-5 cm. high; 

 outer bracts ovate, glabrous, with short weak spines; corollas white or nearly 

 so. Carduus foliosus Hook. C. scariosus Rydb. (Fl. Mont. & Fl. Colo.) Moun- 

 tain valleys: Sask. S.D. Colo. Utah B.C. Submont. Mont. 



30. C. lacerum Rydb. Stem stoat, 6-10 dm. high, sparingly arachnoid; 

 lower leaves oblanceolate, 2-3 dm. long, pinnatifid, with rather broad, ovate or 

 lanceolate divisions ending in weak spines, glabrous or slightly long-hairy and 

 green above, grayish tomentose beneath; upper leases lanceolate, sessile and 

 clasping, with narrower lobes and stout spines; heads more or less clustered, about 

 4 cm. high and broad; outer bracts ovate-lanceolate, glabrous, ending in short 

 stout spreading spines 3-5 mm. long; corollas rose-colored. Carduus lacerus 

 Rydb. Valleys: Utah. Submont. Jl-S. 



31. C. diffusum (Eastw.) Rydb. Stems several, 6-9 dm. high, glabrous or 

 slightly floccose when young; leaves pinnatifid, with triangular lobes and rather 

 stout yellow spines, glabrous or slightly floccose beneath when young; stem-leaves 

 somewhat decurrent; heads scattered, 3-4 cm. high, scarcely 2 cm. broad; bracts 

 lanceolate to linear-lanceolate, slightly tomentose on the margins, the outer and 

 middle ones spine-tipped; spines in age spreading; inner bracts attenuate into 

 slender, purple, straight tips; corollas rose-purple; pappus plumose except the 

 slender tips. Cnicus Rothrockii diffusus and C. diffusus Eastw. Carduus diffusus 

 Heller. Canons: Ariz. Utah. Jl-S. 



32. C. bipinnatum (Eastw.) Rydb. Stem glabrous or slightly arachnoid, 

 5-8 dm. high, branching above; leaves pinnatifid, with numerous linear or linear- 

 lanceolate divisions, which are deeply parted at the base on one side, or sometimes 

 pinnatifid-incised, with weak spines and spinulose-ciliate, glabrous or slightly 

 deciduojsly floccose beneath; heads scattered, 3-4.5 cm. high, 2-2.5 cm. wide; 

 outer bracts ovate-lanceolate, with short \veak prickles, 3-5 mm. long, the inner 

 purplish, soft; corollas purplish. Cnicus Drummondii bipinnatus and C. bipinnatus 

 Eastw. Carduus bipinnatus Heller. Carduus truncatus Greene. Canons and 

 sage plains: Colo. Jl-S. 



33. C. calcareum (M. E. Jones) Woot. & Standl. Stem stout, 4-6 dm. high, 

 slightly arachnoid, branched above; leaves 2-3 dm. long, distinctly decurrent, 

 pinnatifid, with triangular or oblong lobes, with short and stout yellow spines, 

 glabrous or nearly so on both sides, shining; head scattered, sessile, about 2.5 

 cm. high; bracts glabrous, the outer ovate, with short spines, the inner subulate- 

 acuminate; corollas rose-colored. Cnicus calcareus M. E. Jones. Mountains: 

 Utah. Submont. Mont. Jl. 



34. C. lactucinum Rydb. Stem 5-10 dm. high, glabrous, striate; leaves 

 very thin, glabrous, dark green, pinnately lobed, the lower petioled, 3-4 cm. long, 

 the upper clasping, with rounded auricles; lobes broadly ovate or semi-orbicular, 

 angular, armed with yellow spines 3-10 mm. long; heads scattered, about 3 cm. 

 high and as broad; involucre glabrous, about 2 cm. high; bracts ovate to lance- 

 linear, well imbricate, brownish green, darker towards the end, the innermost 

 not much elongate, with soft tips, the rest ending in weak spines, 2-6 mm. long; 

 corolla rose-colored. Under overhanging cliffs: se Utah. Son. 



